Talk:Anthropic principle/Archive 1

www.anthropic-principle.org
The anthropic principle is NOT a tautology. The fact that conditions be conducive and that we exist must necessarily be true does not make for a cosmological principle.
 * Off to a flying start here. Do you even understand what a TAUTOLOGY is? How could anyone who understands the dictionary definition of the term "tautology" imagine that anyone could think "anthropic principle" might be an example of one, any more than it is an example of "bacon and eggs"? Then that sentence is followed up by one which is just some sort of incomprehensible alphabet soup. Why not write out what you want to say, and then proof read it, and rewrite it before you annoy everyone by posting bulk loads of obscure and semi-literate drivel here? The secret of good writing is proof-reading and rewriting. Try it on this material. You might even produce something worth reading. Myles325a 03:44, 17 August 2007 (UTC)

The fact that the actual observed structure of the universe occurs in dramatic contrast to the modeled expectation... where *many* fixed balance points are commonly or "coincidentally" pointing directly toward carbon-based life, *does* indicate that there is some good physical reason for this otherwise completely unexpected structuring, that is somehow "specially" related to the existence of carbon-based life.

The Anthropic Principle is a cosmological principle, so you most certainly *can* falsify it if you can show that the *surprising* configuration that we ended up with isn't contingent on the existence of carbon-based life, as is indicated by the physics that drove physicists to formalize the observtion as an "ecological correction" to the cosmological principle, which erroneously extends mediocrity where it does not apply.

~

Anthropic-Principle.ORG supports the physics for the anthropic principle that applies to a quasi-static example of Einstein's static cosmology, which notes that Einstein's cosmological model was never proven wrong, and he had no reason to abandon it, rather, he simply didn't know about the particle potential of the quantum vacuum, so many assumptions don't really apply.

1) In Einstein's static model, G=0 when there is no matter density.

He brought in the cosmological constant to counterbalance the runaway recollapse effect that occurs in this model because we do have matter, but in order to get rho>0 out of Einstein's matter-less spacetime structure, you have to condense the matter density from the zero pressure metric, and in doing so the pressure of the vacuum necessarily becomes less than zero, P<0, which causes expansion, while holding the universe stable and near-perfectly-"flat". (*Note that the background changes everytime that you do this.) It becomes evident from this "new-light" that most natural way to create new matter in Einstein's model, ("the most compatible with the spirit of general relativity"), also holds it flat and stable, (instability being the only reason that he abandoned it), so any other conclusions that have been made since Einstein abandoned his finite universe without this knowledge are therefore subject to suspect review, especially the reinterprtation of the negative energy states.

2) Add the physics for the observed universe that produces the anthropic principle to this finite, closed, bounded structure and what you get is a very strong statement about a biocentric structure that "evolves" perpetually forward to higher orders of entropic efficiency.

~

The WAP is subject to cosmological and environmental interpretation that makes it stronger or weaker, and this becomes problematic when people introduce probabilities where none are necessarily called for:

''Weak anthropic principle (WAP): "The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirements that the Universe be old enough for it to have already done so." ''

That's a very strong statement in a single finite universe, but regardless, "not equally probable" was expected to mean that there is no other possible configuration once the stability mechanism that explains the otherwise completely unexpected structuring of the universe, so many fixed balance points that are all commonly/coincidentally pointing directly toward carbon-based life, indicate that there is some good physical reason for it that is somehow “specially” related to the existence of carbon-based life.

The clear implication is that we are directly connected to the stability mechanism, (which is exactly the kind of thing John Wheeler tried to put forth, for that exact reason). The evidence is most apparently telling us that we should look for something about us, or something that we do that explains why this is so. That doesn't mean that we should ignore the other more-distant possibilities, it just means that "variants" and their assumed probabilities are not what is most apparently indicated by the evidence, so they don't supercede nor equal the most apparent implication, per the scientific method.

sites where carbon-based life can evolve aren't restricted to Earth by the evolutionary physics, although they are restricted to a "plane" of similarly evolved galaxies, so that's where the expectation for life elsewhere is, and that is also an indication of what needs to be considered in context with the mechanism for stability.

~

The anthropic principle came about from an honest effort by physicists, like Herman Bondi, Fred Hoyle, Robert Dicke, and Paul Dirac, who kept running up against the same problems that we have today when trying to give a "causallity responsible" explanation for the physical structuring of the universe. Brandon Carter proposed the AP as an alternative cosmological principle to the type of Copernican extremism that led to the "Perfect Cosmological Principle", noting that it was equally arrogant to presume that we have the right to ignore the physics and large-scale observational evidence, as it is to presume that we are at the center of the universe. Carter pointed out that "our situation is not necessarily central, it is inevitably privileged to some extent". This point is critically important to this, because the anthropic principle readily extends to, and cannot be restricted from incuding the bands of every spiral galaxy that evolved within the same "layer/habitable-zone" of conditions, (time and location-wise), as our own galaxy, (in terms of the commonality and continuity in the evolution of the same basic raw materials that were produced by our observed Carbon Chauvinistic Universe). In this case, the principle is "biocentric", meaning that life is *more-generally* important to the physics of the universe at this particular time in its history, and so it will *necessarily* be every bit as common to the universe as the physical need for it demands. In this same scientific context, real HONEST scientists will ask questions like, "I wonder if intelligent life does something that *cumulatively* affects the physics of the universe that makes it necessary to the process?" There is a valid physics question about the apparent and evidenced intrinsic finality of goal-oriented thermodynamic structuring in nature that has nothing to do with god, nor any form of intelligent "designer", but this is rarely, (if ever) recognized by either side of the "debate". There is an openly hostile and ideologically motivated effort to downplay scientific interpretations that include the appearance of "anthropic specialness" which occurs as a result of the debate, and the effect is to blind science to the potential that the anthropic principles has for making predictions about life elsewhere in the cosmos, as well as more locally. If the most accurate cosmological principle is biocentric in nature, then the principle is telling us the good physical reason why the forces are constrained in the manner that they are. This science should not be ignored because politics and misplaced perceptions about geocentric arrogance get in the way.

http://www.anthropic-principle.ORG

Proponents and versions
I have added a paragraph after the Barrow & Tipler definitions pointing out that these differ considerably from those of Carter. I think this causes a lot of confusion because most professional physicists/astronomers use something much more like Carter's version, whereas Barrow & Tipler are the reference of choice for "outsiders". Carter is partly to blame: in particular the "must" in the SAP has been interpreted by B&T as a quasi-theological necessity, but careful reading suggests that Carter simply meant the universe "must" allow life because it does contain life! He points out that this remark is only useful if you believe that there is an actual ensemble of universes (a multiverse in modern terms), so for Carter both WAP and SAP refer to selection effects. Carter's ambiguity was exploited by B&T almost to reverse the meaning of the SAP: for Carter (and, e.g., Susskind) it is a strong counter to design arguments, whereas B&T's version essentially is a design argument.

82.6.76.199 13:30, 5 June 2006 (UTC)

No, Carter did not originally support an ensemble of universes. As noted by him at the conference in Poland, he introduced the principle with John Wheeler in mind, since it was John who had urged him to formalize principle in order that he might add his idea of the kind of anthropic specialness that causality responsible physics requires, which had absolutely nothing to do with "ensembles" of theoretical speculation.

In the article in question, at the start of the section titled "World Ensembles and the Gravitational Constant", Carter says: It is of course always philosophically possible &mdash; as a last resort [...] &mdash; to promote a prediction based on the strong anthropic principle to the status of an explanation by thinking in terms of a 'world ensemble'. By this I mean an ensemble of universes [...] So Carter certainly introduced this, as I said above; although his support for it is equivocal. Wheeler is not mentioned at all in this context.

It is true that Carter says that the SAP can make 'predictions' without bringing in world ensembles, e.g. that the curvature of the universe must be small enough to allow life to evolve before the universe re-collapses. But the prediction is redundant because we already observe this directly; and I think this applies to any such prediction. Therefore I still maintain that Carter's SAP is only useful if world ensembles are taken seriously. PaddyLeahy 16:21, 26 March 2007 (UTC) (formerly 82.6.76.199)

cause and effect, the fined-tuned universe
- The Anthropic Principle (pick the version of your choice) requires that a universe remain amenable to life but only up to a point. I would define that point as being the first time that someone stands up at a scientific conference and speaks the words "anthropic principle" (or the equivalent waving of pseudo-pods or whatever). At that point the anthropic principle has done its job and it packs up its bags and goes home. The A.P. tells you nothing about the future, just that he past was conveniently arranged for you to reach a point where you can appreciate the (possibly improbable) course of events that lead to the "discovery" of the A.P. This should be a sobering thought to those who believe that the properties of the universe we see are highly improbable, since if this is the case then the chances that the universe will remain amenable to life after the discovery of the A.P. are by no means guaranteed. Your universe might very well undergo runaway inflation or something equally unpleasant shortly after people hit on the idea of the anthropic principle. --G.

- I have reformulated the section Proponents and versions such that I feel the criticism below regading confusing cause and effect and the term fine-tuned universe are no longer valid. Maybe these users could pull their talks and signal approval?

I expect that people will criticise that I added "(weak)" to that section. However, it is wrong to discuss all three versions under one umbrella. To make the article more uncontestable, it is better to concentrate on the weak version. It would be sensible to move the 3rd paragraph up, but then the section would scare away readers unfamiliar with the topic.

Highlander 00:17, 1 June 2006 (UTC)

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I think that anthropic principle appears to confuse cause and effect. Because the universe is the way it is, intelligent life came up. If it were different, different life may have come up, right? Please help correct my misunderstanding. -

Help me understand this, please. The Antropic principle can be interpreted as "The fact that the universe has a highly unlikely set of properties can be explained by the fact that if it didn't, we wouldn't be here wondering about it", right? And this is source for controversy as many think that it is not true that the statement explains anything, it just exposes a correlation. But what are the odds that you (yes, you) came to exist? The odds that the spermatozoid that combined with your mother's egg was the one that would lead to you were small. Combine that with the odds that your parents met. And with the odds that your parents existed. And so on until the original living cell. The odds that all that happened are extremely dim, probably smaller than the odds that the universe has the right set of constants to be stable and hospitable to life. And still you are there. I only see two ways to explain that: either predestination or Antropic Principle (if that incredibly unlikely set of events hadn't occurred, you wouldn't be here finding it unlikely). Personally I don't like predestination and I think it is an even more unlikely explanation than the antropic principle to this issue. Now, if the Antropic principle is an acceptable explanation for your personal existence, why isn't it a good explanation for the universe's hospitality?

Herbys

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Some food for thought before personal prejudice eats this topic alive:

"The unmatched human-potential for directly affecting the symmetry of our expanding universe defines good physical reason for why intelligent life would necessarily be required to arise as a practical means for satisfying the increasing entropic impetus of a universe where negative pressure increases as the vacuum grows"

www.anthropic-principle.ORG

4/30/2005

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I strongly feel that the Anthropic Principle (or one version of the Anthropic Principle) is widely misunderstood. It is often stated as saying "the parameters of our Universe are (mysteriously) within narrow limits which allow the origination of planets, water, intelligent life, etc." However, this is backwards. The only type of Universe which can have intelligent observers is one with parameters within such limits.

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It's not just me then who has a problem with

The universe appears to be "fine tuned" to allow the existence of life as we know it.

then...A less contentious phrasing is the exact reverse: Life as we know it is finely tuned to the universe. Are the shapes and positions of the human eyes, nose and ears "fine tuned" to allow the use of spectacles?

I think this article needs work. I, for one, find the entire argument for the "anthropic principal" to be specious and oversimplified. Life evolved to fit the conditions of the existing universe; the universe was not "fine-tuned" by a cosmic entity to allow for the existence of life. If the basic constants of the universe were different, then there would probably be another intelligent race out there awed by the fact that the universe was so perfectly tuned for their kind of life!

Another thing. How is it possible for a principal to be true if it can be restated in a manner exactly opposite? Stormwriter

It doesn't matter if we think about carbon based life or a more open view about life. Fact is, if the universe wasn't fine tuned to a very strict set of variables, it wouldn't have lasted enough for it to harbor ANY typo of life. A universe that lasts only a few milliseconds and it's a trillion degrees in temperature doesn't leave much room for life, even if you depart a lot from our current definition of life. Much less, intelligent life.

Herbys

Reply:Both non-predestination and the Anthropic Principle both rely on a point of view which does not depend on exactly YOU coming into being at this time and place. The Anthropic Principle is a social construct, because it is communicated to other human beings - so it depends on being humans in general being there. Similarly, the concept of yourself, your identity, still leaves room for chance.

Highlander 13:14, 31 August 2006 (UTC)

Of course TODAY's life is fine tuned to the needs of the Earth. The argument is that a universe which can have life to explain that same universe, must necessarily be fine tuned to harbour the BEGINNINGS of life. That means that the universe must eventually have the conditions that were in the primeval oceans hundreds of millions of years ago. After that, life fine tunes itself to the universe's changes. - CJWilly

i think the article needs work too. for one thing, the term needs disambiguation. some people use the term "Anthropic Principle" to prove that the universe was hand-tailored for us (also called anthropic coincidences, a better term), some people use the term to show that we are the glasses that fit the nose and eyes. some people use the term to describe observation [/selection] effect, (which is a better term anyway), to describe the fact that we are unduly amazed by the perfect fit between the glasses and the face. one or more uses of a term warrants its disambiguation, doesn't it? (i found a good disambiguating article on the matter at: http://www.anthropic-principle.com/primer.html )

'' If the basic constants of the universe were different, then there would probably be another intelligent race out there awed by the fact that the universe was so perfectly tuned for their kind of life! -- Stormwriter''

I don't think that the anthropic principle in any form really supports the word probably...

Plasticlax

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Removed this......


 * A less contentious phrasing, and one generally overlooked by proponents of the anthropic principle, is the exact reverse: Life as we know it is finely tuned to the universe. In other words, life exists because it can exist. Phrased this way, it is easier to see that the anthropic principle does not necessarily give human life "special status" in any particular way, and is more easily understood through the application of evolutionary theory.

Because in listening to proponents of the anthropic principle, they don't phase it that way because they don't actually believe that.

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Is the weak form of the principle really controversial? It seems to just state an obvious fact that might otherwise be overlooked. (What I think one of the above comments about being `unduly amazed' is referring to.) I was under the (uninformed) impression that it was only the stronger form that was controversial. Either way, it would be nice if the article could be more explicit about this.


 * I agree with you - the weak form is tautological, the strong controversial (for being overly certain of what may apply in other universes). There are also forms in between the weak and the strong (as one might expect) which have been discussed since the origin of the theory.  EofT

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The article should include references to the ideas of the PAP (Participatory Anthropic Principle, and the FAP (Final Anthropic Principle) and other notions such as the HAP (Holistic Anthropic Principle). I might expand it eventually. Stormwriter, I disagree with you about the anthropic principle, I find it useful, though in the end it may explain nothing. That it can be explained in the reverse is not the point, the point is just the fact that there's a perfect fit. Yes, if the universe were different in its basic constants (if thats possible at all, or if its possible that different constants could sustain life; both questions which are philosophically interesting), the different observer would marvel that the universe fit them. However, if that were true maybe it would fit them; and maybe since its true we exist, it fits us. The following is a good webpage to draw information for the article from: http://dialogos3.tripod.com/dial3.htm. I will paste here something I wrote earlier today on the subject, for the purpose of not only generating discussion (which I understand Wikipedia talk isnt for), but also for eventually improving the content of the article:

I am not a theist, but this isn't because I disbelieve in the anthropic principle, but for other reasons. I am among the people, who, when asked if they believe in God, doesn't know how to respond, because I don't know what I'm being asked about, I don't know what God is. You can say, I follow the Wittgensteinian argument that talk about metaphysics is nonsensical; but, more broadly, and more articulated, its just a statement of this: people say God not only created the universe, but existence itself--but that would require either God be outside of existence, ie non-existant!, or a pantheistic/deistic conception. In the latter case, which has been argued by some philosophers, such as Spinoza and Plotinus, that God is equilalent to the whole of Being or of existence, can be made to work, because you could argue that God is existence, and existence created itself into being, by some means (which I believe, as I'll explain later). However, saying God is the whole of being is just deflating the entire idea of God, you might as well cross out the words "nature" and "existence" and replace them with "God".

On the different types of anthropic principles: most arguments against it, seem to miss some major issues, in that they resort too much to science and physics without looking at things philosophically. That is, scientific oriented thinkers tend to think the only thing at stake is the nature of the 'universe' and of 'matter', but really what is at stake is the issue of 'existence'--what it means for something to exist at all-- and, more peripherally, the issue of 'consciousness'.

They seem oblivious to the issue of whether you can be certain anything exists at all after your death, or if anything exists at all outside of your thought. The latter, about things existing external to thought, has shown up in the history of philosophy under the term Idealism, in Berkeley, and Hegel, and even in David Hume. It is at least misguided in one way: there is certainly something we talk about being "external" to us, regardless of metaphysical distinctions. There are similar problems with the former, in that we assume there are other conscious people, and that these people will have perceptions of the world at a time frame after our death. However, what is meant in asking these questions is more broad and profound: what does it mean for something to "exist" with nothing percieving it.

Argumentors against the Participatory Anthropic Principle, think that the view relies specifically on a scientific interpretation the Copenhagen interpretation of the Uncertainty Principle, saying that the observer is part of the construction of reality. But there is no reason to be scientific about it at all, and one needs to accept no scientific premises or interpretations of scientific theory. The issue is more plain: what does it mean for something non- percieved to exist?

I understand and do not refute theories such as Inflation theory; I accept the idea that there could be muliple universes (although I am a skeptic as to how it is important, because, as you noted, they are obliterated or non-existent to us, which I will deal with later). However, this does nothing but support all forms of the Anthropic Principle, not offer an alternative. Because, among those universes that 'exist' and are there with no 'observer', one has to ask--do they really exist, did they really ever exist? One can propose that the universe exists in potentially infinite amount of possibilities--but the only manifestation that will really be real and exist, will be the one with the observer. And this one, with the observer, will meet laws necessary to sustain him. The possibility that other universes have observers may seem interesting, but also it is unclear as to whether we could really talk about them existing, as well, unless we can interact with them; because, for us, what doesn't effect our perceptions practically doesn't exist.

As such, we can say that the only universe that we can ever be concerned with as 'existing' is ours. The multiple universe possibility inherent in inflation theory, as only a potential, and in no substantial way, a reality. --- this brings to broader and substantial questions about the metaphysical and conceptual and logical (ie philosophical and non-scientific) issues/problems behind physics theories like inflation theory. That it looks like the possibility of multiple universes is inherent in inflation theory may reflect some distortion in the nature of conceptualizing about it.

There are also other deep problems; such as the issue of whether there really could be any different way of ordering the universe than the way we see; and what exactly is manipulated to bring into being any inumerable amount of laws, that, in one combination brings consciousness? But these issues arent necessary to go into.

A long time ago, I did this thought experiment: many scientists like to think of the universe as existing in terms of data like binary which is, by itself uninterpreted.Even if this isn't exactly accurate, which I guess it isn't, its at least assumed that how reality appears depends on the structure of the observing entity. Because its uninterpreted, we may frame it in inumerable abstractions and order it in many different ways. However, with the possibility of an abstraction that involves an observer; the universe "comes into being", it crystalizes or becomes concrete around the observer, in a way ordered to support or sustain its existence.

