Talk:Age of the universe/Archive 1

Old comments
Sorry, but some of this stuff really is too hard to make sense of by making minor corrections, so i've cut it out (today Boud 13:38, 3 Dec 2004 (UTC)) and pasted it here in case anyone wants to make sense of it:


 * This allows us to describe how the universe has evolved over time using an equation like this: $$t=t_0(1+z)^3(1+w)/2$$.  As you can see, things are starting to get a bit more tricky, but this equation simply relates the age of the universe to the redshift.  This particular example has an additional term w, which comes from something called the equation of state, relating the pressure and density of the universe (p=wdc^2, where p is pressure, d is density and c^2 is the speed of light squared).

For a standard model (cosmological constant = constant or zero, no quintessence), we have w = -1, and this equation gives t = t_0 (1+z)^0 = t_0  so time is constant and the universe doesn't expand at all. Maybe this is one of the early historical models with some minor error, but i don't recognise it. Boud 13:38, 3 Dec 2004 (UTC)


 * Things do start to get technical here, but there is a nice confirmation of this model which actually validates it against recent observations. Coming back to the math, the change in the distance is related to time with the redshift relation $$t=t_(1+z)^2$$.  However, there is an additional change in time related to redshift as $$t=to(1+z)^{1/2}$$, which (the product of both) brings us back to the original form for our "dust" w=0 universe.  The idea of time-variable time probably sounds bizarre, but this is expected since there is no "absolute" concept of time in General Relativity.

The two formulae look weird, i can't make sense of the discussion, and saying that there is no absolute concept of time in GR is misleading, since GR applied to the universe in the standard FLRW model very definitely has a favoured time axis in the comoving coordinates system.

The Planck stuff needs some checking too - i'm not familiar with stuff that theoretical, so i'm not sure whether it's meaningful or not. Boud 13:38, 3 Dec 2004 (UTC)

I was the originator of the discussion on the Talk:Universe page where a large part of this content came from. It wasn't meant to be turned directly in to an article, so the quality isn't great and there are some typos in the formulas. However, I would be glad to tidy up what currently exists in the article and hopefully resolve any remaining confusion. Nodem 00:23, 23 Feb 2005 (UTC)

CNO studies
Does anyone have citations for the "some recent studies" mentioned in the CNO section? &mdash;Joe Jarvis 14:43, May 24, 2005 (UTC)


 * I was about to post that question myself. If a section or statement does not have a citation, it is thus unverifiable by Wiki standards and should be removed.  However, this section provides a valuable bit of information to the article so... we should try to find some peer-reviewed articles or texts that discuss the CNO statements (try Google Scholar). If we can't, the section should be removed. Astrobayes 22:53, 23 June 2006 (UTC)


 * Nobody? Ok, I'll find references for this section and add them myself. Cheers, Astrobayes 22:19, 30 June 2006 (UTC)

Hi, I moved this section to after the "Age Based on Cosmological Parameters" section. I think that since the CNO studies are speculative it's a good idea to put them after the generally accepted argument based on cosmological parameters and the Friedmann equation. This way the article flows a little better, since the canonical WMAP value gets explained more or less right away... Wesino 09:38, 15 November 2006 (UTC)

I changed "roughly 14.7 billion" to "roughly 15 billion." When you only have accuracy to within a billion years, you don't keep a fraction of a billion years part of the estimate. Significant digits.

graviational
I do more basic proofreading than science, which led me to this apparent typo: "Obviously, the entropy increases (due to graviational in fall) and this has the effect that the universe has become cooler than this simple model predicts." I almost corrected it to "gravitational", but that makes the sentence look backwards. Gravitational in fall of a meteorite, for instance, would convert gravitational potential energy to heat energy, and get hotter, not cooler - although I agree that it would increase entropy. Did I discover a typo and/or a more serious mistake? Art LaPella 02:36, August 22, 2005 (UTC)

I do not know where you are looking. Please direct me to the page with "graviational" Pdn 16:28, 22 August 2005 (UTC)OOps I see the page and the item on it. I will ponder it and maybe consult someone if needed. Good call - it does look odd. Pdn 16:46, 22 August 2005 (UTC)

This whole section looks amateurish, but I am not sure I'm qualified to fix it. One example is that the author refers to the Planck temperature as "measurable" and tries to project forward from it. But that is trying to look way past where we can see - we can't see past the "surface of last scattering" of the CMB. The stuff about Planck temperature is all done by estimating backwards in time from then, and using particle physics, and so it cannot serve as a useful age marker. In fact, things ran so fast near the Planck temperature that the time interval to get way below it is inconsequential compared to the present age. I am not sure if I could get Ned Wright, for example, to fix this. (see ). There is a generic Wiki-problem here - there is a lot of good information out there already, and it is not clear that Wikipedia can attract authors who want to spend time on poorly supervised pages repeating what they have said elsewhere, or what is in books. Wikipedia may be turning into a forum for creationists, "General Semanticists" (General Semantics), and other cranks to vent their ideas. I mean, really, do you have to study the works of Korzybski to learn that dogs do not create handbooks or literature, or that words are to be distinguished from the objects they refer to? Pdn 16:58, 22 August 2005 (UTC)

I've experimented with Template messages when dealing with something wrong that I can't fix - simple example, Baotou. Templates might embarrass this stuff away, or at least warn people not to believe it. Here are some templates that we might want to choose from for the "Age based on temperature" section here: (I removed templates afterwards - they made the talk page show up in categories. 8/27/05)

Beyond that, I think Wikipedia is too democratic. Nobody is really equal, even though some situations go smoother by pretending they are. In particular, I would establish a class of newbies, forbidden to edit except indirectly, on a new provisional edit page that has to be approved by others. A newbie could graduate if enough text or changes are substantially approved. A banned user returning as a sock puppet would have to qualify all over again. Art LaPella 20:51, August 22, 2005 (UTC)

Temperatures
2943K the temperature of a dully-glowing poker? I think not: iron melts at a mere 1811K. I don't feel adequately qualified to edit the page, though.
 * I've done a bit of poking (heh) around other articles. Unless you're using a tungsten carbide poker (melting point 3143K), you don't really stand a chance of getting a poker anywhere near that hot. I thought for a bit that it might have been a mistake with someone mistaking fahrenheit for kelvin, but even if that were the case the poker would be far from dull (iron melts at 2800 degrees fahrenheit, and alloys like steel at less than that). Anyway, I'll edit it now. --Dom 01:10, 22 December 2005 (UTC)

Planck Temp
The bit about the Planck temperature and the comments following in the article are really a minefield of numbers and concepts that are not well described...and I do have the education to understand them, they're just poorly written. Would the original author of these statements please respond as to what she or he was trying to convey? It doesn't add much to the article as it stands and should be rewritten. If a scientist can't follow it, it will certainly turn away non-scientists who come here looking for interesting and educational material. Astrobayes 22:57, 23 June 2006 (UTC)
 * I don't understand it but I can trace the editing history. It was first written at the end of this edit by Nodem, followed by this correction, after which Zeimusu copied it when he started this article with this edit. Nodem hasn't edited lately but Zeimusu has. Art LaPella 03:33, 24 June 2006 (UTC)


 * I have rewritten this section, Wikified it, and given it an understandable basis. As it stood before, it was a mess and added nothing to the article.  Now the opposite is true, while still retaining the original intention.  I hope everyone enjoys it now. Astrobayes 22:19, 30 June 2006 (UTC)


 * I think the "derivation" of the age of the Universe in terms of its temperature should be removed not only because the argument is difficult to follow, but because it is just plain wrong. Here is why:


 * For a physically-motivated counter example, one can compare the age of two spatially flat universes with the same CMB temperature (2.7K), but where one model includes a cosmological constant and the other does not (where the matter density is adjusted appropriately to keep the curvature zero). You find that the universe with the c.c. has a larger age than the other.  Therefore, because the ages are different but the  temperatures are the same, the age of the universe cannot depend on the CMB temperature alone. Historically, the fact that the cosmological constant increases the age of the universe was one of the early arguments that suggested that a c.c. was necessary in the standard cosmological model, since there appeared to be globular clusters that were older than a matter-dominated Universe without a c.c.  See Friedmann equations but there doesn't seem to be a reference to the age as a function of various other cosmological parameters that I can find.


