Talk:Fermi paradox/Archive 5

Simulation argument
This article has a glaring omission in its failure to mention the "simulation argument", from what I can tell. See Nick Bostrom's Simulation Argument for details; by contrast, WP's own simulation argument seems cluttered and confused. In brief, the simulation argument claims one or more of the following three facts are true:


 * 1) Higher intelligences have almost certainly no interest in running a simulation of lower civilizations.
 * 2) It is almost certainly impossible to go post-human or become an advanced civilization.
 * 3) We are almost certainly living in a simulation.

The core observation is this: if indeed it is technologically possible to build computers the size of planets (i.e. if point 2 is false), then it becomes trivial to simulate the entire human race, and the universe we live in. In fact, its trivial to run millions or billions of such simulations. Thus, by probability, we have a one-in-a-billion chance of living in a "real" universe, and a 0.999999999 chance of living in a simulation. If point 3 is false (we are not living in a simulation), then it seems that simulations are never run. So either point 1 is true (running simulations is boring and is never done) or point 2 is true (its impossible to build computers that are 10^30 more powerful than those we have today.)

The relationship to the Fermi paradox is this: if point 3 is true (we are living in a simulation), then the aliens aren't out there, because they're not a part of the simulation. Alternately, if they are out there, then they can't be technologically advanced, because that would soak up too many cpu cycles for the simulation. That is, one cannot "simulate" a computer, one must emulate: if we are living in a simulation, and if we build a computer that is 10^30 more powerful than those today, whomever is running the simulation may decide "screw this, its using up too much compute resources, terminate". Likewise, if the aliens build such a beast, the simulation could not go on; ergo, if there are aliens, then they cannot be advanced much farther than we are, and thus we can't yet communicate with them.

If point 2 is true, then, again, the aleins cannot be very technically advanced, which is why they are not sending us messages,

If point 1 is true, then, super-advanced civilizations that aren't interested in running simulations are also probably not interested in talking to us. Thus, the simulation argument pretty much knocks out the Fermi paradox, no matter what.

(The last bit above is the most difficult: although they may not want to talk to us, how come we don't see their engineering works in our telescopes? Answer: maybe we do: maybe this is the so-called dark matter of physics: gravitationally attractive matter that is not luminous, and thus not visible in telescopes. Its not luminous because, presumably, if you are building a super-giant computer, one would not want to waste huge gobs of energy by radiating it out into dark space. Instead, one keeps it shut up, trying to minimize waste heat by employing reversible computing techniques. Since modern estimates from cosmology say that 90% of all matter in the universe is dark matter, then maybe 90% of the matter in the universe is a part of some giant alien computer. ... which  is why  we can't see the aliens. so there. Again, curiously, this article seems to fail to review this possibility).

I do not have references for the above; however, they are presumably written up somewhere, by someone; maybe by Bostrom. linas 04:07, 1 August 2007 (UTC)


 * I'm googling some references, planetarium hypothesis is the common name given to the idea that there are no aliens because we live in a simulation. See e.g. http://www.astro.virginia.edu/class/murphy/astr342/Lectures/A342L07.pdf Note that PDF provides a number of hypothesis that are not discussed in this article. How, exactly, did we get close to "FA" status with such glaring holes in te article content? linas 17:52, 2 August 2007 (UTC)


 * I've read this content and fail to see any glaring holes. Remember this article is about the Fermi paradox itself, not about all related issues.  Furthermore there are many possible solutions - one of the main references lists 50 of them.  So related, but not directly related, arguments should be included by reference.  Physics arguments about planet formation should show up in "how likely are planets" section.  Arguments that we are likely living in a simulation can surely be referenced, but the detail above should be handled by reference, not inclusion (since there are many other explanations, and not enough room to explain them all in this detail).  Panspermia is a great topic, with its own article, but the effect on the Fermi paradox is limited to how likely life is to arrive, and how different it might be.  The article is presumably an FA (or close to it) since it provides a good introduction to the topic, with a reasonable level of detail, with good references.  Is it exhaustive? Certainly not - it's hard to be exhaustive on this topic.   Anyway, specify what you think is missing and discuss it here!  LouScheffer 19:17, 2 August 2007 (UTC)


