Talk:Timeline of the Big Bang

From Wikipedia, the free encyclopedia

WikiProject Physics This article is within the scope of WikiProject Physics, which collaborates on articles related to physics.
??? This article has not yet received a rating on the assessment scale. [FAQ]
??? This article has not yet received an importance rating within physics.

Help with this template Please rate this article, and then leave comments to explain the ratings and/or to identify its strengths and weaknesses.
This article is part of the History of Science WikiProject, an attempt to improve and organize the history of science content on Wikipedia. If you would like to participate, you can edit the article attached to this page, or visit the project page, where you can join the project and/or contribute to the discussion. You can also help with the History of Science Collaboration of the Month.
B This article has been rated as B-Class on the quality scale.
??? This article has not yet been assigned a rating on the importance scale.
Peer review This article had a peer review that has been archived It may contain ideas that you can use to improve this article.

Contents

[edit] Big Bang and entropy

As a non physicist, I would like to ask about the nature of entropy and the big bang. As entropy increases over time, one would assume that the Big Bang occurred in a condition of incredibly low entropy, and that the big bang itself is a situation of increasing entropy over time... My question is, how and when did this low entropy situation occur? The inflationary epoch? Before? Was it built into the vacuum fluctuation? How is it that the structures we have today have evolved in a situation of increasing entropy, whilst the lower entropy universe at the big bang was almost structureless, and, prior to inflation, almost completely chaotic? John D. Croft 00:25, 17 May 2007 (UTC)

[edit] Asking for a merge

[edit] Let's get 'er done

I wanna merge the articles. Let's get 'er done. -- Zalasur 07:23, Mar 23, 2005 (UTC)

I think it's worthwhile having one article covering the timeline of the universe from the Big bang up to now, and having a separate article that summarizes this material and also includes projections about the future of the universe. Personally, I oppose the proposed merger for this reason. --Eric Forste 04:25, 12 Jun 2005 (UTC)

[edit] bigbangisdeliciouscosito

I'm not sure who is more confused. The person asking the question or the person answering the question.

[edit] External Link

Should we rename this page: "timeline of the early universe"?

you have my vote. -- looxix 10:02 Apr 11, 2003 (UTC)
Me too -Lethe | Talk
Me three -John D. Croft 12:12, 28 August 2007 (UTC)

[edit] CP violation

I'm curious. In the periods where quarks/antiquarks and electrons/positrons were annhiliated, was the excess possibly caused by change-parity violation? And if this is so, doesn't this suggest that even these are made of even smaller particles, because for the cp effect to occur, the particles mustn't be assymetric?

Sorry man but Who Knows???? Skeletor 0 (talk) 17:14, 15 April 2008 (UTC)

I have seen it suggested that the CP Symmetry violation needs Time to be factored in to give it Symmetry. CPT Symmetry then would have been the situation before the plank era, and CP violation would have led to the creation of time itself, with a specific arrow from past to future! Anyone with more information there whocan help? John D. Croft (talk) 23:56, 15 May 2008 (UTC)

[edit] 10-48 seconds?

Hi, does anyone have an idea where the 10-48 mentioned on this slide of a presentation titled "A Timeline of the Universe" come from? (http://astro.uchicago.edu/home/web/mohr/Compton/HTML_five/sld022.html) -- Schnee 14:40, 9 Jun 2004 (UTC)

A typo? Given that it is about 5 orders of magnitude smaller than the Planck time there's little else it could be! Dazza79 (talk) 00:20, 24 February 2008 (UTC)

[edit] Grand Unification Epoch expansion factor?

Should the " cm" be removed from this sentence? It reads as if it was 10^10 cm and expanded by a factor of 10^20 to result in a size of 10^30, which is too large, surely.

:For the period of time between 10-35 seconds and 10-33 seconds, it is believed that the size of the universe expands by a factor of approximately 1020 to 1030 cm.

Also about the quark-annihilations, should this instead read "resulting in one quark remaining for every billion matter-antimatter interactions?"

:Birth of quarks, which appear in particle-antiparticle pairs. Quarks and anti-quarks annihilate each other to create photons, but quarks are created at a ratio of approximately 109 (1 billion) anti-quarks to 109+1 (1,000,000,001) quarks, resulting in one quark per billion matter-antimatter interactions. Free quarks multiply rapidly. -Wikibob | Talk 14:37, 2004 Jun 25 (UTC)


[edit] i'm pretty sure the currently observable universe is larger than the Planck length

This sentence: "The diameter of the currently observable universe is theorized as 10-33 cm which is known as the Planck length." seems to me to be at best very badly worded, and possibly even wrong. I was going to change it to something like "The diameter of the currently observable universe would have been only 10-33 cm at the end of the Planck time. This distance is known as the Planck length". But is that even true? Might not current the size of a "Planck volume" from the Big Bang depend on the details of the inflationary period and the age of the universe? -Lethe | Talk

[edit] This isn't true

Quote. Imagine a block of ice and an aluminium Coca-Cola can. If you increase the temperature to an extremely high value, then both objects will vaporize, producing a mixture of water and aluminium vapor which can be considered a single entity. If the temperature decreases, then below a certain value the aluminium will condense and freeze and stop interacting with the water vapor. Unquote.