The issue of God is a more abstruse matter, as I commented on at the start. However, proponents of this, don't really treat the notion of 'God' in a traditional manner; they just use the term to refer to a pervasive "consciousness" or drive towards complexity in the universe, finally realized in what we see in humankind in its drive to abstraction and truth. In Western history, the idea of God, anyway, has always been said to be a reflection of perfection, an idea of the perfect or the divine or the ideal--as talked about in Plato when he talks about the Good--or, as its called, in modern thought, the Supreme Being. Many Christian philosophers, like Descartes, have sometimes dropped the word 'Supreme', talking about God as plainly 'Being', an ontological category referring to the substance of all things. Hegel, in his Idealistic philosophy, gives a teleology in which all of nature resolves all its contradictions, unity and difference, in what he calls the 'Absolute Spirit'. In proponents of this anthropic principle, these are synonymous with God. A truth about humankind and culture and society is that we are driven towards abstracting; resolving contradictions, unity and difference (as per Hegel); finding meaning; and the idea of the Good and perfection. In fact, the idea that we are somehow the result of a "playfulness," an "experiment," or even a "fall" from God and/or the spiritual world, and that we are groping to find our way back is an ancient and common idea to both Eastern and Western religions.

Another way of saying this, which I'm not necessarily subscribing to, is that our consciousness is driven by the force of God. And furthermore, since the universe and nature is formed to sustain our existence, if you accept the anthropic principle, in its weakest form, the universe has a directionality towards our consciousness, and in turn, towards our own personal directionality towards the idea of the Good, of God.

As such, philosophers and theologans, like Pierre Teilhard de Chardin, have argued, that all of nature is a constant evolution in a sort of teleology that is driven by the fact of God. God is equivalent with 'unity in nature'.

This is not circular in any way, because it doesnt seek to 'prove' God's existence; rather, it just finds that God is a perfect description for this creative force in nature. (For similar reasons, Descartes' arguments in favor of God, really aren't circular, as they are often claimed to be by analytic philosophers, if you realize he just descriptively equates perfect Being with God)

Brianshapiro

Because this is a contentious issue, is there some way to identify the subject as such more explicitly? Is there a sensible way to include arguments against proposed by recognized theorists, as opposed to the ideally disinterested synthetic author of the wiki? Is the synthesized author of the wiki actually disinterested? I mean, should it be?

I am one of those who finds little value in the Anthropic Principle as its stands (I am suspicious of any scientific argument based on speculative statistics, especially the use of the probability of the occurrence of some past event being revised to 100%), but I won't pursue the matter unless there is some way to disinterestedly cover the topic. The wiki is not here to add new knowledge, it is here to summarize existing facts about knowledge.

Has anyone encountered a good, published, peer-reviewed criticism of the Anthropic Principle? Brent Gulanowski 16:09, 19 Dec 2003 (UTC)

i think it is a good thing to keep in mind that we are limited to observing what does not limit us.(it is not limited to physics, eg in psychology man-woman) for example one can imagine a radiation source that would prohibit cosmic lay out's like we observe. that we do not observe such does not imply they are impossible. another thing that strikes me is that when someone would propose cosmic dimensions would organise toward lifeforms, i would tend to agree. similar to our definition of a globe as a bubble, or an atom as a globe,(iow. physical accretions of mass tend to be globular) ecosystems organise surrounding ,even planetary values to propagate life, possibly because the actual synthesis of matter and energy is life, and physics appears to point to synthesis. for example that bigger universes strip metal from smaller ones implies they make evolutionairy jumps towards supporting life against the better odds (in the bigger universe). so next to an anthropic principle there could be a biotic principle, and perhaps we would not live in an universe that does not strive for life. (wich taking the anthropic principle in consideration is quite possible). the fine tuned universe i would not take to literally, if for example the universe has an age, (i know most think it does, wich i would call the anthropomorphic principle), it has as many shapes as eg. electrospins, that we observe only a few of that reminds of pretty finetuned with a pot-meter or other traditional indicator. the anthropic or biotic principle would allways predict on a smaller cosmic scale the anthropic (etc.) principle would be better met. otoh the discussion may actually boil down to optimism versus pessismism. are the odds for of against you? 24.132.171.225 (talk) 03:11, 14 September 2009 (UTC)

truism?
In the first paragraph is "Critics call it a truism." Is there anyone who doesn't think that the weak A.P. is a truism? It is something that has to be true - it couldn't be any other way. Bubba73 01:46, 23 Jun 2005 (UTC)
 * I didn't like the first sentence as an intro: "In its weak form, the anthropic principle is a truism". You can revert, but I'd like to work on the intro. --goethean ॐ  02:48, 23 Jun 2005 (UTC)


 * I agree with you that it shouldn't be the first sentence. I'm not sure that only critics call it a truism. I'm talking about the Weak AP only, shich I assume is what is meant by "its most basic form".  Bubba73 02:50, 23 Jun 2005 (UTC)

Re Peak's revert - you should really discuss something like that rather than reverting it for the third time. Anyway, can someone explain to me how it is not a tautology? I've read the truism and tautology articles. Also, as goethean suggested above, I reverted "In its weak form, the anthropic principle is a truism", but not in the first sentence. Improvements are of course welcome :p ··gracefool |☺ 23:40, 22 September 2005 (UTC)

Reply:

A tautology is adding something redundant, e.g. qualifying an attribute of an object twice. A truism is similar, but it is in the form of a logical statement, and as long the statement is interesting to someone, it is not redundant. e.g. (leaving same-sex marriages aside for a moment): "The female bride" is a tautology, "Brides are female" is a true statement, "The bride was female" is a truism (and is redundant, but only as long as it is obvious to the reader of the truism that the statement "Brides are female" is true, which it might not be).

The weak anthropic principle can be expressed in mathematical terms:

The probability to live in a universe that allows intelligent human life to exist under the condition that human life exists in the universe is exactly 1.

Be A="human life exists in the universe(it is implied that it is intelligent)" and B="the universe exists", then the truism is "A and B => A", which implies the weak anthropic principle which is: "P(A and B|A)=1", which means probability of A happening if A and B equals true. This means the WAP follows from a truism, but is not necessarily one.

That "critics call it a truism" is not a failure of the WAP, but a sign that these critics are not most intelligent lifeforms around, since how can you refute a statement by saying that it is true?

--Highlander 19:28, 29 December 2005 (UTC)

Parody
I was wondering if it would be possible (or indeed wise) to add a section mentioning parodies of the anthropic principle. Of course, I suppose it's a bit of a long shot -- the anthropic principle isn't exactly the butt of as many parodies as, say, Schrodinger's cat -- but I can think of at least one example. --Yar Kramer 05:52, 13 October 2005 (UTC)

About the anthropic principles on /.
The weak anthropic principle can be expressed in mathematical terms:

The probability to live in a universe that allows intelligent human life to exist under the condition that human life exists in the universe is exactly 1.

So you(someone who is arguing for the religious interpretation of the SAP) don't have a point. You would spent your time better at debunking the SAP(strong anthropic principle) and the FAP(final anthropic principle) both of which are either bullshit or logical trickery.

By the way, the last time I visited wikipedia to look up the definition, the WAP was formulated the wrong way around, and the SAP was formulated correctly - now it seems to me the SAP has no value different from the WAP(except that is has a diffent motivation), and the WAP by Carter is formulated in accordance with the mathematical definition above. Moreover, the german version of WAP/SAP differ.

The FAP is logical trickery, because if intelligent beings would ever die out completely, nobody in the universe would have the required intelligence to notice that the statement is wrong - so the statement cannot be refuted, it has a boolean value of "true" as long as philosopers exist, but it can be considered harmful insofar as it inspires the confidence that life and human life could never die out, even if the entire intelligent life-forms in the universe decided to commit universal seppukko just to put the theory to a test(of course, if they did that, maybe they would never have been intelligent at all, SCNR).

Likewise, intelligent design is logical trickery, because it cannnot be refuted without complete knowledge of the history of our universe; So, let me add the bon-mot: "Only an omniscent God can refute intelligent design, and I am sure he'll do that, if he exists." The inherent danger in the ID ideas is that ID proponents somehow believe that because one their claims cannot be ultimately refuted (except by God), they somehow have the authority to declare the rest of science "bullshit". There is no logic in that unless you are on crack.

--Highlander 18:01, 29 December 2005 (UTC)

Given that I feel like Arthur Dent in front of the poetry-reading Bogon, I thought I would cast a little more dark:

In the weak antropic principle, it seems completely irrelevant that it be life as we know it, or the life form be carbon. According to my understanding of the principle, it is irrelevant and confusing. I would re-phrase WAP as follows:

"Given that you can think and observe the universe, and you are part of the universe. Of all possible universes, the only universe you can possibly observe is one where the physical conditions allow for your existence."

Regarding SAP: "The Universe must have those properties which allow life to develop within it at some stage in its history." This is redundant. It states the obvious in a non-obvious way. If another method of explaining the AP is necessary, I submit the following:

"You are the evidence that the universe we inhabit has properties which allow life to develop within it at some point in it's history"

Regarding FAP: "Intelligent information-processing must come into existence in the Universe, and, once it comes into existence, it will never die out." I have seen and know of self-aware intelligent beings die. There is plenty of evidence that intelligent beings can die on a grand scale. There is no scientific evidence that the universe preserves the existence of self-aware intelligence. Furthermore, this assumes the universe will not come to an end. The FAP should perhaps be filed under theology/christianity/Heaven and Hell.

The closest reasonably scientific true statement I can imagine which can align with FAP is "Intelligence has a natural tendency for a dominion over matter and space. All matter and space may therefore ultimately fall under the dominion of intelligence". Nick R Hill 00:02, 13 February 2006 (UTC)

Lest we all forget the poignant maxim: "Reality is relative to the measuring apparatus." MPD 18 March 2006


 * "The probability to live in a universe that allows intelligent human life to exist under the condition that human life exists in the universe is exactly 1."

This is incorrect. It is certainly true that if you exist, you are existing in a place that allows you to exist, at least for a moment. That much is obvious. However, the unstated assumption in your statement is that humans exist (which we know to be true, but it is still an unstated assumption). The correct form is "If humans exist, the propability that they exist in a universe were they can exist is exactly 1".

Is this nitpicking? Of course it is. However, it is a very important point to make, since anthropic principle is usually given as the answer to the question "Why is the universe as it is?" Answering that question with a version of anthropic question that can be expressed as you did is really saying "the universe is like this because we couldn't live in a different universe"; it makes us, or rather allowing our existence, the reason why the universe is like this. This, of course, might very well be true, but it is no longer a matter of science and shouldn't be dressed up as such.

In short, your version of antropic principle dries up to "Universe is as it is because God created it for us to inhabit", which may or may not be true but is not something that cosmology could answer either way.

80.186.134.28 22:18, 23 April 2006 (UTC)

Lest we forget
Lest we all forget the poignant maxim: "Reality is relative to the measuring apparatus." MPD 18 March 2006

A good comment
I noticed this comment in one of the above discussions and found it highly appropriate and accurate:

"It's not just me then who has a problem with 'The universe appears to be "fine tuned" to allow the existence of life as we know it.' then...A less contentious phrasing is the exact reverse: Life as we know it is finely tuned to the universe. Are the shapes and positions of the human eyes, nose and ears 'fine tuned' to allow the use of spectacles?"

-Silence 04:07, 14 April 2006 (UTC)

Why no opposing visions?
How come in this article there is a sections dedicated to the views of the proponents of the Anthropic principle but not those of the opponents? Myself I know too little about this subject to be able to add it, but someone out there should be able to add such a section, not?

Someone, sometime

Reply: As the (weak) anthropic principle is a truism, i.e. true by logic, critics of it would either need to claim access to other sources of information beyond our common reality, or would need to misformulate the WAP to attack it, such as in the strong anthropic principle. Actually, other wordings of the SAP are more along the lines of "Someone created the universe such that we, or at least some other beings(able to please God) exist". While this formulation of the SAP is fine as an argument between two believers, it isn't a reasonable statement for improving scientific knowledge, which is working with the tools of Occam's Razor and the assumption that experiments may be repeated to support or disprove a hypothesis (allowing some margin for uncontrolled effects and yet unknown effects) to promote a hypothesis to receive merit as a theory or law.

Highlander 22:37, 31 May 2006 (UTC)

Unclear expression
From the intro: "If something must be true for us, as humans, to exist, then it is true simply because we exist."

This can be interpreted as either "we know it is true because if it wasn't, we wouldn't exist" or "it is this way because we wouldn't exist otherwise". The former is simply deducing additional information about the structure of the universe from known facts (we exist), the latter is claiming that the universe was custom tailored for us - which may or may not be true but is a matter for the Intelligent Design article. So, please clear this up, and possibly reference the appropriate articles about creationism or ID if you think that Anthropic Principle has ties to either (as it does if the latter interpretation is used).

80.186.134.28 22:01, 23 April 2006 (UTC)


 * Actually, they both imply the same situation; the interpretation that "it is this way because we wouldn't exist otherwise" is just another of saying that the obvious fact that we exist is evidence. There's no comment whatsoever as to "tailoring". siafu 02:20, 24 April 2006 (UTC)

Warning! Note that many versions of the anthropic principle exist.
This article has slowly improved over time, but it is still flawed. Many versions of the anthropic principle exist, not just the three that were listed here before I added another option.

If we are going to present arguments for or against any point of view, let us be precise in noting which form of the anthropic argument this argument refers to. If we cannot tell which form it refers to, and someone insists on quoting such a criticism within this article, then we must note within the article that the criticism is vague, and does not specific its target. RK 00:54, 18 June 2006 (UTC)

I am sort of frustrated with the style of arguing quoting experts. John D. Barrow and Frank J. Tipler did not use a wording of the anthropic principles that actually is anthropic, that is, referring to humans. Instead they talk about carbon-based life, life and intelligent life. This is why I support the sections on the Anthropic Cosmological Principle despite having an odd feeling when seeing them come before the section on variants.

So actually some of these anthropic principles should have different names, maybe universal principle or principio sapiensis (consider intelligent life other than humans as well).

As another reference point I'd like to offer Peter Schaefer's (2005) formulation of a weaker weak anthropic principle, which is named the Solipsistic Anthropic Principle:

All observations of an observer must allow the observer to exist, and to read about the Solipsistic Anthropic Principle right now.

Highlander 11:19, 26 August 2006 (UTC)

Origin, Reasoning, and Evidence - the CMB
I'll clean up the section "Origin, Reasoning, and Evidence for the weak anthropic principle". Improvements are:


 * less red links which would spawn new copies of this grand topic


 * references to other sources better sorted

Regarding the topic, the universe will always appear to work according to laws of the universe that are valid everywhere, because you need at least to observe the observer. This doesn't mean the laws will be easy to operate with. Highlander 13:07, 13 August 2006 (UTC)

I was planning to fill-in the red links with pages that explain their relevance in context with the article. Island1 11:55, 13 August 2006

Well, it looked a bit too red for me, and the links where partly redundant. I am optimistic you can still connect every point you want to make, at least every topic that can stand by itself.

Also the Anthropic principle text looked perfectly cromulent to me before that. Maybe you try to pack too much into the section, or just your main point into the section .. Highlander 16:54, 13 August 2006 (UTC)

No, my mistake. You are perfectly correct about everything that you say, (except that I think that Krauss' quote is highly relevant and should be included, as with previously included quotes, since it is not easy to find in the long article at edge.org) but I would like to mention that I'm fairly certain that I can easily prove that Brandon Carter was voicing John Wheeler's idea of a "Strong", causally-responsible connection between the forces of the universe and human existence, so I thiink that the title, "Origins Reasoning and Evidence For" was more accurate. Island1 13:36, 13 August 2006

Okay, I finally understood some of what you were saying, Highlander, and I made some clarifying edits accordingly, I hope, let me know. Island1 20:46, 13 August 2006

I made some links go blue, and split the section, this means you may have the entire quote there Highlander 07:52, 15 August 2006 (UTC)

Thank you, Highlander. I'm going to remove the rest of the red, at least temporarily, until I am more familiar with the protocol for new topics, as I didn't do very well in my first attempt. Also, I am making changes to the section names that are more accurate.Island1 5:35, 15 August 2006

Highlander, in your note you said that you had split the section, (which I don't disagree with), because the astro-ph/0508047 anomaly might soon be explained away if CMB radiation has a positive effect on the formation of planetary systems).

This is not even funny, but Krauss also said, "I want theory to be wrong, not right, because if it's wrong there's still work left for the rest of us.

There is a clear predispositioning among scientists toward "explaining-away" evidence, rather than following the scientific method which at least gives equal time to the Occam's razor implication for for anthropic preference that is called for by the observation, which occurs chronologically *before* they start explaining-away evidence, while inventing conditions and universes that fall into the category of an theoretical speculation. Part of the problem has to do with the misplaced perception that anthropic favoritism requires geocentric arrogance, (that we truly are at the center of the universe), but that comes from a failure to look, because it is easily supported that the physics for the anthropic principle isn't limited to our planet, since it also applies to planets near stars in every galaxy that evolved under the same conditions as our own system, time/"location"-wise in the history of the universe. This is further discussed in the paper that I've linked, below, but the coincidentally balanced "goldilocks constraint" limits the possibility for intelligent life to evolve elsewhere in the universe to a fine-layer of galaxies that are similar to our own in terms of the evolution of similar raw materials under common conditions.

This would be the "ecliptic" that Krauss referred to, so yeah, there should be evidence that the CMB radiation has a positive effect on the formation of planetary systems, but the "ecliptic" is "special".

The previously mentioned "predispositioning" says that this won't be noticed, so the consensus will be wrong.

Is the Strong Anthropic Principle Too Weak? http://arxiv.org/abs/gr-qc/9812093

Island1 14:43, 13 August 2006

I should have included that the Fermi paradox supports the above given facts, since contact with other life should not be expected YET, since there hasn’t even been time even for radio transmissions from nearby planetary-systems in our own galaxy to reach us, given that the above physics supports that all intelligent life is equally developed, technologically as all other intelligent life is. So the anthropic principle actually resolves the problem, while making a testable prediction about the most likely locations for life elsewhere in the cosmos. The Fermi paradox isn't. Rather, it is a misrepresentation of the mediocrity principle, which is another pure "copernican-extension" that doesn't actually extend to the time domain. Island1 14:43, 13 August 2006

I hold this belief that a metaverse(cf. multiverse, a metaverse is: (do ask me in person) ) tends to explain away wonders in its universes. Maybe you could explain multipole theory so that I understand what kind of correlation is found with the ecliptic.

The physics you suggested supports that all intelligent life is ABOUT equally developed. So my guess is that it is somewhat likely either that estimates for the viability of a civilization such as ours are wrong, or that advanced civilizations avoid (verifiable) contact out of wisdom, fear, or economic reasons. These are boundary events AFAICS.

Highlander 16:24, 16 August 2006 (UTC)

Ehm, it just came to me, can you explain how the Anthropic Principle didn't always cover the Cosmological Anthropic Principle as well? Isn't this just evidence presented that our universe is just one of several which are possible in the realms of mathematical (meta-)physics?

Highlander 16:54, 16 August 2006 (UTC)

If the microwave background at the multipoles is correlated with the geometry and direction of motion of the solar system, and the incoherence manifests via octopole and quadrupole components in a bound universe, then there should be a center of gravity at the center of the visible universe that correlates to the ecliptic. - The anthropic principle isn't about evidence presented that our universe is just one of several which are possible when the configuration that we observe follows the least action principle, rather than uncertainty, as a causality responsible mechanism for stability, rather than the cop-out that string theorists are accused of making. It is the failure of any theory to answer that question that forces them to rely on the AP, which leaves a very bitter taste when it gets used to "explain-away" causality. Science would support that the unidentified physical reason behind the AP is what enables the universe to take the form that it does while still holding to the least action principle, so this is what needs to be researched in context with anthropic significance, without bias. Also, be careful about what assumptions about the nature of universe are being accepted and then projected into more advanced theories, as nothing has been settled, and the physics takes on drastically different meanings, depending on what universe we actually live in.

