Talk:Formation and evolution of the Solar System/Archive 1

Archive 1

Archive 2

Archive 3

Outline created

I have created an outline for the completed artcile. It is embedded in the article as comments. As the various sections are ready to be fleshed out, they can be uncommented. The outline itself is:

• Initial Formation
  • The solar nebula
  • Problems with the solar nebula model
• Subsequent evolution
  • The inner solar system
  • The asteroid belt
  • The outer planets
  • The Kuiper belt and the Oort cloud

--EMS | Talk 19:07, 9 July 2006 (UTC)

Current edits

I have done some reorganizing on this article to enable the overall outline that I had for it. Hopefully this will guide the future development of this article (or at least the current merge effort).

I don't like the "Future of the solar system" being here. Much of that belongs in the Sun article IMO since that is what is being discussed. The rest is the antithesis of the "Formation" part of this. (Perhaps we should rename this article "History of the solar system"? Then its name and focus would better match, but I still would like much of the "Future ..." stuff placed in the "Sun" article.) --EMS | Talk 15:50, 26 July 2006 (UTC)

It's a bit ironic that you think that, really, because the "Sun" article seems to think it can leave explaining its "Origin" to this article. :=) I can understand your desire not to have the "Future" section, but given how chaotic the "Sun" article is I think the info is safer here. Still, I'd agree to switch it over if you honestly felt it was interfering with the structure of the piece. Perhaps focusing more on the fates of the various planets and explaining how the Sun's weakened gravity would shift their orbits, and what would happen when they ran out of heat, would make it more topical? Serendipodous 17:39, 26 July 2006 (UTC)

I think that you should refrain from doing too much with the "Future" section for the time being, but do retain it until we have figured out what to do with it. As I see it, we need to either move it elsewhere or rename this article. However, I also think that we should refrain from making big decisions until things settle back down a bit. This is one case where there are several (potentially) "right" answers. --EMS | Talk 18:40, 26 July 2006 (UTC)

Move

Well, I did it. I hope you don't mind EMS, but it seemed the right thing to do. I've also shifted some refs and a nice image over from the "Sun" article to here. Serendipodous 10:26, 27 July 2006 (UTC)

Also, I've copied and pasted a section from the Sun article on the faint young sun paradox; it probably should be reworded, but for now the information is here Serendipodous 10:38, 27 July 2006 (UTC)

Actually on second reading it doesn't have much to do with the nebula model itself. Dropped it. Serendipodous 19:21, 27 July 2006 (UTC)

There was an awful lot of repetition in this article, so I deleted some paragraphs and moved others around to make the narrative smoother. Serendipodous 22:30, 27 July 2006 (UTC)

---

I have no big objections to what you have done. The renaming works, and the consolidation of the content (and the removal of redundancies) was something that I has started yesterday but had no chence to work on today. I don't like the shortening of the lead, but it seems to work well with the article in its current state. So for now I will leave the lead alone, and see that as something to address in the future when this article is in better shape. --EMS | Talk 01:38, 28 July 2006 (UTC)

Bad move

Serendipodous - You did not do the move of this article properly! Each article has a "Move" tab. When you use the "Move" tab to change the name of an article, the article history will also be moved and (unless you explicitly choose not to do so) the talk page and its history will also follow, as well as a redirect being left behind. For a "young" article like this not much harm was done, but please in the future use the "Move" tab so that everything is moved and not just the article content. (It also does not help that you failed to put a "copied from" remark in the comments for the original version of this article.) --EMS | Talk 13:41, 28 July 2006 (UTC)

Sorry; I was afraid if I did that, that all the redirects I'd made would have to be redone. Serendipodous 14:17, 28 July 2006 (UTC)

For previous redirects, you get double-redirects. They do need to be fixed, but that is an issue either way. --EMS | Talk 17:07, 28 July 2006 (UTC)

Question / Point / Suggestion / Whatever

While reading the section on the initial formation, specifically that part which deals with the inner planets and why we think that the inner planets are all rocky, while the outer planets are gas giants, and I wondered if this was still more or less unchallenged, in light of recent discoveries of extra-solar planets. Basically, I know that a lot of the extra-solar planets we've found tend to be both very large and very close to their stars. Now, I don't know that we know that these worlds are gas giants or not, but wouldn't seeing that cast doubt on the idea that the inner planets are all rocky because gas giants couldn't form there? Is there any published research on this idea, one way or another, or am I just walking into walls?  :) In either case, just thought I'd put that thought forward in case anyone here knew, or has better means than I of finding out. And, no, I'm not saying that the section in question should, with all dispatch, be edited to reflect this idea, as it is only original research. Cheers. DAG 04:14, 2 August 2006 (UTC)

