Talk:Chronology of the universe/Archive 2

Archive 1

Archive 2

Temperature

There is very little info about the temperature of the Universe during the various epochs. — Preceding unsigned comment added by 174.88.8.190 (talk) 21:31, 17 October 2014 (UTC)

Capitalization of universe

There is currently a discussion about the capitalization of Universe at Wikipedia talk:Manual of Style/Capital letters § Capitalization of universe. Please feel free to comment there. —sroc 💬 13:15, 19 January 2015 (UTC)

Discussion of capitalization of universe

There is request for comment about capitalization of the word universe at Wikipedia talk:Manual of Style/Capital letters#Capitalization of universe - request for comment. Please participate. SchreiberBike talk 00:31, 4 February 2015 (UTC)

Notification of request for comment

An RfC has been commenced at MOSCAPS Request for comment - Capitalise universe.

Cinderella157 (talk) 03:23, 22 March 2015 (UTC)

Fate of the Solar system

Pardon me but shouldn't this:- "the core of the Sun will become hot enough to trigger hydrogen fusion in its surrounding shell" say "the core of the Sun will become hot and dense enough to trigger helium fusion with hydrogen fusion continuing in its surrounding shell" ? — Preceding unsigned comment added by Ianchristie (talk • contribs) 03:22, 27 March 2015 (UTC)

https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#Stars

Hello can you view the entitled link please and let me know your thoughts. I'm kind of stuck in order to grasp the article as a whole... Regards. -- Space Ghost (talk) 06:25, 28 June 2015 (UTC)

The universe started ionized - at high energies you have nothing but high-energy particles, no neutral combinations. The "recombination" era is when the initial ionized era ends. Tarl.Neustaedter (talk) 21:23, 28 June 2015 (UTC)

Tarl.Neustaedter: Okay, noted, I'm guessing, this means that population III stars formed from this ionized place, but before the III stars formed, the ionized place went through stages e.g., the 'Dark Age'/transparent age, Abiogenisis molecules were also involved which became transparent along... Correct me if I'm wrong please. About 'reionization epoch', the article states the universe is composed of plasma in the 'reionization epoch' section? Which plasma is it talking about? -- Space Ghost (talk) 18:59, 29 June 2015 (UTC)

You need to read the article Reionization. Population III stars is simply a way of describing stars which formed before a lot of metals were around, so they were formed of primordial materials of Hydrogen, Helium and Lithium. It wasn't an organized process of event 1, then event 2, then event 3 - it was a messy process with varying conditions across the universe . Recombination took place because the universe cooled from expansion, allowing particles to drop to low enough energies to form atoms. Re-ionization took place because energetic events were taking place (galaxy formation, quasars, supernovas), which required aging stars, dumping energetic photons back into the mix. The first pop III stars probably formed before recombination started, but were still forming long after the re-ionization took place. Tarl.Neustaedter (talk) 20:19, 29 June 2015 (UTC)

Tarl.Neustaedter: Hello, sorry for delaying in getting back to you, I got involved into an unexpected thing. Anyway, thank you for the summary. I appreciate it.

What you stated, III stars started before recombination epoch, Galaxy/Galaxy formation and evolution article state that, about 300,000 after the Big Bang. What I'm trying to understand now, i.e., the universe was composed with ion after the Big Bang occurred, and ionized era ended as recombination era started. Now that I'm thinking that III stars were created before the recombination era started, protogalaxies started to occur from this period onwards right? reionization occured during this period, right? If so, why 'Dark Ages'? the universe was busy, right? (I'm gonna read through the article you stated; I skipped it last time because it was long...) -- Space Ghost (talk) 19:35, 1 July 2015 (UTC)

Per WP:TALK#USE, this conversation has gone on a bit far, so I'm going to close the discussion. The purpose of talk pages is to discuss improvements to the articles, not for a general discussion of the subject matter. That said:

• The first stars (and galaxies) were almost certainly created well before recombination, during the so-called dark ages. Even when the universe was entirely plasma, gravitational collapse almost certainly still occurred. After all, stars are mostly plasma themselves (at high temperatures all atoms disassociate into nuclei and free electrons - plasma). We can't know for sure when the first stars and galaxies were created, we can't see that far back.
• The dark ages were called that because the universe was occupied by plasma, and was thus opaque. Any photons generated were simply absorbed by free electrons and then re-emitted. We see the remnants of this glowing cloud in the cosmic microwave background radiation today.
• When recombination occurred, temperature dropping enough that free electrons could be captured by nuclei, photons could then travel longer distances before being absorbed and re-emitted. It wasn't a sudden process, it was a gradual process. The stated timeframe of 377,000 years is approximate and probably not uniform - some places taking longer than others. When most of the matter of the universe had recombined to make neutral particles, the universe became mostly transparent.
• Today, most matter is again plasma, but intergalactic matter is at low enough density that we can get photons from most of the way across the universe.