Water and aluminum raised to a temperature that both vaporize becomes a mixture of aluminum, hydrogen, oxygen, and various ions and is part plasma (gas heated to the point that electrons break free creating ions), part gas. When the temperature is decreased, aluminum OXIDE, water, hydrogen peroxide, and hydrogen gas will condense and freeze out of the mixture.

Perhaps "Imaginine a block of a and b" where a and b are elements and don't chemically react at gas temperatures. argon and gold may do the job if they start as frozen, and then heated, and then frozen back again.202.156.2.36 12:17, 24 May 2005 (UTC)

Remember to be bold, dude: if you see something you know is wrong, change it. I fixed it. --Superiority 05:06, 7 November 2005 (UTC)

[edit] Should we merge this with Timeline of the Universe?

At first I was hesitant to merge the two articles together but now I belive the two should be merged. Any thoughts?

See my reply to Zalasur above. --Eric Forste 04:30, 12 Jun 2005 (UTC)


[edit] Should we merge this with Timeline of the Universe?

We should merge them cause the Timeline of the Universe is very low on info on the early seconds of the big bang. Timeline of the Universe might have to be expanded even more.

I agree that information from Timeline of the Big Bang about the early seconds ought to be summarized in Timeline of the Universe, but I think that two articles ought to remain, after this process is done. I'll work on summarizing early data from Timeline of the Big Bang in Timeline of the Universe if you don't merge them. --Eric Forste 04:51, 12 Jun 2005 (UTC)
I do not think the articles should be merged. There should be a summary in ...Universe linking to ...Big Bang. Firstly, there is much to talk about in respect to the Big Bang (as can be seen with the size of the article) and I think merging would just clutter things up and diffuse the subject matter. Secondly, while I subscribe to the Big Bang theory it is still under development, and any subsequent changes would be better applied to the smaller article than the large one. Mr. Brownstone 15:16, 30 July 2005 (UTC)

[edit] Logarithmic version

Over at Logarithmic timeline someone suggested a reverse log timeline could be applied to the Big Bang, so I genned up a first draft (improvements welcome).--robotwisdom 2 July 2005 01:46 (UTC)

[edit] I think this is a mistake with this page

The page currently says: "For the period of time between 10-35 seconds and 10-33 seconds, it is believed that the size of the universe expands to a size of approximately 10-32 m to 10-22 m."

Shouldn't it be "10-32 m 10+22 m"? I have two astronomy texts which say it increased by a factor of 1050. I would fix it, but I'd like input to make sure I'm right first.

[edit] Mixed up epochs

It says, "The Epoch of Nucleosynthesis covers the time from 3 minutes to 379,000 years after the Big Bang." But if you click Nucleosynthesis (piped to Big Bang nucleosynthesis) it says "It only lasted for about three minutes". This is a contradiction. I think it only lasted 3 minutes, but in that case your other epochs need to slide over to make room, or else some epoch has two names or something. Art LaPella 23:10, 29 September 2005 (UTC)

You're tight. BBN stopped at +3min. At 400.000 the universe became transparent and CMB decoupled from matter. I'll fix it tomorrow, if novody was faster. --Pjacobi

There's another paradox in this section, "At this point the universe consists of about 75% hydrogen, 25% helium and trace amounts of deuterium, lithium, beryllium, and boron", so 3 minutes after the big bang BBN is finished and we have all of the abundant light elements formed.... but then... "379,000 years after the Big Bang: The temperature of the Universe is approximately 3000 kelvins. At this temperature hydrogen nuclei capture electrons to form stable atoms."