It is a good question, and has a generally agreed-upon answer: Planetary orbits can change, especially when interacting with a protoplanetary disk and/or something like the Kuiper Belt. So the hot Jupiters most likely formed much farther from their host stars (beyond the "frost line" alluded to in this article). Now when such a body forms, it is initially in the center of a gap cleared out by its formation. However, if the body is perturbed into an orbit that brings it close to the inner edge of the gap, it will then draw in material from that side of the gap. Since that material has less energy, the body will be pulled inwards. If the disk is dense enough, this process will keep pulling the body more and more inwards until the disk gives out near the star itself.

A body can also be pulled outwards in a similar manner (and that is how Uranus and Neptune got into their current orbits under the 2:1 Jupiter-Saturn resonance models). Note that the radial velocity observations, which are so good and finding hot Jupiters, will be especially terrible and finding "cold" Jupiters.

BTW - This is mentioned in the secion of the history of formation hypotheses. --EMS | Talk 02:37, 3 August 2006 (UTC)

Indeed it is mentioned down there. Perhaps I should have read a bit more thoroughly...  ;) DAG 03:11, 3 August 2006 (UTC)

I am giving this thread some moew thought, and the hot Jupiters do count as a problem with the solar nebula hypothesis. So I will add a mention of it there. --EMS | Talk 21:16, 3 August 2006 (UTC)

Primary/2ndary atmospheres??

The oldish theory of primary (primordial) atmospheres being replaced by secondary ones - for the terrestrials - is now somewhat obsolete. There are some arguments telling us that current atmospheres are direct derivatives from the primary atmospheres, without need of any novel secondary atmosphere formation. The most important argument is:

• Earth [H²O:HDO] isotope signature says: the water comes from the vicinity of Earth's formation place, not from comets (who would be the source of the 2ndary atms).

Quaþ tomas.kindahl@comhem.se --83.250.61.193 12:45, 8 August 2006 (UTC)

It is interesting to note that I can only find sources for that info from the 70s. Might be worth removing. Serendipodous 23:49, 20 November 2006 (UTC)

Future dates

The article states that the sun will blow up 7.5 billion years from now, but I have always thought it was 5 billion years. Also, it is speculated that the Andromeda Galaxy could collide with the Milky Way about 4 billion years from now, so would that affect the Solar system? AstroHurricane001 22:38, 26 October 2006 (UTC)

As to the first question, the Sun won't blow up per se, so much as puff up, and throw some itself into interstellar space. This will first begin to happen, as you have always thought and as far as we know, in about 5-6 billion years (the commonly quoted total lifetime of the Sun, 10 billion years, gives a figure of 5.5 billion years, given that the Sun [and the Earth] is about 4.5 billion years old). The Sun then spends a billion years or so puffing up before it gets a new lease on life in the form of helium fusion in the core, which will cause the Sun to settle down for a period. Of course, eventually, after say 100 million years, the helium in the core exhausts itself and the Sun puffs up again. This time it never really returns to normal, and the "puffing" throws out much of the outer layers of the Sun (this won't be explosive so much as it will be like a really strong solar wind), leaving the carbon/oxygen core of the Sun behind, a white dwarf. All told, the time between now and the point where the Sun is a white dwarf is about 7-7.5 billion years or so (e.g. after about 12 billion years or so since the Sun "turned on"). So, that's where the different numbers come from.

As to Andromeda, odds are that the Solar System won't be affected. Why, you ask? Well, space, as has been observed many times before, is big. REALLY big. So the odds of having another star, say, get close enough to us to disrupt the Solar System (none-the-less actually "hit" it) are very tiny (but not zero...). Of course, the galaxy as a whole would go to pot, but hey, we'd be fine.  :) DAG 00:06, 27 October 2006 (UTC)

Merge with Solar nebula?