 * A very much more elementary reason this argument cannot be correct is the following. Suppose the age of the universe t is inversely proportional to the square of the temperature (as asserted).  Then since temperature is inversely proportional to the  Scale factor (Universe) this implies that the scale factor a(t) goes like t1/2.  This is patently false for the vast majority of the history of the universe -- again see the Friedmann equation page (today the scale factor is growing nearly exponentially, and during matter domination between redshifts of about z=1 and z=10,000 it went like t2/3).  The only case where this argument is true is during radiation domination.  Since the fraction of the Universe's total energy density in radiation is currently around 1 part in 10,000, this is clearly not the case today.


 * So the only reason that this argument can give anything close to the correct value is due to some kind of numerical coincidence.


 * Now, what is true is that if you do the integrals required to calculate the age of the universe carefully, they all turn out to be of the form 1/(Hubble parameter today) times (function of the fractions of matter, radiation, etc.) So a good back-of-the-envelope statement is that the age of the universe is roughly today's Hubble parameter.  Inserting a reasonable value -- 72 km/s/Mpc -- in Google gives an age estimate of 13.6 Gyr, which is almost precisely correct (and for the right reasons!)


 * I would be happy to do the appropriate edits but it would be good to get some feedback from others who have contributed to this section before I do so... Wesino 16:20, 9 November 2006 (UTC)


 * So it's been about a week, and no defense of the "Age in terms of Planck Temp" section has appeared. So I decided to be bold and delete it.  I think this is justified based on the comments made above.  If anyone takes issue with this, then let's discuss it. Wesino 09:34, 15 November 2006 (UTC)


 * Hi Wesino. I don't have a problem with the section being deleted. It was part of a discussion that someone else posted into this article as is. I took a quick stab at updating it a while back, but I couldn't possibly do it justice in a Wikipedia page. It is derived from a principle and, in fact, not "some kind of numerical coincidence". I don't mind discussing it further if you are interested. Thanks Nodem 05:21, 27 November 2006 (UTC)


 * I'm glad you're OK with the edit, Nodem. I didn't mean to offend by calling it a "numerical coincidence." However that's the only reason I can think of for the calculation giving anywhere close to the right answer, except during radiation domination (which anyway is a poor approximation to our Universe at z < 10,000 or so).


 * It's possible that there's a principle behind it, but it seems that the principle must be false, or at least in severe conflict with observations. As explained above, the essential reason is that it gives a time-temperature relation, and thus a time-scale factor relation, that would


 * imply the universe is decelerating (since a(t) ~ t1/2) in conflict with SNIa observations,
 * Without going into detail, the relationship a(t) ~ t1/2 was from a normalized model and should not be interpreted in the context of the standard model. Also, the universe is not necessarily accelerating/decelerating. This is a conclusion drawn from one specific model using a set of assumptions. The standard model may be right, but until someone detects a WIMP, explains/resolves the various dark energy issues (like where theory and observation conflict by 120 orders of magnitude), I would stick to statements like: "The high-z SNIa appear to be fainter than a simple matter dominated FRW universe based on their observed host galaxy redshift. This may be due to the fact they are further away, which in turn could be that the rate of expansion has increased, which if due to some invisible force, that if we now insert into the mass/energy budget of the universe we could partially fix another problem, although at the expense of the cosmological principle". Statements of the type "the universe is doing this or that" can become a lot of rope from which one could easily hang. Yes, the current observations are very impressive (considering a decade or two ago there was almost nothing), but they are far from conclusive. Also note that there are some pretty bright folks developing alternatives (like MOND), so I'm not a minority voice in questioning the absolute truth of Lambda CDM.
 * disagree with observations of structure formation, which need a matter dominated epoch a(t) ~ t2/3 followed by dark energy domination,
 * Again, the relationship a(t) ~ t1/2 should not be treated in a comparison like this.
 * be in conflict with the cosmic microwave background anisotropy, and especially the location of the first peak (since this essentially measures the angular diameter distance to the surface of last scattering, which depends on the behavior of the scale factor since then),
 * ditto
 * require us to replace the Friedmann equations and thus Einstein gravity. In fact, since the radiation density is extremely tiny today, to get a(t) ~ t1/2 matter could not gravitate at all -- definitely in conflict with observation.
 * ditto


 * All of this is pretty standard stuff, these arguments can be found on various Wikipedia pages (as well as in the scientific litertature and textbooks on cosmology).
 * True, I've taken all the classes and have quite a few textbooks at this point (I even had to read some of them... believe it or not). Nodem 16:50, 27 November 2006 (UTC)
 * If you want to talk further but don't want to do it here, you're welcome to post to my talk page. That way others can benefit from/contribute to the discussion if they wish. Wesino 09:50, 27 November 2006 (UTC)


 * From your responses to my points it seems like you're quite enthusiastic about this idea. Lambda-CDM has a few problems and perhaps someday a better theory will be found.  But right now you're talking about a "principle," which is associated with a "normalized model" that can be compared to LambdaCDM as far as age calculations go, but can not be compared to classic LambdaCDM predictions or cosmological observations, apparently only predicts (or assumes?) an age-temperature relation, and -- perhaps most importantly for an encyclopedia -- isn't backed up by reliable sources.  Perhaps someday it'll be worthy of a journal article or more.  But I think we can both agree that for now it doesn't belong in an encyclopedia.


 * I want to say something more and please, please don't take it as condescension. If you've taken classes on this stuff, please go back and re-read your notes!  The model accepted by the vast majority of cosmologists has gained its status by passing a HUGE number of nontrivial tests over decades of research.  Any replacement will have to pass all of these, and more.     And until one has demonstrated this, claiming to have an alternative in hand is dodgy business indeed.  Wesino 17:41, 27 November 2006 (UTC)


 * Yes, dodgy business indeed! That's why I've not invested any time to this for the last year at least. My results don't actually agree with the currently accepted value for the Hubble parameter. I end up in the region of 63, so someone has got it wrong! It wasn't my intention to have this thing swept into a Wiki-article (I originated the "Strong Priors" section and this got sucked into a discussion).  Nodem 18:10, 27 November 2006 (UTC)


 * ...of course some would argue that the whole field was a bit dodgy. 63 isn't too far off -- who knows, maybe someday it'll be worth a Wiki article?  Keep truckin', best, Wesino 22:01, 27 November 2006 (UTC)

Accuracy template
Some similar language was added long ago, as described above at. Now someone has deleted the warning language without fixing that problem, so I replaced it with an official Wikipedia template. Art LaPella 04:58, 15 December 2005 (UTC)


 * You can't leave a dispute template up on a page for two months without doing anything to fix it. The editing activity since that time has not addressed the dispute.  What are you doing to fix this? Sections cannot be permanently disputed. --TreyHarris 20:58, 18 February 2006 (UTC)


 * As described above at, someone who knows this subject better than I do has decided that the entire section, in addition to the sentence I objected to, is nonsense. If I can't leave a dispute template indefinitely, then I hope Wikipedia has some other alternative procedure to being taken over by nonsense, just because no one still here understands the exact nature of the nonsense. Deleting the entire section would be OK with me. Art LaPella 22:44, 18 February 2006 (UTC)


 * Then you delete the nonsense. If somebody puts it back, you can engage them on this page, and you can have an actual dispute.  "This section is disputed" means not that someone has at some point disagreed with the section, but that people, on the talk page, are disputing it at the moment in order to reach a consensus.  Once the dispute ceases progress, the template goes; you can't just walk away from the dispute. --TreyHarris 23:49, 18 February 2006 (UTC)


 * OK (gulp!) Is there anyone out there who wants this paragraph to go back in? PDN didn't, as described above. Here is the major section I deleted:
 * Thanks to the bold one it's gone :-) I had stared at the section and modified a bit (see below) and thought: What's going on here?, but said to meself: Self, we don't know enuff 'bout this - leave it be. Onward, Vsmith 04:45, 19 February 2006 (UTC)

Age based on temperature
In its most basic form, the Big Bang theory is based on the idea that the universe was smaller, denser, and hotter in the past. Assuming, therefore, that the initial temperature of the universe is known, and that the change in temperature over time is accurately modeled, the age of the universe can be extrapolated from a measurement of the current temperature of the universe (approximately 2.7 K).