Regards, Tarl.Neustaedter (talk) 05:01, 2 July 2015 (UTC)

Tarl.Neustaedter: Okay, thank you. I appreciate what you done so far. Made me understand things in a simple way... -- Space Ghost (talk) 07:38, 2 July 2015 (UTC)

Clarifying the Summary

I found a number of confusing/misleading turns of phrase in the summary, and corrected them. Unfortunately I forgot to log in until just before the last one - the others show up as IP 81.2.68.136. MrDemeanour (talk) 17:53, 24 July 2015 (UTC)

Inconsistancies Regarding Inflation

Under Electroweak epoch, text says: Between 10−36 second (or the end of inflation) and 10−32 second after the Big Bang.

Under Inflationary epoch (sub-heading under above) text says: Unknown duration, ending 10−32(?) second after the Big Bang.

In article Inflation_(cosmology), text says: In physical cosmology, cosmic inflation, cosmological inflation, or just inflation is the exponential expansion of space in the early universe. The inflationary epoch lasted from 10−36 seconds after the Big Bang to sometime between 10−33 and 10−32 seconds.

I suggest the authors of this article and the Inflation article get together and workout consistent compatible language.

BuzzBloom (talk) 16:35, 5 September 2015 (UTC)

There seem to be two different theories about when inflation ended. We need to make this clear. Since we cannot see further back than the end of inflation (can we?) there doesn't currently seem to be any way to decide between the theories. Dbfirs 23:46, 13 December 2015 (UTC)

Inconsistencies within Electroweak Epoch

Under 'Very Early Universe - Electroweak epoch', the following is stated: "the electroweak epoch began 10−36 second after the Big Bang". Directly in the next sentence, it is stated: "the electroweak epoch began when the inflationary epoch ended, at roughly 10−32 second." and this completely contradicts the previous sentence. Which one is it? Did the Electroweak epoch begin 10-36 seconds after the big bang or did it begin 10-32 seconds after?

JamesYeoman (talk) 10:36, 30 August 2016 (UTC)

What you're missing is that the two timeframes are according to two different theories: "traditional big bang cosmology" vs. "inflationary cosmology". See a slightly more detailed explanation at Electroweak epoch. Tarl N. (discuss) 12:40, 30 August 2016 (UTC)

Very early universe

This hyperlink redirects to the same page the user came from. — Preceding unsigned comment added by 71.191.3.123 (talk) 19:27, 2 October 2016 (UTC)

There are further circular links in the article, such as the one for the Dark Ages in the table. Awkward. They should be removed and the terms bolded. --Florian Blaschke (talk) 00:49, 7 October 2016 (UTC)

Inconsistency in dating of the Dark Ages

The table says that the Dark Ages lasted from 0.38–150 Ma, but the text says 150–800 Ma (without citation). Moreover, in the following paragraph, Loeb (2014) gives 10–17 Ma for the "Habitable Epoch" he postulates, which is consistent only with the value in the table. The epoch from 150 Ma on already belongs to the "Reionization" epoch according to the following sections, and the table. The material immediately following the 150–800 Ma is inconsistent and seems to conflate (erroneously) the reionization epoch with the Cosmic Dark Ages; all the mentioned galaxies (not only the first one) appear to belong to the later reionization epoch, not the Dark Ages, and if this is so, this material is not germane to the Dark Ages section anyway and should be moved to the "Reionization" section. The hatnote linking to List of the most distant astronomical objects also seems to belong there and not to the Dark Ages section. (As far as I understand, the "Dark Ages" span the time between the end of the recombination epoch 0.38 Ma and the beginning of the reionization epoch 150 Ma, when the first stars were formed, hence the reionization epoch is also considered the beginning of the Stelliferous Era, and the formation of the oldest galaxies clearly does not belong to the Dark Ages.) However, I cannot exclude that the article is misleading as to the dating of the relevant epochs – I'm not an expert and therefore I hesitate to change the article myself. --Florian Blaschke (talk) 00:40, 7 October 2016 (UTC)