These two articles cover a lot of the same material and essentially complete each other. I think they need to be merged. Serendipodous 01:38, 20 November 2006 (UTC)

I object to this. The Solar nebula article is about that hypothesis solely, and so is able to deal with it in more depth. This article is concerned with much more than that. If anything, we should cut down on the Solar nebula write-up here to make for a cleaner division of coverage between the two articles. --EMS | Talk 23:23, 20 November 2006 (UTC)

I replied over at the other article's talk page; but I guess it would help to have everything in one place. To summarise: strip away everything from Solar Nebula concerned only with our solar system and move it here, and generalise that article to how planetary systems form, for which it seems to be halfway there already. Spiral Wave 01:01, 24 November 2006 (UTC)

This can work if done properly. When I created this article, the intent was to show how the Solar System took on its current form, highlighting recent seminal work involving the 2:1 Jupiter-Saturn resonance. However, its scope and even its name has changed since then. I'm still not sure that I like this idea, but Wikipedia is a dynamic encyclopedia such that it makes little sense to keep things in one form because that is how it has been done up until now. --EMS | Talk 03:52, 24 November 2006 (UTC)

That work on the resonance crossing seems even more of a reason to bring the Late Heavy Bombardment content over here; it's all part of the same thing. I think it's still staying within its original scope - the special knowledge we have of our system. The other article already has a skeleton of generic planet formation there, there are just a few gaps to fill in. Any way you look at it there's a lot of duplication and material going beyond the original scope of the other article, so I feel something should be done with it, and it seems a shame to waste it. Spiral Wave 11:30, 24 November 2006 (UTC)

I like where this is going; a partial merge rather than a complete merge, which would make this already long article unmanageable. (sorry about not responding to your post over at Solar Nebula btw; I forgot to put it on my watchlist). Serendipodous 15:15, 24 November 2006 (UTC)

Do keep in mind that related articles will necessarily have some overlap, so that a reader does not have to constantly flip between articles to get a reasonably clear and complete picture. That said, I do agree that talk about the late heavy bombardment belongs here instead of in the other article. I would have to check the history, but I do not recall that as having been in solar nebula when I started this article. So what you are proposing may just be some needed cleanup. --EMS | Talk 18:30, 24 November 2006 (UTC)

Yes, I suppose it is cleanup to a large extent; plus some more material to replace what will be taken from Solar Nebula, to flesh out the formation process described (there are still some big gaps). The only other thing is a renaming of the article, to reflect it's no longer about the Solar nebula, but any protoplanetary nebula. Nebular theory already redirects there. Perhaps Solar Nebula could be the redirect, and this could become 'Nebular theory of planet formation' (or similar)? Spiral Wave 19:10, 24 November 2006 (UTC)

Sounds good to me. Serendipodous 21:49, 24 November 2006 (UTC)

A redirect of solar nebula to nebular theory will work. If the only entry in the history of the redirect is the creation of the redirect, the move will be premitted. That is the case with nebular theory. (However, I wonder if a title like formation of planetary systems may not be a better idea.) --EMS | Talk 00:20, 25 November 2006 (UTC)

I do prefer that sort of name, but I was trying not to get too far ahead of myself. The only other issues seem to be making sure the gravitational instability method gets a fair treatment - at present it's all core accretion; a planet formation article (also an existing redirect there) needs to at least mention both for NPOV - and deciding which article the historical/philosophical bits go in. Probably the other one, not here.

Is there anything else to decide on? Is there a set time it's considered 'fair' to leave a question open before making these sorts of changes? (I'm new) Spiral Wave 01:16, 25 November 2006 (UTC)

Let me put it to you this way: There is a Wikipedia guideline called Be Bold. The gist of it is that if you see something that badly needs changing, then go ahead and change it. In less definite cases, including large scale edits, it is better to discuss your ideas first as you are doing here. If a poll was being done, there would be a need to wait, but in this case there is a consensus amongst the interested editors that you have a good idea here. So you are encouraged to proceed when you are ready as it is unlikely that anyone new with an objection will express it until they are hit in the face with your changes. If you want to play it safe, then you should post a note at talk:solar nebula about the results of this discussion and wait a day or two to see if anyone new comments before proceeding. --EMS | Talk 01:38, 25 November 2006 (UTC)

Heh, well, that seems fair enough. No-one has said anything to me or Serendipodous against my positive comments over there, so I guess we might as well get started whenever. If one of you two wants to start, please do, otherwise I'll have a go as soon I have a fair amount of time for it. Certainly I'll help beef up the other article. Seems smoothly integrating that content over here is the most sensible way to begin though. Spiral Wave 02:09, 25 November 2006 (UTC)

If I had my way, I'd shift the entire article over here. Since I'm not clear on which sections you want to keep and which sections you want to shift, perhaps it's best if I hold back and let you make the first move. Serendipodous 18:22, 25 November 2006 (UTC)

I'm also happy to see what you do first and work with it as needed. --EMS | Talk 20:33, 25 November 2006 (UTC)

Okay, I'll get started on both sometime in the next few days. Spiral Wave 00:35, 26 November 2006 (UTC)

Gah. So much for the 'next few days'. Apologies for agreeing to do something, then doing nothing; real world interference, sorted now. I'll definitely make a big dent in this very soon. Spiral Wave 20:52, 5 January 2007 (UTC)

Serendipodous and EMS - I'm starting this today, apologies again for taking two months(!).