An expanding (or contracting) universe is given a scale factor to indicate its current size in relation to a fixed point. This could be a simple distance, or a dimensionless ratio of one distance (the size now) divided by a size in the past. In the case of a ratio like this, the present scale factor of the universe is one, and for an expanding universe, the scale factor in the past is less than one. Given a universe with scale factor $$a$$, the redshift $$z$$ of an object in the universe is simply the inverse of the scale factor minus one: $$z={1-{(1/a(t))}}$$, or $$a(t)={1/{(1+z)}}$$.

The temperature of the universe at a given time is inversely proportional to its scale factor at that time; somewhat analogous to a gas that would cool down if expanded, or heat up if compressed, the temperature of the universe is thus related to redshift as $$T=T_0(1+z)$$. We can do a quick test by using the current temperature of 2.7K and the redshift of CMB as 1089 to calculate the temperature of the decoupling surface $$T= 2.7*1090 = 2943\mathrm{K}$$ (this is the temperature of the universe when the CMB was emitted.)

In a universe like our own, most of the contents is in the form that does not exert a pressure on its surroundings (clouds of hydrogen gas, stars, planets etc). This is a pressureless, or "dust" model. For this kind of cosmological model, the evolution of the universe (scale factor at a specific time) is $$t=t_0{(1+z)}^{-3/2}$$. Putting in the redshift of 1089 for the cosmic microwave background and a current age of the universe $$t_0 \approx 13.7$$ Gyr indicates the CMB was emitted around 380,000 years after the birth of the universe.

The earliest measurable point in the evolution of the universe is the Planck time, when the universe would be at the Planck temperature. The Planck temperature represents the maximum attainable temperature in the physical universe and can only be attained via an extreme event, such as the evaporation of a black hole (the Planck temperature is the Hawking temperature of a black hole with a radius of the Planck length $$4.5 \times 10^{30}$$K). Therefore $$Tp=To(1+z_{\mbox{max}})$$, where $$T_0=2.725$$K and now $$z_{\mathrm{max}}$$ is the maximum redshift as if seen from the Planck time $$t_p$$. Using the radiation dominated formula above, we arrive at an age of the universe of 11.667 Gyr.

This is not the end of the story however: First we must take into consideration the matter domination, which in this calculation is equivalent to a change in the value of the Planck time itself. This is a fairly simple integration and results in an age one third greater at 15.556 Gyr. Finally, this model was also simplified by considering that the entropy of the universe is constant. Obviously, the entropy increases (due to graviational in fall) and this has the effect that the universe has become cooler than this simple model predicts. The difference here is around 13.5% (the temperature would be 6.5% higher if entropy had not increased, so the age difference is this squared). This adjustment finally brings the temperature calculated age down to the WMAP age.

380, 000 Years
I would like to point out that the 380 000 year age seems to be here just to put a hole in the page. I did not edit the page because I do not fully understand the math he has used. The idea of using bad science to 'prove' a religous theory is not a new idea, it is little more than kicking over someone elses sand castle because you can not build one that stands on its own. [Richard Bailey]


 * I'm taking it out because it makes no sense. We have dinosaur fossils from over 65 million years ago.  It's absurd to have something like that in this article.


 * er... read it again: current age of the universe approx 13.7 Gyr gives us around 380,000 years for the age of the universe when the CMB was emitted. Replaced the deleted para. Vsmith 20:56, 29 January 2006 (UTC)

Open Idiocy
380,000 years as the age of the Universe? This doesn't even deserve to be dignified with a proper response. It needs to be removed immediately - as it stands, it compromises the integrity and perception of empricism that Wikipedia holds dear. Justifications of ludicrous religious theories, regardless of how widespread they are, doesn't deserve a place in an encyclopaedia.

This trend in Wikipedia towards including right-wing political, religious and moral sensibilities as valid 'criticism,' no matter how outlandish or utterly falsified by modern science, is disturbing and an indication of intellectual laziness and misguided belief that simply because there are two opposing positions, the factual middle ground is somewhere evenly between the two. In reality, almost no respectably accreditted scientist supports Creationsim, yet it seems that we must always qualify an article on evolution with the 'opposing view' of Creationism. Really, these opposing opinions deserve no more place in Wikipedia than the 'stork theory' in human reproduction.

Idiocy is widespread and commonplace: this is no excuse, however, for it to be given equal footing with our current, rational understanding of the world.
 * (above post by 146.87.193.90 moved to bottom of page)


 * To repeat my comment from above in the section entitled 380,000 years:
 * er... read it again: current age of the universe approx 13.7 Gyr gives us around 380,000 years for the age of the universe when the CMB was emitted.
 * Perhaps we need to reword that bit as at least two users have mis-read it. Vsmith 03:05, 6 February 2006 (UTC)

OK, I reworded the offending sentence to, hopefully, avoid further confusion. The whole section needs a re-write as it is a bit much for the average user (me included :-) Vsmith 03:26, 6 February 2006 (UTC)

Should we perhaps link to an appropriate Wikipedia Creation Myth page?

The first sentence needs to be changed
I am a physicist, I have studied astrophysics, astronomy, and cosmology for years, and this is my suggestion: the first sentence of this article has to go, and asap. Because it is simply not true. It states, "Nothing is certain as to the extent of either the age or size of the universe..." That is factually at odds with the very laws of physics used to calculate the age of the Universe. Not only is there a currently accepted age of the universe, which is calculated in several different ways arriving at the same order of magnitude but in fact, the age of the universe is currently accepted within about 1.4% error. Since this is fact, it needs to be presented in this article as such; just click here for a clear and concise explanation of actual measurments of the age of the universe that are not based upon cosmological models for those measurments, such as the big bang. To leave the first sentence as it currently stands would be an egregious offense to the policies of WP to promote NPOV for this subject. I plan on making a change soon and I would like suggestions from those of you who have researched this subject, and understand a way to present it to a general audience for their maximum benefit. I realize how this can be a confusing issue for many people. To be able to do something as complex as measure the age of the universe requires advanced mathematics well beyond what most people are comfortable with, so there needs to be some way to balance the presentation of these measurments from their actual foundations, with a readability for a casual observer. I'd like to work on a solution to this as soon as possible and all feedback would be welcome. Thank you for your time. C.Melton 00:12, 11 February 2006 (UTC)

I agree. I am also an astrophysicist who has studied cosmology. The statement is equivalent to saying nothing is certain about the number of legs dogs have, when in fact the majority of evidence suggests that four is the number. Soloist 14:11, 17 February 2006 (UTC)


 * Me and my Mutt had a discussion and reached an agreement: the answer is four. Deleted the Nothing is certain... bit. Now you astrophysics guys go to work on it :-) Vsmith 15:27, 17 February 2006 (UTC)

Just did an edit on the first paragraph. It seemed to get overly technical "very" quickly. I think that a casual reader should be able to gather that the Age of the Universe is just the time between the beginning (=Big Bang) and today. But I think this casual reader could easily be lost in the sentences about integrating proper time along curves (which linked to the Minkowski space article, which makes no sense in this context). Also, the comments jumped directly in to the various alternative models without really explaining the consensus view first (which should really be the purpose of this article, right?).