How can the universe consist of atoms before atoms exist? Maybe it should be specified that the universe consists of isotopes or nuclei of 75% hydrogen, 25% helium, etc. --Akira-no-Baka

It says "hydrogen, ... helium ... deuterium" etc., but it doesn't say atoms, just as the Sun article mentions hydrogen, helium, oxygen etc. but not atoms. At that temperature the universe would be a plasma of independent nuclei and electrons. According to atom: "Atoms are canonically distinguished from ions by their balanced electrical charge.", that is, nuclei in a plasma aren't atoms. Perhaps the semantics is debatable, but that's what it means. Yes, it would be helpful to add the word "nuclei" or "plasma", as part of the bigger rewrite discussed above. Art LaPella 21:17, 21 October 2005 (UTC)

[edit] Mixed up epochs unscrambled

I couldn't get the professional scientists to fix this, so here I go without you. My version could easily be improved. However, I'm confident my version is better than what was there before, as described above.

The temperature estimates kept conflicting, so I removed many of them rather that guess. Similarly, I removed the estimate of the size of inflation, as I could find no consensus for that figure elsewhere. And I removed the sentence that claimed hydrogen nuclei formed after 1 second, because a hydrogen nucleus is a proton, and it says protons and other hadrons formed earlier. Other sources seem to agree with the earlier time.

I often relied on [1] to help unconfuse this page.

Timeline of the universe has similar problems. First let's see how this change turns out. Art LaPella 23:19, 29 October 2005 (UTC)

[edit] timeline???

Um...I was kinda hoping to see an actuall timeline here....do you think you could make one? -Dr. Cribbit (message made by editing the page.)

Does that mean me in particular? If you mean an actual graphical line, no I don't have much experience with graphics. If you don't, I'm not sure what else you would want. Art LaPella 04:39, 2 November 2005 (UTC)

Cribbit: I mean anyone. And by geographical, I'm assuming you the type of timeline that's a stright line and there are notches on it with times and events and stuff? That was kinda what I'm looking for...

Yes! I was expecting a timeline too. I was looking to compare with Timeline of Motorized bicycle history --CyclePat 20:14, 26 November 2005 (UTC)
I'm missing something. That bicycle timeline has neither a straight line with notches, nor graphics. It looks like this timeline, but without the pictures. Art LaPella 00:13, 27 November 2005 (UTC)
Opps! Maybe I should have read a little about the article first. I was just looking at overal format. How was I to know that somewhere in the text (13.7 ± 0.2) x 109 was the year or some sort of indication of time. This article seems to have much more text information. Sorry. --CyclePat 03:17, 27 November 2005 (UTC)
Maybe this kind of confusion could have been prevented by making the Big Bang itself part of the timeline that starts at "The Big Bang and matter formation". That is, the paragraph preceding "The Big Bang and matter formation" should be the first event, dated at 13.7 billion years ago, followed by the Planck epoch a split-second later. Art LaPella 17:17, 27 November 2005 (UTC)

[edit] cleanup

I've been trying to clean this article up. It was in pretty sorry shape before. Some information in the previous article was wrong, or at least poorly worded, but a lot of it I've omitted out of laziness/limited time. If some interested parties could compare the present version to this version and put pertinent, credible seeming information back in, it would be appreciated. Otherwise, I'm sure I'll get to it... sometime. –Joke 00:30, 30 January 2006 (UTC)

I couldn't fix this sentence: "It is not known how inflation During inflation..." Some words were apparently lost before the word "During", but I can't guess what the words were. Art LaPella 05:11, 31 January 2006 (UTC)

[edit] Recombination

I think the era of recombination could be explained better here if you make some mention of Hydrogen atoms and perhaps the Bohr model.

If my understanding is correct, before "recombination" the protons and electrons were separate, and after "recombination" the protons and electrons form Hydrogen atoms.

When light of any frequency passes through a gas of free protons and electrons, it is all absorbed; because the motion of the electrons and protons is not quantized, it can absorb light of any frequency.

Once the electron gets into the quantum shells of the proton and the electron/proton pairs form hydrogen atoms, the electrons can then only absorb light which has a frequency high enough to move the electron out of the 1s Bohr orbital.

If light has to pass through layer after layer of Hydrogen gas, eventually all of it will be absorbed except for the light that has a low enough frequency that it does not knock the electron out of the 1s orbital.

The light that is not absorbed has a maximum frequency the same as as blackbody radiation of a surface of about 3000 K. Whether the observed 3 Kelvin of the Cosmic Background is due to a doppler effect and recession velocity, or whether it is due to some expansion of space having some effect on the wavelength seems to still be some controversy.

Also, it should be pointed out that this phenomena may actually describe a "first" combination of electrons and protons into hydrogen atoms, unless you have a steady-state or cyclic model of the universe. I think the term "recombination" comes from studies of chemistry where experiments separate the particles, then let them recombine. In Big Bang theory, the "re" does not really apply.JDoolin 16:55, 27 August 2006 (UTC)

[edit] Just Pondering

Wouldn't it be horrible if a vacuum metastability disaster occured while you were in the restroom? What if the last thing you did was use the toilet? Think of that next time you're on the john. Cissel 22:10, 18 September 2006 (UTC)

[edit] Confusion about structure: baryogenesis

Baryogenesis is described to in the "very early universe" section. Later it is described in the Quark-Hadron phase of the "early universe" section. I think this article needs more consistent structure.