Island1 18:29, 16 August 2006

I want to raise a flag that "JB" seems to be trying to make changes that are ideologically biased, rather than being honestly scientific, which is against wiki policy.

Island1 15:09, 17 August 2006

Well, I find it strange that Anthropic principle now is referred to as Anthropic Cosmological Principle. How about just The Anthropic Principle in Cosmology? And that you talk about evidence. I have the feeling you are following a red herring: If the Anthropic principle indeed is a truism, it doesn't need evidence, at best it needs examples. It has been suggested that Biocosm be merged with this node, so JB is acting in a natural way. I'll re-read the intro.

Highlander 12:03, 19 August 2006 (UTC)

Because, for example, an anthropic principle in a multiverse is not a cosmological principle, (unless all universes are anthropic), which is what the following statement of fact indicates without adding theoretically speculative extra entities, and unobserved conditions:

The actual structure of the universe is in "dramatic contrast" to the "expectation", so many fixed balance points that are commonly pointing directly toward carbon-based life indicate that there is some good physical reason for it that is somehow "specially" related to the existence of carbon-based life.

The fact that it is a truism doesn't make the unexpected physics any less significant, so it is important to note that this indicative evidence differentiates between, 1) "yeah, conditions had to be right, so what?" and 2) "yeah, conditions had to be something different from the normal expectation", truism or otherwise. The aspect of truism is commonly used in the first sense without consideration for the nature of the physics in order to downplay the implied significance that Carter, Dicke, Hoyle, and others have pointed to as evidence for an anthropic cosmological principle, so nobody's "feelings" about this evidence matter, without proof that extra entities are necessary. - - Maybe I misread JB though, (and if I did, then I apologize), because the way that you reinserted the term, "randomly" reads just fine in context with everything that I just said. - - Also, the observed universe is carbon-rich by a ratio of approximately 10:1, but carbon based molecules and chains also form more readily when the ratio is reversed, (as is the case on Earth!), 10:1 in favor of the next most plausible life-form that we have been able to imagine, (silicon based life), so there is absolutely no justification for speculation about other forms of life in context with the known physics. Again, extra entities must be justified with something more than... "maybe conditions are different elsewhere", so I "think" that you're chasing a red herring". Island1 20 August 2006

Okay, point noted regarding carbon-based life being favored. But since I opened up time and location for discussion, I felt like opening up the carbon base as well. I think of the Anthropic principle as the simplest truism you can get away with - the restriction to carbon seems unnecessary, because it leaves the safe ground of a truism. I re-inserted the random elsewhere because I felt that it was maybe what JB meant. Regarding the term Anthropic Cosmological Principle I see what you mean. However, cf. Anthroposophy, it derives from human in Greek, so it is tied to our cosmos (or set of cosmos' ?) already, and I guess if it would ever be necessary to extend the principle to aliens, the term would be kept as in sloppy terminology.

A concise anthropic version of the AP could simply say humans instead of carbon-based life.

BTW.: A version of the strong AP I came with is: There will always be philosophers in the universe(Because otherwise the weak AP will be worthless).

Highlander 16:57, 19 August 2006 (UTC)

I just wanted to study gravity, and frankly, I wish that the AP didn't exist... but. Anyway, I think that an unfounded leap of faith was made to call the principle anthropic, since the evolutionary physics can't be strictly limited to our own galaxy, much less the Earth. Wheeler was on the forefront of Carters mind in Cracow. Island1 20 August 2006

Regarding the change labeled "The cosmic microwave background has nothing to do with the anthropic principle. It's a necessary consequence of the Big Bang, but not anthropy."

The removed link claims that something called multipole theory shows a correlation between the CMB and the eclipse. This is an extraordinary claim requiring extraordinary evidence, but if verified would belong here. Highlander 12:12, 2 December 2006 (UTC)

Intro needs help, regardless
Although some may think otherwise, this intro is in definite need of some help. See the first sentence : "The Anthropic Principle represents an effort by some physicists to explain the structure of the universe by considering how the forces are precariously balanced in a manner that constrains it to evolve to a point that it produces carbon-based life at a specific time and location in the universe." It ought to be "constrained against" not "constrained to". If it were "constrained to" then it would mean that forces were constrained towards the creation of planets like our earth, i.e. the "creative forces" (btw, what is meant by "forces" anyways?  Can we come up with a better word than that?) have a greater tendency to create life as we know it on earth, in more instances than not. However, as far as we can tell with our limited ability to search the universe so far, we have found no reason to believe that is the case at all. In fact, the opposite is true. See Merriam Webster, m-w.com, where the definition of constrains is given as: "to force by imposed stricture, restriction, or limitation". Thus, this sentence says that the universe is precariously balanced in a manner that forces it to evolve. That simply does not make sense.

Island1 17 August 2006 Yes, "constrained to" most appropriately does mean that the forces are constrained "towards the creation of planets like our earth", but this is a facet of the evolution of the constraint on the matter field that gets layed-down by the big bang. Both Carter and Dicke noted that this means we are "inevitably priveledged" to whatever level of relevance, and it can't be both, "constrained against" and "inevitibly priveledged" at the same time. Automatically discounting or willfully lowering the necessarily implied significance isn't what is called for by the physics, rather, it is typically motivated by something else, less scientific. The "selfish biocosm" would be one example, and John Wheeler's derivation is another, of good scientific physical reasons why the universe is necessarily "anthropically constrained" which will be excluded if "anthropic preference" is discounted or downplayed from the view of science. http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec28.html

Island1 17 August 2006 Looking back on it, this is exactly the reason why I stuck with the more awkward statement that I originally made before "JB" broke it up for further dissection, because there are three critical facets to this that can be taken apart separately when the first sentence gets separated from the rest of the point:

The Anthropic Principle represents an effort by physicists to explain the structure of the universe from the fact that the forces are coincidentally balanced in a manner that constrains it to evolve to a point that it produces carbon-based-life at a specific time and location in history the universe, in dramatic contrast to what is indicated by any practical model of turbulance driven structuring that should result from our big bang.

The actual structure of the universe is in "dramatic contrast" to the "expectation", so many fixed balance pointsthat are commonly pointing directly toward carbon-based life indicate that there is some good physical reason for it that is somehow "specially" related to the existence of carbon-based life.


 * The Introduction, much of sections 1-3, and much of this Talk page are very badly written. Moreover, nearly everything that leaves me baffled and deeply dissatisfied has been contributed in the last 100 odd days. A reader of this entry as it stood 24 hours ago would never suspect that large parts of Barrow and Tipler (1986) are clear and engaging. I have spent the last several hours trying to clean up this article, but more work is still needed: whole paragraphs of what I found earlier today left me so baffled that some of my editing work is, frankly, a stab in the dark. This article is in very bad need of tender loving care by the likes of Nick Bostrom.132.181.160.42 05:37, 25 August 2006 (UTC)

I think that Highlander should put the previous revision back in place as Highlander left it, before I do it myself. The above person has no idea what the anthropic physics is about, and Nick Bostrom's speculations have been shown to fail when extended to the time domain anyway. Island1 25 August 2006

Mr .42 is a but right that the intro needs care, since it fails to tell what the Anthropic principle actually is. However, having yet another expert on the subject might not help that much, since experts tend to add their own version of the AP, and because the experts Barrow and Tipler offered two wordings of the AP which in my opinion also are not the clearest possible wording. Thus we end up with the situation that the experts introduction of the subject is not the best source for an accurate wording. I do not feel the edits by Mr .42 were meant to be harmful, but given that we are looking for a truism, then the words The Anthropic Principle is a convenient heading .. do simply miss the target. Highlander 13:34, 25 August 2006 (UTC)

Regarding the talk page being badly written, I have been told that it is nice to leave the talk in place like a historic record to give others a clue what is going on. I am not opposed to clear or rewrite some sections, but I have no idea what the proper procedure is. Highlander 13:34, 25 August 2006 (UTC)

That's because Carter made no real statment telling "what the Anthropic principle actually is"... and furter formulations at his advice are different flavors, rather than complete statements about the anthropic physics. I agree that it is extremely important not to allow personal bias to enable one flavor or another to dominate, which is why I commonly dispute assumptions that will benefit my own interpretation... if they are not warrented. But it is equally important not to allow them to include statements that exclude interpretations like John Wheeler's.

This statement, for example by Mr. 42 is a biased attempt to insert randomness where it it is not justified, based on an assumption about sensitivity to iniitial conditions that is not indicated by any physics that is associated with the anthropic principle:

and the randomness of events during the subsequent several seconds

The statement is not justified, since the balanced conditions that define the anthropic physics start unfolding from the moment of the big bang, and then continue to appear periodically throughout the evolution of the universe. Seriously, that statement needs to come out.

Mr 42's statement: Given the extreme simplicity of the universe at the start of the Big Bang, and the randomness of events during the subsequent several seconds, the friendliness of the universe to complex structures such as galaxies, planetary systems, and biology, is unexpected... by any model of turbulence driven structuring that we have ever been able to derive.

That last part is not just a minor incidental fact, yet people keep trying to get rid of it!

http://jersey.uoregon.edu/~imamura/209/mar31/anthropic.html

This is the opening statement from uoregon.edu: Anthropic Principle We may occupy a preferred place or preferred time in the Universe (we may also occupy a preferred universe).

Note that if some of the finely-balanced quantities were not finely-tuned then our Universe would have grossly different properties. The properties would in fact be so different that it is highly likely that life (as we know it) would not develop and be around to ask the question of why the Universe is special. This statement and variants of this statement are the gist of the Anthropic Principle.

My (now much revised) statment: The Anthropic Principle represents an effort by physicists to explain the structure of the universe from the fact that the forces are coincidentally balanced in a manner that constrains it to evolve to a point that it produces carbon-based-life at a specific time and location in history the universe, in dramatic contrast to what is indicated by any practical model of turbulance driven structuring that should result from our big bang.

Mr. 42: ''In physics and cosmology, the Anthropic Principle begins with the observation that the universe appears surprisingly hospitable to the emergence of life, even complex multicellular life, in at least one particular place and time, namely Sol III. Given the extreme simplicity of the universe at the start of the Big Bang, and the randomness of events during the subsequent several seconds, the friendliness of the universe to complex structures such as galaxies, planetary systems, and biology, is unexpected. The Anthropic Principle is a convenient heading for physical and cosmological reasoning that takes into account the existence of a biosphere on Earth in an essential way.''

Mr. 42's claims that sections 1, 2, and 3 need work are highly suspicious since he claims "that nearly everything that leaves me baffled and deeply dissatisfied". Mr. 42 seems to think that Nick Bostrom wrote the anthropic principle, so empirical evidence for an anthropic specialness, and staments made by its originator leave him "deeply dissatisfied" and baffled, since it conflicts with his belief in observation selection biases that don't necessarily pertain.

I am removing Mr. 42's unjustified statment and I think that we should watch what happens to sections 2 and 3 carefully. Island1 25 August 2006

eh oops... I seem to have edited a version that wasn't current to your changes, Highlander, which happened because I already had it up on my screen and thought that it was the latest revision. I would like to reiterate though that my original statement is more accurate in less steps than any so far. Please review it in context with the statement by uoregon.edu, and you'll see why I made my statement as concice as possible, in one **complete** sentence. Island1 25 August 2006

Here is my last edit which you skipped. Notice how it actually gives an example of the AP, as the strongest version of the WAP I do think of. I have no time today to fully check it against the changes, maybe someone would like to review it:

 In physics and cosmology, the Anthropic Principle begins with the observation that the universe appears surprisingly hospitable to the emergence of life, even complex multicellular life, in at least one particular place and time, namely Sol III. The cosmological models developed by theoretical physics like the Big Bang-theory allow chains of events and different selections of parameters in the mathematical models which would not be hospitable to intelligent life as we know it. 

 The Anthropic Principle tries to explain this riddle by stating that the observations of an observer who is entirely inside his universe (by definition) must be consistent with his existence. However, different wordings of the principle and similar principles do exist, leading to controversy. 

 As formulated above it is a truism, since any valid cosmology must be consistent with the existence on Earth of biochemistry and human beings. It is the balanced nature of the evolutionary physics defining anthropic significance that stands out. Similarly, most anthropic coincidences are balanced between the extremes of a spectrum, ranging from the Earth's ecosystem, to the near-perfect balance between the strength of gravitation and the cosmological constant governing the expansion of the universe. 

 The Anthropic Principle is often misunderstood as discouraging any further research into the origins, state and development of the universe. It however does not rule out further discoveries, though it is a restriction. 

Highlander 16:48, 25 August 2006 (UTC)

The cosmological models developed by theoretical physics like the Big Bang-theory allow chains of events and different selections of parameters in the mathematical models which would not be hospitable to intelligent life as we know it.in dramatic contrast to what is indicated by any practical model of turbulance driven structuring that we have ever been able to derive. The second statement correctly identifies the significance of the problem that the other ignores. It is the whole reason that Dirac developed his Large Numbers Hypothesis where Dicke got his anthropic coincidence from. It is the only reason that string theorists are forced to use the AP. The Anthropic Principle tries to explain this riddle by stating that the observations of an observer who is entirely inside his universe (by definition) must be consistent with his existence....in spite of the fact that this occurs in dramatic contrast to the normal expectation. Similarly, most anthropic coincidences are balanced between diametrically opposing extreme runaway tendencies of the given anthropic coincidence... ranging from the Earth's ecosystem, to the near-perfect balance between the strength of gravitation and the cosmological constant governing the expansion of the universe. It is very important to note that any sustained deviation in either direction rusults in a cumulatively runaway effect, because this sends conditions racing so far away from our wildest dreams for what constitues conditions that are conducive to life that speculation about other possibilities is meaningless.Example, expansion/recollapse. Example: The runaway greenhouse effect, vs. Long term tendencies toward glaciation that are predicted by empirically derived milankovitch models. Etc... examples... if necessary.Island1 25 August 2006

The cosmogenic anthropic principle
Let us call "An observer will have observed only facts which are necessary for its existence" "the cosmogenic anthropic principle". What do you think about it? If it is wrong, is it because an observer may measure and thus collapse the quantum wave functions? Will the CAP appear to be true right after the observation taken?

Highlander 20:09, 25 September 2006 (UTC)


 * Pedantic note: the formulation should be more along the lines that an observer can only be guaranteed to observe values necessary for its existence at its origin; an observer could observe many contingent facts which have no bearing on its existence, and even observing values necessary for its origin could well be a temporary condition - what if they went to another universe where values are different? Of course, one could address that by saying that an observer is only guaranteed to observe at any moment the values necessary for the observer to exist at that moment... -- Gwern (contribs) 20:36, 25 September 2006 (UTC)

This principle is unnecessary.
This much is fact:

In the first sentence of the second paragraph under 'criticisms,' there is a link to 'tautology' that actually leads to 'trusim.'

What follows is opinion:

I want to believe the above mis-link was intentional, because a 'tautology dressed as a truism' is, in some ways, the perfect metaphor for this 'principle,' sometimes called a theory, though it has no claim to the term.

There is absolutely nothing to this principle - there never was, and there never will be - other than a truism inheirent in the scientific method (theories inconsistent with the universe as it is are dismissable) which was unrecognized as such by string theorists (due to their unfamiarity with the scientific empiricism?) and later misinterpreted and modified by others, creating a scientific zone of confusion into which poured theistic apologists who now exploit it to advance intelligent design.

Don't blame the thiests for doing what they will always do - blame string theorists who forgot how to be scientists. Unless of course, as I sometimes suspect, they conceived the entire thing as a social experiment, or even, possibly, a joke. In that case - more power to them, the world always needs more jokes, and this one is a doozy.

If this is so obvious, why does no one see it? Because the anthropic principle is always applied to particle physics - never to anything about which anyone has any tangible understanding - although it easily could be. Here, therefore, is the reductio ad absurdum that should have ended this discussion 30 years ago.


 * Four astronauts, Eliott the Empiricist, Stewart the String Theorist, Cory the Confusable, and Theo the Theist crash land on an alien planet. Having survived the crash, the four realize that all their windows have broken. They are panic stricken because they have no space-suits, and assume they will die for lack of oxygen. But they don't die - they are able, in fact, to breathe normally.


 * "Fantastic!" shouts Eliott. "There is oxygen in the atmosphere! We can remain alive until we are resucued!"


 * "Thank God!" says Theo.


 * "I'm not convinced," says Stewart. "Given the number of planets in the universe, and the percentage that have any oxygen at all, the chance of crashing on a planet with the exact amount of oxygen capable of supporting life is astronomically low."


 * "He's right!" shouts Corey, who is verifying the information in the ship's encyclopedia. "The chance is only one in 10 to the power of 60,000! We'd be fools to assume that!"


 * "Actually," says Eliott, "it already happened, so we'd be fools not to assume it."


 * "But those ways of looking at it are utterly ireconcileable!" shouts Corey.


 * "Wait!" says Stewart, "I have an idea. I admit, that the possibility of crashing on a planet that supports life is remote, but we needn't concern ourselves with the probability of crashing on a planet that does not have oxygen."


 * "What are you saying?" asked Corey.


 * "Well," said Stewart, "I'm proposing something new - a principle that may seem radical. We can statistically favor the probability that we might have landed on a planet that supports life. Doing so is justified by the logical deduction that the planet we are on must have enough oxygen to sustain life, or else this very discussion would not be possible."


 * "Uh..." said Eliott, "isn't that the same as just accepting what we can all clearly see, rather than postulating something else that could have been, had things been different?"


 * "No!" shouts Corey. "Don't you see? He is saying that this planet supports life because there is no possibility that it would not support life!"


 * "Uh..." said Eliott.


 * "That this planet supports life is a constant!" says Corey. "All other factors that make up the universe exist only to the extent that they support this. It is the single, immutable truth of exitstence."


 * "Yes!" says Theo, chiming in. "And don't you see? The purely random universe is one in which there is virtually no chance we would be alive! Clearly, an outside force, a designer, established the nature of the universe, including, of course, the sustainability of life by this planet as its single, immutable truth, because he loves us and wishes for us to worship him. I assert that this new principle can best be understood in light of the ancient texts I base my understanding of absolutely everything else on."


 * "Amazing!" says Corey. "We should demand that your theory be printed in astronomy textbooks, side by side with existing theories, under a large heading that states that no theory is necessarily better than any other."


 * Eliott turns to Stewart. "You totally confused them with that weird probability talk," he says. "Shouldn't you explain to them that they are getting it wrong?"


 * "Shh...," says Stewart. "If they keep talking about my principle, I might get tenured!"


 * Sevenwarlocks 15:58, 27 September 2006 (UTC)


 * We are not editing a physics handbook but an encyclopedia. You may say "What's the difference?". The difference does exist and is crucial for understanding why we need the article. In a physics handbook (or university course) one does not need to present ideas which are not stricly physics but more philosophy. One needs not include all views and even more importantly, to treat them equally. An encyclopedia is completely different. We are supposed to present all the views. We should have articles not only on physical but also philosophical and religious views. We should present not only theories based on shaky ground (like Heim theory) but also pure crap (like Time cube) if it is well known enough ("newsworthy"). The articles should inform the reader about the mainstream view on any idea but also on minority views. Therefore, the article is needed as dozens of scholars publish papers on anthropic principle. According to ISI Web of Science there were 13 peer reviewed papers on "Anthropic principle" in years 1991-1995, 18 in 1996-2000 and 45 in 2001-2005. Please, notice the increasing trend. Anyway, this is certainly newsworthy. Friendly Neighbour 17:23, 27 September 2006 (UTC)


 * Well, OK, point taken.


 * I don't dispute that such an article should exist. Maybe my comments should be on a physics bulletin board and not here. However, this particular article can, and I see from the discussion, has been, criticized for numerous things. I could add a number of criticisms, and may, but as I tried to do this, I found it was almost impossible to discuss what is wrong about the article outside the context of what is wrong about the principle itself, given this subject's connection reality creation.