So I changed things a bit and made the first two sentences as simple as possible to get the idea across. Then I tried to preserve some of the discussion of other possibilities (which were largely about universes without a big bang and infinite age; I added an example of a model with a big bang but of infinite age) as well as some of the comments about the ambiguity of defining time properly in SR/GR. Hope others find that this makes the opening paragraph clearer too Wesino 10:04, 15 November 2006 (UTC)
 * Note: This section has a lot of lying bastards. Current research shows that the age of the universe is a MINIMUM of 13.73 billion years, there is no proof for or against it being older. And really, we don't know enough to say for sure. 85.156.0.200 (talk) 18:05, 8 April 2008 (UTC)

Problem With A Reference - Removed
I have a problem with this reference given in the article. It is only in the Pre-Print Archive - a database in which anyone can present any original research and it is hence not in a peer-reviewed professional journal (appropriate journals for this topic would include ones like Physical Review D or the Astrophysics Journal). Any source cited that argues problems with a scientific consensus on some issue bears the burden of proof and such can only be truly reliable if it is peer-reviewed research. There are plenty of articles that discuss the problems, drawbacks, or other limitations of one model or another in professional journals and therefore we should - in the interest of quality - include more peer-reviewed articles than non peer-reviewed articles. I have therefore removed the poor reference and replaced it with better ones. Astrobayes 11:18, 20 June 2006 (UTC)

Strong Priors Section
I have also added an additional comment, backed by several peer-reviewed journal articles and one peer-reviewed Ph.D. thesis, that adds a very important point to the editor's comment about strong priors. The impetus for adding these references and my comment was that the editor seemed to be saying that you cannot trust a conclusion or result unless you consider the model first, but this is not the entire story. The model used helps constrain the confidence interval, but does not invalidate the measurment if a different model obtains slightly different results - this amounts to correctly normalizing the data, not invalidating models which the original editor seemed to suggest. There are two branches of statistical tools used in science: frequency statistics (what most people are familiar with) and Bayesian statistics. Only the latter is a tool that adjusts statistical results based upon a model (i.e. prior) being used. Since this important tool is used so often in science (I used it quite frequently when I did astrophysics research as an undergraduate), it is important that it be mentioned because it constrains our confidence intervals for age of the Universe measurments. In other words, we cannot simply eliminate a particular scientific measurement we may or may not agree with just becuase it comes from one model and not another. If this edit is reverted, there should be an overwhelming support to the contrary cited by peer-reviewed research for as it stands, it adds important NPOV content to the article. Astrobayes 12:09, 20 June 2006 (UTC)

Age based on what time frame of reference?
While there are several methods to calculate the age of the universe as we know it and they have produced similiar results, one must wonder, what does this "age" really mean? Does that mean age in our time? Age in relative time? Age in warpped time? Since there's an age, there must be a start, and I believe the most commonly accepted theory is the Big Bang; in which case, while the universe is a singularity, the space-time is warpped at the point from the heavy gravitational fields, wouldn't the calculation of time (using our common time-units) be largely inaccurate as well? Even if we use String theory to avoid the singularity problem, the fact that time is messed up at the point doesn't seem to change. Allan Lee 16:08, 10 July 2006 (UTC)

Title - 'Age of the universe' vs 'Age of the Universe'
Shouldn't the title of this page be 'Age of the Universe', i.e. capitalized Universe as it's a noun (and there's only one of it)? If not, then the capitalization of the first sentence in the article needs to be changed... --Mike Peel 06:59, 1 August 2006 (UTC)


 * "Do not capitalize solar system and universe." ( http://www.science-teachers.com/articles/phpBB2/viewtopic.php?t=8 ) "It is not necessary to capitalize a word merely because there is only one thing it can possibly refer to: ... the words equator, north pole and universe need no capitals, because they aren't strictly proper names. Some people choose to capitalize them anyway; this is not wrong, but it's not recommended." ( http://www.cogs.susx.ac.uk/doc/punctuation/node27.html ) Googling the word "universe" shows that it's written as "universe" about twice as often as "Universe". So I would prefer not to capitalize either use of the word "universe", but the issue is close enough that I haven't uncapitalized any "Universe"'s either. Art LaPella 18:19, 1 August 2006 (UTC)

Seems the article may need adjusting
Something about the Carnegie Institute of Washington here:, I especially like that first sentence about the wrench on the universe's evolution bit, but that's just me. Homestarmy 23:52, 8 August 2006 (UTC)


 * No, this is just reporters who don't know what they're talking about, as usual. I especially like the "180 billion light years" figure, which was obtained by an incorrect calculation (naively adding 15%) applied to an incorrect value (156 billion light years, as widely misreported in the popular press a couple of years ago).


 * For an accurate report see Ned Wright's News of the Universe. -- BenRG 13:58, 9 August 2006 (UTC)

This is in reference to this paper:. The lead author is from Carnegie, the other 14 are not. The observations were made using the 1.2 meter Fred Lawrence Whipple Observatory, 2.1 meter KPNO, 3.5 meter WIYN, 8.2 meter Gemini Observatory, and 10 meter Keck-2 telescopes. The following quote was from the Discussion section at the end of the paper:


 * "our Large Magellanic Cloud distance would imply a 15% decrease in the Hubble constant to H0 = 61 km s 1 Mpc 1. This improbable result brings into question the Key Project metallicity corrections and reddening values not only for M33, but also for the other galaxies in the Key Project."

I can't seem to get to Ned Wright's page anymore. Did he go somewhere else? Nodem 16:50, 2 January 2007 (UTC)

Reference removed
I've removed  Evolution of Population II Stars, as the link doesn't work (it redirects to the springerlink homepage). It's possibly, but I'm a bit doubtful about that. Mike Peel 19:43, 16 September 2006 (UTC)

What the hell is a Gyr?
For the first half of the article, the age of the universe is given in billions of years. Then the article switches to giving the age in "Gyr" units, whatever that is supposed to mean, and "Gyr" links to an article which also doesn't define it. Someone needs to fix this, or I'll just replace them all with "billion" and assume that is probably correct. --Xyzzyplugh 23:49, 27 September 2006 (UTC)


 * Gyr is a standard abbreviation for Giga-year or billions of years (aka $$10^9$$ Julian rotation periods of the Earth around the Sun). Other abbreviations of SI prefixes that will probably be found in physics articles and the other natural sciences would be things like: Bly = "billion light years", pc = "parsec" which is another way of writing 3.26ly or "3.26 light-years."  In the natural sciences, the numerical prefixes are used continually and the shorthand for those is to use the first letter of each, e.g. G for Giga, T for Tera, k for Kilo, c for Centi, f for Femto, etc.  It was not a mistake in the article to use the abbreviation but I agree that the article would be best served by using consistent units.  The Giga article now reflects this.  I hope that helps!  Cheers, Astrobayes 00:12, 28 September 2006 (UTC)


 * Who is the target audience of this article: cosmology professors or cosmology students? That is to say, is it meant for academic specialists looking for information on the latest research or is the intended audience those less versed in the speciality and may simply be seeking basic information in an easily accessible form on a basic aspect of cosmology? I pose that question because judging from the argument used above by Astrobayes middle-aged academic specialists were more the sort of audience he had in mind. That is, the sort of person who reads "physics articles" every day as part of their profession. As opposed to the average layman who probably last read a physics article back in college or high school; and even then it was probably something out of Scientific American.