@Drbogdan and Dbfirs: You appear to be knowledgeable about this subject – can you look into the issue I've brought up? --Florian Blaschke (talk) 23:40, 9 October 2016 (UTC)

@Florian Blaschke and Dbfirs: Thank you for your comments - and noted concerns - yes - agreed - some of the material you mentioned may need to be improved - for my part, I've tried to improve some of the text/refs I had added earlier (beginning 4 December 2014) - however, other material (ie, that related to "150–800 Ma" - and onward) may have been added by other editors some time ago (beginning 25 October 2010?) - it's *entirely* ok with me if you would like to improve the material further of course - in any case - Thanks again for your comments - and - Enjoy! :) Drbogdan (talk) 03:29, 10 October 2016 (UTC)

Incomplete Timeline

There is no mention of what happened before the Big Bang. This needs to be mentioned to complete the time...LINE. Wait... If time is infinite, then how are we here now? This inconsistency should be mentioned, as well.108.85.152.134 (talk) 23:03, 13 December 2015 (UTC)

What makes you think that time is infinite? Dbfirs 23:38, 13 December 2015 (UTC)

Space-time is considered to have manifested together at the Big Bang, hence time did not yet exist before the singularity, at least in this universe. 76.10.128.192 (talk) 04:02, 20 January 2016 (UTC)

Before the Big Bang: According to the Kalam argument, everything which has a beginning has a cause. Thus, if we accept the Big Bang as the beginning of the universe, then we need to postulate a cause i.e. something before the Big Bang. I re-state the Kalam argument as follows: If anything exists, then there could never have been 'nothing'. In this statement, 'nothing' implies no matter, energy, force, or potential. Since the universe exists, there could never have been 'nothing'. So it is fair to ask the question "What happened before the Big Bang?". — Preceding unsigned comment added by Dr Reg Broekmann (talk • contribs) 05:53, 16 January 2017 (UTC)

The Kalam argument and quantum mechanics aren't on speaking terms. But that's irrelevant, the big bang was a singularity (in the mathematical sense), information does not cross such a boundary, even if there was anything "before" that. In reality, we can't even observe back to the big bang, our instruments are limited to at the very earliest getting information from the Recombination period, when the universe became transparent. The cosmic microwave background derives from that era. Tarl N. (discuss) 06:53, 16 January 2017 (UTC)

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Size of observable universe

I think it's useful to give an idea how large the volume (or radius) of what become today's observable Universe was at other times. I found it not that easy to find. I'm not looking for particularly precise numbers, so I looked up Friedmann equations and what they say about scale factor a(t). For matter-dominated Universe (which is the case from 47ka since BB up to today), and if Universe is spatially flat or close to it, a(t) is proportional to t^(2/3). Let's check, will this give correct size of 42 mly at recombination from today's radius of 46 Gly? 46000000kly / (13800000ka/380ka)**(2.0/3) = 41946 kly. Good.

Now, earlier times are trickier: at 47ka, Universe transitioned from radiation dominated to matter dominated. Before 47ka, in radiation-dominated universe, a(t) is proportional to t^(1/2). Transition period would require some interpolation for good precision. But let's make a rough estimate by simply using t^(2/3) for 47ka, then using t^(1/2) before that. At 47ka, we get radius 46000000kly / (13800000ka/47ka)**(2.0/3) = 10413 kly. Now, what would be the radius at 1 sec (neutrino decoupling)? Using t^(1/2) here: 10413000ly / (47000*365*24*60*60sec/1sec)**(1.0/2) = 8.55 ly. I'll go with "about 10 light-years".

Where you wrote mly, you apparently meant Mly. - Patrick (talk) 20:31, 5 September 2017 (UTC)

Regardless, 213.175.37.10 (who neglected to sign his contribution) is engaged in WP:OR. Unless we find a citation which specifies size of the universe at those times, we'll have to delete those entries. Tarl N. (discuss) 01:19, 6 September 2017 (UTC)

The 42 Mly radius at recombination is not a number I invented/calculated to put on this page. You can google it. Hmm... Google also found it on "Observable_universe" page.