 * Or, in true Zen-like fashion, always in a state of becoming! We have a good rating because we fully deserve a good rating.  And, at the same time, we are open to additions that might make our good article even better.  Similar in principle to the movie that won the Oscar for Best Picture in . .  say 1965 might be a legitimately, genuinely good movie, and at the same time, we might be able to build on that set of skills and that artistic background and experience and make even better movies today (of course not always, you have to take risks in pursuing good art . . and science?)  FriendlyRiverOtter 00:51, 3 August 2007 (UTC)

Surely if higher intelligences have almost no interest in running a simulation of lower civilizations then if we are a simulation it is not by a higher intelligence or we are not a lower civilization.

By the way, I doubt this is true. We run simulations of just about everything so why would they not.

Also the simulation argument could be put into several different categories eg zoo where it is but also God, they don't want to communicate etc. Reargunner 01:58, 3 August 2007 (UTC)

OK, I added both the planetarium hypothesis and the simulation argument under the and they choose not to communicate section, though there are several places they could go. Also, the primary reference for planetarium is Baxter, not Webb, so I changed the reference. LouScheffer 06:39, 3 August 2007 (UTC)

David Grinspoon’s “The Immortals”
This is one of the later chapters in his book LONELY PLANETS: THE NATURAL PHILOSOPHY OF ALIEN LIFE, HarperCollins, 2003. And he briefly mentioned the theory (p. 400) that mineral-based life may have been the precursor to carbon-based. And that’s when I got what he was talking about.

In the pretty near future, we humans may start using memory chips, connecting our brains to a data base, adding a math module, or a Tagalog language module, maybe "reading" a book via a chip, viewing movies, seeing distant places, etc, etc. And one fine day, some of us may decide that all this is so good we can just leave the biological part behind.

Some of us may choose to not take this step, or may not even take the first step. Thus, people would be different, kind of like people today, some people are extroverts, other people are introverts. . .  only we would be a whole lot more different! And, hopefully we could still respect each other. There’s no reason a priori that we need not. We might just have different realms of activity and different realms of interest. FriendlyRiverOtter 02:28, 4 August 2007 (UTC)

Overtime one would expect that almost all will go mechanical, if only because people died. But how does any of this change the Fermi paradox? Reargunner 03:11, 6 August 2007 (UTC)


 * It's a plausible scenario and it would seem to heighten the paradox. For if we do eventually transform ourselves into machines, space flight will be less dangerous (protoplasm is fragile) and we will probably be less bothered by the time periods required.   FriendlyRiverOtter 23:51, 6 August 2007 (UTC)

4.2.5 proposed
This theory occurred to me, but I haven’t seen it proposed: “For self-preservation, advanced civilizations conceal their existence, being aware of the existence of predatory civilizations.”  Chilling! Relevant movie dialogue: “The jungle sure is quiet tonight.”  “Yeah. Too quiet...” MicroZealous 15:26, 6 August 2007 (UTC)

I think this goes in the section "and they choose not to communicate". I've added a sentence there, with a reference to the section "and it is the nature of intelligent life to destroy others". LouScheffer 15:54, 6 August 2007 (UTC)

Surely one would expect over time that eventually one advanced civilization would win and there would be no reason to hid. Also hunter often set up markers to attract their prey. In all cases we would be back to the paradox. I suppose we should add something about both of these points Reargunner 07:35, 9 August 2007 (UTC)

Used to be something about it. When I go hunting we set up bright lights to attract the prey. I remember there was a B5 show with something similar in the plot. A beacon was sent out promicing an advanced group a great reward in knowledge if they answered the questions correctly. If they succeeded it destroyed them 203.34.248.95 07:49, 5 September 2007 (UTC)

"But" vs "..." (see here)
I prefer the ", but" form myself. It makes fits the basic style of the paradox better, I think, especially in the cases such as "They exist, but they choose not to communicate". Also, I think it reads better in the table of contents. Finally I think there is a Wikipedia guideline about not including punctuation in headers unless it is really needed, which the use of "but" avoids. I did not feel strongly about this myself to change it, but I support the change. LouScheffer 14:51, 11 August 2007 (UTC)