 * "Giga, Tera, Kilo, Centi, Femto"... Yes, those are standard SI prefixes, but like all standards they exist to be broken. Classic examples: the computing terms "kilobyte", "megabyte", "gigabyte", etc. Those SI prefixes presuppose a decimal system. Unfortunately, computing uses a binary one. Thus, a "gigabyte" is actually equal to 1,073,741,824 bytes rather than 1,000,000,000. Something similar might be said of applying SI prefixes to the units for angles and time, all of which are ultimately based on non-decimal (and thus non-SI) systems. One can certainly shoe-horn the SI prefixes on--eg "milliarcseconds" and "nanoseconds"--I notice that it is often a highly selective shoehorning. We may all speak of "kilometres", for example, but who uses "megametres", "gigametres", or "terametres"? Even among professional astronomers one is surely more likely to speak of "thousands of kilometres", "millions of kilometres", and "billions of kilometres".


 * Surely the intended audience should govern the terminology used. Cosmology professors may use "giga-years" in their journal articles, but would they do so in an article meant for a lay audience? After all, the whole idea of communicating an idea is surely to get that idea across. If the terminology gets in the way of that then what is the point of using that terminology? It would be better to use terms the audience is more familiar with.


 * Because it's a standard and standards must be adhered to? Well, maybe. "Gyr" may be "a standard abbreviation for Giga-year or billions of years" among the academic community, and kiloparsec is widely used, is there any cosmologist who uses "kiloyears"? If not then attempts to justify the use of "giga-years" by pointing to the SI prefix system look suspiciously like special pleading. "Giga-year" is used because it has become CONVENIENT to do so. (As to what that 'convenience" might be, I'll take a punt: because billion light year distances crop up an awful lot in cosmology and related disciplines using "Gyr" probably saves the average academic having to type the longer "billions of years" every other sentence on his word processor.) Once the convenience vanishs the urge to use the SI prefix system conveniently vanishes with it.


 * In this same context I note that specialists in other fields have thus far avoided (AFAIK) equivalent terms in their own disciplines. Thus while cosmologists may talk about "giga-years" how many palaeontologists of it being 65 megayears since the dinosaurs met their doom? And how many archaeologists refer to the 12 kiloyears (or thereabouts) since the last ice age ended?


 * None of this is to argue against the use of "giga-year" in its proper place. Like "nanosecond" and "millisecond" it doubtless fulfils a need. But is the place of such term in an article meant for the non-specialist reader? Such a word is surely jargon. That is, a term used by specialists amongst themselves. In any specialised discipline the use of some specialist terms is unavoidable if only because no other corresponding can easily replace them. Others (eg "millisecond") are probably sufficiently well-known and well-understood that one can get away with using them without having the eyes of a lay audience glaze over. But is that truly the case with "giga-year"?129.78.64.102 (talk) 13:29, 11 March 2008 (UTC)
 * Original comment is 1.5 years old. GYA does not occur in the page anymore.  WLU (talk) 15:55, 11 March 2008 (UTC)

standard representation of ages
Could someone please reformat all the ages we have in this article in scientific notation for easy comparison, or perhaps create a table with the method of calculation & age with all the ages using the same exponent on 10? This would make it easy to see differences/similarities in the calculated values. As well, some measure of error for each value would be nice.

What came before the universe?
If the universe has only been around for a finite period of time, then what existed before the universe? What I mean is, if there was nothing before the universe, then how can something be created from nothing? Sounds impossible to me. But if there was something always there to begin with, then where did it come from? Can someone explain this to me like a 2 year old? :) Davez621 07:46, 7 November 2006 (UTC)


 * We don't know if there was anything before the Big Bang, according to the second paragraph of Big Bang. "Age of the universe" is to some extent a widely accepted misnomer for "time since the Big Bang". There are no experts on what happened before the Big Bang because we have no good ways of knowing. I can offer some philosophical mumbo jumbo: if the universe began with the Big Bang, which is a good guess, then we are like artificially intelligent chess programs programmed only for chess, asking how a chess game could have a finite past. What move could have come before move one, and which legal chess move could have placed the pieces on the board? Art LaPella 20:04, 7 November 2006 (UTC)


 * Mathematically, time itself started with the Big Bang, so there's no such thing as "before" the Big Bang, and there was never "nothing". thx1138 05:45, 19 November 2006 (UTC)


 * If you can prove that mathematical model represents the consensus view of reality, then I think you should rewrite the second paragraph of Big Bang. Art LaPella 05:57, 19 November 2006 (UTC)


 * I wasn't talking about the consensus view of reality, just about the mathematical view, which may or may not turn out to conform to reality. thx1138 06:14, 19 November 2006 (UTC)

According to General relativity, time and space are inter-related. The farther back in time you go, the denser the universe was, and the slower the rate of time. Like this article suggests, from a material point of view, there was no "before" the big bang, and any absolute number you assign to the age of the universe is artificial and misleading. johnpseudo 21:03, 15 December 2006 (UTC)

This is a stupid question and I will be removing this part of the article. Going an hour before t=0 is like going a mile north of the north pole, you go south again. There is no time before t=0 it did not exist until the big bang, a singularity is when ALL time and ALL space is in one point. The article as is shows a poor understanding of physics.


 * "What came before" is the most common question amateurs ask here, which is evidence that we should explain the scientific consensus (or lack of consensus) on this issue more thoroughly, not less. And even if it were a stupid question, please find a nicer way to say it. Art LaPella 00:50, 12 June 2007 (UTC)

Well then the article should explain that there is no time before t=0 because the way the article reads hints that there possibly is no explanation when its clearly understood.


 * I thought there was no explanation, but if scientists clearly understand there was no time before t=0, then by all means say so. With references of course. Art LaPella 22:29, 16 June 2007 (UTC)

There is nothing amateur about having a hard time getting their head around the concept of a singularity born of nothing coming into something then exploding into the universe, or a non-reversable time line of revision. Whilst scientific consensus holds that to be the case, scientific consensus has held many strange ideas that just didn't 'sit right' in some peoples minds, such as the world being flat, and everything orbiting the earth.

There's no need to be snide, or hold extremely defensive postures towards scientific theory, because with time, all scientific theory changes or is expunged by new facts or evidence. [shrug] Jachin 06:34, 20 July 2007 (UTC)


 * If you know a better way to express the fact that amateurs, but not professionals, often ask what came before the Big Bang, then please elaborate. I often need to express that fact on cosmology talk pages, and like you, I have argued for more explanation of the subject. Perhaps you confused the person who said "amateur" with the person who said "stupid", to which I objected. Art LaPella 18:44, 20 July 2007 (UTC)

Wait, you didn't answer his question and instead brought up a more disturbing one. If the Universe existed as a single point and time had not yet come into existence, how did it? Cause and effect cannot exist without time as the cause must come in the past. So are we saying the universe is a cause without an effect? 79.181.238.25 00:07, 10 October 2007(UTC)


 * My answer to what came before the Big Bang, which is also my answer to whether the universe is a cause without an effect, is the second post in this section: "We don't know...", although the article now best addresses the subject at Big Bang: "Little is known..." Art LaPella 01:47, 10 October 2007

(UTC)

I think we both ment "effect without a cause." Anyways, "Don't know," is a good enough answer for me. 212.179.204.53 15:40, 10 October 2007 (UTC)

Section on Cosmological Parameters
Just added a section on how the age of the universe is calculated based on knowledge of cosmological parameters. I hope this will be educational since it gives you an idea of how the $$1/H_0$$ back-of-the-envelope calculation gives nearly the right answer, and how to correct it to get exactly the right answer.

In case anyone would like to build on what I've put down, I've placed a simple Python program that I used to calculate the age correction function, a Gnuplot script to make the plot, and some basic instructions on my user page User:Wesino. I'd be happy to answer any questions if someone would like to use those materials to improve the section. Wesino 14:16, 12 November 2006 (UTC)

billion?
First paragraph mentions age in billions of years, but the billion link can mean either thousand million or million million, so it should be stated here more obviously to which billion it is refering, or else change the link on billion to be more specific --anonymous coward. —The preceding unsigned comment was added by 203.54.206.36 (talk) 15:21, 8 December 2006 (UTC).


