Talk:Timeline of the early universe

You have an error in the acceleration time. That acceleration started 6.2 billion years ago, that is, 7.6 billion years after the Big Bang. [Note: Preceding unsigned comment added by 190.215.80.188 (talk) 12:32, 5 October 2015 (UTC)]Reply

FWIW - the above comment about the time the universe expansion began accelerating seems supported by astrophysicist Ethan Siegel "... about 7.8 billion years old, or about 6 billion years ago, some 1.5 billion years before our Solar System formed."^[1] - however, a note by astronomer Joshua Frieman at CalTech notes => "the Universe began accelerating at redshift z ~ 0.4 and age t ~ 10 Gyr."^[2] [Note: "9.4" Gyr? determined using a cosmological calculator.^[3]] - estimated time that expanding universe began accelerating may need clarification - comments from others welcome of course - in any case - Enjoy! :) Drbogdan (talk) 16:17, 1 April 2016 (UTC)Reply

BRIEF Followup: The "7.8 billion years old" age of the accelerating expanding universe seems to be supported by comments made on the following talk page => "User talk:I9Q79oL78KiL0QTFHgyc#HELP: Clarify Time Expanding Universe Accelerated?" - see copy below:

Copied from "User talk:I9Q79oL78KiL0QTFHgyc#HELP: Clarify Time Expanding Universe Accelerated?":

HELP: Clarify Time Expanding Universe Accelerated?

Hello Josh:

IF POSSIBLE => may need help to clarify the best known Time the expanding universe began accelerating - this refers to several Wikipedia pages including "Accelerating expansion of the universe", "Timeline of the formation of the Universe" and "Talk:Timeline of the formation of the Universe#Error in Acceleration time?" - Times presented on these pages (and related ones) seem to vary and include "7.8 billion years old"/astrophysicist ESiegel^[1]; "10 Gyr" (z ~ 0.4)/astronomer JAFrieman^[2]; "9.4 Gyr" (determined from z = 0.4 per Fermilab calculator)^[3]; perhaps other values as well - any help to clarify the Time the expanding universe began accelerating would be appreciated - in any case - Enjoy! :) Drbogdan (talk) 12:44, 2 April 2016 (UTC)

10 Gyrs is approximately right. It is going to occur at a redshift that solves the equation ${\displaystyle \Omega _{\Lambda }=\Omega _{m}(1+z)^{3}}$  Roughly, ${\displaystyle \Omega _{\Lambda }=0.7}$  and ${\displaystyle \Omega _{m}=0.3}$ , so it's actually closer to ${\displaystyle z=0.3}$  which I think puts it closer to the 7.8 billion year estimate. jps (talk) 13:15, 2 April 2016 (UTC)

@jps - Thank you *very much* for your comments - and clarifications - they're *greatly* appreciated - Thanks again - and - Enjoy! :) Drbogdan (talk) 13:21, 2 April 2016 (UTC)

In any case - Enjoy! :) Drbogdan (talk) 13:50, 2 April 2016 (UTC)Reply

  Done - corrected timing of "Accelerating universe" on the "Timeline of the formation of the Universe" article in the "Acceleration section" - to "7.8 billion years (6.0 Gya)" [ie, universe was 7.8 billion years old; 6.0 billion years ago from the present time] - should now be ok - please discuss if otherwise of course - in any regards - Enjoy! :) Drbogdan (talk) 17:04, 9 April 2016 (UTC)Reply

Is the {{Nature timeline}} (the new graphic next to The first second) really appropriate? In this article, time is view more logarithmically and extends long past the present. The graphic presents time linearly, backwards from present, which doesn't seem directly comparable to the text in question. Tarl.Neustaedter (talk) 22:56, 31 March 2016 (UTC)Reply

@Tarlneustaedter: Thank you for your comments - no problem whatsoever - *entirely* ok with me to rm/rv/mv/ce the edit of course - although comments from others first may be indicated - and helpful - should note that discussions re a very similar timeline ({{Life timeline}}) (at "Template talk:Life timeline") may also apply to the {{Nature timeline}} - esp the comments re the "reverse ordering" of the timeline - which may be entirely ok after all, according to some commenters (at "Template talk:Life timeline#Reverse order? Chronological?") (ie, the most recent rocks are at the top, not bottom, of a "geological stratum" - and may represent the best scientific convention of such ordering in the responsible literature) - in any case - hope this helps in some way - and - Enjoy! :) Drbogdan (talk) 23:42, 31 March 2016 (UTC)Reply

This page has two problems:

• it is a cfork of Chronology of the universe
• most of it is no longer about the "formation of the Universe" in the sense of physical cosmology. Of course, since everything is part of the universe, the formation of anything is technically part of the "formation of the universe". This is patently silly: "13.791 billion yrs (7.6 Mya): Betelgeuse forms" is no more relevant to the "formation of the universe" than would be "13.798999998 billion yrs (2 ya): World Trade Center is built". Such information belongs in a "list of stars", not a page on the big bang timeline.