 * I am not at all sure that this article should be so long or comprehensive. Comprehensive is almost always a positive in an encyclopedia article, but is that always so? Here the subject begins with sub-conscious self-mockery, passes through subtle, ironic self-mockery (SAP, WAP...) and arrives, at conscious, nominal self-mockery (CRAP). I'm not sure any reader has any reasonable way of determining how much of this is meant to be taken seriously. Some parts, such as this one...


 * "Copernicus argued that the Earth is not the centre of the solar system, but Carter noted that pure cosmological extensions of this idea are what he called the anticentrist dogma, that led to cosmological formulations like the Perfect Cosmological Principle, which does not result from the evolutionary physics that derives the cosmic coincidences and the otherwise unexplained large scale structuring of the universe that becomes absurdly apparent with the cosmological constant problem. This vexing problem is why the Anthropic Principle has acquired a following among String Theorists trying to choose the correct vacuum solution from the landscape, since no other stability mechanism explaining why this is so has been proposed."


 * ...defy argument merely by virtue of passive language, unclear antecedents, flawed parallel structure, and nested prepositional phrases.


 * In short, I think this article might best be labled as in need of total overhaul, and that its re-release should await a writer who both A) understands the principle, and B) is a writer.


 * Sevenwarlocks 18:16, 27 September 2006 (UTC)

Probability
Is this principle tied to probability issues?

The odds of winning a lottery are said to be small, yet someone always wins. Why should the arbitrary existence of the universe and its physical laws be any different? Pendragon39 01:49, 10 October 2006 (UTC)


 * if you're an adherent to the multiverse theory, then the existance of a universe that is fine-tuned in the manner that ours is, is not remarkable (given an infinite number of attempts, i can eventually hit a bullseye at 15 meters with a dart that i toss blindly). if, on the other hand, this is the only universe there is in all of reality (not an unreasonable belief, considering the meaning of "universe"), it's pretty remarkable that it came out the way it has.  it could have very well come out in a manner that no one could be around to observe it, and in fact, an inhospitable universe is far, far more likely.  that observation is what some intelligent design advocates refer to for support of their position.
 * if you roll a pair of dice often enough, the occasional snake eyes is not remarkable. if you had one chance to roll the dice, and if your very existence depended on rolling "two", i wouldn't want to hold out much hope.  it's much, much more so the case for the fine-tuned universe. r b-j 00:06, 12 October 2006 (UTC)
 * Yes, multiverse 'solves' the odds by rolling the dice again and again. In the case of a single big bang, something remarkable happened and here we are! But this assumes that initial conditions could have differed. Perhaps there was only one way for our universe to evolve, due to as yet undiscovered fundamental laws of physics. Btw, is there such a thing as absolutely fundamental laws or particles? Pendragon39 14:26, 14 October 2006 (UTC)


 * The weak anthropic principle in its most abstract form points out that one cannot be an unbiased observer of events that are necessary for the existence of the observer(oneself). Even attempting to step out of ones box and to calculate a probability for such an event is hard to do the right way, since it is unknown whether all possible universes would have equal chance of existence, or whether e.g. universes with symmetries would be viewed as the more likely ones. Highlander 17:30, 14 October 2006 (UTC)
 * But there is a fundamental difference between a universe where the the constants are forced to what they are, and a universe where they are allowed to be random. This is why the AP is, as I pointed out before (below), more of a tool for introducing possible alternatives rather than weeding out impossible ones. --Swift 05:29, 15 October 2006 (UTC)


 * "is there such a thing as absolutely fundamental laws or particles?" As in: The only possible ones for a universe? We don't know and won't for the forseeable future. The current GUT canditates are all tunable which implies that there is an infinite number of possible universes. These theories are, however, far beyond the realm of anything we will be able to test for the forseeable future. --Swift 05:29, 15 October 2006 (UTC)


 * Then this means the root of causation cannot be fully determined. There may yet be room for God to play a role in ;) Pendragon39 20:04, 15 October 2006 (UTC)


 * Quantum mechanics appears to dissolve causality. There will always be a point at which science cannot provide an explanation as to why certain properties in fundamental particles are the way they are. Pendragon39 01:04, 16 October 2006 (UTC)


 * I disagree. The fact that you only have one chance has little to do with it. If hitting the bullseye is the only way of sparking a civilization that can probe into the question of where the dart landed, it is of no surprise that such a civilization will find itself puzzling over why the dart hit the bullseye so well.
 * It is more like an accident. It happens randomly, leaving some to ask: "why me?". It can also be compared to survivor bias since only a certain scenario will allow for survivors.
 * The anthropic principle has been critizised for being more of a tool than a principle. There is nothing that says that nature's constants were arbitrarily chosen. The laws of physics may very well guide the constants to their current values. See http://www.physicstoday.org/vol-59/iss-10/p8.html for an interesting article on this (it is elementary in the beginning, but have patience; the good stuff is towards the end). --Swift 07:09, 12 October 2006 (UTC)
 * I appreciate both answers and your thoughts :)


 * While we may feel that improbable events are remarkable, are they really? If we remove emotional judgement regarding unlikely events, what are we left with?


 * Arbitrary means 'no reason'. If all possibilities have an equal chance of occuring, why would a (remarkable) outcome be viewed as having to have a reason behind it? Pendragon39 14:26, 14 October 2006 (UTC)


 * "why would a (remarkable) outcome be viewed as having to have a reason behind it?" It wouldn't. The thing is that while the there needn't be a reason behind it, there still may be. This is why the AP isn't a principle by which we can deceide between theories. --Swift 05:29, 15 October 2006 (UTC)


 * Either there is an uncovered scientific reason or it is arbitrary. When someone wins the lottery there is no reason, unless you count being lucky. So, the universe we live in also 'got lucky'. Pendragon39 19:53, 15 October 2006 (UTC)

Schmidhuber on anthropic principle and conditional probability / Solomonoff
I added: According to Jürgen Schmidhuber, the anthropic principle essentially just says that the conditional probability of finding yourself in a universe compatible with your existence will always remain 1. It does not allow for any additional nontrivial predictions such as "gravity won't change tomorrow". To gain more predictive power, additional assumptions on the prior distribution of alternative universes are necessary. See: Algorithmic theories of everything (2000). http://arxiv.org/abs/quant-ph/0011122. See also: The Speed Prior: A New Simplicity Measure Yielding Near-Optimal Computable Predictions. Proc. 15th Annual Conference on Computational Learning Theory (COLT 2002), Sydney, Australia, Lecture Notes in Artificial Intelligence, pp. 216-228. Springer, 2002. http://www.idsia.ch/~juergen/speedprior.html. I also added the link to Ray Solomonoff and his theory of universal inductive probabilistic inference. Discrepancy (talk) 23:39, 26 March 2008 (UTC)

Criticism: direction of causality
The article is quite well writen and objective (at least, to me). I will not (as some of you here, excuse me for saying that) say that the article needs work or is incorrect because I do not agree with the theory in itself. On some points I agree, on others I disagree but that doesn't mean the article needs to be changed. However, I do have a problem with the following in the article:

"Another, obvious, criticism of the anthropic principle is that the direction of causality it asserts is mistaken; humans have evolved to adapt to the universe as it currently is, cosmological constants and all, and not the converse. That is, we exist because we are adapted to the physical universe; the physical universe is not adapted specifically for us."

It's not hard to see what the writer believes here. The word obvious is obviously misused here. Apart from that, the statement that "the direction of causality it asserts is mistaken" may be widely accepted but is debatable. I believe this statement to be in line with evolution theory...

Thus, I have changed the text into: "Another criticism of the anthropic principle is that the direction of causality it asserts is inconsistant with that of evolution theory. This theory claims humans to have adapted to the universe as it currently is, cosmological constants and all taken into account, and not the converse. That is, we exist because we are adapted to the physical universe. The strong anthropic principle states, in contrast, that the physical universe is adapted specifically for us." Info D 16:34, 18 October 2006 (UTC)


 * if we take out "obvious", i think the previous statement makes the point more clearly and consisely. r b-j 02:07, 19 October 2006 (UTC)


 * The main problem I see is the statement that "the direction of causality it asserts is mistaken". Like I said before; it may be widely accepted but is debatable, which is precisely what the principal does: it questions the validity of the direction of causality 'normally' taken! It cannot be that the article says it is a mistake. It's a point of discussion caused by the principal. So yes, I do believe this should be corrected. And that's why I've changed the text a bit... Info D 08:20, 27 October 2006 (UTC)


 * No the anthropic principle is not in conflict with evolutionary theory since the physics is all about environmental enablement. Even the weak anthropic principle notes that "sites" must exist that are conducive to life and evolution.  Natural selection can only work if the environment is conducive to it within the limits of practicality, so if anything, it challenges one aspect of claims that the "anti-randomness mechanism", as Richard Dawkins calls it, is itself. "randomly-enabled".  "island" 27 October


 * Yes, I have found myself tumbling over this 'critisism' wondering if it's not possible for both the anthropic principle and evolutionary theory to be thought of as correct. My mind, at times, doesn't seem to be able to understand the proposed conflict between them! It seems as if evolution theory deals with a whole other subject than the anthropic principle does and in fact there is no real conflict between them. How do you folks see this? Can anyone make this more clear to me? Info D 16:04, 28 October 2006 (UTC)


 * As mentioned elsewhere on this page, the Anthropic Principle is observer bias (a variant of [survivor bias] as mentioned above). So any science that is relevant to the existence of the observer (eg, the research of life on Earth to Human scientists) will be influenced at least through the data collected. The theory of evolution though is just a theory about how Earth-based life changes. It has no dependence on the existence of the observer and is either correct or not based on how accurately it describes how life changes in the real world. I see no real relation between the two. -- KarlHallowell 17:08, 1 November 2006 (UTC)


 * Ok, if no one objects I will remove it soon. Info D 16:44, 3 November 2006 (UTC)


 * Removed: "Another criticism of the SAP and FAP is that the direction of causality it asserts can be considered mistaken; in the view of evolution caused by natural selection, humans have evolved to adapt to the universe as it currently is, cosmological constants and all, and not the converse. That is, life exists because life is adapted to the physical universe.  The strong anthropic principle states, in contrast, that the physical universe has adapted, a priori, specifically for life." Info D 07:26, 7 November 2006 (UTC)

The Buddha's teaching and the Anthropic principle
Interesting point to make is the simularity of this theory with Buddhist cosmology linked ideas. Simply said, Buddhism states that 'worlds' come into existance when there is perception. It is the perception that creates the world, not the world in itself. This seems to take ""Observers are necessary to bring the Universe into being." Barrow and Tipler believe that this can be validly inferred from quantum mechanics." even further by saying that the Universe is created by the observer.

Forgive me if this seems to be too much out of touch with this subject (I might be biased!) but for those interested I can recommend Buddhism and evolution and Fourteen unanswerable questions. Info D 16:57, 18 October 2006 (UTC)

Need to define the principle
The term "anthropic principle" needs to be defined. I don't see why it shouldn't be in the first paragraph. I prefer Rbj's version of the introduction:


 * In physics and cosmology, the anthropic principle is the principle that any valid cosmology must be consistent with the existence on Earth of biochemistry and human beings. This original (and "weak") form of the anthropic principle is a truism or tautology that begins with the observation that the universe appears surprisingly hospitable to the emergence of life, particularly complex multicellular life, that can make such an observation and concludes with that premise that in only such a fine-tuned universe can such living observers be. Given the extreme simplicity of the universe at the start of the Big Bang, the friendliness of the universe to complex structures such as galaxies, planetary systems, and biology is unexpected by any normal model of turbulence driven structuring that we have been able to derive. The anthropic principle also acts as a convenient category for physical and cosmological reasoning that takes into account the existence of a biosphere on Earth in an essential way.


 * Attempts to invoke the "principle" to develop scientific explanations has led to more than a little confusion and controversy.

This version of the intro is short. It defines the term in the first sentence. Subtle problems and concepts should be saved for later in the article IMHO. The current version has bloated to five paragraphs including several external links and doesn't address the subject (I mean in the way an introduction should, ie, define the subject and give the reader a brief outline of what it's about). I don't really want to just paste back Rbj's version of the intro back in, but I don't see what else to do. -- KarlHallowell 16:46, 1 November 2006 (UTC)


 * I'm not going to be a happy camper if I have to rehash this crap again, but I'll just say this:
 * Anybody that thinks thinks that they can project Barrow and Tipler's interpretation into Dicke and Carter's mind need not be "contributing" to this subject, because the cannot defend this position. Anybody that thinks that the anthropic physics necessarily represents a tautology need not be commenting on this subject, and anybody that doesn't recognize the relevance of external links doesn't either.  island 00:20, 2 November 2006 (UTC)


 * okay, Island, to leave your sig (and accurate UTC time stamp) type 4 tildes: ~.
 * Not that it's my version, but i thought Karl's version was concise and (after i edited it) accurate. the Anthropic principle is an evolving concept.  many authors have expounded upon and expanded it since Dicke.  i think that the "Dicke coincidence" should be mentioned (as the first use of the term) in the intro.  but authors like Stephen Hawking have used the term also in a manner that is more consistent with the version that Karl and i both prefer.  i actually do not like all of the variants (SAP, FAP) that Barrow and Tipler brought into it.  from my reading of the lit, what they call the "weak anthropic principle" is simply the anthropic principle of the lit.  i think that SAP and FAP are deservedly called CRAP and moves beyond any real science.  but also, the WAP (and the AP as written about by multiple authors including Davies) is basically a tautology or, more flatteringly, a truism so it has two salient properties: 1. it is true (so disputing it is a loser) and 2. it is a vacuous truth - it says practically nothing and cannot be counted on as a necessary fact to support a theory that makes a larger claim about reality.  but, a third property of a truism (or less flatteringly, a tautology) is that it helps people think about a question.  it helps us order our thoughts to explain something, even if it is says practically nothing other than its premise.
 * there is more to the fine-tuned universe than just the age (in natural units of time) as we presently observe it, or the remarkable (or "coincidental") values of a score of fundamental physical constants. there is the clumping of matter in the early universe (evident from the background radiation seen in the COBE research) and other parameters that i don't know about that needed fine-tuning.  but, today, in multiple monographs (Brief History of Time and others), what the AP means when it is referred to includes Dicke's observation (which was really just an answer to why is the universe about 14 billion years old instead of 4 billion or 140 billion) but is a principle that has been extended to attempt to answer other similar questions, such as why is the fine-structure constant about the reciprocal of 137.036.  a good intro for this topic would be broad enough and comprehensive enough to include these concepts.  i think you should be a little more open minded about this.  Dicke (dunno who Carter is) does not own the AP concept.  (and neither do Barrow, Tipler, or Hawking.) r b-j 01:37, 2 November 2006 (UTC)

I just revised the first paragraph. Not all versions of the AP refer to humans or even carbon-based life. Statements that conventional physics can't explain the evolution of planet Earth from the Big Bang couldn't be more wrong... in fact all arguments involving the AP assume that we can predict the current state of the universe given the known laws of physics. 82.6.76.92 10:54, 26 March 2007 (UTC)


 * We'd need a prominent source to quote for other versions of the AP Highlander 16:34, 26 March 2007 (UTC)


 * How about Brandon Carter, in the article where the AP was defined? Have you read it? PaddyLeahy 17:43, 26 March 2007 (UTC)


 * I have, (among many others), and "Versions" that don't refer to humans are not anthropic, do not define a cosmological principle, and are not even wrong, because they are just a selection effect. Paddy also appears to be assuming that eternal inflation, (which is not a "normal" turbulance driven model), is a proven fact... wrong. island 26 March 2006 (UTC)


 * Wikipedia articles are supposed to describe the actual usage of terms, not the usage we would like to impose for any reason (e.g. strict etymological determinism); even Barrow & Tipler don't insist that the observers are human.

And neither do I, but carbon based life includes humans, and the anthropic *principle* came about because it appears especially relevant that the anthropically pointed features of the observed universe are also commonly related to its structuring, and not because there are some variant interpretations which claim to explain-away this fact, Mr. Cart-Horse. The anthropic principle can define the universe from causality-responsible first principles, whereas anthropic selection effects dodge the issue of causality and first principles with speculation beyond what is observed.


 * Many scientists and philosophers who contribute to the professional discussion of the AP would agree with Nick Bostrom that the AP is indeed an appeal to selection effects; why can't it be cosmological as well? (OK it strictly isn't a principle, but the usage has stuck). Island, if you are responsible for the mentions of turbulence-driven models, can you cite a reference? I do (observational) cosmology for a living and turbulence just doesn't feature in the discourse about cosmological models these days (if it ever did). Oh, and I haven't put in or taken out anything about inflation (yet). PaddyLeahy 19:56, 26 March 2007 (UTC)

While I was at it I deleted the section "More Anthropic Coincidences" which contained material originally placed in the introduction. After many edits, what was left was almost incomprehensible, refered to concepts defined much later in the article, and contained original research. If anyone wants to put this back, place it much deeper in the article and cite references. (NB. This article is full of references to on-line course notes which have an average lifetime of a few years at most!). 82.6.76.92 11:33, 26 March 2007 (UTC)


 * It would be nice to know you from other than an anonymous IP Highlander 16:34, 26 March 2007 (UTC)


 * Fair enough. It was me who made the changes above and I've just registered.

I have to teach this stuff and I get irritated when my students quote confusion from Wikipedia. I'm afraid there is a lot of it in the current article. I see most of the changes I've made so far have been reverted... PaddyLeahy 17:43, 26 March 2007 (UTC)
 * Just because you teach "this stuff" doesn't mean that you have justified changes that you have attempted to make. With all due respect, removing information that is supported by citable .edu websites because you say that they might only be there for a couple of years, spiced with an unproven claim about "original research", reeks of a theorist who believes in unproven or semi-proven theoretical assumptions.island 26 March 2006 (UTC)


 * As regards using .edu websites, do you want to spend the rest of your life fixing dead links? Cite published articles and books, and websites that are maintained by institutions for archival purposes (e.g. arXiv, or some NASA sites). On-line lecture notes are no more peer-reviewed than wikipedia itself.

Neither is arXiv nor NASA, so the only point is that potentially temporary but citable references should be reinforced as soon as possible. Without accusations about underlying motivations, this cannot mean that you should remove highly relevant information just because you think that it might be temporary, or because you are ignorant of the facts. If I seem just a little bit "irked", then you now know a little bit about why.


 * OK, now let's look at the offending text which you (?) have reverted:

"The relevant anthropic coincidences


 * What does this link have to do with anthropic coincidences?

You mean the illustration that is included in this complete lecture which used to be included in the text before someone decided that it wasn't necessary?

http://abyss.uoregon.edu/~js/ast123/lectures/lec19.html

Other than that, do I need to go and get Dr. Schombert? Maybe we should get him in here before you start deleting more stuff simply because you aren't aware of the facts?

"...occur in complete unexpected contrast to all normal attempts to model the evolution of the universe,


 * Any anthropic argument has the form "feature X of the universe is required for the production/existence of observers" which can only be justified if we can model the universe well enough to see what the consequences of feature X actually are. Therefore the anthropic principle is never in conflict with such modelling efforts.

No, the point is that the AP came about because anthropic coincidences appear to be relate carbon based life to the structure mechanism of the universe. That's why it was called the ANTHROPIC principle, rather than some OTHER stability principle/mechanism that could constrain the forces in a manner such as to produce an identical universe that doesn't necessarily require humans, like a "black hole principle", (which, FYI, won't work).

"...and have been "unfolding" since the moment of the big bang, ranging in magnitude from our local ecosystem, all the way up the ladder to the near-perfectly balanced, "flat" structuring of the universe itself.