 * Good question. I suppose Billion most common English form, the American one (10^9), is used. Maybe there should be a reference for European users. Ellohir 10:11, 2 July 2007 (UTC)


 * According to Manual of Style (dates and numbers): "Billion is understood as 109 in the United States, English Canada and most of the rest of the English-speaking world. (In most Germanic and Romance languages, it means 1012.)" The first paragraph link goes to 1000000000 (number) which is specific enough. I presume that link was changed since the December comment. Art LaPella 20:16, 2 July 2007 (UTC)


 * If you presume I'm idiot because I didn't see the link... You're right. Thanks. Anyway, i would add (10^9) in brackets, for the germanic and romance-languages users.

News on the age - add 15%
It seems to me that its about time the page was updated to reflect that scientists who used to estimate the Universe to be about 13.7 billion years old (a figure that has seemed firm since 2003, based on measurements of radiation leftover from the Big Bang) and about 156 billion light-years wide, now based on new distance measuring technique finding implies that the universe is instead about 15.8 billion years old and about 180 billion light-years wide.

I also think that there should be an inclusion of the age of the Universe based on Biblical sources included since it is the same. The basis of the calculation and the background is below taken from http://failedmessiah.typepad.com/failed_messiahcom/2005/07/rabbi_aryeh_kap.html

Rabbi Aryeh Kaplan's View On The Age Of The Universe I thought it would be helpful to again summarize the position of Rabbi Aryeh Kaplan (http://en.wikipedia.org/wiki/Aryeh_Kaplan), z"l on the age of the universe.

Rabbi Kaplan was both an illui (genius) in Torah and an illui in physics (After his ordination he earned a masters degree in physics. As a graduate student, Rabbi Aryeh Kaplan was described in a scientific "Who's Who" as a promising young American physicist), and was arguably the most qualified individual of the previous generation to discuss the interface of Torah and science.

PART 1: Background.

1. As long as no halakha (Jewish Law) is involved, there is no reason to paskin on (decide) an issue. 2. In his Guide to the Perplexed, the Rambam (http://en.wikipedia.org/wiki/Rambam) builds several shitot (philosophies) based on da'at yachid, an individual view of a sage that is not upheld by the majority. As long as this is done for hashgafah (philosophy, outlook) and not for legal issues, this is perfectly fine. 3. One cannot label an idea heretical until one has surveyed the sources. Perhaps Gedolim (the Greats) from earlier generations held the same view. If so, the view is not heresy. 4. Sefer Temunah, an early kabbalistic work attributed to the 1st century Tanna Nehunya ben ha-Kanah, is a work that discusses the kabbalistic import of the shapes of the Hebrew letters. Sefer Temunah is quoted in many different Halakhic sources (including the Beit Yosef) that deal with sofrut – writing Torah scrolls, mezuzot and megilot. 5. Sefer Temunah also comments on the Shmita Theory, the idea that sabbatical cycles existed before the creation of Adam, and that those cycles – those years – were actual physical years. 6. Sefer Temunah states that we are in the 6th 7,000-year sabbatical cycle and that the world is 42,000 years old. 7. The Shmita Theory became known as the Shitat Sefer Temunah. 8. Many pre-ARI (http://en.wikipedia.org/wiki/Isaac_Luria) kabbalists accepted the Shitat Sefer Temunah, including the Ramban, his close student Yitzhak of Akko, and the RADBAZ. 9. The Ramban's position is difficult to understand if you have not first learned Shitat Sefer Temunah. 10. The ARI (Rabbi Isaac Luria) rejected Shitat Sefer Temunah and taught that these cycles were not physical years but were instead spiritual, non-physical years. Rabbi Moshe Cordevero agreed with the ARI. 11. Because of the spread of Lurianic Kabbalah, Shitat Sefer Temunah became less and less known. For the most part, only those few scholars who studied ancient kabbalistic works were aware of it. 12. In 1838, when the Tiferet Yisrael (Israel Lipschitz of Danzig (1782-1860) was the author of Tiferet Yisrael a well-known commentary on the Mishna. He also wrote Shevilei de'Rakiya, an introduction to the principles of Rabbinical astronomy) wrote his essay on the age of the universe that advocated a universe much older than 6,000 years, his works were banned by some hasidim. Others simply ripped the essay out of the larger work. 13. The Tiferet Yisrael's 'crime' ? Not accepting the ARI's opinion as binding. (See #1, #2 and #3 above.)

PART 2: Could The World Have Been Created 'Old'?

1. No Jewish source exists to support this contention. 2. To make the world appear to be billions of years old when it is really 6000 years old is problematic:

a. It makes G-d appear to be deceptive. b. If one accepts the idea that G-d created an 'old' world, why not say the world was created 5 minutes ago and we with it, with all of our memories, etc. ready-made? c. Again, there is no Jewish source for this idea. [It was invented by the 19th century Christian apologist Philip Henry Gosse.]

3. One can believe it if one desires. Such a belief – even absent Jewish sources to support it – is not heresy.

PART 3: The Shita of Yitzhak of Akko (Isaac ben Samuel of Acre (fl.13th-14th century) was a kabbalist who lived in the Land of Israel).

1. He was a student and a colleague of the RAMBAN (Nahmanides (1194 - c. 1270) was a Catalan rabbi, philosopher, physician, Kabbalist and biblical commentator. "Nahmanides " is the common name for Moshe ben Nahman Gerondi). 2. Was one of the foremost kabbalists of his time. 3. Investigated and authenticated the Zohar (The Zohar (Hebrew זהר "Splendor, radiance") is widely considered the most important work of Kabbalah, Jewish mysticism. It is a mystical commentary on the Torah (the five books of Moses), written in medieval Aramaic and medieval Hebrew. It contains a mystical discussion of the nature of God, and, among other subjects, the origin and structure of the universe), which was then published in his lifetime. 4. Is often quoted in the Mussar classic, Reishit Hokhmah. 5. In his work Otzar HaHayyim, Yizhak of Acco writes that, because the sabbatical cycles referred to in Shitat Sefer Temunah existed before Adam, they must be measured in Divine years, not human years. 6. Therefore, Sefer Temunah is speaking of Divine years when it states that the world is 42,000 years old. 7. According to midrashic sources, a Divine day is 1,000 earth-years long. 8. A Divine year would therefore equal 365,250 earth years. 9. So, according to Yitzhak of Acco, the Universe would be 42,000 x 365,250 earth-years old. 10. That calculation comes out to 15.3405 billion years, very close to current estimates for the Big Bang as adjusted by the recent finding that corrects the previous estimate by +15%.

Part 4: Conclusion.

1. There does not have to be a conflict between science and Torah on the age of the universe. 2. Pre-Ari Torah-teachings have in fact been confirmed by modern science.

I appreciate that this may challenge personal sensibilities of those who maintain this article, never mind the lack of definition of 'spiritual day'. --Mrg3105 22:24, 28 December 2006 (UTC)


 * The scientific evidence for adding 15% has been previously discussed at . Art LaPella 00:34, 29 December 2006 (UTC)


 * If that is in archives I hadn't seen the tag to Archive. --Mrg3105 08:49, 29 December 2006 (UTC)


 * isn't in Archives. Just click it. Art LaPella 17:36, 29 December 2006 (UTC)

I've reverted your edits for several reasons, including: You may also want to look at the many discussions over at Talk:Big Bang about the inclusion of religious interpretations in scientific articles.Mike Peel 10:27, 29 December 2006 (UTC)
 * The introduction to this article starts off with "The age of the universe, according to the Big Bang theory, is the time elapsed between the Big Bang and the present day." That should immediately give you the idea that this article is about science, not religion, or even philosophy. If you want to discuss religious views on the age of the universe, please do it in a new article such as Age of the universe (religion).
 * You need to provide references to reliable sources. Blogs are not considered to be reliable sources.