Ordinary Person 06:49, 21 November 2006 (UTC)

[edit] Mixed up epochs (redux)

I notice there are several inconsistencies between the early universe epoch times in this article, in Graphical timeline of the Big Bang and in the individual epoch articles. For example, this article says the hadron epoch was 10-6s to 10-2s; Graphical timeline of the Big Bang says 10-12s to 10-6s; and hadron epoch says 10-6s to 1s. Does anyone mind if I try to tidy up these inconsistencies, and maybe add some references at the same time ? Gandalf61 17:24, 3 February 2007 (UTC)

Okay, this is what I propose as a consistent timeline for the early universe as far as the origin of the cosmic microwave background, and a nomenclature for the various phases:
  • 10-43s : Gravity separates from other forces
  • 10-32s : Inflation ends; quark-gluon plasma created by reheating
  • 10-12s : Weak force separates from other forces; W and Z bosons no longer created; weak force becomes short range force
  • 10-6s : Quarks become confined in hadrons
  • Hadron epoch : 10-6s to 1s - as temperature falls, new hadron-antihadron pairs no longer created; general annihilation of hadron-antihadron pairs; remaining heavier hadrons decay leaving only protons and neutrons
  • 1s : Neutrinos cease to interact with other particles due to falling density
  • 3s : Electron-position pairs no longer created; general annihilation of electron-positron pairs leaving one electron per proton; universe now dominated by photons
  • 300,000380,000 years : electrons and nuclei combine to form atoms in recombination; photons no longer react significantly with matter; universe is transparent to photons; origin of cosmic microwave background
There is a lot of consistency from different sources over the milestones and their times; much less consistency over the naming of the epochs/eras. For the milestone times I have generally followed Allday Quarks, Leptons and the Big Bang, except for the milestone where quarks become confined in hadrons, which I have taken from Gribbin The Universe: A Biography. Things I have left out are:
  • Baryogenesis : there seems to be no clear consensus on whether the asymmetry between matter and anti-matter originated in the "grand unification epoch" or the "electroweak epoch".
  • "Inflation epoch" : I haven't used this term because there does not seem to be a clear consensus on when exactly inflation ends, although it must be sometime in the electroweak epoch.
  • "Nucleosynthesis epoch" : I haven't used this term because this epoch would have to be placed inside the "photon epoch", creating the problem of what to call the interval between the end of the "lepton epoch" at 3s and the start of nucleosynthesis at 100s.
Feedback is very welcome. If there are no big objections then I will start making this article, the Graphical timeline of the Big Bang, and the various epoch articles consistent with this timeline. Gandalf61 12:28, 4 February 2007 (UTC)
Had further thoughts. Reinstated inflationary epoch in my proposed timeline - see above. Gandalf61 17:37, 6 February 2007 (UTC)
Have updated individual epoch articles and Graphical timeline of the Big Bang. Will update this article next. Gandalf61 12:00, 18 February 2007 (UTC)
There really is no "hadron epoch". When hadrons form out of the quark-gluon plasma, their rest mass is already much larger than kT, so annihilations are not replenished by pair-creation events. Immediately after the end of the Q-G plasma the available particles are photons, neutrinos, electrons, muons and the light mesons (+ antiparticles). It is probably fair to "date" the lepton epoch from this point. I'd update myself, but don't know how to adjust the graphics! PaddyLeahy 22:22, 16 May 2007 (UTC)

[edit] Formation of the Universe (Intro)

The sentence before last of the introduction :"Finally, the epoch of structure formation began ,[...], superclusters formed." This presents the predictions made by the "bottom-up" theory. There is also, I am sure amongst yet others, the "top-down" theory that says the highest order organisation (super clusters and clusters) formed first, and THEN working downwards the rest formed (galaxies, then stars, etc...)

Presenting one view of things is good, please present others, or let the reader know this is ONE theory on which there is no scientific consensus. 132.149.107.65 13:10, 12 July 2007 (UTC)

There are many theories, as plasma cosmologists and creationists often remind us, but which ones should be mentioned without violating WP:Undue weight? I found many Internet articles on Hawking and Hartog's theory, but I couldn't find anything on Wikipedia except Cosmic variance and Flexiverse, neither of which says superclusters came before galaxies and stars. Just how popular is this theory if it doesn't even have its own article? Art LaPella 21:21, 12 July 2007 (UTC)

[edit] Nucleosynthesis

RE: At this time, there are about three times more hydrogen ions than helium-4 nuclei.