 * How do coincidences "unfold"? How do coincidences have "magnitude" (apparently meaning a length scale)?

Semantics? Vocabulary?... Just what part of my description of the evolution of the matter field do you not like?... and do feel free to change whatever WORD that you don't like without worring that I might undo it since you haven't justified it.

"The universe appears to be surprisingly hospitable to the emergence of life at a specific time and "location" in the history of the universe, particularly, complex multicellular carbon-based life.


 * This basically repeats the first sentence of the introduction, but in a more confused way. E.g., is it particularly suprising that life is carbon-based as opposed to, say, silicon based?

I didn't write it, and now it appears that you're going to wrongly argue that silicon based life is a realistically plausible alternative to carbon-based life, even though I have already established in this very forum why this is a common falacy. Now we have a "skeptic" that is "helping"... GREAT!

"It is possible to use anthropic reasoning to make testable predictions about the features of the observed universe from the average of extreme opposing runaway tendencies that are known to be inherent to the anthropic coincidences,


 * This is just too vague. What are these tendencies?

You don't know that the anthropic coincidences are balanced between diametrically-opposing cumulatively-runaway tendenceies that define the goldilocks enigma? What are you doing here?

"...as well as to choose from a multiverse of different configurations, in lieu of a more viable stability mechanism.


 * I can't parse this... should it be "It is possible (a) to use... as well as (b) to choose... or "It is possible to use anthropic reasoning (a) to make... as well as (b) to choose... Neither seems to make much sense.

It's that hard for you to correlate the use a tool to make a choice, huh?

"Carbon-based life is either a necessary to the observed structure and stability of the universe,


 * a necessary what??

Whoops! ...a necessary constraint on the observed structure... I'll fix that, I promise, but please don't delete the whole page over it!

"...or it is a part of an engine of creation that favors such outcomes for no "special" reason.


 * "engine of creation" = universe? If so it would be worth spelling out such a powerful and value-laden metaphor explicitly. Is the introduction the right place to get into this? And the universe doesn't have to favour carbon-based life very much, just allow it to occur once on a trillion trillion planets. No version of the AP has solved the problem of the origin of life.

I don't like it either, but I didn't write it, and I didn't change everything when I restored important information that you deleted.

"So a proven identification of a stability mechanism is expected to settle this question of causality,


 * "So" suggests the conclusion of a logical argument, but this is the first explicit mention of either stability or a "question of causality"; no case has been made. To make any such argument explicit would be too long to feature in the introduction, so move to the main article (and remember, no original research!).

Nope, causality only comes into question if you can prove that the AP isn't the *cosmological *principle* that it was so-dubbed to be by Brandon Carter after Robert Dicke related Dirac's Large Numbers specifically to biological features that appear to constrain the values of the fixed constants in a manner so as to produce carbon based life at a special time and location in the evolution of the observed universe.

The first words out of Carter's mouth in Krackow... "John Wheeler asked me to say".

Don't pretend that you can use semi-speculative theories to say that the AP can be "weak" without hard proof that variant interpretations *prove* that it isn't a structure *principle*.

"...which means that the strong anthropic principle (SAP) can be further supported or falsified. If falsified, only the weak anthropic principle (WAP), essentially a tautology, remains.


 * SAP and WAP are not defined at this point in the article; and when we do define them we find that there are competing definitions of what they mean, so further talk is required; again, there is no place for this in the introduction.

You're incorrectly trying pit the implications of the observed universe, (for which the AP got its name), against semi-established theoretical speculation in order to say that they are equally acceptable. Fraid not.

Is Our Universe Natural? http://arxiv.org/abs/hep-th/0512148 ''It goes without saying that we are stuck with the universe we have. Nevertheless, we would like to go beyond simply describing our observed universe, and try to understand why it is that way rather than some other way. Physicists and cosmologists have been exploring increasingly ambitious ideas that attempt to explain why certain features of our universe aren't as surprising as they might first appear.''

This "surprising appearance" comes from the "undeniable fact" (quoting Lenny Susskind), that compels Richard Dawkins and Leonard Susskind to admit that the universe "appears designed" for life. There is no valid "weak" interpretation without a multiverse, because what is otherwise unexpectedly observed without the admission of speculation, is most-apparently anthropically constrained toward the specific time/location production of carbon-base life, and even intelligent life, (Paul Davies notes that "it looks like a fix", while Richard Dawkins has in the past stated that this appears to occur "in a very special way", regardless of his personal belief about what this does or does not mean to his pet theory). The confidence that Susskind and Dawkins express with thier admissions comes from the fact that they are qualified by their shared yet unproven "beleif" in multiverse theories, but their interpretation is strictly limited to equally non-evidenced "causes", like supernatural forces and intelligent design.

It is this first most-apparent implication that makes Leonard Susskind say that "we will be hard-pressed to answer the IDists"... if the landscape fails, although Lenny doesn't seem to be aware that *natural bias* is the default, if we're not here by accident, so ID doesn't even enter the picture and can't be inferred without direct proof. If we are not here by accident, then the default scientific approach is that there is simply some relevant physical reason why we are "needed" into existence by the natural physical process of our evolving universe, and this is what our intricate link to the commonly-balanced nature of the forces most logically indicates is going to be the case.

But Semi-established theories do not erase the fact that the prevailing evidence still most apparentely does indicate that we are somehow specially necessary to the structure mechanism, until they prove that it isn't so. We certainly do not automatically dismiss the "surprising appearance" by first looking for rationale around the most apparent implication of evidence. That's like pretending that your number one suspect doesn't even exist! There can be nothing other than self-dishonesty and pre-conceived prejudicial anticipation of the meaning that motivates this approach, and often *automatically* elicites false, ill-considered, and, therefore, necessarily flawed assumptions, that most often elicite equally false accusations about "geocentrism" and "creationism". That's not science, it's irrational reactionary skepticism that is driven without justification by sheer disbelief and denial.

There is no valid basis for invoking weak interpretations to wipe-away the otherwise indicated significance, unless you're just debating with an extremist creationist. A scientist is obligated to accept the fact that she or he is being directed toward a bunch of balance points in nature that are intricately related to both the structure of the universe and the existence of carbon based life, and this is expected to somehow account for the otherwise completely unexpected structuring of the universe from first principles.

You can know that you're dealing with a self-dishonest scientist if they do not recognize that the above statements are factual and correct.


 * I'll wait a few days for reactions before trying to edit this again. PaddyLeahy 19:56, 26 March 2007 (UTC)

And then check back in three months after people have hacked your terminology and context apart before somebody criticized what was lef of your wording and deleted everything that you wrote because it looks funny and they assume that facts are actually "original research".island 27 March 2006 (UTC)

The Weak Anthropic Principle Is not necessarily a Tautology
Prove that the WAP is necessarily a tautology that cannot define causality or I'll be returning the statement to my last edit of it.

(WAP): The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exist sites where carbon-based life and by the requirements that the Universe be old enough for it to have already done so.

Since the values can be restricted by a real physical need for anthropic structuring that affects the probabilities to cause the quantities to take on the values that they do, then this statement can be falsified as it stands by proving that this is not so.

To claim that some unproven interpretation invalidates this is just wrong. —The preceding unsigned comment was added by Island1 (talk • contribs).


 * please sign your talk page edits, island.


 * it depends on whos defining it. i don't necessarily support how Barrow/Tipler put it.  and it also requires the fact that we observers are around to obserse the universe with us in it.  from Merriam-Webster:

anthropic principle Function: noun either of two principles in cosmology: a: conditions that are observed in the universe must allow the observer to         exist -- called also weak anthropic principle b: the universe must have properties that make inevitable the existence of         intelligent life -- called also strong anthropic principle


 * definition a: is pretty self-evident as a tautology, providing the trivial fact that we observers exist in the universe we observe. definition b: that the universe must have been forced to take on these properties is not a tautology simply because it is not even known to be true.  it could have been chance and we just happen to be around to see it.  it also have happened to take on such properties (to eventually allow for life) and no one would ever be around to see it.
 * also, if you read some of this stuff (in anthropic principle), there is nothing about the WAP that invalidates it. it's true, but being a tautology, you cannot draw other conclusions from it.  x + $1/2$ = $1/2$((x+1)2 - x2) is true also, but it doesn't tell us much about what x is. r b-j 04:14, 2 November 2006 (UTC)

Right, and a "principle" requires an element that determines intrinsic nature, so the correct proven identification of the stability mechanism should be expected to clear up the question once and for all, which means that the principle can be further supported or falsified, and is relegated to the ranks of a circular reasoned tautology if and only if it can be proven that we are not necessary to the coincidentally balanced physics that appears to require an anthropic principle. "island", 2 November 2006


 * well whatever is in that gobbledigook, it can be worded much more simply. here is what the issue is about:  whether the SAP, which is not a tautology, is defensible.  it really is an issue of causality.  sure, after the fact the early universe must have had these properties that would permit structure, matter, and life because here we are and that fact cannot be disputed (WAP).  but is there some anthropic bias that would have forced the universe to take on such properties for these living observers to observe it (the SAP)?  even though it isn't yet to be shown false, i find it hard to believe that this position is even considered natural science (it makes for a good theistic explanation, which the IDers want to cloak with "science") by reputable natural scientists that know of the arrow of time and that events at earlier times are the causes of events at later times which are the effects.  and i have no confidence that it is falsifiable.  it surely seems to me that the SAP is speculative at best and just not good conservative empirical and deductive science.
 * i really don't think the whole paragraph belongs, island, that it is original research, but it is saying that if there can be a causal link of carbon life to the structure and stability of the universe, then the SAP has some support. but if not, we are just the lucky benefactors of some universal structure that's a helluva lot bigger than us, the SAP is rejected (like aether) and what remains is the WAP and lots of questions for why the universe would have bothered to have such structure and stability (let alone existence).
 * this historical stuff with Dicke should be in the intro (crediting him with the earliest coining of the concept), but otherwise, there is little in the version you made, even with others trying to tighten in up and to simplify the conceptual reference, that made it better or more accurate than what User:KarlHallowell wrote with some subsequent fixing up (some by me). that version is better, clearer, more concise, but lacks the reference to Dicke and "Dicke's coincidence" (a term with no Google hits other than in WP, but i know what you mean).  can we somehow cross-synthesize a version that is accurate, includes Dicke but goes beyond Dicke to include what other, more recent authors are basically saying what the AP is and make this more accessible and informative to a reader less familiar or unfamiliar with the term? r b-j 06:19, 2 November 2006 (UTC)

I have no idea what you're talking about when you speak of "original research", but I'd like for you to please be very specific, because I think that it may have something to do with the fact that I am equally baffled by the fact that somebody that is contributing to this topic doesn't know what Dickes' coincidences are with a fairly good in-depth understanding of them, because this means that they can't know how the physics defines "location and time" etc, other evolutionary features like the flatness problem that are relevant. Try looking in wikipedia under inflationary theory for the closest at hand mention of Dicke's coincidence, but don't stop there you might try Dirac too, good grief.

I am also taken back by the fact that Karl thinks that the requirement in physics that a principle requires an element that determines intrinsic nature, is "gobledigook".

So I'm at a complete loss as to how to deal with this, but I'm going to leave the final statement as it stands in the interest of political correctness in science. Tipler and Barrow MADE Dickes' observation into a "weak" uncontroversial statement, and they admit this in their book. HIGHLANDER!!!... "island", 2 November 2006

The intrinsic element in the weak anthropic principle(WAP) appears to me to be that we are observers, and thus think we know how observers work, including the need to exist at all, thus making the WAP a tautology.

Thus we set out in a solipsistic way, only granting others existence when we use Nick Bostrom's Self-Sampling Assumption that we belong to a reference class of observers. This we need to do, because otherwise, talking to a forum would be pointless. Highlander 17:25, 2 November 2006 (UTC)

I'm mostly satisified with the changes that have been made, although a couple of things bother me. The first is the fact that physicists and even evolutionary biologists find it necessary to posit a multiverse to "explain-away" anthropic significance. Leonard Susskind even went as far as to say that "we'd be hard-pressed to answer the IDers if the landscape fails'. Lenny obviously doesn't recognize the difference between natural bias and intelligent design, but Richard Dawkins said that "the the anthropic principle delivers its devastatingly neat solution" [to creationists abuse of the principle].  He said, "Physicists already have reason to suspect that our universe - everything we can see - is only one universe among perhaps billions. Some theorists postulate a multiverse of foam, where the universe we know is just one bubble. Each bubble has its own laws and constants."

So how is it that the weak anthropic principle doesn't define anthropic relevance without a multiverse to lose the MOST APPARENT significance in? Without a multiverse the WAP tells us about a special form of environmental enablement that can't be avoided without postulating unproven extra entities, and the SAP then becomes about "why" this is so. "island", 2 November 2006

Just an FYI, but Richard Dawkins is doing a radio show today and this is my question for him that I think will very likely be asked:

"I'd like to ask Professor Dawkins what mechanism he thinks controls his "anti-chance process" if interpretations of scientists like Paul Davies' are correct? In this case, isn't natural selection guided by the practicality of environmental enablement and constraint, per the weak anthropic principle, which restricts the physics to require gradual uphill slopes, "sites" where life can arrise and evolve"? I didn't ask for reasons not to believe phyisicsts, like Davies, I'd like your opinion on exactly where the link between evolutionary theory and the forces of nature would be, if Davies is right about purpose in nature, without god?"

I think/hope that the answer will be along the lines of the following: http://pespmc1.vub.ac.be/ASYMTRANS.html

Illustrated: http://pespmc1.vub.ac.be/ASYMILL.html "island", 2 November 2006


 * As might be guessed, I agree with r b-j here that the WAP is essentially a tautology (more a truism rather) since it is dependent only on the existence of observers which has already been demonstrated. I do think however tautologies are useful. For example, "2x-4=0, iff x=2" is a tautological statement, but this tautology can be used to show that the relatively complicated statement "2x-4=0" is equivalent to a simpler and generally more useful statement "x=2".


 * The WAP doesn't depend on the existence of multiple universes in order to be correct. Some other variants may have that dependency.


 * I continue to be puzzled by the insistence of certain people to avoid defining the term, "anthropic principle". For example, in the first sentence of the version I currently see:


 * In physics and cosmology, the anthropic principle is an umbrella term for various dissimilar attempts to explain the structure of the universe by way of coincidentally balanced features that are necessary and relevant to the existence of carbon-based life.


 * A literal reading of this sentence gives bizarre consequences. Suppose my crackpot theory is that the universe is constructed out of carbon atoms. Since carbon atoms are necessary and relevant to the existence of carbon-based life and I attempt to explain the structure of the universe with them, then my theory is an anthropic principle? Looks like it fits the above to me. Instead any anthropic principle is an elaboration of the idea that since an observer exists, then the structure of the universe must be consistent or compatible with the existence of that observer.


 * I'm not trying to channel anyone here or push an agenda. It's just that a wikipedia article about the "anthropic principle" should very quickly define what the term means. Further, there are numerous dictionary entries we can use as inspiration. We can make this article useful.


 * Finally, I note some discussion about whether certain formulations of the anthropic principle are scientific or not. My take is that the SAP and FAP (perhaps some other variants as well) aren't scientific (namely some things which appear not to be observable have to be true before those versions are true), but they clearly have a place in an article about the anthropic principle since they are part of the history. -- KarlHallowell 23:20, 24 November 2006 (UTC)


 * listen, Karl, i agree with you (not that i was trying to author any OR, just state, to the common person, what is meant by the AP. and i was really picking up on your edit which i thought was mostly accurate, from what i read.  "island" didn't think our composite edit was accurate, and, being an electrical engineer, i didn't want to take that on unless i felt more confident that i was reading the literature right (i think i was, but not enough to start an edit war here).  i totally agree that "island's" edit made the intro oppaque.  whether it is accurate or not or more accurate or not (vis-a-vis all of the lit that he mentioned, i only read pieces of it.  to repeat what i said before:
 * this historical stuff with Dicke should be in the intro (crediting him with the earliest coining of the concept), but otherwise, there is little in the version you made, even with others trying to tighten in up and to simplify the conceptual reference, that made it better or more accurate than what User:KarlHallowell wrote with some subsequent fixing up (some by me). that version is better, clearer, more concise, but lacks the reference to Dicke and "Dicke's coincidence" (a term with no Google hits other than in WP, but i know what you mean).  can we somehow cross-synthesize a version that is accurate, includes Dicke but goes beyond Dicke to include what other, more recent authors are basically saying what the AP is and make this more accessible and informative to a reader less familiar or unfamiliar with the term? 
 * if you change it back, i will support it (in a revert contest). r b-j 03:49, 25 November 2006 (UTC)


 * I completely follow your line of thinking, Karl, but the question is, where do we take the authority from to redefine the WAP from Barrow/Tipler's definition(13 years after Carter "ecological correction") with the carbon-based lifeforms to its most abstract version that the observer must be allowed to exist? Because it must survive the editing process of wikipedia as well.Highlander 14:45, 26 November 2006 (UTC)


 * the term "Anthropic principle" has existed for a long time before the Barrow/Tipler book but perhaps without the prefixes, "weak", "strong", or "final" (or "completely ridiculous") and, semantically, appears to be equivalent to Barrow/Tipler's weak version. actually, i don't think that there should be so much emphasis on the Barrow/Tipler treatment of the term.  certainly a mention or even a section discussing the various meanings of variants of the AP should be there, but i don't see why the article should be so much about Barrow/Tipler.  personally, i think the SAP and FAP are certainly not tautologies and are controversial, to say the least.  i don't observe many non-ID scientists buy into the SAP or FAP (or CRAP) theories at all and i see no scientific means of experimentation to test such and thus are not falsifiable and therefore are more philosophy than actual science.  histortically, it should start with Dicke (what "island" called the "Dicke coincidence" which is a term that does not appear after Googling except for WP and derivatives).  i think the intro section should have some of this original coinage from Dicke retained but should revert back to the version that Karl wrote and that i modified.  much less gobbledigook. r b-j 19:43, 26 November 2006 (UTC)

Hawking??
"Hawking (2004) suggests that our universe is much less 'special' than the proponents of the anthropic principle claim it is. According to Hawking, there is a 98% chance that a Big Bang will result in a universe of the same type as ours. However, some question whether the equations Hawking employs to reach this conclusion are scientifically meaningful, and what sort of universe can be said to be of the "same type as ours"."

There is no reference given for this statement. I don't know what same type means. Does it mean having the same constants for the fundamental forces? —The preceding unsigned comment was added by LinkinPark (talk • contribs).

In his book, a brief history of time, Hawking references both the anthropic principle, and the weak anthropic principle quite a few times. Most of the references came as he discussed origins, and humanity's purpose. My memory is foggy, and currently, I don't have the book (so if someone does, feel free to correct me), but one of the examples he used the principle for was explaining the thermodynamic forward arrow of time, and that the universe can only support life under our current conditions, which is time going forward, or space expanding.

He explained further that all life, or intelligence, would begin regressing if space stopped expanding, and started contracting. Is that the principle being demonstrated?

Hope that helps. 17:54, 5 January 2010 (UTC) —Preceding unsigned comment added by 209.105.184.250 (talk)

Headline text
It's absolutely crucial that whoever posted Hawking's 98% probability claim provides a citation. Can anybody direct me to where this claim is made?


 * take it out. i don't know one way or another. r b-j 04:43, 13 January 2007 (UTC)

Italics
There's an awful lot of italics in this article that don't conform to the manual of style. Can someone do some copy-editing? Lou.weird 18:07, 24 February 2007 (UTC)

Lacks Examples
It surprises me that this lacks details on the many examples that support the principle. I will return when I have time and add a bunch of them (Gravity, strong and weak nuclear forces, ratios, distances, etc.) SunSw0rd 14:26, 28 February 2007 (UTC)

AP, WAP, and tautologies.
Hi Rbj, you made a couple of changes to this today which I don't think are helpful but I don't want to get into an edit war so I'll put it to you here:


 * The terminology of the AP is such a mess that even terms like WAP are ambiguous (e.g. Carter vs. Barrow & Tipler). So I think its better to explain the various definitions in the body of the article rather than anticipating one particular definition in the introduction.