 * Mike, you are not being very scientific. The article is about both religion (the primary stated origin of and therefore age of Universe) and the later 'scientific' challenge to this statement. This has been the scientific pursuit in the attempt to disprove the primary statement. The fact that the most known view in English is based on the Christian view of the Universe, itself based on the Greek beliefs, and was ignorant of other available views is not the issue. It is simply a faulty approach to gathering knowledge by the generations of scientists as defined by "scientific - since 1589, from M.Fr. scientifique, from M.L. scientificus "pertaining to science," from L. scientia "knowledge" (see science) + -ficus "making" + facere "to make" (see factitious). Originally used to translate Gk. epistemonikos "making knowledge" in Aristotle's "Ethics." First record of scientific revolution is from 1803; scientific method is from 1854; scientific notation is from 1961. from O.Fr. science, from L. scientia "knowledge," from sciens (gen. scientis), prp. of scire "to know," probably originally "to separate one thing from another, to distinguish". It seems to me the early Christian scientists not only separated the Jewish understanding of the concept of Universe/Creation, but completely ignored it. The fact is that it is the scientific discussion that is included in the religious interpretation because it came before science! One can not negate precedence of concepts. If there was no statemet of Creation in the Jewish Scriptures, there would never be a requirement to inquire into it's varacity as is indeed the case in all other non-monotheistic cultures :-)--Mrg3105 12:08, 1 January 2007 (UTC)


 * Try reading Scientific method. Then have a look at the Big Bang article, where similar issues have been discussed, and see how they have resolved it. Specifically, see the "Philosophical and religious interpretations" section, specifically the first section: "While the Big Bang is a scientific theory that is not based on any religion, some similarities have not gone unnoticed. There are both theological and philosophical implications, since some religious interpretations and world views conflict with the Big Bang origin of the universe." I am not opposed to the discussion of pre-scientific "measures" of ages of the universe, but a) I don't want to see them intermixed with the scientific discussion (which could promote confusion between the two), and b) I don't want to see original research, hence I want reliable references for the information in the article. Mike Peel 12:52, 1 January 2007 (UTC)

I'm interesting in finding a reference that isn't POV pushing for 'now based on new distance measuring technique finding implies that the universe is instead about 15.8 billion years old and about 180 billion light-years wide.' as quoted by the original poster. It appears that through pretending there's new findings they're corroborating this as 'fact' alongside validation of the '7 days' and '6,000' years myth of fictional time frames. If that's the case, and people lived 800 years in the old testament, are these 'holy years' and thus lived for 292 million years? Or can we play pick and choose about what numbers are based on what base unit count in accordance with what sits better with real science to try and bring credence to fairytales? Jachin 06:44, 20 July 2007 (UTC)


 * The 15.8/180 figures were reported by a bunch of "reliable sources", including cnn.com and New Scientist . They're completely wrong, though. This isn't politics, just clueless reporter syndrome. Observable universe discusses the various wrong numbers. -- BenRG 19:02, 20 July 2007 (UTC)

POV problems
While I understand that the views expressed in this article are generally accepted among Wikipedia administrators, one cannot overlook the very biased POV in this article. I see no mention of young Earth debate, or of any ideas of the age of the universe, for that matter. The entire article is written from the view of a macroevolutionist. I'm not asking for the views currently being expressed to be obliterated, but for the information and theories to be provided in a balanced POV. Yurimxpxman 18:27, 20 February 2007 (UTC)


 * The young earth position is not included because it would be giving undue weight to a fringe hypothesis. I'm not sure what you mean by "macroevolutionist"; this article is about cosmology, not biology. It is a science article so it reflects mainstream scientific research in this area.thx1138 07:54, 28 February 2007 (UTC)


 * Ndteegarden expresses the basic matter well. I suggest you read WP:NPOV "undue weight" section. Also, note that you seem to be under the common misunderstanding that the Big Bang and related issues are somehow related to each other. Evolution and the age of the universe are essentially unrelated issues. They are not. One is the concern of biologists and paelontologists the other of cosmologists and astronomers. JoshuaZ 08:13, 28 February 2007 (UTC)


 * 'The young earth position is not included because it would be giving undue weight to a fringe hypothesis.' From Wiki:NPOV: "For example, the article on the Earth only very briefly refers to the Flat Earth theory, a view of a distinct minority."  If you can mention that some people believe in a flat Earth, you can mention that some people believe in a young Earth–even briefly.  Because a young Earth is not a belief held by only a tiny-minority, it deserves a decent explanation. --Yurimxpxman 03:02, 7 April 2007 (UTC)


 * At the risk of being slapped on the wrist, I've gone ahead and created a neutral section covering the creationist position, since that is obviously what Yurimxpxman wanted to see. Bearing in mind the guidelines on  due weight I have tried to include about the right amount of material. Comments welcome.  SheffieldSteel 04:14, 7 April 2007 (UTC)


 * If that's the right amount of due weight, then I would prefer substituting Young Earth creationism for James Ussher, with a less precise date, or maybe just "See also Young Earth creationism". Ussher is history; creationism is a well-known current Point Of View among non-scientists. Art LaPella 04:48, 7 April 2007 (UTC)

Creationist POV bit
Removed the following:
 * ==Other Views==
 * Although many people presume that the universe was created by a Big Bang some 15 Billion years ago, others believe that the universe is in fact much younger than previously thought.
 * The age of the Universe depends on the person's world view. Say, for example, a person was an evolutionist.  He would believe that the universe was created through an explosion of gasses about 15 Billion years ago.  Creationists, on the other hand, believe that the universe is rather young; between 15 and 20 thousand years old.

Poorly stated and seemingly quite out of place, should be discussed in the creationism article. Vsmith 23:57, 15 May 2007 (UTC)

Questions
From reading this article and the discussion page, I have three questions. 1. According to the law of Conservation of Energy, is it possible that the universe has always existed or that it is in an endless cycle of collapse and expansion? 2. Because light is slow relative to the size of the Universe, do these age calculations only tell us how old the universe was several billion years ago? Or is that factored into the calculation. 3. Do religious origins automatically eliminate a theory from the interest of scientific research? Is the "young universe" theory disproven or simply rejected because of where it came from? These are all honest questions asked by a seeker of knowledge. I will check back on this page to look for answers. I hope I can find them here. 63.231.51.78 05:03, 20 June 2007 (UTC)
 * 1. We don't know what was before the Big Bang, or if "before the Big Bang" is even meaningful. Therefore we don't know if laws like the Conservation of Energy would apply at the singularity. I could go on about which laws could be honored or broken by an endless cycle, but I'd be making stuff up that nobody really knows.
 * 2. Scientists take it for granted that what they see across deep space is from ages past. If the age of the universe estimate is wrong, it wouldn't be because they didn't think of that problem.
 * 3. It's true that scientists don't ordinarily devote much time these days to a theory with a religious origin, but they did in the 1800's when they first started to conclude that 6000 years wasn't enough. Young earth creationism is debated at the talkorigins page http://talkorigins.org/origins/faqs-youngearth.html . Art LaPella 06:30, 20 June 2007 (UTC)

Biocentricism
Biocentricists, such as Robert Lanza, would argue that time is merely an attribute given by a perceptor (human, terrestrial non-human, or extra-terrestrial life) to measure the apparent motion of an object. To say the universe is x years old, is just to say that the earth would be able to evolve around the sun x amount of times since the beginning of the universe by current rates of orbit. If you remove the perceptor from the equation, then all time would take place instantaneously. Time, in this sense, is movement of matter and other entities that exist within the universe, multiverse, etc. Explained here: http://www.theamericanscholar.org/archives/sp07/newtheory-lanza.html

NPOV
This page does not list all thoeries of the age of the universe, such as creationism. I saw that someone had removed a section that tried to state the other theories instead of improving it. JacroeBlank 00:38, 3 July 2007 (UTC)


 * WP:Undue_Weight. Basically, an article does not need to mention every viewpoint on a topic. "Articles that compare views should not give minority views as much or as detailed a description as more popular views, and may not include tiny-minority views at all. For example, the article on the Earth only very briefly refers to the Flat Earth theory, a view of a distinct minority". GSlicer (t • c) 01:12, 3 July 2007 (UTC)


 * Creationism is not a minority view. There are millions, if not billions, of people worldwide that believ in creationism. It should at least get a mention in the article. Like the guideline says, "The article on earth only very briefly refers to the Flat Earth theory". At least it gets a mention even though there's less people in the world that believe in the flat earth theory then creationism, and there's a mention in the article! So why can't we just put a mention of creationism in this article?