Short summary for anyone is wondering why big chunks are being removed and/or added: Overlap between this and Solar nebula is quite bad, though more conceptual than actual content. I'm moving Solar System-specific content from Solar Nebula to here, so that article can be generalised to planet formation (which already links here) without reference to our system in particular, and this one will have a few gaps filled. It will take a few days to iron the bugs out, so please discuss rather than reverting if anything looks out of place. Spiral Wave 15:51, 21 January 2007 (UTC)

Thanks! My main issue with the merge was that the late heavy bombardment wasn't mentioned here, and you've dealt with that really well. What this page needs now is more references. Serendipodous 18:00, 21 January 2007 (UTC)

Oh, there's plenty more to do yet. All reference to our own system needs removing from Solar nebula, there's plenty of gaps in there in the formation process, and I'd like to elaborate on the 2:1 crossing in the formation and evolution article, there's a lot of re-ordering to be done there to make the evolution process 'smooth'. I'll do a big chunk more tonight. Spiral Wave 18:45, 21 January 2007 (UTC)

The Solar Nebula having a mass of 0.1-0.001 solar Mass?

"One of these regions of collapsing gas (known as the solar nebula) would form what became the Sun. This region had a diameter of between 7000 and 20,000 AU[2][4] and a mass just over that of the Sun (by between 0.1 and 0.001 solar masses).[5] "

What the hell? How could a region containing 0.1 Solar Mass form a star of 1 solar mass?

Headbomb 21:26, 27 January 2007 (UTC)

The crucial bit is 'just over that of the Sun'; i.e. 1.1 - 1.001 solar masses total, with the disc being the extra 0.1 - 0.001 (though that's a slight simplification, because the protosun was still accreting the disc and was a little less than 1 solar mass to begin with). Spiral Wave 22:54, 27 January 2007 (UTC)

The relevant passage reads: "One of these regions of collapsing gas (known as the pre-solar nebula)[7] would form what became the Sun. This region had a diameter of between 7000 and 20,000 AU[3][8] and a mass just over that of the Sun (between 1.001 and 1.1 solar masses).[9]"

I don't believe that it's possible to get three decimal places of accuracy in this context. Someone should revise this passage accordingly. Kevin Langdon 04:55, 24 June 2007 (UTC)

Interesting edits

See this diff for some edits relating to the angular momentum problem that I reverted. They did not impress me as being quite right, but I do want the feedback of other editors on this. --EMS | Talk 20:54, 12 February 2007 (UTC)

A lot of those ideas seem taken from the Binary Research Institute webpage, which is basically a group of amateurs, boffins and outright cranks trying to make a case for a binary companion for the Sun. I have no idea whether to consider their opinions "legitimate", but regardless, unless the contributor sources his comments they are original research.Serendipodous 23:50, 12 February 2007 (UTC)

Agreed. The idea of a companion for the Sun is one that comes and goes over time, and while it's possibly worthy of a mention, without a reputable source it's simply OR. Spiral Wave 01:00, 13 February 2007 (UTC)

Solar Evolution

"In one billion years time, it will claim its first casualty: the Earth."

Well, apart from Mercury and Venus, unless I'm missing something fundamental in this rather overly dramatic phrase ... Daen 16:40, 7 March 2007 (UTC)

It could stand to be made clearer; whether it is overly dramatic is a matter of opinion. Serendipodous 17:13, 7 March 2007 (UTC)

The confusion is because there's a difference between the Sun's expansion swallowing planets, and the increased heat destroying the necessary conditions for life. I've had a go at making the distinction explicit. Spiral Wave 17:29, 7 March 2007 (UTC)

"[...] however, due to the relative rarity of helium as opposed to hydrogen, the helium-fusing stage will only last about 100 million years"

How is helium rare, after the Sun has been creating it from hydrogen for billions of years ???