 * Isn't it fair to say that all versions of the AP involve the implicit Q&A "Why is the universe observer-supporting?... Because we wouldn't be here to see it if it were not." Where they diverge is where to go from there, e.g. to what extent you think this counts as an explanation, what you need to add to it to make it an explanation (e.g. multiverse, God, participatory principle etc). I added some words to this effect a few days ago but they got instantly removed.

PaddyLeahy 21:56, 31 March 2007 (UTC)
 * A petty gripe, I know, but an argument doesn't conclude with a premise, simply from the definition of "premise".


 * hi Paddy. despite the trouble i seem to get into (lately now regarding ID, of which i want to repeat that i am not a supporter of the crap that comes from the likes of the Discovery Institute), i am trying to keep articles consistent, readable, and accurate.  i don't want an edit war either.
 * now, i am admittedly ignorant of the "Carter" version or definition of the WAP. only the Barrow & Tipler version which seems to be the one reverberated by the dictionaries.  here is from Merriam-Webster:

anthropic principle Function: noun either of two principles in cosmology: a: conditions that are observed in the universe must allow the observer to         exist -- called also weak anthropic principle b: the universe must have properties that make inevitable the existence of         intelligent life -- called also strong anthropic principle

here are several online definitions of "tautology":

Needless repetition of the same sense in different words; redundancy. An empty or vacuous statement composed of simpler statements in a fashion that makes it logically true whether the simpler statements are factually true or false;

... a statement that cannot be denied without inconsistency.

... a statement that is necessarily true;

Needless repetition of an idea, statement, or word ... true by virtue of its logical form alone


 * even though none of these explicitly defined it as a vacuous truth (the first example did call it a "vacuous statement", i believe that these definitions are the equivalent to vacuous truth. and although the SAP and FAP (Barrow and Tipler's definition) are not vacuous truths (hell, they may not even be true, i don't believe it and they seem to reverse cause and effect - i liked the CRAP commentary), the WAP does fit the definition of a tautology.


 * now there are at least a couple of ways to have a vacuous truth. one is to include both a premise and the logical complement. "Either George W. Bush is a fascist or he is not a fascist."  that is the kind of tautology that is most often used in examples.  it might be something like saying x + (1-x) = 1 .  essentially the only other way to do it that i am aware of is to posit a premise and then conclude with the idea that is equivalent.  now you can dress up the conclusion so that it doesn't immediately look like it is equivalent to the premise like x + $1/2$ = $1/2$((x+1)2 - x2) .  now both equations are true, but they don't tell us much about what x is.  particularly expressed as the M-W definition: conditions that are observed in the universe must allow the observer to exist is much like a tautology.  it is like saying "if things were different, they would be different".  and that is a statement that begins with a premise and ends with words that are semantically the same as the premise.


 * now often the problem with using a tautology to make an argument is to try to extend it to support another point (which may be contested). but you can't do that.  just because the tautology is vacuously true, because it is vacuous, the truth of it cannot be used to build an argument.  however, it would be a loser to try to deny the truth of a tautology which is why they are sometimes called "truisms". (one that my advisor said to me was that to finish my thesis, i have to begin it.  a tautology in which the conclusion is entirely contained in the premise.)


 * so could you tell us what the other versions of the WAP are? r b-j 23:58, 31 March 2007 (UTC)


 * In Carter's Krakow article (which introduces the terms AP, WAP and SAP), he defines the WAP as: "we must be prepared to take account of the fact that our location in the universe is necessarily privileged to the extent of being compatible with our existence as observers". He uses Dicke's argument as an illustration; note that for Carter, "location" is a space-time position. This is neither a fundamental principle nor a truism, but a warning!


 * Carter's original version of the SAP, involved restrictions "not merely on our location within the Universe but on one of the fundamental parameters of the Universe itself..." (italics in original). His explicit definition of the SAP is: "the Universe (and hence the fundamental parameters on which it depends) must be such as to admit the creation of observers within it at some stage. To paraphrase Descartes, 'cogito ergo mundus talis est'." Barrow & Tipler take "must" as normative (any universe must...), but the latin tag ("I think, therefore the world is such [as it is]") makes it clear that Carter means: our universe "must"... (because we exist in it). This certainly is a truism. B&T explicitly make constraints on fundamental parameters part of the WAP, providing said constraints are selection effects (i.e. when a multiverse is invoked); but Carter explicitly associates multiverse arguments with the SAP.


 * I maintain that this is not just a historical note. Many discussions of the AP in the cosmological literature stick to something like Carter's versions of the definitions, on which all anthropic arguments are discussions of selection effects. In my experience most scientists regard B&T's version of SAP, let alone FAP, as non-scientific. As for other definitions of WAP, everyone seems to feel free to re-express it in their own words, hence when you get legalistic their definitions are not exactly equivalent. But I guess most are close to either Carter or B&T. PaddyLeahy 01:53, 1 April 2007 (UTC)


 * a note to Highlander: in a normal, meaningful, and non-vacuous sentence, it is true that "conclusions follow from premises, not the other way around", but in some tautologies, the conclusion is semantically identical to the premise, which is what makes it a vacuous truth.  the text you removed didn't say that the premise followed the conclusion but that the premise followed the premise or that the conclusion was the same as the premise which is what it is in this kind of tautology. r b-j 00:48, 1 April 2007 (UTC)


 * Isn't this article contentious enough already without using it to illustrate a confusing (and not widely accepted) use of "premise"? PaddyLeahy 01:53, 1 April 2007 (UTC)

Origin of AP
I propose to edit this section as follows (i) remove suggestion that the phrase "anthropic principle" might not be due to Carter; (ii) Remove quoted phrase "ecological correction" which does not appear in Carter's text and needs more explanation before it means anything to most readers; (iii) replace the reference to the cosmological principle (and its confused definition which mixes up laws with initial conditions) with one to the Copernican principle (AKA principle of mediocrity) which Carter was directly responding to; (iv) remove term "anticentrist dogma" attributed to Carter as he doesn't call it (exactly) that; (v) re-write the long and now-garbled 1st sentence of 2nd para which seems to be trying to say several different things, not all relevant to the AP; (vi) remove the anachronistic refs to the cosmological constant (which deserves its own section, or at least mention as one of the prime examples) and to string theory (discussed in a later section); (vii) mention Carter's definitions of WAP and SAP (but defer explicit definition to the Variants section); (viii) The statement by Wallace seems to be an example of the SAP not the WAP, on anyone's definition; but I will replace it by AP in the hope this wording will be acceptable to all. PaddyLeahy 19:45, 2 April 2007 (UTC)
 * it'll likely be fine with me. i must confess (sheepishly) that i wasn't aware of this particular variation in definition.  (but it should be included, the B&T definitions, which i thought were essentially the common defs, should not be the only influence.  otherwise Wikipedia is essentially endorsing that def.) r b-j 22:18, 2 April 2007 (UTC)


 * I'm working slowly through this article or I'd have noticed before: the Penrose quote you added, although citing B&T, actually describes the Carter version of WAP... and Penrose's next paragraph after your quote more-or-less describes the Carter SAP, explicitly citing multiple universes as a feature of SAP not WAP. Looks like Penrose hadn't actually read B&T at the time, and just assumed they used the "usual" definitions. Later, in The Road to Reality, Penrose makes it clear that he is following Carter and has a note saying that B&T are different. Given this, when I get around to adding the Carter WAP & SAP to Varients, I'm tempted to remove the Penrose quote as it's liable to confuse. What do you think? PaddyLeahy 10:28, 3 April 2007 (UTC)
 * Wow! you're right. i did add that quote.  (i didn't remember doing so, but it's clear that i did.)  i must have gotten it on-line somewhere because i do not have that book.  even before i found the history of the addition of that quote, i must say that i really liked that quote.  i felt (in contrast to B&T, even though Penrose cites B&T) that it was a very nice description of the concept of the WAP (which, to me, is the only AP really worth thinking about in the context of science - the S|F|CR APs are for the philosophy classes).  so as far as what I think, i wouldn't support removing it.  i think it's a really good quote (and i thought so before i came to a concurrance that it was added by me) which, i suppose, is the reason i tossed it in.  also, i don't see how it conflicts substantively with the B&T version or the very simple (and concise) version that comes out of the M-W dictionary.  i think it's an elucidating quotation. r b-j 21:52, 4 April 2007 (UTC)


 * Well, Penrose says "The most clearly acceptable of these addresses merely the spatiotemporal location of conscious (or 'intelligent') life in the universe. This is the weak anthropic principle." This is definitely Carter's version. Whereas B&T as quoted a few lines earlier include the fundamental physical parameters... which is precisely what Carter reserves the SAP for. It is this contrast between fundamental and accidental parameters which makes Penrose use the word merely... as the larger context of his quote makes clear. So I agree it's a good description of Carter's WAP... maybe we should just [...] the reference to B&T! PaddyLeahy 22:09, 4 April 2007 (UTC)

OK, so I did what I suggested and also added the Carter definitions to the Variants section, and re-arranged that, correcting a couple of errors. I took out the M-W definition because the article would reach infinite length if we included all dictionary definitions, which are presumably based on the original literature that is quoted. As Rb-j says, MW is in good agreement with B&T. PaddyLeahy 02:56, 5 April 2007 (UTC)


 * but it's (m-w of WAP) such a good and concise definition! i like much of what you did Paddy, but not all of the organizational stuff. i would suggest that all of the varying definitions of WAP be put in one little section, all of the varying definitions of SAP in another, etc.  i might like to make some changes along those lines.  i also do not see the great difference in definitions (B&T vs. Carter) that you do.  but lemme read it and cogitate it more.  i think that there might be a common thread of concepts that can be strung together.  dunno if you agree. r b-j 19:03, 5 April 2007 (UTC)


 * Hack it if you like, of course. My reason for doing Carter WAP & SAP followed by B&T WAP & SAP is that in my reading the B&T WAP essentially covers both of Carter's versions (i.e. is equivalent to Carter's AP), whereas B&T's SAP is something different and IMHO quite flaky (you seem to agree with the latter point anyway!). Let me try to say this again one more time (oversimplifying just a bit):


 * Carter: WAP = selection within one universe; SAP = selection from many universes
 * B&T: WAP = selection; SAP = necessity.


 * In a later paper, Carter explicitly calls the AP the Anthropic Selection Principle, which backs up my (& Bostrom's) interpretation of Carter, at least. PaddyLeahy 19:58, 5 April 2007 (UTC)

Observational Evidence
I moved this section later in the article as it is quite controversial... many say that there can be no observational evidence for the AP. I also edited it substantially to point out that the two specific items of evidence quoted are very debatably evidence for the AP itself, and I removed some nonsense about the "Goldilocks zone of the universe" which is not even hinted at in the cited references. At some point I will add to this section an argument that the multiverse version of the AP can be tested, since it predicts that any fine tuning should be just "good enough" rather than perfect. But first I'll have to find a reference! PaddyLeahy 23:53, 4 April 2007 (UTC)

Overall Organisation
The two sections Anthropic Coincidences and The Anthropic Cosmological Principle at the moment don't seem very structured. The former you would expect to list a number of examples, but after the first there are just some general comments about the AP. The latter starts off as if it was going to be about the B&T book, which I suppose is why the title is in italics, but the last three paragraphs are unrelated. I propose to focus these two sections on the topics suggested above, and move the the general comments to a new section Character of the Anthropic Principle or something like that, to be placed after the Variants section where they should be easier to understand.

For the Anthropic Coinicidences I propose to put a "main article" flag pointing at fine-tuned universe which has a detailed list, and put here just a few highlights from that article including mention of Dicke's work. The current text conflates two separate contributions by Dicke: his 1961 paper which is the classic application of the (Carter) WAP, and his 1970 comments, amplified in a 1979 article with Peebles, which is an example of Carter SAP and is sometimes called the "Dicke Coincidences" argument. It would make sense to move the description of fine tuning from Observational Evidence to here. I would also include the Cosmological constant since it has been claimed that this is the only successful application of the AP.

I would change the title of the other section to  The Anthropic Cosmological Principle (Book) to avoid further confusion. What would people feel about moving the definition of the FAP to this section? AFAIK it is mainly associated with this book and has not been taken up much elsewhere.

As these are significant changes I'll wait a few days for comments before making them. PaddyLeahy 11:36, 11 April 2007 (UTC)


 * so far, Paddy, i'm rooting for you. if this Intelligent design bru-ha settles down a little, i'd like to pay more attention to this.  just to let you know, i am not a physicist, but an electrical engineer with some technical chops on some physics (as any decent engineer should have) and some "experience" reading some of the pop-books on the article subject.  even though we have two definersa of the AP here, what interests me is trying to, as much as possible without misrepresenting either of the two definers, integrate concepts in common from both.  as much as their definitions allow (and, from a cursory look, i don't think they're so far apart). r b-j 00:31, 13 April 2007 (UTC)

So I would advise against attempting to merge these definitions! I also found a nice article by John Leslie (1986) which (among other things) spells out exactly how Carter's definition was misread to produce the teleological version. Which is not to say the teleological version shouldn't be discussed, since it now has a life of its own. PaddyLeahy 11:49, 15 April 2007 (UTC)
 * Here is a quote from Carter (2004) : "Indeed the term "anthropic principle has become so popular that it has been borrowed to describe ideas (e.g. that the universe was teleologically designed for our kind of life, which is what I would call a "finality principle") that are quite different from, and even contradictory with, what I intended."

(Unindent) I've done as I suggested and also attempted to rationalise the rag-bag this produced in the new Character section. I have genuinely tried to preserve all the ideas in the sections I've moved around, though I have deleted a number of sentences which just seemed to duplicate ideas stated elsewhere. The article remains quite repetitious, and very long. (Like this talk page; if anyone knows how to archive most of it, it would be a good idea to do so!).

What now? I added fact tags to two of the moved items: one that the AP can represent attempts to "take into account the existence of a biosphere on Earth in an essential way." This seems much too specific. I know that some contributors to this talk page believe it, but I would like to see a citable source. The other case is now in Evidence, viz the idea that we might find a "specific mechanism" for the SAP (originally found in the "Anthropic coincidences" section). This seems highly unlikely; again, is there a citable source that such a mechanism might be found? Also, It seems to me that the introductory sentence needs revision. The definition "a cosmological structure principle" surely only applies to the Barrow SAP? For Carter it is a principle of methodology. Comments (or bold changes) please! PaddyLeahy 21:40, 15 April 2007 (UTC)

Deleted paragraphs, and Criticisms section
It's been more than a week since I added text to Observational Evidence pointing out that the WMAP alignment has nothing to do with the AP, and no-one has reverted it or argued otherwise. I have moved it the page on the Copernican principle, where it belongs. I also removed from Criticisms the following paras:


 * Hawking (2004) suggests that our universe is much less 'special' than the proponents of the anthropic principle claim it is. According to Hawking, there is a 98% chance that a Big Bang will result in a universe of the same type as ours. However, some question whether the equations Hawking employs to reach this conclusion are scientifically meaningful, and what sort of universe can be said to be of the "same type as ours".

("Hawking (2004)" and the later discussion is untracable, see earlier comments on this talk page.)


 * Hawking's wave function of the universe, he and others have claimed, shows how our universe could have come into existence without any relation to anything existing prior to it, i.e., could have come out of "nothing." As of 2004, however, this work remains debatable. Moreover, as Hawking wrote in 1988, "What is it that breathes fire into the equations and makes a universe for them to describe?...Why does the universe go to all the bother of existing?" (Hawking 1988). That "there is something instead of nothing" is the fundamental problem of metaphysics. Although it has been argued that it is a fallacy to even consider "nothingness" as a possible form of reality, of existence, and that, fundamentally, only something can ever, or must, exist.

(This does not seem to be relevant to the AP at all.)

Also removed the two items with fact tags as no-one has tried to justify them:


 * The anthropic principle can also act as a convenient category for physical and cosmological reasoning that takes into account the existence of a biosphere on Earth in an essential way. More often, as in the definitions already quoted, "anthropic" is taken as refering to intelligent life in general and not just human life on Earth.

(First sentence above originally from Anthropic coincidences; second added by me as a caveat.)


 * Perhaps we will find a specific mechanism which shows why carbon-based life is necessary for the observed structure and stability of the universe; this would support the SAP but at the same time demote it from a principle to a simple consequence.

(My attempt to make sense of the following, originally also in Anthropic coincidences:)
 * Carbon-based life is either necessary to the observed structure and stability of the universe, or it is a part of an engine of creation that favors such outcomes for no "special" reason. So a proven identification of a stability mechanism is expected to settle this question of causality, which means that the strong anthropic principle (SAP) can be further supported or falsified. If falsified, only the weak anthropic principle (WAP), essentially a tautology, remains.

I moved the Paul Davies options list to Character since it is not really a criticism of the AP. I plan to re-write discussion of the tautology issue, pointing out that specific applications of the AP are certainly not tautologous even if general principle (in some versions) is. I don't see why Schaefer needs to be mentioned here, but if he is it should be a cite to a specific text, not a link to his web page. I may add the three objections mentioned by Carr & Rees (1979). PaddyLeahy 11:23, 18 April 2007 (UTC)
 * still rooting for you, Paddy. but i don't see the problem with the current version of the paragraph above. r b-j 00:27, 19 April 2007 (UTC)

Thanks for the support... by the time you added that comment I'd changed the tautology para, and removed all the others so I'm not clear which "current" para you mean. Quite a lot of consilidation done tonight; I'm much happier with the current text than before. From my POV the main remaining problem is the lead paragraph which I hope the current text demonstates is seriously misleading. Here is my proposed new version:


 * In physics and cosmology, the anthropic principle was originally the rule of reasoning that we should take account of the constraints that our existence as observers imposes on the sort of universe that we could observe. The term has since been extended to cover supposed "superlaws" that in various ways require the universe to support intelligent life, usually assumed to be carbon-based, and occasionally to be specifically human beings. Anthropic reasoning involves assessing these constraints by analysing the properties of universes with different fundamental parameters or laws of physics from ours, and has frequently concluded that essential structures, from atomic nuclei to the whole universe, depend for stability on delicate balances between different fundamental forces; balances which only occur in a small minority of possible universes — so that ours seems to be fine-tuned for life. Anthropic reasoning also attempts to explain and quantify this fine tuning. Within the scientific community the usual approach is to invoke selection effects from a real ensemble of alternate universes; competing strategies, occasionally also called anthropic, include intelligent Design.

This would allow some shortening of the second para discussing controversies. You can see that I plan to have Anthropic reasoning re-direct to this page. You can also see that I think we should avoid getting hung up on the tautologous nature of some statements of the AP (including the one you like), because I do think that misses the point.(c.f. new first para to the Character of Anthropic reasoning section). Oh, another proposal: merge the Bostrom section into the Variants, i.e. add his self sampling assumption as an AP-type statement. What do you think? PaddyLeahy 03:10, 19 April 2007 (UTC)

OK, done that, since no-one objected. For comparison the old lead was:
 * In physics and cosmology, the anthropic principle is a cosmological structure principle that has evolved over time to also become an umbrella term for various dissimilar attempts to explain the structure of the universe by way of coincidentally balanced features that are necessary and relevant to the existence of carbon-based life, or possibly even more specifically, human beings. The most common (and "weak") expression of the anthropic principle is a tautology that begins with the observation that the universe appears surprisingly hospitable to the emergence of life, particularly complex multicellular life, that can make such an observation and concludes that in only such a fine-tuned universe such living observers can exist.  This is stated concisely as "conditions that are observed in the universe must allow the observer to exist."