Clusters and superclusters timeline

The text says that they started to form 150 mya, but I can't find any reference to this in the subarticles about the topic. -Theklan (talk) 22:57, 2 December 2017 (UTC)

Technical errors/ambiguities on the page, knowledgeable editing required to fix them

Can someone please edit the article to clean up/correct/clarify our coverage on these 4 points which are badly or maybe wrongly described:

1. Dark ages lasted up to minimum 150my and maximum 1000my. So when we say "cooled to 60K" we muist be assuming some specific time, whereas the temperature was probably very different at 150my and 1000my.
2. We mention baryogenesis but attach no time to it. (I've added the best value I can find, but no cite)
3. We mention bayrogenesis as part of the very early universe but quarks as only forming later. That's got to be incorrect.
4. We mention inflation theory and state that it lasted more than 10^-32 s, but that time before then is meaningless in that theory. But we also state that inflation theory is part of traditional BB theory and occurred at 10^-32s. Can we clarify the wording here and put modified theories (if this is what's meant) in a different section so it doesn't cause confusion.
5. Does the EW epoch include the inflationary epoch, exclude it, or "depends on interpretation/definition"?

Thank you!

FT2 ^{(Talk | email)} 17:57, 9 April 2018 (UTC)

Dark Ages - why?

There is a lack of a concrete explanation of why there is a dark age - too hot for star formation? Asgrrr (talk) 13:26, 2 January 2018 (UTC)

Stars need time and right conditions to form. Hot hydrogen gas is rather reluctant to form star-sized overdensities. Even cold gas (~100K) needs time for small deviations from almost uniform gas distribution to become more pronounced due to self-gravity. — Preceding unsigned comment added by 213.175.37.10 (talk) 17:36, 7 March 2018 (UTC)

I've added a bit to mention some of the reasons for this. FT2 ^{(Talk | email)} 16:05, 24 May 2018 (UTC)

Habitable epoch inconsistency

The Habitable epoch section contains inconsistencies with material contained elsewhere on the page. The Habitable epoch section states: the background temperature was between 373 K and 273 K, allowing the possibility of liquid water, during a period of about 6.6 million years, from about 10 to 17 million after the Big Bang and speculated that primitive life might in principle have appeared during this window. Later in the Chronology of the universe page in the Star Formation section it clearly states that elements heavier than Lithium where first formed in this period and so the elements necessary for life and water such as Oxygen and Carbon were not formed until 560 million year after the Big Bang. In the first 20 minutes of the Big Bang (Nucleosynthesis) only Hydrogen, Helium and Lithium were formed. So 10 to 17 million after the Big Bang it is impossible for there to be liquid water as claimed. The suggestion that primitive life formed during this period is surprising. All references for the above are contained on the Chronology page. The Nature article referred to in the section appears to have inadequately peer reviewed. DJM1961Br (talk) 23:48, 8 January 2017 (UTC)

The article wasn't in Nature, but in the Journal of Astrobiology. The paper is available at ArXiv (here). He speculates that hyper-massive stars could have been created and lived their entire lifspans by then, creating the heavier elements in question. Not to say that the article isn't speculative - formation of non-incandescent planets out of supernova remnants that early is decidedly unlikely. Tarl N. (discuss) 02:25, 9 January 2017 (UTC)

Agreed the article was not published in Nature. I very much doubt the paper represents the mainstream or standard view of the cosmological community on the formation of the early universe. The section is inconsistent with later material on star formation. — Preceding unsigned comment added by DJM1961Br (talk • contribs) 04:49, 9 January 2017 (UTC)

I also think the article is fairly speculative, and should not be mentioned in this article. Deleting this fragment... — Preceding unsigned comment added by 2A00:CA8:A14:6A01:4685:FF:FE33:1E8B (talk) 20:52, 28 August 2017 (UTC)

Some of that discussion is still present. The topic seems too controversial (read: entirely implausible) to belong here, at least without much stronger caveats. (The idea that life needs water and other heavy elements misses the point that it also needs thermal gradients, or at least energy gradients, which a uniform-temperature universe would not provide, not matter how comfortably warm that temperature is.) Jmacwiki (talk) 16:40, 29 May 2018 (UTC)

Inflation needs a reference!