Because it takes 2 hydrogen atoms to make one helium atom, and then three helium atoms to make one carbon atom. This means that even if all the hydrogen in the core is transmuted into helium, the Sun only has a sixth the useful fuel it had initially. Serendipodous 14:20, 12 March 2007 (UTC)

Actually it takes four hydrogen ions (ie protons) to make a helium atom (see Proton-proton chain), so you can half your estimates again. But as the pressure at the core increases, from all the extra helium being dumped there, the resulting reactions speed up. It's all down at Stellar evolution#Mid-sized stars and Helium flash. Spiral Wave 15:19, 12 March 2007 (UTC)

Great links; added them to the article and clarified. Serendipodous 15:34, 12 March 2007 (UTC)

Clarified the clarification(!): for future edits, remember that the core is a plasma. Spiral Wave 17:00, 12 March 2007 (UTC)

Capture theory reference near the end...

I'm not knowledgeable enough to edit this piece. But the end para struck me as a little odd. Firstly the Capture Theory is definitely not new, this I know - I remember it being mentioned at school in the 1960s (that dates me). As I understand it, it was dubious in the first place because the physical dynamics of such an encounter would not create a sufficiently massive and stable cloud of matter orbiting the Sun that could account for our entire system.

But more importantly, if this (or the exploding companion star hypothesis, which I suppose ought to be mentioned historically, it was well popular and even more unlikely) were true, then solar systems should be very very rare indeed - since the odds against such an encounter are, ahem, astronomically rare given interstellar distances. But the discovery of more and more exoplanets surely obviates this whole approach, even without a detailed critique of the dynamics - solar systems are very common indeed. So how can it be revived, or am I missing something? Tarquin Binary 05:39, 21 March 2007 (UTC)

OK, gottit. Interesting, actually...

[1]

However, while I do understand the difference here (tight cluster situations change the encounter probabilities a whole lot - dunno about the encounter dynamics myself, not qualified), I suspect that given my initial puzzlement as an educated layman, it might be helpful to distinguish this more plausible hypothesis from the earlier (discredited) one I mentioned above for the sake of others who have been taught older cosmogonies. Maybe there should be a section on older theories just for that sake? Tarquin Binary 05:57, 21 March 2007 (UTC)

Age

This article states: "The oldest rocks on Earth are approximately 3.9 billion years old."

However, Age of the Earth states:Modern geologists consider the age of the Earth to be around 4.567 billion years

Which one is right? AndrewRT(Talk) 22:06, 28 April 2007 (UTC)

They both are. The Earth is believed to have formed 4.567 billion years ago, and the oldest rocks on Earth are 3.9 billion years old. The Earth has very few rocks from its earliest formation periods, because of plate tectonics. The ultimate age of the Earth is determined by meteorites, which are older than the oldest Earth rocks. Serendipodous 22:20, 28 April 2007 (UTC)

Actually: the figure 4.567 is the age of the Solar System. Earth is younger by maybe 10-30 million years. Otherwise correct. Said: Rursus ☻ 07:03, 29 October 2007 (UTC)

Future of moon

The article currently states: "As it does so, conservation of angular momentum causes Earth's rotation to slow, making the days longer by roughly one second every 60,000 years. In roughly 2 billion years, the Moon's orbit will reach a point known as "spin-orbit resonance", and both the Earth and the Moon will become tidally locked." Now, if Earth's day is lengthening by 1 second ever 60,000 years, then in 2 billion years Earth's day will be a little over 33 hours long. How, then, can the Earth ever present only one side to the moon, if the moon completes an orbit in 28 days? Zelmerszoetrop 17:59, 15 May 2007 (UTC)

And to make it worse, the Moons orbital period will get longer as it receeds from the Earth. I took a look at the reference, and it is small paperback FAQ written by an amateur astronomer such that I would not consider it to be reliable source for predictions involving lunar dynamics. Therefore I have removed the section on the Moon. (Although maybe a section on how moons and their orbits will evolve in general is germane.) --EMS | Talk 16:47, 20 June 2007 (UTC)

Caption on Saturn pic

The caption on the Saturn pic states:

(brightness has been exaggerated in this image)

This implies the brightness has been altered artificially, which is incorrect. The brightness comes from Saturn being infornt of the sun from this perpective. PseudoEdit ^(yak) _(track) 03:34, 6 June 2007 (UTC)

Sagittarius Dwarf Elliptical Galaxy

At some point information (apparently found here: http://curezone.com/blogs/m.asp?f=1207&i=2) was edited (rather crudely) into the SaGDEG article which suggests that our Solar System was originally part of SaGDEG and that we're currently settling into the Milky Way (after circling it for 2 billion years) as the Milky Way, being a cannibalistic galaxy, is absorbing SaGDEG. i figure that if this theory holds any weight, it should probably be included in some part of the "Origin of our Solar System" article.69.215.235.20 04:50, 19 June 2007 (UTC)