You shouldn't have removed the tag without at least giving other users a chance to reply here. The template states that the neutrality of this article is disputed, not that there's actual POV. I'm gonna add it one more time. Please don't remove it again until we, and other users, have a chance to talk about this. -- JacroeBlank 03:22, 3 July 2007 (UTC)


 * Others haven't responded because this is a dead horse issue we've seen over and over again. Creationists are an insignificant minority among scientists, although we presumably disagree on who counts as scientists. "One important bellwether for determining the notability of fringe ideas related to science, history or other academic pursuits is the presence or absence of peer reviewed research on the subject." (WP:FRINGE) If everyone were equal, then creationists are at least a very significant minority among non-scientists, but if everyone were equal then (please take this as an illustration, not an insult) about 5% of the population believes in Santa Claus. That said, I have argued for a See also link at . Art LaPella 04:09, 3 July 2007 (UTC)


 * So, shall we edit feces as a nice food? Billions of flies can't be wrong. Let's keep the article on based experiments, or we'll have to edit most football club pages with "Thousands of people think this is the best team in the world". PS: Sorry for the horse. Ellohir 11:51, 3 July 2007 (UTC)

Okay, since Wikipedia is WP:NOTPAPER encyclopedia, can we at least have a "Other theories" section with a list of links to the other articles? No text will be added to the article itself and we can at least show other views of this topic. -- JacroeBlank 13:02, 3 July 2007 (UTC)


 * I think the logical place for alternatives to the Big Bang would be on that page, rather than this one. We wouldn't expect flat-Earthers to be mentioned on an article discussing how the radius of the Earth is measured, after all. In fact, their mention in the Earth article itself is confined to a historical reference in the "human viewpoint" section. 70.255.36.5 20:42, 3 July 2007 (UTC)


 * The Big Bang is not the only theory out there. There would be no harm in doing listing the other explanations on this page. JacroeBlank 22:42, 3 July 2007 (UTC)


 * The "short and smarmy" answer is that the Big Bang is the only "widely accepted theory" espoused by "very reliable sources" in the sense of "sources that know what they're talking about". A couple of wikilinks under "see also" might not be inappropriate - and I actually have a rather good book on the history of figuring out how old the universe is - which might delve into what used to be credible, but isn't anymore. Wily D  22:46, 3 July 2007 (UTC)

As a member of one religion I have a point of view on that religion. I do not require proof that my religion is right. That is the difference between science and religion. For facts about the physical world I live in, I will depend on science and the ethics of the people who practice science. Whatever the religion of a good scientist one will report the truth of their findings without regard to their religion. If my religion said the earth was supported by a pillar of stone then the photograph of the earth floating in space would make me doubt my religion or my interpretation of my religion before I would doubt the evidence before my eyes. This article should be based on science not religion. Science is not a popularity contest, it based on proven facts. When there is doubt about the facts, as there is in the exact age of the universe, a good scientist will report that doubt.


 * In fact, we do. In science, we have some doubt about the age of the universe - realistically speaking, it's about a plus or minus 200 million year uncertainty on the 13.7 billion year age.  I think the article covers that well though. Wily D  13:50, 25 October 2007 (UTC)

Not so much NPOV as what's useful
Up above me. Please sign your comments. Anyways....I would like to know why the article is called Age of the Universe but only discusses the age in cosmology, but not in various religions and cultures. Should the name be changed to Age of the Universe in Cosmology, or maybe have a tag for where to find articles on the age of the universe in various cultures and religions. Basejumper2 12:47, 25 October 2007 (UTC)


 * [new section created]
 * Honestly, I think this is a good point. What are people who search for "age of the universe" likely to be looking for -- the best scientific answer, or a rundown of mythical cosmologies? It could be either one. And if it's the former then they could just look in the Universe article, while if it's the latter there's no obvious place to look but here. I think it would be more useful to move the present content into Universe and replace it with a brief summary and link to Universe followed by figures from Vedic cosmology, Bishop Ussher, etc. (though I don't feel too strongly either way). -- BenRG 13:41, 25 October 2007 (UTC)

I came to see a discussion on various theories of the age of the universe through time. I recall in school being told the age of the universe was 10-11 billion years, and that was only 15 years ago. I'd like to hear how it changed. I also want to know what Bushists think, and what evidence there was for it being infinitely old when that was the dominant belief. Basejumper2 06:07, 26 October 2007 (UTC)


 * I've added a disambiguation note at the top of the article. Currently it just directs readers to Creationism, where there are a couple of alternative ages given from various religions and mythologies. If anyone can think of another good top-level article than Creationism, it might be a good idea to add that in too. Sheffield Steel talkstalk 13:21, 26 October 2007 (UTC)


 * On reflection I've changed the link to point at Origin belief since that page is much wider in scope, hence less biased. Sheffield Steel talkstalk 19:25, 29 October 2007 (UTC)

Contradiction re WMAP-based age
Currently the section "Age based on WMAP" says the age based on WMAP data alone is 13.7 ± 0.2 Gyr, while "Assumption of strong priors" says it's 13.4 ± 0.3 Gyr. I could probably find the correct numbers by reading the WMAP report, but I'm hoping that someone with more direct knowledge of this stuff will do it. -- BenRG 23:19, 20 July 2007 (UTC)


 * Also, the grammar in the first paragraph of the "Assumption of strong priors" was confusing. I've edited this to make more sense (to me), but I may have removed some level of meaning that was not apparent to me.  A once-over by a pro (I'm only an oceanographer) wouldn't go amiss.  Cheers, --Plumbago 08:08, 3 August 2007 (UTC)


 * There's now no contradiction between the various ages quoted in the article. Accordingly, I'm removing the contradiction tag. Sheffield Steel talkersstalkers 19:06, 7 August 2007 (UTC)

CNO
This needs to be rewritten. Most of the references don't support the original point. Also, the issue of globular cluster ages needs to be more throughly outlined. Most globular models show ages that are more than the universe, but most people doing those models suspect that this is due to a lot of uncertainties in those models.

Roadrunner 23:08, 14 August 2007 (UTC)

Age based on CNO cycle
Some recent highly controversial studies found the carbon-nitrogen-oxygen cycle to be two times slower than previously believed, leading to the conclusion that (via the CNO cycle) the Universe could be about one billion years older (roughly 15 billion years old) than previous estimates.

The real age of the universe
the universe is 14 billion years old —Preceding unsigned comment added by 78.151.143.116 (talk) 19:46, 14 January 2008 (UTC)
 * Really? See Verifiability. Art LaPella (talk) 22:42, 14 January 2008 (UTC)
 * That's only one and a half standard deviations off the WMAP3 value - which is not crazy or anything. Wily D 22:44, 14 January 2008 (UTC)
 * The real question is why is this on the page and why is discussion continuing, when no changes to the page are suggested (or possible given the lack of sources). Anyone for just removing it?  WLU (talk) 23:02, 14 January 2008 (UTC)
 * It's not the end of the universe, (which apparently isn't coming at all), so we relaxed a little and let things slide. It's just not worth fussing over. Wily D  15:00, 15 January 2008 (UTC)

Assessment comment
Substituted at 20:13, 2 May 2016 (UTC)