"cosmic inflation... is believed to have been triggered by the separation of the strong and electroweak interaction." This is a central part of the explanation of inflation (though I have been told that it is no longer accepted). Whether it is, or was, believed to be true, it needs a reference. Or it needs to be removed and perhaps replaced with appropriately non-conclusive wording. Jmacwiki (talk) 14:29, 2 June 2018 (UTC)

Time expansion rather than physical expansion

One of the greatest puzzles of the universe is whether time is expanding rather than volumetric expansion. The reason for this idea is that with a cubic expansion of time at +669s/m^3 pandirectionally, distances can remain diminutively static and all motion is decelerating at a rate equal to the gravitational constant. The internal appearances would remain identical and unchanged to observers but radiation energy would exist without matter and this has been proven consistent with Zero Point Energy and Stochastic Electrodynamics. It also explains where all forms of energy descend to in creating a cyclic model of construction and destruction. Time should be considered a physical part of the universe and introduces irreversible. Volumetric expansion is only apparent because time expansion makes distance appear to increase. Any comments?Ashattock (talk) 20:06, 2 June 2018 (UTC)

Not unless you have a reliable source stating the above, as such. Tarl N. (discuss) 04:53, 3 June 2018 (UTC)

I'm not an expert on this, but don't our observations of Pulsars provide strong evidence against any such theory? Dbfirs 06:22, 3 June 2018 (UTC)

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 — Preceding unsigned comment added by 122.167.131.202 (talk) on 14:30, 24 July 2007

They meant by mass, but didn't say it. Alfa-ketosav (talk) 20:02, 22 April 2019 (UTC)

Requested move 14 November 2019

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: Withdrawn by nominator _{ZXCVBNM (TALK)} 18:49, 15 November 2019 (UTC)

---

Chronology of the universe → History of the universe – This is the better article title because not many people know what chronology means. I would also like to ask whether universe is capitalized. Interstellarity (talk) 12:09, 14 November 2019 (UTC)

• Oppose This article is not about the "history" of the universe, but past, present and future. Also, I refuse to believe chronology is a "hard word" for most people to understand._{ZXCVBNM (TALK)} 21:09, 14 November 2019 (UTC)

---

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

What is the origin of "377 000 years after BB"?

The age of the universe at the recombination appears in this article as "377 000 years". I do not necessarily question that value, but in this article it is simply given as a well-known fact - no source, no reference to an article that explains it all. I assume that the value is based on some assumptions, but what are these assumptions? Where-ever I look in WP, "380 000 (something)" is stated as a fact, but nowhere how this value has been derived ... Hilmer B (talk) 16:37, 24 September 2018 (UTC)

See note in ref#3 (revision as of 09:40, 29 January 2020) for Hinshaw, Weiland & Hill 2009. Alan G. Archer (talk) 17:04, 2 February 2020 (UTC)

First Molecules/Recombination conflict

The section of First Molecules is giving a timeline at about 100,000 years, which I understand comes from the linked article. However, the article is referencing a Nature Journal entry which only states that the molecules could only start forming during the recombination epoch, and doesn't give any specific time when this would be.

The following section on Recombination then gives a conflicting date of 370,000 years, which would make most readers assume that the first molecules would have formed much earlier than the recombination.

I'm not sure what the preferred way to resolve this conflicting information should be, but wanted to highlight this issue. --elentir (talk) 16:15, 9 November 2020 (UTC)

I found a source which discusses the recombination timeline for various ionization levels of both helium and hydrogen, with the earliest recombination to HeII around 18,000 years after the big bang and HeI at around 100,000 years, which matches the timeline for the earliest molecules. I think the Recombination section needs to be expanded to include this data as recombination covered a timespan of several hundred thousand years (~18,000y–~370,000y), finally ending with decoupling.

See graph on pg. 8 for best illustration of timeline. Signals From the Epoch of Cosmological Recombinationelentir (talk) 12:16, 11 November 2020 (UTC)

References

Semi-protected edit request on 17 March 2021

This introductory sentence is ambiguous and is not reflected in the detailed text of the article.

From about 9.8 billion years of cosmic time,[7] the slowing expansion of space gradually begins to accelerate under the influence of dark energy,

I think the editor meant to say this:

From about 9.8 billion years of cosmic time,[7] the expansion of space gradually begins to decelerate under the influence of dark energy,

But before making this change, please confirm my suspicion that the original sentence is not supported by the main text. If so, the sentence needs to be deleted entirely. Thank you.