That is an interesting speculation, but the source that you give for it is far from being a reliable source. If you can find articlea in scientific journals that supports this idea then it could be included. Otherwise there is no evidence that this is being taken seriously in the scientific community. --EMS | Talk 16:47, 20 June 2007 (UTC)

our Solar System's Fture

The future of our solar system actually goes by this:

In 1.1 Gyrs

Sun will get slightly bigger, all land life on Earth is gone Diameter: 5 current factors

In 3 Gyrs

Acually in 3 billion years our solar system will truly start to change, on Earth all oceans will boil,life known are completely impossible, and it's atmosphere will cause greenhouse effect. Sun's diameter will roughly be 60 times curretn factors. Only Mars surface will be flood of vast ocean levels, could possibly support marine lifes.

In 4 Gyrs

Sun is roughly 140 times current factor on diameter,it is about subgiant branch.

In 5 Gyrs

Sun's diameter reaches factor of 170, into RGB slightly past Venus orbit. However due to loss of sun's mass Earth and Venus' orbit will move further out to prevent it from being engulfed, However on Earth oceans and atmosphere will has been driven off into space, Earth is a scorch cinder. Even Venus will just be a molten wasteland with nothing on the surface. Mercury is certainly swallowed up. However Saturn's and Jupiter's moon-Europa and Titan when temperatures warm up beautiful ocean worlds can send some better atmospheres create for some descent life. Suns diameter: 170 current factors - roughly 0.79 AU

• Venus moves to 1.0 AU - current orbit of Earth
• Earth moves to 1.4 AU - almost as big as current Mars orbit
• Mars moves to 2.0 AU - nearly to asteroid belts position

In 7.5 Gyrs

Sun reach Asympotic Giant Branch swells again. It almost reaches current Earth orbit. however Venus and Earth moves even further out again failing engulfments. Suns diameter reach 210 current factors - roughly 0.99 AU

• Venus moves to 1.2 AU - two fifths between current Earth and Mars' orbit
• Earth moves to 1.7 AU - two fifths between current Mars orbit and asteroid belt
• Mars moves to 2.5 AU - orbit times 1.5

In 8 Gyrs

Sun forms planetary nebula and evolves rapidly into white dwarf sun Sun is over 10,000 times smaller after planetary nebula. Al the planets will move further out.

• Venus reach 1.35 AU - between current Earth and Mars' orbits
• Earth reaches 1.85 AU - between Mars and asteroid belt orbits
• Mars reaches 2.8 AU - orbits nearly double—Preceding unsigned comment added by Freewayguy (talk • contribs)

The information on the timescale for the Sun's future was taken from this source: [2]. It is quite possible there are other hypotheses out there. Perhaps they should be discussed for their relative merits. Serendipodous 08:26, 18 July 2007 (UTC)

Sources, sources, sources

I want to get this article included in the Solar System series. That means I have to get it up to GA, which means this article needs to fix its most glaring issue: Sources. This article's number of citations needs to double. I'd appreciate any help in tracking sources for this information down. Thank you. Serendipodous 06:25, 29 July 2007 (UTC)

Is it bright or dim?

We currently say this:

Eventually, all that will remain of the Sun is a white dwarf, a hot, dim and extraordinarily dense object; half its original mass but only the size of the Earth. Were it viewed from Earth's surface, it would be a point of light the size of Venus with the brightness of a hundred current Suns.

So, is it dim, or will it have the brightness of a hundred suns? --Doradus 04:25, 24 September 2007 (UTC)

Good point. The contents of the first sentence are well established. The second senstence is totally inconsistent with it. (White dwarves are not 100 times as bright as the Sun currently is to begin with, and the "size of Venus" is quite variable due to its changing distance from Earth.) I have resolved this isuse by removing the second sentence. --EMS | Talk 04:36, 24 September 2007 (UTC)

The recent revision of the Future section for some reason deleted about five citations. I got that line from here.

Here on Earth, we'll feel the wind of the ejected gasses sweeping past, slowly at first (a mere 5 miles per second!), and then picking up speed as the spasms continue (eventuially to reach 1000 miles per second!!) The remnant Sun will rise as a dot of intense light, no larger than Venus, more brilliant than 100 present Suns, and an intensely hot blue-white color hotter than any welder's torch. Light from the fiendish blue "pinprick" will braise the Earth and tear apart its surface molecules and atoms. A new but very thin "atmosphere" of free electrons will form as the Earth's surface turns to dust.