--dab (𒁳) 20:14, 13 May 2016 (UTC)Reply

Chronology of the Universe doesn't have a timeline. If we merged this timeline with that article, it would just be unmerged again. Serendi^podous 20:25, 13 May 2016 (UTC)Reply

I agree with Dbachmann that putting a bunch of galaxies', stars', and planets' ages in this article feels unnecessary -- especially since they all have to be kept up to date as more research is done on each of those celestial objects, and on galaxy/star/planet formation ain general. What about just including the oldest known galaxy/quasar, star, and planet? 2601:441:4102:9010:6C02:87A4:248A:9E70 (talk) 21:05, 5 March 2017 (UTC)Reply

It's an exact match for what should be at the redirect page -->Epoch (cosmology) except for the lead section. It should be moved there and a lead written to suit. ~ R.T.G 00:21, 15 February 2019 (UTC)Reply

Hello! This is a note to let the editors of this article know that File:CMB Timeline300 no WMAP.jpg will be appearing as picture of the day on October 26, 2016. You can view and edit the POTD blurb at Template:POTD/2016-10-26. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. — Chris Woodrich (talk) 13:18, 14 October 2016 (UTC)Reply

The diagram at the beginning (today's picture of the day) says that "Big Bang Expansion" is 13.7 billion years. Wouldn't this just be the age of the universe, which, per information elsewhere in the article, would be about 13.8 billion years? John M Baker (talk) 02:01, 26 October 2016 (UTC)Reply

The picture might be a little bit out of date. 2601:441:4102:9010:6C02:87A4:248A:9E70 (talk) 20:50, 5 March 2017 (UTC)Reply

I'm confused why it matters that the early universe was of the right temperature for liquid water at some point. There wasn't enough oxygen for water to exist, nor enough silicon or other heavy elements to form rocks, nor enough carbon or nitrogen for any CNOH-water life to evolve. It isn't made clear why a habitable temperature would matter, or make that span of time Habitable. Today when we find gas giants in the habitable zones of their stars, we don't call them habitable because they don't have rocky surfaces and are mostly made of hydrogen -- just like the early universe. 2601:441:4102:9010:6C02:87A4:248A:9E70 (talk) 20:50, 5 March 2017 (UTC)Reply

Someone added it, citing an article that it's possible that life commenced that far back. I suspect it qualifies as WP:FRINGE, particularly since temperature isn't the only important variable, entropy matters too. Tarl N. (discuss) 00:18, 6 March 2017 (UTC)Reply

13.733 billion years (66 Mya): first mammals. - Is this line corect. I thought that it was 160 million years ago --Daduxing (talk) 07:21, 2 June 2017 (UTC)Reply

No, and it's also not relevant to the article. Removed. Serendi^podous 10:22, 2 June 2017 (UTC)Reply

It seems that the age of many stars mentioned in the timeline is wrong by orders of magnitude. Massive stars - like Mu Cephei, Beta Orionis, etc. - cannot be up to 10 GYr old. --Geheimrat Viper (talk • contribs) 22:14, 15 October 2017‎ (UTC)Reply

Hmm. Yeah, Mu Cephei is 10 million years old, not 10 billion years old. Lemme look at the timeline (sic) of those additions having been made. Tarl N. (discuss) 03:41, 16 October 2017 (UTC)Reply

I removed Rigel and Mu Cephei. They'd been there for years, I don't have the patience to track down who added them to see what else they did. Don't spot anything else as egregious as those two, if you spot anything else, fix it or mention it here. In general, I think the timeline is far too dense and could use at least an order of magnitude thinning down. Tarl N. (discuss) 03:52, 16 October 2017 (UTC)Reply

This article claims the Dark-Energy Dominated Era began at 7.8 Gy of cosmic time, without a citation. Elsewhere on the Wiki, the time is given as 9.8 Gy cosmic time, with a citation from 2006. I'm correcting this article by moving the Acceleration sub-headline to 9.8 Gy time. Until a source for the 7.8 Gy figure can be found that is more recent than 2006. 2601:441:467F:E7D2:D041:8BC2:333D:F4B0 (talk) 04:03, 14 June 2019 (UTC)Reply

In fact, I found a source from 2008 giving the figure 8.8 Gy cosmic time (5 Gya, z=0.5) and put the Acceleration there. 2601:441:467F:E7D2:D041:8BC2:333D:F4B0 (talk) 04:13, 14 June 2019 (UTC)Reply

Given that the article of events in the future is called "timeline of the far future", wouldnt it make more sense for this article to be called "timeline of the past"? — Preceding unsigned comment added by 47.227.192.150 (talk) 21:41, 14 October 2020 (UTC)Reply

Should we remove this? It's probabbly an error in conversion of scientific notation. Also Capella is 590–650 Million years old and is listed here as 8.08-8.58 billion years (5.718-5.218 Gya)Celestialobjects (talk) 03:30, 27 January 2021 (UTC)Reply

Yeah. Go ahead. Serendi^podous 04:40, 27 January 2021 (UTC)Reply

I stumbled on this page completely by chance, but I love it. What I kept thinking, though, was "how big was the universe when this or that thing was happening?" Could this be added, or would it mess up the structure of the article, or is it just impossible given current knowledge? This isn't my area of expertise, so I'm reluctant to add anything myself, but if another editor could make suitable changes that would be much appreciated. Thanks in advance. RomanSpa (talk) 18:38, 15 August 2021 (UTC)Reply

While yes, I know the current agreed-upon answer is 13.8 Billion yrs, but the JWST took pics of really young galaxies, that were basically fully formed really close to the big bang. Should we try changing the big bang time to 26.7 billion? or do we not have enough evidence for it? I guess you would need to recalculate the rest of the events to correspond with it Periodicpro18 (talk) 19:44, 26 July 2023 (UTC)Reply

The page Epoch (cosmology) redirects to this page, but this page does not define "epoch" for cosmology. As far as I can tell this entire article uses the word "epoch" as a synonym for "era" rather than as one specific time as would be correct of an Epoch. Johnjbarton (talk) 17:33, 16 August 2024 (UTC)Reply

• Epoch (astronomy): In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity.
  • The claim is referenced and verified.
• Ryden, B. (2016). Introduction to Cosmology (2nd ed.). Cambridge: Cambridge University Press.
  • Clearly uses the word as a synonym for "era", eg "During some epochs..."

Johnjbarton (talk) 17:52, 16 August 2024 (UTC)Reply