 Not done: The page's protection level has changed since this request was placed. You should now be able to edit the page yourself. If you still seem to be unable to, please reopen the request with further details. Asartea ^{Talk | Contribs} 13:22, 17 March 2021 (UTC)

"the expansion of space gradually begins to decelerate under the influence of dark energy" <- this is definitely not correct. Dark energy is a positive acceleration on the expansion of the universe. Gravity is a negative acceleration (aka deceleration) on expansion. What the original sentence is getting at, while gravity was initially slowing expansion early on in the universe, around 9.8Gy the universe was big enough for the amount of dark energy to overcome the effects of gravity resulting in positive acceleration. elentir (talk) 11:19, 23 March 2021 (UTC)

I updated the stat and took a stab at clarifying it; as always, feel free to copy-edit it if there's a way to use simpler words without sacrificing accuracy. As always, visual information like a labeled graph drawing of the inflection point would help our readers too. Rolf H Nelson (talk) 22:41, 27 March 2021 (UTC)

Lead sentence

The opening sentence currently reads The chronology of the universe describes the history and future of the universe according to Big Bang cosmology. The earliest stages of the universe's existence are estimated as taking place 13.8 billion years ago, with an uncertainty of around 21 million years at the 68% confidence level.

An editor is trying to change it to The earliest stages of the universe's existence are estimated as taking place 13.800000001 billion years ago (in the year 13799997982 BC), with an uncertainty of around 21 million years (years 13820997982 BC to 13778997982 BC) at the 68% confidence level.

Thoughts? Personally, I think the current sentence is easier for readers to understand, and I think specifying the years BC is confusing, harder to read, and adds unnecessary complexity to the sentence. Also, 13.800000001 implies a misleading specificity to the estimate. Schazjmd (talk) 18:39, 8 August 2020 (UTC)

I think the warning ^{(This figure is unduly precise)} would apply. Tarl N. (discuss) 18:48, 8 August 2020 (UTC)

The article quotes an age of the Universe of 13.8 Gyr with an uncertainty of 21 million years. An uncertainty this large would make quoting ages and dates to the nearest year meaningless. Quoting a meaningless precision would make no sense. I believe the lead sentence should remain as "taking place 13.8 billion years ago, with an uncertainty of around 21 million years at the 68% confidence level". — Preceding unsigned comment added by TowardsTheLight (talk • contribs)

I've invited the IP editor to make their case here. Schazjmd (talk) 20:45, 8 August 2020 (UTC)

Each year the uncertainty range would effectively shift by one year, making it not the original uncertainty range. In 2020 it should be 13.800000001 years ago with an uncertainty of 21 million. In 2021 it will be 13.800000002 years ago. And so on. 2A01:119F:31B:5D00:CDA:B9B8:6D94:5EE (talk) 15:17, 22 September 2020 (UTC)

Currently the center of uncertainty is 13.800000005 years ago, not 13.800000004, not 13.800000006. It's in the year 13799997982 BC, with an uncertainty of around 21 million years (years 13820997982 BC to 13778997982 BC), not years 13820997981 BC to 13778997981 BC, not years 13820997983 BC to 13778997983 BC. 2A01:119F:31B:5D00:CDA:B9B8:6D94:5EE (talk) 01:48, 19 November 2024 (UTC)

You're assigning a degree of precision to the estimates that isn't reflected in the sources and, on a scale of 13+billion years, isn't even meaningful. Schazjmd (talk) 15:45, 22 September 2020 (UTC)

If it was 13.8 billion years ago in 2019, it would be 13.9 billion years ago in 100002019. So in 10002019 it would be 13.81 billion years ago, and in 1002019 it would be 13.801 billion years ago, and so on. 2A01:119F:31B:5D00:453A:2110:9DE4:8C78 (talk) 05:11, 30 September 2020 (UTC)

You're just repeating your insistence on an unsupported precision. You haven't convinced anyone that the change to the lead is an improvement to the article or helpful to readers. Schazjmd (talk) 15:01, 30 September 2020 (UTC)

Why did this even go that far? This is obvious trolling and/or complete incompetence regarding the subject. --46.91.53.11 (talk) 18:59, 28 May 2021 (UTC)

first stars -date proposed

This news article suggests that we now have tentative scientific basis to date the first stars between 250 and 350 my after the Big Bang.