Serendi^podous 07:30, 24 September 2007 (UTC)

I am not sure what to make of this. I have done some research, and it seems that only the newest and most massive white dwarves have surface temperatures as high as 150,000^o C anda corresponding luminosity 100 times that of the Sun. Such stars will quickly cool down, and it seems that the average white drarf only has 1/100th of the luminosity of the Sun. So even if the newly revealed core of the Sun was as described above, that would only be a fairly transient state in the Sun's evolution. So my conclusion is that we should be proceed with care in describing how things will look from the Earth in the very distant future.

diamond hype?

Isn't the sentence "Two billion years farther on, the carbon in the Sun's core will crystallize, transforming it into a giant diamond" inaccurate hype?

Notwithstanding the Harvard press release quoting Metcalfe as saying "Our Sun will become a diamond that truly is forever", surely one sees this as just fluff for Valentines day?

I've tagged the claim in the article as dubious. For a more scientifically sober treatment see the paper by the same Travis Metcalfe: Testing White Dwarf Crystallization Theory with Asteroseismology of the Massive Pulsating DA Star BPM 37093

Notice that Metcalfe writes in L136 in section 4: "the liquid mantle above the crystallized core is expected to be fully mixed and significantly enriched in carbon because of phase separation." This means the core is Oxygen rich (or even pure crystalline oxygen as one of Metcalfe's models shows in Table 2.)

See also the Introduction of Barrat's paper: Crystallization of carbon-oxygen mixtures in white dwarfs.

Maybe the diamond hype originated by a dumbing down of "crystallized", see this NASA article which concludes "At the bottom of this crust is a crystalline lattice of carbon and oxygen atoms. Since a diamond is just crystallized carbon, one might make the comparison between a cool carbon/oxygen white dwarf and a diamond!" -Wikianon (talk) 12:26, 4 January 2008 (UTC)

The article cited above ('Crystallization of carbon-oxygen mixtures in white dwarfs' by Barrat) states, 'We have also considered the possibility of a completely ordered C-O crystal. A possible candidate is an equimolar compound having the CsCl structure, i.e. a BCC lattice with carbon and oxygen sites forming simple cubic sublattices (Dyson, 1971).'

I am not a physicist (or a geologist), but I draw two things from this. First of all, it is clear that the authors of this paper are not certain as to what specific crystalline structure will be formed when the sun does cool to this extent. Diamond is one type of crystallized carbon, but graphite is another. So isn't the statement that the sun will eventually form 'a diamond' as true as saying that it will form 'a lump of coal'?

Secondly, the crystalline lattices that form from cooled white dwarfs consist of a mixture of carbon and oxygen. A diamond, however, is a crystal whose basic structure consists of a lattice of only carbon atoms. So not only the structure, but the basic composition of our sun at this point will be radically different from that of diamond.

I am going to eliminate the word 'diamond' entirely from this sentence and replace it with something that is actually true. The purpose of articles on scientific subjects is to educate people, not to entertain them with fairy stories.

Cal (talk) 19:31, 17 January 2008 (UTC)

Notes

See this source —Preceding unsigned comment added by 68.126.0.30 (talk) 01:29, 9 January 2008 (UTC)

Current Status

This article still needs alot of work. Only the "future" section is okay. Most I post orange tag a while ago. Still this artilce needs about 30 or 40 more oline source the beginning part and the body part is still in poor shape. --Freewayguy (Meet) 02:36, 12 January 2008 (UTC)

I've got a lot on my plate right now, but I still intend to return to this page eventually. Serendi^podous 03:33, 12 January 2008 (UTC)

"Good article" nomination - not quite there

1. Well written?: Almost pass

2. Factually accurate and verifiable?: Almost pass

3. Broad in coverage?: So-so

4. Neutral point of view?: Pass (but see issue re nebular hypothesis)

5. Article stability? Pass

6. Images?: Pass

This is a promising article. Things that can be tweaked (and i will do a little bit of it, esp. refs) are:

• Improve the referencing. Many of the references are to web-based articles and the references show only a title. If the links ever go dead, there is no additional information to help the reader re-locate and verify a source.

• The article opens with a couple of phrases: "...theories concerning the formation and evolution of the Solar System are complex and varied, interweaving various scientific disciplines, from astronomy and physics to geology and planetary science. Over the centuries, many theories have been advanced...". However, the history section moves straight to "the" current hypothesis, leaving the reader without a clear sense of them being either varied, or of many of them having been advanced. This suggests the "History" section is incomplete.