 * My complaint about that form is that there is nothing to connect the first "half of the sentence" with the following statements. There is no leading punctuation to draw the eye and the sense of the flow onwards and one does not expect sub-headers to be continuations of headers above them. The result is that the "but" part of the section header just looks like a mistake in editing: a hanging conjunction of a second part of the header that got missed when the header title was shortened, or some such. I can bet you that if the "but form" goes in, it won't be too long before someone "corrects" the "mistake" because they can't follow the flow. For this reason the "but form" is, in my opinion, unworkable and confusing.
 * An argument can be made for the "flowing form" or "completely separate" headers (break the continuity between header and sub-headers totally), but half breaking them makes the header structure useless and confusing. --Vedexent (talk) - 15:53, 11 August 2007 (UTC)

Perhaps we could re-write the headers without hanging punctuation at all
 * No other civilizations currently exist
 * No other civilizations have ever existed
 * It is the nature of intelligent life to destroy itself
 * It is the nature of intelligent life to destroy others
 * Human beings were created alone
 * They do exist, but we see no evidence
 * Communication is impossible due to problems of scale
 * Communication is impossible for technical reasons
 * They choose not to communicate
 * They are here unobserved

LouScheffer 17:14, 11 August 2007 (UTC)


 * Works for me. I just saw problems with the "but form" as being confusing. I see little difference, other than personal aesthetics, to prefer one form over the other, as long as the header structure is clear to the first time reader, so if you think that form is clearer, I don't see a problem with it - but I didn't see a problem with the current form either, other than it doesn't meet a guideline (which is not a rule, but ad hoc advice that applies to most situations, not all, and I don't think applies here where the headers try to "integrate" in this fashion). -- Vedexent (talk) - 23:58, 11 August 2007 (UTC)
 * Much better, thanks. -- Procrastinating@ talk2me 18:32, 4 September 2007 (UTC)

To include or not to include, that is always the question?

Detectability of Oxygen
How far away from earth might the oxygen signature of our atmosphere be spectographically detectable? The flip side is how far away might an exo-terrestrial planet's atmospheric oxygen signature be detectable? For example,Gliese 581 c,d are larger (5-7x earth) terrestrial planets 20 lyrs distance. So it might seem possible that at a far distance, any visiting simple (to re-build) mini-robotic craft (with a spectographic capability) could survey it's environment. Hence a fast and easy way of surveying for surface life; thus for our planet, over 2 billion years of exposure.Zanardm 06:00, 15 October 2007 (UTC)
 * That isn't the best way to find oxygen. If you build TPF-C, you can determine that there is both life and technology on Earth from a distance of >10 parsecs (32.6 ly).  If you want it badly enough (~20 billion  USD, probably), you can detect everything in the Solar system down to Ceres or Vesta that far out.  A lot cheaper and faster than a probe.  Note: Gliese 581c isn't what I'd call habitable, but that is another discussion. Michaelbusch 06:40, 16 October 2007 (UTC)

Currently 241 exoplanets. [url="http://en.wikipedia.org/wiki/Gliese_581_c"] A few are terrestrial such as Gliese c, d at 5x and 8x earth mass; sufficient mass to be geologically active, and hence a magnetosphere, diverting a stellar wind, and thus preventing eroding of any atmosphere and oceans. An O2 spectographic signature from a exoplanet atmosphere is a sign of photosynthesis. Earth has had such oxygen signature for 2 billion years; while just technological for say 200 yrs; that is 1 part in 107 (200/2 x 109). So if one divided 2 billion years into bins of 200 years each, one would require 107 such bins until one discovered an exoplanet with an oxygen signature, that had a technological civilization. This is assuming that our earth history is typical. Re-expressed: one would need a database of 10 million exoplanets with an atmosphere oxygen signature before finding a technological civilization! How many terrestrial planets are there in a galaxy of about 1011 stars? The pattern for exoplanets seems to be tending towards abundance. If only 1/10 of stars had 1 terrestrial, then 1010 terrestrial exoplanets. Would an O2 signature for 1/1000 exoplanets seem too high? If not, then aren't there approximately 1000 (1010/107) technological civilizations in our galaxy? Zanardm 06:41, 3 November 2007 (UTC) comment added by Zanardm (talk • contribs) 06:21, 3 November 2007 (UTC)
 * You are discussing the Drake equation, which is infamous for producing wildly different answers. The key unknown is the mean technological lifetime of a civilization, since it is uncertain by the most orders of magnitude. Michaelbusch 07:24, 3 November 2007 (UTC)