That means that the date in the lead image is likely to be very significantly out, and articles referring to the Population III stars need dating fixed. don't have the scope to do it myself, pointing it out here so that with luck some others interested in cosmology will be able to update as needed. FT2 ^{(Talk | email)} 18:09, 24 June 2021 (UTC)

Above 150 GeV

Quote: "Before temperature falls below 150 GeV, average energy of particle interactions is high enough that it's more succinct to describe them as exchange of W1 W2, W3, and B vector bosons (electroweak interactions) and H+, H−, H0, H0⁎ scalar bosons (Higgs interaction)." So, as usual, interactions are described as an exchange of bosons. But exchanged between what kind of particles? — Preceding unsigned comment added by Koitus~nlwiki (talk • contribs) 22:40, 26 June 2021 (UTC)

Little is understood about physics at this temperature

Could some clarification be provided as to what is not understood? Is there an inherent problem with using the regular laws of physics, or is it just that doing so would lead to difficulties/contradictions? — Preceding unsigned comment added by 185.3.145.39 (talk) 08:10, 22 October 2021 (UTC)

As per the article -> "different hypotheses propose different scenarios. Traditional big bang cosmology predicts a gravitational singularity before this time, but this theory relies on the theory of general relativity, which is thought to break down for this epoch due to quantum effects."

In other words, relativity and quantum mechanics contradict each other. elentir (talk) 13:11, 23 October 2021 (UTC)

Early waterworld

@Elentir~mediawiki: I have read the paper and had a look at the articles metrics. It's doing very well on social media, apparently, but no other publications cite it. I agree with 24.135.89.212 that this paper is way too speculative and gained way too little traction in the field to warrant a paragraph (WP:UNDUE). Kleuske (talk) 11:01, 15 December 2021 (UTC)

@Kleuske:I'm fine with that argument for removing. I was reverting because of the previous user's claim for deleting it is completely wrong. "First oxygen will be made many billions years later after explosions of first generations of stars. At age 10 million years, only hydrogen, helium and small fraction of lithium existed in forms of hydrogen clouds." Oxygen and other heavier elements easily existed by that point in the Universe.elentir (talk) 19:55, 15 December 2021 (UTC)

Fair enough. Kleuske (talk) 10:18, 16 December 2021 (UTC)

Historical tense

Hi,

A general query. I note parts of this page mix tenses: in some places the 'traditional' tenses taught in school are used - when talking about things which happened in the past, past tenses are used. But in other places, the newer style of tenses are used which I think are learnt from watching documentaries - using the current tense for things which happened in the past. I think it is called "historical tense" and it seems to be getting loose all over the world. It's rather jarring when used to excess (as it now is) and I hope Wikipedia doesn't get infected! Is there a policy? As an encyclopedia, whichever form is being used should be consistent throughout the website I would argue - and certainly should be within a single article. I'd happily correct any cases on this page to traditional tenses but I wouldn't want to spend time doing that if it might get undone as being unnecessarily nit picky (I think it's just good grammar - and good grammar helps readability).

An example is below, with my comments in squiggly brackets {}.

Thanks, Gordon

The decoupled photons would have filled the universe with a brilliant pale orange glow at first, gradually redshifting to non-visible wavelengths after about 3 million years, leaving it without visible light {traditional tense: past tense used for past events}. This period is known as the cosmic Dark Ages.

At some point around 200 to 500 million years, the earliest generations of stars and galaxies form (exact timings are still being researched), and early large structures gradually emerge {historical tense: present tense used for past events}, drawn to the foam-like dark matter filaments which have already begun to draw together throughout the universe. The earliest generations of stars have not yet been observed astronomically {traditional tense: present tense used for present events. Presumably, if 'historic' tense were also used here, it would have to become future tense: to describe current events, i.e. "The earliest generations of stars will not have been observed..."!}. — Preceding unsigned comment added by Gordon Panther (talk • contribs) 02:13, 8 January 2022 (UTC)

Template that links to religius views?

I dont want to make a change, in an important article, without prior consense Galahad1822 (talk) 00:15, 18 April 2022 (UTC)

This is a science-based article, I don't think introducing religious views is appropriate. Schazjmd (talk) 00:19, 18 April 2022 (UTC)