This is a subtle mis-statement. At the end of the nucleosythesis period, Helium nuclei (almost all He4 and the tiniest amount of He3), account for approximately 25% of the MASS of ordinary matter in the universe - excluding the left over supersymmetric matter.

This proportion is well known. It can be directly observd in various ways, because the proportion of different nuclei only changes in the interior of stars,and in gas clouds ejected by previous generations of stars within galaxies. Everywhere else, the proportion remains almost the same, only disturbed by antiprotons from the decay of the lightest supersymmetric particle. (A topic on which I published a Physical Review Letter with John Hagelin and his student in 1989).

Because most of the hydrogen is in the form of protons, H1, and very little as deuterons, H2 deuterium nuclei, the statement above would mean that the total mass of Helium nuclei (alpha particles) would be 33% more than the total mass of protons (Hydrogen nuclei)!

The sentence would be better rewritten as:

At this time, there are approximately three times more hydrogen ions by mass than helium-4.

Alex Hankey, Physicist

[edit] Grammar

Timeline of the Big Bang#String Theory epoch says: "According to Maldacena's conjecture, has a counterpart from the ten-dimensional interior on the fourth dimensional surface." I leave the scientific merit of this sentence to the scientists here, but grammatically the sentence is incomplete without a subject (grammar). What "has a counterpart..."? Art LaPella 20:48, 24 July 2007 (UTC)

Resolved. Art LaPella 02:26, 26 July 2007 (UTC)

[edit] Units of time

The usage of billions and trillions of years in this article is problematic given the long and short scales. I'd prefer replacement with the SI units (gigaannum or teraannum respectively, abbreviated Ga or Ta).LeadSongDog 22:07, 25 July 2007 (UTC)

[edit] Discussing the Discussion?

This discussion would become much more profitable if it were separated into Discussion About the Topic vs. Discussion About the Article.

Even without the discussed changes to the subject matter, the article needs fixing. As of 20070821, there is far too much switching back and forth of verb tenses, to the point of ambiguity and confusion.

rowley 18:05, 21 August 2007 (UTC)

Wikipedia:Talk page guidelines states: "Talk pages are for discussing the article, not for general conversation about the article's subject", although in practice Discussion About the Article can depend on some Discussion About the Topic as long as we remember what the goal is. Although I haven't changed the verb tenses, I agree it would be clearer to describe the Big Bang and its sub-events in the past tense. Art LaPella 20:43, 21 August 2007 (UTC)
Either most or all of your new heading capitalizations should be reverted, according to Wikipedia:Manual of Style (headings)#Capitalization. Art LaPella 20:51, 21 August 2007 (UTC)
Yes, I thought so too, so I've reverted the capitalisations. Gandalf61 10:53, 22 August 2007 (UTC)


[edit] Umm....

May I ask who came up iwth 1 trillion years for heat death of the universe? I knwo full well where the 100 trillion came from.(Doctor Who, for those who don't know) 82.12.86.64 21:19, 26 August 2007 (UTC)

[edit] RFC - Timings need careful expert checking

The timings as cited in this article, and Big Bang nucleosynthesis need careful checking by a physicist.

For example, we are told in this article that:

  • "Nucleosynthesis: Between 100 seconds and 300 seconds after the Big Bang"

and also:

  • "nucleosynthesis only lasts for about three minutes"

which are fairly consistent (but could be more accurate).

But in Big Bang nucleosynthesis we are told:

  • "There are two important characteristics of Big Bang nucleosynthesis (BBN): 1/ It lasted for only about seventeen minutes (during the period from 3 to about 20 minutes from the beginning of space expansion) ..."

This suggests the timeline, and mentions of all timings in the related sub-articles, need checking. FT2 (Talk | email) 00:00, 6 September 2007 (UTC)

Big Bang nucleosynthesis was not a single event. It was a series of linked atomic reactions which took place at different rates over a period of time - a detailed list of these reactions is given here. Different authors locate the start and end of nucleosynthesis at different times. The start of nucloesynthesis is typically set at 100 seconds because this was when the universe was cool enough to allow deuterium nuclei to form. The end of nucleosynthesis is more difficult to fix because the process didn't just stop - reaction rates slowed down as the universe expanded and cooled. It's like trying to fix the exact time at which you fall asleep. 300 seconds is quoted here, but this source puts the end of nucleosynthesis as late as 35 minutes ! It would be inapproriate to explain all these complications in a summary timeline article, so "between 100 second and 300 seconds" is a simplied timescale. Gandalf61 13:25, 6 September 2007 (UTC)
True, but would it be inappropriate to summarize the above as something like "on the order of 100 to 300 seconds", thus relieving the contradiction? Art LaPella 20:14, 6 September 2007 (UTC)