If one added a relational database, cross-linking the greater than 4.6 Byrs age of a stellar system to those exoplanet terrestrials with an O2 atmosphere signature, then one would have only those binned planets that have had a long term O2 signature. Hence the resultant database would be much smaller; not 107, but rather 3 (?) orders less - that is, perhaps a manageable 104 planets?Zanardm 03:49, 5 November 2007 (UTC)
 * You speak in terms that are not used in the astronomical community. But since at the moment we know exactly one planet with an oxygen atmosphere (you're presumably sitting on it), we have no way of saying what the number of planets with oxygen-bearing atmospheres is.  We also cannot yet say that oxygen is a usual requirement for intelligent life on a planet, or what the required time to evolve/probability of evolving a technological species is, or how a species lives on average.  All of those factors are in the Drake Equation and discussed in that article to about as far as anyone can reasonably go. Michaelbusch 03:55, 5 November 2007 (UTC)

Dec. 12, 1901, Guglielmo Marconi receives radio signal in Newfoundland, Canada, sent from Cornwall, England
And maybe that was the first time we can be pretty sure some signal leaked into space (although there had been experiments before that). "On December 12, after losing one kite, a second was launched with the aerial attached and a signal from Poldhu was heard unmistakably by Marconi and his assistant Kemp." The signal was morse code for the letter S ("dot-dot-dot").

So, we can give a definite time. This Wednesday, December 12, 2007, our Earth as the center of a sphere of expanding radio signals of our own making, this sphere is 106 light-years in radius. Or, if you prefer approximate round numbers, roughly 100 light years in radius. That compares to our Milky Way which is approxately 50,000 light-years in radius (100,000 light-years in diameter). And of course our galaxy is a relatively flat spiral. FriendlyRiverOtter (talk) 03:47, 11 December 2007 (UTC)


 * In 1888, Heinrich Hertz performed lab experiments which demonstrated that radio waves could travel through air (space?) . He also demonstrated that radio waves (initially called "Hertzian waves") seemingly had all the properties of light waves (of course they do!, for as we now know, they are both part of the electromagnetic spectrum).    FriendlyRiverOtter (talk) 23:43, 14 December 2007 (UTC)

One of Marconi's earlier experiments was to send radio waves to his brother and a farmer waiting about a kilometer away, and with a hill in between. The brother and the farmer fired a shotgun when they received the signal carrying morse code.

so a civilization remains radio-visible for about a hundred years, and then advancing technology and prudence?
That could be the story here on Earth, for now we have fiber optics and more tightly focused microwaves. And at a certain point, we might start reasoning, although we don't know that there are any baddie bads out there, out of caution and prudence. ..

So this solution would essentially be, "Everyone is listening, no one is sending." And that combined with there not being too many civilizations to begin with ("Rare Earth" type of reasoning, etc.). FriendlyRiverOtter (talk) 00:24, 18 December 2007 (UTC)

Anthropic bias
Editor 76.102.2.245 deleted the sentences on anthropic bias. But this was added due to previous confusion. Depending on the numbers you assume, you can get a expected number of civilizations per galaxy << 1. But clearly our galaxy has at least one. Does this mean the assumptions are wrong? Not necessary - we are not objective observers.

It's exactly like estimating the fraction of the time railroad crossing gates are down. An objective view would say they are mostly up. But if you make your observations from a train, you'll conclude most of them are down. LouScheffer (talk) 17:15, 17 December 2007 (UTC)


 * We can conclude that we are at least somewhat lucky. The question is, How outrageously lucky?  One issue is the transition from single-cellular life to multicellular, the whole "Cambrian Explosion" issue, because for most of Earth's history, single-celled life was the only game in town.


 * Another issue is the physics constants, for these constants seem to be just right for there to be stars, and thus chemistry, and thus life (Lee Smolin has an interesting evolutionary theory for anyone interested).  FriendlyRiverOtter (talk) 00:42, 18 December 2007 (UTC)