 * The anthropic principle has led to more than a little confusion and controversy, partly because several distinct ideas carry this label. All versions of the principle have been accused of providing cheap explanations which undermine the search for a deep physical understanding of the Universe. Some applications of the principle assume the existence of a multiverse, while others re-introduce the Argument from Design for the existence of God. In both cases, it has been suggested by some that the principle is untestable, and therefore not science.

PaddyLeahy 15:31, 23 April 2007 (UTC)

In the defense of the weak anthropic principle as defined by Carter
Recently the criticism of "the Anthropic Principle" of two paleontologists, Steven Jay Gould and Caroline Miller, have been added to the critism section of Anthropic principle. In using the term "the Anthropic Principle" is where these criticisms fail first, because they are essentially setting up their own strawman to beat up, by using the "Strong Anthropic principle" as defined by Barrow and Tipler as their target. This version has a teleological component which of course must go against the grain of scientists working in paleontology.

Steven Jay likes to make fun of the AP by saying that AP applied to barnacles would mean that "that ships had been invented to provide homes for barnacles". A weak Anthropic Principle would instead have the barnacle argue that someone must be around in the universe to construct these ships, which is a true proposition, and also that the hulls of these ships must have the property that barnacles may cling to them, which is true but does not mean that there is a well-meaning constructor of ships giving ships this property - quite to the contrary, ship design will try to avoid having barnacles slowing down the ship.

Caroline Miller says that "In a non-anthropocentric universe, there is no need for multiple universes or supernatural entities to explain life as we know it". She is mixing two different ideas in this sentence which are not related and rather opposites to each other. It also runs against her wishing to strengthen science, since the idea that other universes with other properties might exist is a scientific idea from another discipline, that is scientific in the sense that mathemathics is a science(The complication here is that we may never be able to observe these other universes, and thus make a scientific observation, even if we can deduce their properties and simulate them in a computer).

Highlander 15:02, 16 September 2007 (UTC)

AP, evolution and design
The following appears in the current article, re Carter's ideas on the number of low-probability evolutionary links:


 * A. Feoli and S. Rampone[23] argue for a higher number of low probability links, given the size of our universe and the likely number of planets. The higher number of low probability links is less consistent with the claim that the emergence of life and its subsequent evolution requires intelligent design.

Where does the last sentence come from? Feoli & Rampone themselves point out that a possible "finalist" strategy would be to design a large enough universe that even unlikely life is sure to arise somewhere. PaddyLeahy 16:16, 23 April 2007 (UTC)

Anthropic bias and anthropic reasoning
I removed the last sentence of this section, viz:


 * This may also be a way to overcome various cognitive bias limits inherent in the humans doing the observation and sharing models of our universe using mathematics, as suggested in the cognitive science of mathematics.

Cognitive and anthropic biases are two different things, despite a thorough-going attempt to confuse them in the Anthropic bias article (to which I have added a Totally Disputed template). PaddyLeahy 19:16, 23 April 2007 (UTC)

propose new intro par, followed by massive rewrite
I am puzzled to note that in the endless ruminations of the introductory passages of this article, the misuse of the word “constrained” has never been eradicated, like some particularly nasty form of tumour. Firstly, proper usage tells us that it is ALWAYS “constrained BY…”(some circumstances) NEVER “constrained to”. If you feel the irresistible urge to use “constrained to…” you are probably half-remembering the correct “restricted to”. And “constrained” means limited to, or restricted to; it does NOT mean, as the sense here evidently requires, “permits” or “allows”. I cannot imagine that the writer who has rescued and reinstated “constrained” rewrite after rewrite, has intended to convey the notion that the “initial conditions” obtaining at the beginning of the Universe, NECESSARILY meant that life such as us would come into being, because if he does, then he is over-determining the argument. It need only be said that without such conditions, life as we know it, could not come about, but other specific conditions PERMITTED it.


 * Que? The verb "constrain" is used exactly twice in the whole article, neither time in the lead paragragh. The wrong usage is halfway through the article (but I think it does mean "restricted", not "permitted"). Maybe the noun "constraint" is a bit over-used, but always means "restriction", I think. The idea is that in order for life to be permitted, the laws/initial conditions must be restricted in various ways; arbitrary laws etc will in general (allegedly) not permit life. PaddyLeahy 23:02, 17 August 2007 (UTC)

I am suggesting in a roundabout sort of way, that SOMETHING like the following redraft of the initial paragraph MIGHT better serve the purpose of providing the average Wikipedia user with a well-written, carefully drafted cogent and non-technical account of what is, in the end, a topic whose basic gist has a lot of common sense in it. At the moment, I cannot but agree whole-heartedly that the article itself and theTalk page is full of grammatical and spelling errors, is stylistically awkward, employs tortured context leading inevitably to unnecessary confusion, and is needlessly technical and prolix.
 * As you noticed, there have been a lot of edit wars about this article. This tends to cause people to let stand text which at least is harmless, if not elegant. Don't worry about this talk page, much was written long ago by non-longer-active wikipedians. PaddyLeahy 23:02, 17 August 2007 (UTC)

"In physics and cosmology, and as applied to Planet Earth, the anthropic principle holds that we as humans must take into account that the conditions we observe in our immediate vicinity in space are not be typical of conditions in space elsewhere, as conditions near us have the peculiar property of being able to maintain carbon-based life forms such as ourselves, and conditions most everywhere else in the Solar System are not conducive to life as we know it. A consequence of this is that we see a part of space and experience a slice of time that is not typical of space and time overall. Scientists are generally occupied with describing general and typical properties of nature, and so there can be serious methodological problems for them as a consequence of the Anthropic Principle, for the Principle assures us that the nature that we experience around us is almost certainly not representative of conditions that obtain most everywhere else in the Universe, places where life could not exist. For example, had the Earth been situated a little closer or further away from the Sun, water would have boiled away or frozen, and our type of life form would have most probably been impossible. Concerning the two planets that adjoin us, Venus on the side nearer the Sun, and Mars on the side further away from the Sun, neither appears to support life. And again, life would have been impossible in the Early Universe, and the early Solar System, where conditions were much more violent, and similarly, life may not be possible on an Earth in billions of years time, when the Sun will have swallowed it up. So we are constrained to viewing Nature from the vantage point of a small window in space and time, and nothing of what we see through that window is properly representative of the general conditions pertaining to the Universe considered as a whole. Many physicists believe that Earth is in a “Goldilocks” position, where the environmental and temporal conditions are “just right” for life to occur. The Anthropic Principle can be characterized as being a formal construction of the common idea of the “Goldilocks principle”. It proposes that humans live in a privileged and unusual time and space, simply by virtue of it being a time and space that is conducive to life."


 * Sorry, this does not do the job. Per WP:LEDE, the first section should be a concise summary of the rest of the article. But despite that fact that your version is longer than the existing one, it misses vital points, most notably, that "Anthropic principle" is a label applied even by professional cosmologists and philosophers to several distinct ideas...unless this is accepted there is a permanent revert war between people trying to get the "right" definition into the lead. It also fails to define anthropic reasoning and anthropic bias, which it should, since both those re-direct to here.


 * Much of your lead is devoted to a specific example application of the WAP, which is not mentioned in the main text (though it could be if you can find a suitable reference). Also it is a bit controversial to claim that life is impossible on Mars: see Viking biological experiments. Your first sentence restricts the AP to humans and planet Earth: this is not consistent with any of the versions used in the professional literature (see explicit quotes given in the article: Carter's "we" is evidently "we observers", not "we on Earth"). Your contrast of Earth vs. elsewhere in the Solar system is very small-scale when most current discussion refers to our Universe vs. other universes in the multiverse (& you don't need the AP to notice that the Earth's surface is very different from the rest of the solar system). Finally, "Goldilocks principle" is a recent neologism by Paul Davies, so not really a "common idea", and certainly not used as a technical term by physicists (unlike the AP). Although I havn't read Davies' book he seems to use it to mean fine tuning rather than the AP as such.
 * Update: apparently "Goldilocks principle" has been used by climatologists for a while, but it is not as well-known or widely-used as "anthropic principle". (e.g. based on the relative development of their wikipedia articles!) PaddyLeahy 00:44, 18 August 2007 (UTC)

Some possibly useful material for inclusion in some form:

1. An example might be made of a boy who says to his father: “Isn’t it lucky that we are living here in the French Riviera, where the weather is so good, and the food so fine. Just think, had we been deposited down a few thousand miles south, we would have to try to survive at the South Pole!” Father might explain that neither luck nor providence had anything to do with it. “We are here just because the land and climate here IS so conducive to our existence. People settled here thousands of years ago for that very reason, and no one lives at the South Pole, because it is impossible for us”. The anthropic principle might warn us though, that if we could not travel, we might well assume that the French Riviera, or California, were typical of conditions on Planet Earth. In fact, if we count the oceans, we can readily see today that the French Riviera and California are typical of rich farming lands and mild climates that are conducive to human habitation; they are not typical of the Earth’s surface in general. By analogy, we can take note of how we imagine conditions in other parts of the Solar System. Earth is not a “typical” planet – it harbours life. Therefore, we are in a privileged site, and should not assume that other places are similar. And to extend this line of thought further, we can think of the Universe as a whole. We exist in THAT part of it that permits us to exist, and in that TIME that allows for our existence. These are privileged places and times, and not characteristic of the Universe at all places and all times, and we should be aware of that when we start to imagine what might be taking place elsewhere.

3. One thing that struck me reading the material on WAP and SAP, is that no matter how divergent the different universes might be in the multiverse, there is still an underlying reality that binds them all together. This appears to be mathematical in nature. No one is supposing that there might be a Universe in which 2 is the same as one, and in which a 6 – chambered revolver with one live round will have a 50 – 50 chance of firing that bullet with every pull of the trigger. Are mathematical laws in some sense uncreated? Myles325a 05:27, 17 August 2007 (UTC)


 * Unfortunately, inventing your own examples and thinking for yourself like this counts as WP:OR and therefore is not allowed. We have to find appropriate secondary sources and summarise them. PaddyLeahy 23:02, 17 August 2007 (UTC)

(OP myles325 replies) Paddy, I appreciate the time you have put into this project. So you can probably understand how I feel, when, having spent a couple of hours trying to nut out a suitable introduction to this piece, and appending a modest disclaimer to the effect that it is only volunteered as SOMETHING to focus discussion, I receive a peremptory “nope, this is not good enough”. I knew that it was “not good enough”. My intention was, in a tactful fashion, to point out that the original piece is confusing, badly-written, and tries to cover too many bases in too cramped a space. I would have appreciated it if you or others had taken a look at the general direction in which my notional introductory par was heading, and noted how clear the exposition was, how cogently it explained the main ideas, and how neatly subsequent and more complex material might dovetail with what had gone before. And then perhaps, you might have opined that one or other such elements in my offering might merit incorporation, but that another may not. Instead, I receive a blanket rejection.

As a professional editor and manual writer, let me say that the exhortation that the initial pars of an article must contain references to all the threads of that which is to follow should be taken with a very large bucket of salt. There is nothing more discouraging to a lay reader, looking up Wikipedia on some subject, to find an initial sentence which runs on forever, and contains more esoteric references than the Kabala. Wikipedia is chock a block full of material like this. It certainly gives the lie to the notion that amateur editors are, by virtue of their proximity to the lay readership more inclined to write accessible material. In fact, the reverse is true. It takes training to write material that is easy to read and simple to understand. This is why the aristocratic Scientific American can run relatively straightforward expositions on difficult subjects, while Wikipedia, the “people’s encyclopedia” in its proletarian zeal manages to render even simple things complicated.

It is the very antithesis of sound pedagogy and effective communication to swamp the novice with everything up front, and then to explicate all references in telegraphic fashion under small subheadings below. Yes, there should be an introductory sentence / paragraph which makes the most general reference to specifics, but the overriding concern is that it be general, not that EVERY caveat, particular, and divergence need get a nod at the outset. It is laborious to intemise the problems of the manner in which some writer has approached his subject, it being often easier to rewrite the material from scratch, but allow me to make some micro-criticisms of where I think problems occur in the first pars of this entry, line by line.

Par1, line1. It is not good practice to write that a principle “says” something. It holds or affirms it.

Par1, line2 To characterise AP as a “rule of reasoning” so early in the piece is unnecessary and confusing, especially as there is no attempt to explain what “rules of reasoning” might be. Is there a document to look up?

Par1, line. The writer now segues from concerns of WAP to those of SAP. But this is too early, and the largely common sense concepts of WAP have not been properly identified.

Par1, line5 The term “super laws” is introduced here, unnecessarily, and without explanation.

Par1, line6 The hypothesis that the universe is predestined to produce life is a tenet of one small subdivision of AP-related matters, and few scientists hold to it. Why is it getting so much airplay here, in the first sentences of an introductory par?

Par1, line4 The distinction between “carbon-based” and “specifically human” here is a bright red herring. There is nothing here to say WHY this distinction is being made. And the phrasing is awkard.

Par1, line5. Here the writer confidently informs us that those who reason anthropically are involved with analysing the properties of universes other than our own. Wikipedia readers, (and I myself) might be surprised to learn that we have discovered other universes, and know them well enough to study their properties. This is a copy book example of a writer too close to his material. We may hypothesise how “other universes” might behave if such existed and possessed fundamental structures different to ours, but we don’t know if parallel universes are anything more than philosophical and science fiction fantasies. To talk about them as if you were as familiar with them as you might be with the ham and eggs on your breakfast table is to confuse and irritate readers.

Par1, line6 The subject of the verb “frequently concluded” is “anthropic reasoning”. But it is not “anthropic reasoning” which makes conclusions, it is the logician or researcher who employs such reasoning. This grammatical error is compounded by the fact that this sentence begins “AP involves assessing”, so that it is defined as a process at the start, but then becomes a participant later. And how can AP “frequently conclude” something?

Par1, line 5 on. This sentence goes on forever.

Par1, line10 The term “usual approach” is clumsy and confusing, and so is the strange idea that results are obtained by “invoking” some concept or other. And in what sense can an “ensemble of alternate universes” be termed “real”? And why is the newly introduced term “anthropic bias” printed in bold? And how does it explain anything to employ a multiplicity of terms to end up with the result that all this “anthropic reasoning” leads ineluctably to, you guessed it, “anthropic bias”? Surely there are more coherent ways of explaining this? And why in the last line of the 1st par, do we get, after a semicolon, and almost as an afterthought, “competing strategies, occasionally also called anthropic, include intelligent design”? The term “competing strategies” is added here, with nothing to prepare the reader for it. And it is simply nonsense, or just atrocious writing, to state that another name for “competing strategies” is “anthropic”. What on earth does this mean? And how can “intelligent design” be said to be a subset of an undefined term “competing strategies”.

Well, that’s the first par. And it gets worse, but I will not labour the point. Except perhaps to add that you use the word "label" when you intend "term" or "name". Labels are sticky pieces of paper you put on bottles. Frankly though, I don’t think this is good enough. It is a mess, and I wonder what it must have looked like before it was massaged into this shape after endless rewrites. So, although my preliminary piece might have been “long”, I can’t think that it is inferior to this goulash. Have ANOTHER look at it, without the egoistic element of defending your baby, and see what you think, Paddy. And others. We can hammer this into shape. And remember, keep it Simple! Myles325a 05:35, 18 August 2007 (UTC)


 * Sorry to be negative. What can I say? I know I don't own this article, and I'm not against change...if I was the sole author it would look quite different (not that I would have ever got round to writing it). But I think your draft para set off in the wrong direction, for the reasons given. I'm all for keeping it as simple as possible. You highlight two quite separate problems:


 * Bad grammar and poor prose (+spelling, you said earlier). Please fix this wherever you see it (though your own prose here is remarkably polysyllabic: I hope you are taking the piss and will not introduce this into the actual article).
 * Complex ideas which you think are introduced too early, and in some cases you think are highly speculative and over-emphasised. Well, most discussion of the AP is highly speculative; the parts that everyone can agree on tend to be rather trivial. This applies to both the technical and the popular literature. I think these complex and speculative ideas are properly the main focus of the article, and hence should be referenced in the lead. It would be great if you could express these ideas more clearly, including by expanding the lead (by at most a factor of two, I would say).


 * For orientation, here is my take on a few issues you highlight. (excuse the listiness, it comes naturally to scientists):
 * For other universes, see multiverse. Elements of this idea are now mainstream physics, and the whole concept is mainstream among physicists who take the AP seriously (a significant minority, I would guess, including various Big Names cited in the article). "Investigating other universes" means following through the logical consequences of theories of physics which are different from the ones known to apply in our Universe (if only by adjusting a single number). This really does encapsulate what physicists do when they "work on the anthropic principle", i.e. apply anthropic reasoning.
 * Observers vs. Carbon-based life-form vs. humans. There is an obvious problem with the AP: suppose we take it as referring to humans on Earth. As Stephen Jay Gould says, humans are the result of a colossal string of accidents. Therefore the AP seems to "explain" every one of these accidents (e.g. the K-T impact) by saying "if it didn't happen, we wouldn't be here to wonder about it". If you are the Queen of England, your existence is tied via your family tree to the entire history of Europe. Therefore is everything in history explained by the existence of the Queen?? (The same probably applies to the rest of us but not so obviously). Clearly this puts the cart before the horse. The problem here is that you have chosen too narrow a "reference class" in Bostrom's terminology. The AP seems to carry more weight if we make the class of "observers" to which it applies more general, because this reduces the "historical accident" problem. This is why some writers think it even a mistake to insist on carbon-based life, though since we don't know any other forms of life the most general AP is hard to apply. I havn't put this objection explicitly in the text because I havn't found a source (I suspect it is in Bostrom's book, but I havn't read it all...just skimmed the on-line chapters).
 * Bolded items in the lead are the subjects of redirects to this article. This is a WP:MOS issue (see redirect). Doubtless they could be incorporated less clunkily.
 * Definitions: due to the huge edit wars over explicit definitions of the AP, I think it helpful to cite primary sources on this point and emphasise that the definitions are not equivalent, in some cases even contradictory. It is no good pretending that deviant definitions (e.g. the B&T SAP) do not exist: they are quoted all over the internet, especially on creationist sites (and in published sources meeting WP:RS). PaddyLeahy 12:32, 18 August 2007 (UTC)

tone
As a non-expert, i think some of the article need significant work on the style and tone of the text. Much of it seems very informal, similar to a conversation or lecture --Goldfinger820 09:38, 17 October 2007 (UTC)

Universe Link
I change the link on the word "Universe" to the mathematical definition. The AP speaks heavily bias of a sample, and the idea of what is an in not observable (which is much more related to Mathematics and Set Theory than to Physics. That's not to say that AP doesn't affect Physics, but it is primarily a Principle of Mathematics. —Preceding unsigned comment added by Holshy (talk • contribs) 19:33, 26 November 2007 (UTC)


 * I'm sorry, but I strongly disagree here. It's pretty clear that the physics meaning of "universe" is intended here (see multiple universes for a related example). Second, the anthropic principle is not a mathematical tautology. Its truth depends on the presence of an intelligent observer which is given by our presence, a bit of physical evidence. Finally, the mathematical concept of universe is just too different. What belongs in the mathematical universe? How does it relate to what we traditionally call the universe, particularly how do we mesh observation with mathematical objects? I imagine you can find ways to link the two concepts of "universe", but this article isn'tt the place to do that especially in the first paragraph. -- KarlHallowell (talk) 00:51, 27 November 2007 (UTC)


 * Agreed, this is about the physical universe, not mathematic ones. I can't see it falling primarily under the domain of math.  WLU (talk) 21:31, 27 November 2007 (UTC)

Meduso-Anthropic Principle
There is a link in the Hawking radiation article labelled "Meduso-anthropic principle".