[edit] Ultimate fate of the Universe

The latest edit was inadvertently saved. My latest version would have been:

There are several speculations, theories about the ultimate fate of the universe. The term is widely used, although in fact it does not mean ultimate fate which would imply an END. The speculation is primarily about the question of whether it will have an END, and then What will its end be IF it will have one. The corollary heretic question is whether the Big Bang was a real beginning of space-time, or something already existed before it? Where did matter/energy come from to accumulate into a singularity at the time of the big Bang? These are two questions that we find hard even to contemplate.
I shall leave any alteration to another editor. LouisBB (talk) 22:09, 30 January 2008 (UTC)

[edit] Grand unification epoch

Before I was sidetracked I came here to find out: Why do we call the above 'Grand Unification epoch, when the gravitational interaction was already separating, and why only ends when the strong nuclear force separates from the electroweek force? LouisBB (talk) 22:32, 30 January 2008 (UTC)

The name comes from grand unification theory, which is the standard name in physics for a theory that unifies the electromagnetic, weak nuclear and strong nuclear forces. A theory that also attempts to unify the gravitational force is known as a theory of everything or ToE. Gandalf61 (talk) 00:18, 1 February 2008 (UTC)
Thanks Gandalf61. It is clear enough, when it is explained. Unfortunately the name confuses the uninitiated as it gives the impression that forces unify in this epoch.
Having just been loking at the Graphical timeline of the Big Bang article and some of the earlier discussions here I was surprised to see, that your suggestions of last february have not materialised. I am referring to separation of the individual interactions/forces from the others, as I always understood thet the individual fundamental forces supposed to have separated from all others. The abbreviated reference to the forces, such as week force, strong force could also confuse. Would it take much space to use consistently full names? Sorry about the nitpicking, but I am translating the graph and I want to be right. LouisBB (talk) 22:30, 3 February 2008 (UTC)

[edit] Wikipedia's CNB article says neutrino decoupling occured 2 seconds after Big Bang

This article says one second in the hadron epoch section —Preceding unsigned comment added by 72.65.170.104 (talk) 21:41, 26 February 2008 (UTC)

[edit] Someone keeps changing my corrections

The grand unification epoch did not occur between 10^-43 seconds and 10^-35 seconds after the Big Bang It ended 10^-36. And the electroweak epoch did not occur between 10^-32 seconds and 10^-12 seconds after the Big Bang. It began at 10^-36 when the Grand unification epoch ended. My source is Introduction to Cosmology by Barbara Ryden, which is an upper level college textbook. What do people think I'm just making these changes for fun?

AGAIN someone deleted by corrections. The electroweak epoch didn't "merge electromagnetism and the weak interaction into a single electroweak interaction." They were already unified in the Grand Unified epoch and earlier in the Planck epoch. The strong force just separated from the electroweak force. It became stronger. (I have the same source as above to support this) It even says this earlier in the article! What is the point of correcting these articles if people just delete your corrections? i thought this was supposed to be an encyclopedia anyone correct! —Preceding unsigned comment added by 72.65.170.104 (talk) 04:06, 27 February 2008 (UTC)

I'm not a scientist, but if your source is Introduction to Cosmology by Barbara Ryden, you would have gotten a more serious answer if you had included your source in your WP:edit summary, and/or named the book in a WP:reference. If you WP:Cite your sources, you're more likely to at least get a debate on whether your sources are good enough. Art LaPella (talk) 05:13, 27 February 2008 (UTC)
I dont understand big bang theory myself but I do understand wikipedia theory. Please give us something we can verify, ideally through reliable sources. Thanks,

SqueakBox 05:17, 27 February 2008 (UTC)

Introduction to Cosmology by Barbara Ryden is a very reliable source published in 2003. Like I said it is an upper level college textbook used at Brown university where I attend, and sometimes teach. The corrections I made about the times of the epochs comes from the bottom of page 196.

And the other correction I made about the electroweak epoch is extremely obvious. This wikipedia article contradicts itself. In the Grand unification epoch section it says "Eventually, the grand unification is broken as the strong nuclear force separates from the electroweak force." It became stronger than the electroweak force. The electroweak force (electromagnetism and the weak force) were already unified in the Grand Unified epoch and earlier in the Planck epoch. But in the electroweak epoch section it says that electromagnetism and the weak force unified, which is ridiculous. Also the link to the "the dark ages" is for the period in mid-evil history, not a link for the time before recombination and decoupling, possibly because there is no such article, so I'm going to delete that link. Someone should make a Dark ages (cosmology) page though.

I suggest resubmitting your change, but citing your source this time, preferably as described at Wikipedia:Citing sources. If you have no citable source for the second change, you could at least use an WP:edit summary referring to this talk section Talk:Timeline of the Big Bang#Someone keeps changing my corrections. I wouldn't WP:revert (undo) such a change, and I'm pretty sure SqueakBox wouldn't either. I won't speak for the scientists here, but I'm pretty sure they would either accept the change, or at least give you a good explanation why not. We just need to distinguish you from adolescents playing with the article for the hell of it. Wikipedia:Registering would also be helpful, after which you could describe yourself on your Wikipedia:User page. Art LaPella (talk) 22:31, 27 February 2008 (UTC)
The problem now is that the epochs are no longer consecutive. The grand unification epoch is "Between 10-43 seconds and 10-36 seconds after the Big Bang", the inflationary epoch is "Between 10-35 seconds and 10-32 seconds after the Big Bang", and the electroweak epoch is "Between 10-36 seconds and 10-12 seconds after the Big Bang". Also, the supporting articles grand unification epoch and electroweak epoch no longer match this article. Art LaPella (talk) 21:47, 28 February 2008 (UTC)

Well I can easily put the electroweak epoch first, but it does overlap with the inflationary epoch.

I see that the times in the separate articles no longer match this article, but the sources aren't listed with page numbers in those articles, so it's not to easy to check. I can consult some other professors at Brown. Or you could find out who listed those sources and ask them if they can find a page number that supports the times they listed. —Preceding unsigned comment added by 72.65.160.182 (talk) 04:36, 29 February 2008 (UTC)

I found that the person who listed those sources was User:Gandalf61. I invited him to comment here; see User talk:Gandalf61#Timeline of the Big Bang. Here are links to Gandalf61's edits: [2] [3] Art LaPella (talk) 05:59, 29 February 2008 (UTC)
  1. Inflation has to start when the grand unification epoch ends because it is the phase transition at the end of this epoch that triggers inflation. Whether we put this at 10-35 or 10-36 seconds does not greatly matter to me - there are no doubt reliable sources for both figures. Important thing is that we should be consistent, and not imply that there was some unexplained gap between the two events.
  2. Whether you count the inflationary epoch as being part of the electroweak epoch or as a separate stage preceding the electroweak epoch is a trivial matter of terminology. Personally, I like the simplicity of a conceptual model in which the epochs are sequential, and do not overlap, but I wouldn't fight an edit war over it.
  3. Important considerations for anyone making changes here is (a) give sources (as already said); (b) make sure that there is consistency between this article, the individual epoch articles and the Graphical timeline of the Big Bang - at present they are not consistent. Gandalf61 (talk) 08:18, 29 February 2008 (UTC)
As I suspected, sources differ on both the start and end times of the inflationary period. I have:
10-36 seconds to 10-34seconds (Liddle An Introduction to Modern Cosmology p107)
10-36 seconds to 10-32seconds [4]
10-35 seconds to 10-33seconds [5]
10-35 seconds to 10-32seconds (Allday Quarks, Leptons and the Big Bang p335; Gribbin The Universe: A Biography p49)
As I said, I don't feel strongly about which set of times we use, as long as we are consistent. To make things consistent for the time being I have changed the start of the inflationary period to 10-36 seconds in this article, in the Inflationary epoch article and in the graphical timeline. Gandalf61 (talk) 17:08, 1 March 2008 (UTC)

I didn't actually edit the inflationary epoch. I just edited the the grand unification epoch and electroweak epoch. I see what you're saying about it being simpler to have the electroweak epoch and the inflationary epoch separate, but if they did overlap we can't change it just for simplicity's sake. I think we should move the electroweak epoch into the very early universe section. But if we do this should the electroweak epoch come first or the inflationary epoch? Or should we combine them into the inflationary/electroweak epoch and of course list the separate times of their duration? —Preceding unsigned comment added by CosmologyProfessor (talk • contribs) 05:18, March 2, 2008