It links to this article, but this article does not mention a Meduso-anthropic principle.

Maybe someone should put some info in this article on the Meduso-anthropic principle, or change the labels of links elsewhere, or maybe even write an article all about the Meduso-anthropic principle, whatever the hell that is.

Ordinary Person (talk) 03:09, 3 April 2008 (UTC)

"We have seen"?
In the Criticisms section the phrase "we have seen" is used twice. Who is this mysterious "we"? It makes it look like part of the section was ripped off from somewhere else. -- Hi  Ev  19:37, 11 July 2008 (UTC)


 * I guess I wrote that, intending "we" to mean "the reader and the writer". You could replace it with "as explained above" or something similar I suppose. PaddyLeahy (talk) 05:19, 14 July 2008 (UTC)

Unhappy with the wording of the intro
I'm unhappy with the the intro as worded by 70.172.197.215. For example, what is a "theoretical universe"? Also, the weak AP doesn't speculate about the probability, it states that the conditional probability of us observing such a universe under the condition that we exist in it is exactly 1 (100%) (If this sounds like circuitous reasoning, it is and that is ok because the weak AP is a truism). Also, with the line "Our human understanding dictates.. " there seems to creep opinion into the first paragraph and I'm not quite sure whether it makes any sense with the second part of the sentence at all - I think the line "In other words, the only kind of universe we can experience [firsthand] is one that supports human life" shows enough mental flexibility that we do not need to point out that the thinking is limited by being human - after all we don't point out that mathematics "1+1=2" is limited by human understanding either.

Highlander (talk) 08:48, 21 July 2008 (UTC)

The Anthropomorphic Principle
My complaint about this article is that it uses the wrong title - 'anthropomorphic' might be a long word but it is just as or more correct as anthropic - check both on Google. This wouldn't bother me but the article doesn't even mention the more correct name, I only know they are connected because of the redirect. Please at least mention the alternative name - unless its against current Wikipedia newspeak of course. Lucien86 (talk) 14:14, 24 October 2008 (UTC)


 * The title is not just the random collision of two dictionary words, any more than other names such as Pathetic fallacy (does not mean a particularly pitiable fallacy) or Axiom of Choice (does not mean the preferred axiom). "The Anthropic Principle" is a distinct idea, first clearly pointed out by Brandon Carter more than thirty years ago and given that name by him. Very clearly he did not mean "anthropic" in the sense of "anthropomorphic" (i.e. attributing human characteristics to non-human things) but in the sense of having something to do with people (he really meant: to do with intelligent observers).
 * Google references to an "anthropomorphic principle" are nearly all garbling of the correct title, with the more familiar "anthropomorphic" substituted for the obscure "anthropic". No doubt Carter picked the obscure word partly because it would have meant virtually nothing to his audience, allowing him to impose his own definition on it. The redirect exists for the benefit of people following up such garbled mentions, but I don't think we should refer to it in the lede, any more than similar redirects such as Theodor roosevelt. PaddyLeahy (talk) 16:56, 24 October 2008 (UTC)


 * Yes but others have used the name "the strong and weak anthropomorphic principles", I'm pretty sure I first read it in an early edition of 'The Emperors New Mind' - later editions do use Anthropic. Why not put a version of your answer above into the article? Lucien86 (talk) 19:55, 24 October 2008 (UTC)
 * Cite?! I've never seen a source deliberately use "anthropomorphic" for this concept, other than popular sources that simply confuse words or misquote. If some primary source actually does this, I'm happy to note that in the article. LotLE × talk  20:25, 24 October 2008 (UTC)

Has Carter's WAP ever been criticised?
Carter's weak anthropic principle is basically just a (very special and blatantly obvious) case of taking into account the phenomenon of conditional probability when doing an experiment under special conditions. I find it hard to believe that this principle has ever been meaningfully criticised, and in fact I can find no evidence of any such criticism in the article or on the talk page. Therefore I am going to replace the word "all" in the third lede paragraph ("All versions of the principle have been accused...") by "most". Or is there something I have missed? Are there really people who claim that we should draw conclusions from the "surprising" fact that we live on a planet, rather than somewhere in open space far away from all galaxies?

The current wording seems to date back essentially to this edit by PaddyLeahy, and I found no justification for "all" either in the edit summary ("Re-arranged content as suggested on talk page") or in talk page comments that date from the time, so I assume it was just a mistake that nobody has noticed yet. --Hans Adler (talk) 16:13, 10 November 2008 (UTC)

That Last Statement...
In the article:

"Steven Jay Gould [53] [54], Michael Shermer[55] and others claim that the Anthropic Principle seems to reverse known causes and effects. Gould compared the claim that the universe is fine-tuned for the benefit of our kind of life to saying that sausages were made long and narrow so that they could fit into modern hotdog buns, or saying that ships had been invented to house barnacles. These critics cite the vast physical, fossil, genetic, and other biological evidence consistent with life having been fine-tuned through natural selection to adapt to the physical and geophysical environment in which life exists. Life appears to have adapted to physics, and not vice versa."

---

That doesn't seem contrary to the anthropic principle to me. Life will always adapt to fit its environment; this will always be true. The anthropic principle only needs to offer an explanation of how life can be birthed (from inanimate matter), not how it subsequently evolves. That is, so long as the conditions were right enough to allow an evolvable sort of life to develop. And then that there existed enough, what shall we call it, "room for development"?, so that something with consciousness may arise... But those conditions (as I would imagine it) are a lot less meaningful than the conditions needed to spark that sort of evolvable life in the first place. Perhaps I misunderstand. But what is the alternative, that intelligent life is somehow shaped by means of the physical properties of the universe somehow? That the requirement for evolution and processes of natural selection become irrelevant somehow? I don't get it.

Edit:

Thinking about this a bit more; perhaps we can imagine 3 or 4 distinct steps:

0. Conditions allow life.

1. Conditions allow evolvable life.

2. Conditions allow evolvable life to evolve into conscious beings.

3. Conditions allow evolvable life to evolve into conscious beings who are us.

Step 0 is the biggest step (i.e. definately requires the anthropic principle to explain), step 1 is a smaller step (as the conditions for step 0 have inevitably already been met), step 2 is even smaller (for the same reason). I'm not sure if step 3 is even relevant? (as, due to the anthropic principle we only need this one to occur once; we are inevitably that conscious being; i.e. step 2 and 3 are one in the same) In any case, I don't think the anthropic principle in any way precludes the process of evolution and natural selection. Right? So what is this guys argument? —Preceding unsigned comment added by 123.243.152.5 (talk) 17:08, 19 December 2008 (UTC)

Proposed Discussions on nuclear stability and the chemical periodicity
The article mentions chemical laws of life but does not make them explicit. I thus propose a structure for their introduction. This is original research, but someone might fill in the gaps:

1. The law of binding energy ensures that nuclear synthesis of heavy elements reaches the range of iron (26) and nickel (28) and that heavier elements are scarce. Iron is the heaviest really-common element, and it is essential as a trace element in all living things. Mammalian life would not exist without hemoglobin, which requires iron; iron is a huge part of the mass of the Earth's core and allows the Earth to have a magnetic field that protects the Earth from violent radiation. If the law of binding energy allowed only elements up to calcium as the limit of nuclear synthesis, then iron would be scarce enough to prohibit the formation of life. Beyond iron and nickel, the elements drop off rapidly in commonness even if they are stable. To be sure, some toxic elements (lithium, beryllium, fluorine, and vanadium) are scarce enough that they rarely pose threats to life -- which might cause one to ask why these elements are themselves scarce.

Maybe zinc (30) wouldn't be a huge problem at the low point of binding energy except that toxic copper would be more common than it is. Germanium (32) seems untroublesome, but get past germanium and heavier elements cause trouble. If such an element as zirconium is the low point, then some very toxic substances (arsenic, selenium, bromine) are common. The inert gas krypton is of course non-toxic, but in our universe it is rare. Krypton would probably be common enough to flood the lower atmosphere and suffocate life. Thus if the law of binding energy fails to allow iron, then life probably does not exist; if the law of binding energy allows elements much heavier than iron, then toxic elements proliferate and perhaps a krypton-rich lower atmosphere precludes respiration.

Copper is scarce, but it seems essential to technological civilization, if not to civilization itself.

2. The periodic law is what it is. The innermost electron cloud can contain only two electrons, which implies that the top row of elements is only two (hydrogen, helium); if it allowed four or more, then hydrogen could be far more electropositive, even acting somewhat like an alkali metal. Hydrogen would thus tend to react with any electronegative substances to form powders or rocks. Terrestrial planets would then be hydrogen-rich, and the hydrogen compounds would not be so volatile. Helium, the second-most common element would probably be reactive. All planets would be of the scale of gas giants even if they have rocky, powdery, or liquid surfaces. Atmospheres would hardly exist. I wouldn't go into much speculation about the nature of scarce lithium (likely a halogen) or beryllium (an inert gas). In the next row, scarce boron is an alkali metal, and carbon is an alkali-earth metal with wildly-different chemical properties. Carbon-based life would be impossible. Whether the second row has six or eight, one finds further complications: nitrogen and oxygen are vastly different, and even if oxygen has four (instead of six) valence electrons, it would be a poor basis of life contrasted to carbon in our universe. Fluorine is scarce enough that it could not take the role that nitrogen does; neon might take the role of oxygen (and it would be common). Biochemistry would be a mess if not impossible.

3. Another significant reality is that carbon and silicon are vastly different in their chemistries. Carbon can form double and triple bonds, and silicon forms single bonds almost exclusively. Carbon compounds with non-metals are generally more volatile than those of silicon; at the extreme distinction, carbon dioxide is a gas that plants can work with in photosynthesis, and silicon dioxide is a hard rock. Terrestrial planets seem to need silicon dioxide as a rock, but life needs carbon dioxide to be a substance suitable for photosynthesis or an easily-excreted waste from respiration. If carbon forms no double bonds, than carbon dioxide is a hard rock like silica, and respiration is impossible. If silicon has much the same chemistry as carbon, then silicon dioxide is a heavy, suffocating gas that covers small, hot (due to gaseous pressure) cores of rocky or metallic planets. Life seems to need solid surfaces at some stage of evolution.

The difference between the pairs of nitrogen and phosphorus in chemistry is more subtle but obviously significant to life, as the elements are both essential to life and do not act alike; much the same is true of oxygen and sulfur. --Paul from Michigan (talk) 06:36, 26 December 2008 (UTC)
 * This would need reliable sources to be included in the page, right now it looks a lot like original research and might also be way too specific for this page. WLU (t) (c) Wikipedia's rules: simple/complex 16:54, 26 December 2008 (UTC)

That of course explains why I put it on the talk page.--Paul from Michigan (talk) 16:04, 1 January 2009 (UTC)


 * Another thing to keep in mind is that life has evolved on Earth to match the available element distribution. One would expect rare elements to be toxic merely because life hasn't evolved to handle high quantities of those elements. Why this is important, is that we don't know that life couldn't exist under a radically different distribution of elements (well as long as it is sufficiently complex, 75% molecular hydrogen and 25% helium isn't going to cut it). -- KarlHallowell (talk) 20:37, 6 January 2009 (UTC)

Of course, aluminum is a very common element, but it figures little in terrestrial life despite its commonness. Silicon is also extremely common, and aside from creatures manipulating practically-inert silica as defenses not part of the creature, the only significant use of silicon in living things is by diatoms. It and alumina would be a good materials for rigid shells and skeletons except that the substances are inert to biochemistry. Argon is the third-most-common stable component (in distribution) of the atmosphere, but as an inert gas it has no biological role and could never have one.

As for some of the other elements and their scarcity:

Hydrogen and helium are primordial and common; so are lithium, beryllium, and boron, but they are rare and they are easily destroyed in stars. The small fractions of these elements might drift into brown dwarfs and planetary bodies, but such are their only means of survival. The triple-helium process operates at a rate compatible only with the very short half-life of Be8; if that isotope were stable, then such a yellow-dwarf star as the Sun would pop its core before life could entrench itself long enough to permit intelligence. If Be8 were even less stable, then the triple-helium process would be even more difficult. In any event, beryllium doesn't look like the sort of element that life could exploit.

Fluorine does not form in the nuclear synthesis that makes carbon, nitrogen, oxygen, and neon possible (although neon is scarce on Earth, it isn't scarce in stars. But it is inert, so it is irrelevant to life). Scandium and vanadium are apparently bypassed in processes that make calcium, titanium, chromium, and of course iron in the hottest, densest cores of the largest stars. Fluorine, scandium, and vanadium probably form in exotic nuclear processes that allow elements heavier than nickel to form. --Paul from Michigan (talk) 17:01, 1 February 2009 (UTC)

The intro looks like creationist work
The introduction and the first section of the article should give a brief overview or explanation of the subject and the historical development. The intro gets a B-, the first paragraph an F. Both emphasize the "fine tuning" required to allow humans to exist, which is a strong indicator or creationist involvement. The second section gets around to the origin of the term with Brandon Carter and the WAP, which is the primary concept.

Obviously our universe must be almost exactly like it is in order for us to exist. If things were different, they would not be the same. That is all the WAP says. It simply means there must be lots of universes, which is pretty much an foregone conclusion to anyone but a creationist. The entire thrust of the article is to emphasize the incredible improbability of a universe exactly suitable to us, which is irrelevant. What we really want is the probability a random universe would be capable of forming stars or something similar, and keep them going long enough to allow complex observers to evolve. Scientists who have investigated that by varying all the major parameters (not just the creationist favorites) have concluded that about 1/3 of all possibilities have that potential.

That is actually good news for creationists, although they are too dense to realize it. If only humans could do science, then obviously there could be no God because God is not human. Since they don't comprehend the logical necessity of multiple universes, they have to assume their God has high a priori probability, so they need life to be possible under almost any conditions (as well as other improbable coincidences). Obviously it is best to keep religion out of a science article, but the current version already allows it too much influence.

Usually I would just go ahead and revise, but this page probably is well guarded by Wikignomes poised to pounce on interlopers. I'll just lurk for awhile first. Fairandbalanced (talk) 01:25, 5 February 2009 (UTC)


 * I agree that the introduction is degenerating (not that it was ever very good). If anyone has been wikignoming this article it's been me and I've pretty much given up so go ahead and edit. But a few points.
 * Don't assume that anyone other than a creationist ought to believe in lots of universes. I work in a large UK university which has few if any creationists on the staff but I think the majority of my colleagues (including physicists) regard the idea of multiple universes as somewhere between a logical fallacy and a sign of deeply pathological science. The idea has enough prominent (and other) supporters that it deserves its place here but please don't present it as a forgone conclusion.  (Also, multiple universes are compatible with a creationist stance, c.f. plurality of worlds.)
 * You need to be a bit more nuanced about the AP. Depending on how specific you are about the "observers" it ranges from silly to quite interesting to useless. I agree that if you specify "humans" in the biological sense as the current intro does, then you are putting absurdly strong requirements on the "universe" because almost any tiny change in the history of Earth up the point that humans emerged about 200,000 years ago would have given a different result (c.f. Wonderful Life). As you become less specific about the observers, the constraints the AP gives become more general and interesting, but when the observers are completely undefined as in Carter's original paper, there is very little you can say (for instance, the requirement for "stars or something similar" may be very parochial). From the structure of the AP argument, though, the "observers" do have to be capable of pondering their place in the universe, hence the recent edit replacing "intelligent life" with "life" misses the point.
 * If you're going to quote a claimed result that 1/3 of all universes contain stars you must give citations and also explain what the "major parameters" are that are varied and what is assumed to be the same (keeping the same laws and just adjusting the constants is very far from investigating "all possible universes"...actually that's a category like "all sets" in mathematics which is too big to be described).
 * Finally, science articles on topics with major religious implications should discuss those implications. Anything else would be unencyclopedic. PaddyLeahy (talk) 09:19, 5 February 2009 (UTC)

My understanding of the term tautology applied to logic is that a tautology can be a good thing, as long as there are people who don't understand the implication that the 2nd statement must be true, when the first one is. Also, the correct term of what the weak AP is would be tautological implication, reading the tautology article. Highlander (talk) 23:42, 6 February 2009 (UTC)

I now read the intro paragraph again, and it pretty much explains the difficulty in maintaining an article on something which has been defined differently by each proponent. Of course it might better to have a boring and to the point intro that gets more people hooked reading the article, but the first 2-3 lines are actually a good enough summary of most APs. Highlander (talk) 23:54, 6 February 2009 (UTC)

New Anthropic Principles
Someone (206.131.57.230) came up with this:

Reverse anthropic principle (RAP): However, it is possible that the anthropic priciple works in reverse: such as that the only universe that we can observe is one compatible with human life. In other words, if the universe did not support life, we would not be here to question why it did not. We require the universe, not the other way around.

IMO, this is the same as the weak anthropic principle and as such it should be removed from the article. I won't do this though since I kind of wish anyone good luck in cleaning up the terminology, even if it is attempted by potentially adding more confusion. Do me a favor and write a book about the RAP, so we can fulfill wikipedia's request for references ..

Maybe I should explain that a "weak" principle is not one that is a weak argument, but often is instead logically more compelling because it is trying to prove less. —Preceding unsigned comment added by Highlander (talk • contribs) 19:54, 18 February 2009 (UTC)

Argument for and against God
Interestingly, one can use the AP as both an argument FOR the existence of God, and an argument AGAINST his existence.

Using the AP, one may paraphrase: "The universe is incredible, and so finely tuned. It's very unlikely to have arisen that way by chance, hence we need a God to explain it" But on the other hand, the contrapositive (via conditional probability) essentially is an argument against the need for a deity:

"If the universe were other than it is, we wouldn't be here to observe it. Therefore we have no right to be surprised at the improbability of our existence. We cannot therefore use the fine-tuning to argue for God's existence."

In other words, P(observers see intelligent life | observers exist) is very close to 1. —Preceding unsigned comment added by 87.194.171.29 (talk) 02:44, 20 February 2009 (UTC)

Criticism section undermines criticism
The criticism section has the following text: "This reasoning does, however, demonstrate that intelligent life is impossible under these transposed fundamental parameters." which is incorrect. It should not say "intelligent life" here, but instead something like "carbon based life" or "carbon-DNA-based life". Since we don't know the origin of the first living cell, we cannot even demonstrate from the basic laws of physics that we get intelligent life in _this_ universe. Not to mention the fact that the words "life" and "intelligence" are so ill defined as to be almost meaningless. Passing judgement on all other universes becomes absurd. Oh crap, this became a rant. Anyway, I suggest change to "carbon based life". --Boxed (talk) 01:24, 22 February 2009 (UTC)
 * Agreed, as far as we know or don't intelligent life might exist(in an abstract sense) even for completely different fine-tunings Highlander (talk) 13:54, 22 February 2009 (UTC)

Criticism section criticism
I find the criticism section worth criticising near the end.

Ok, so the wAP is a tautology. It still teaches us that sometimes, the unlikeliness of our own existence does not require an explanation.

The criticism by Mosterín about infinite possibilities not implying existence appears to be good at first, until you realize that Mosterín does define the word "exist" just as he likes, instead of clearly distinguishing between existence as in existence within and in connection with our universe, and existence in an abstract mathematical sense, with only a tenous link to our universe in the form of mathematics and possibly simulations.

Now Lee Smolin has a nice theory that may be true or not, but of course he has to be against the wAP, because the wAP means that we in fact do not need a theory that makes our existence more likely, although it leaves us with a warm fuzzy feeling that fine-tuned for life universes are abundant. It appears Lee Smolin's followers try to prove their own theory by disproving of the wAP. —Preceding unsigned comment added by Highlander (talk • contribs) 21:45, 31 March 2009 (UTC)