Read my point (1) above. The start of the inflationary epoch has to coincide with the end of the grand unification epoch because the phase transition at this time is what triggers inflation. When you moved the end of the grand unification epoch, you should have moved the start of the inflationary epoch for consistency. But you didn't, so I sorted it out for you.
As for your second point, if you want to say that the electroweak epoch extends all the way from the separation of the strong force to the separation of the weak force, then inflation occurs during the first part of the electroweak epoch - neither one comes first, because they overlap. As you have created the overlap, I will leave you to decide how best to explain it.
The distinction between the Very early universe section and the Early universe section is that the physics of the Early universe section, after the end of inflation and baryogenesis, is well understood, whereas the physics of the Very early universe section is still, to some extent, speculative. Your enlarged electroweak epoch straddles the boundary - physics is well understood at the end of it, but not at the beginning. This was another reason for making a distinction between the inflationary epoch and the original, shorter electroweak epoch. Again, I leave to you to decide how best to handle your new longer electroweak epoch. Gandalf61 (talk) 09:53, 2 March 2008 (UTC)

[edit] Reason for problem

Hi guys, I just want to suggest that the reason why this article is giving you so much trouble is because you are trying to merge several different incompatble theories. Just a heads up.Skeletor 0 (talk) 16:43, 15 April 2008 (UTC)

That's a bit cryptic. Which theories would they be, and in what way do you think they are incompatible ? Gandalf61 (talk) 16:41, 15 April 2008 (UTC)

Hold on one sec I gotta change computers. Back in a min. Skeletor 0 (talk) 16:44, 15 April 2008 (UTC)

Ok I'm back and I thought that maybe it not a problem but it's certainly a source of confusion. You have string theory and super symmetry which are not anywhere near each other. String is almost the opposite of super symmetry. I see how you are trying to explain all the theories but it is very confusing. Skeletor 0 (talk) 17:08, 15 April 2008 (UTC)

The article is using string theory as shorthand for the more precise description superstring theory, which does indeed incorporate supersymmetry. However, I agree that the "string theory epoch" section is misplaced - the period it refers to, when the universe is filled with a quark-gluon plasma, occurs much later, after inflation and reheating. Also the term "string theory epoch" is not a standard term in cosmology and seems to be a Wikipedia neologism. Easiest way to fix this is to remove the whole "string theory epoch" section, which I will do now. Gandalf61 (talk) 08:23, 16 April 2008 (UTC)

Glad I could help and sorry if I was a bit rude. Skeletor 0 (talk) 16:56, 17 April 2008 (UTC)

[edit] General Dismissiveness

This article has a lot of excellent information. But here and there is included a statement of general dismissiveness that, while perhaps technically supportable, goes a bit overboard in my view.

Here is just an example:

"However, as of yet there have been no observed Population III stars which leaves star formation a mystery."

Partially correct -- no Pop III stars have been observed, but that doesn't mean star formation is some complete "mystery." Just read Extreme Stars, At the Edge of Creation [2001] by James Kaler to get some idea of much we do know about star formation and evolution. It's true Pop III stars aren't exactly "pinned down" in all their specifics, but surely they are constrained in their possibilities. I seriously doubt that the failure to observe any means their existence is in question. Obviously that failure is more due to the fact that this population of stars resides somewhere in a neighborhood that is 13 billion years away. It's hard enough seeing entire galaxies 11 and 12 billion years distant.

Notice any other examples that I might be talking about?

DCCougar (talk) 00:29, 21 April 2008 (UTC)

Yes I see what you mean, (nice catch by the way!) I don't know why this statment is in the article. We actually know alot about star formation. In fact I just had to do a school project on it so I know we know alot. What I think the statment is trying to say is that we dpn't know a lot about population III star foemation but I don't get that either. Star formation back them would not have been much different. in fact it would have only been faster. The citation used is three years out of date and should no longer be counted. Never the less I have only changed it to "However, as of yet there have been no observed Population III stars which leaves their formation a mystery.[7]"

I could not find a citation to back me up but I know that more is known about pop III stars then the article lets on. Skeletor 0 (talk) 18:01, 23 April 2008 (UTC)

[edit] An Error

The article seems to suggest that the inflationary era was after the Planck Era, and after Supersymmetry. I was of the belief that it occurred before the Planck Era, and that it was the "energy dumping" that occurred at the end of the inflationary period that filled the universe with matter. This would imply that it came first. Should we shift the order and ammend the figures to reflect this? John D. Croft (talk) 23:56, 15 May 2008 (UTC)

The linked articles Planck epoch and inflationary epoch each contain several references which confirm the times and order of events in the timeline article. Do you have sources that support your alternative view that inflation occured before the Planck epoch ? If not, then I think the article should be left as it stands. Gandalf61 (talk) 00:07, 16 May 2008 (UTC)

[edit] http://discovermagazine.com/2006/jan/physics

This source states that the Universe in 10^-6 seconds was a symmetrical non-causal liquid, should this fact be added? —Preceding unsigned comment added by 24.22.111.99 (talk) 22:38, 17 May 2008 (UTC)