• A slight restructure to get some material in a more logical order may help (a proposal is below). This also relates to my other point...

• I think it may benefit from a more thorough treatment of alternatives to, and problems with, the nebular hypothesis, particularly given the "hot Jupiter" issue. Currently the article leads with the phrase "The current hypothesis of the Solar System's formation is the nebular hypothesis..." and goes on from there, giving the impression that this is fairly settled. The subsection that deals with problems with the hypothesis is in a later section, and the challenges to the hypothesis presented by exoplanet discoveries are not mentioned in that later section (though they do get mentioned in the first section!). Not much weight appears to be given to alternative hypotheses. If that is because they are minor and not widely supported then that is fair enough: Wikipedia:NPOV#Undue_weight. I'm open to other opinions on this, but think it needs to be more carefully addressed.

• My suggestion for structure overall is:

1. Statement about the age of the solar system and general views about its likely longevity, and then some "tasters" re how it has not always been the same, as a way of introducing the idea that it has an origin and an evolutionary path.

2. History of ideas about solar system origins pre-nebular hypothesis

3. Statement of the nebular hypothesis without any of the criticisms

4. Description of origins and early evolution consistent with this hypothesis (the stuff in the "Pre-solar nebula" and "Formation of planets" sub-sections and most material in the "Subsequent evolution" section).

5. Section called something like "Limitations and challenges to the nebular hypothesis". Aggregate such material here from "History of solar system formation hypotheses" and "Problems with the nebular hypothesis". Deal with capture theory. If appropriate, have an "alternative hypotheses" sub-head.

6. "Future" pretty much as-is.

• I think there may need to be a more thorough treatment of the subject of moons, including naming of specific examples of moons that fall into different categories, including retro-orbiting (not explicitly mentioned at present). I admit that the "moons" heading is tricky to fit in to the above schema, because one of the key features of moons as a class is that they did not all evolve at the same stage in the solar system's development. Just slot it in wherever at this stage.

• Bearing in mind I'm not an expert in the field, I'd have thought this article would then be GA and well on the way to FA.

When these issues are addressed, the article can be renominated, and I hope that'll be soon! If you feel that this review is in error, feel free to take it have it reassessed. Thank you for your work so far. hamiltonstone (talk) 11:48, 1 February 2008 (UTC)

Edit conflict and hopefully nothing worse

Hi Serendipodous - I was fixing the references when I hit an edit conflict with you. I managed to patch them up, but noticed the article had shrunk. I am not sure whether I've done something inadvertent, or you're holding material at a sandbox while you work things over. Hopefully nothing has been lost. Chat on my talk page if you want, but I will do nothing further on this article today (well, tonight - I don't know where you live, but it's midnight here). I'll drop back in another day and see where it's at. Cheers and apologies for any inconvenience. hamiltonstone (talk) 12:48, 1 February 2008 (UTC)

Found another site--Freewayguy (Meet) 01:44, 9 February 2008 (UTC)

Mistake in mass numbers, under "Evolution of the Sun and planetary environments"

At the end of that section, the article says that up to 90% of the original mass of the star will be crystallized in the evolution of the white dwarf. However, previously in the same section, it is said that the Sun will have lost up to 40% of its mass. It can't be down to 60% at one point, and still have 90% at some later point.

I'm guessing that, based on the discussion of crystallization in the White dwarf article, that this article should state that up to 90% of the mass in the Sun's white dwarf could be crystalline, which is some fraction (50-60%?) of the Sun's original mass. I'm hesitant to change it myself, be cause I don't know what the right answer is. But as it sits, there's a logical inconsistency. Aerodave (talk) 21:11, 24 February 2008 (UTC)

Declining Orbit?

Would this article be the appropriate topic page for including the following information?:

Is the earth theorized to be in a declining orbit? Why is there no detected decline in orbit? What's the theory behind why the planets weren't aborbed into the sun a long time ago? Could we add something to this article about the gravitational balance of the solar system, and a calculation as to how much mass outside the sun in our solar system could be vaporized before we would expect an upset in that balance? 69.215.156.229 (talk) 13:25, 26 March 2008 (UTC)

I seem to remember Stephen Hawking mentioning it in A Brief History of Time, but as I recall, the amount of energy lost by the Earth per second was so minute that the Sun would have long since faded to black before Earth ever collided with it. According to Wikipedia, the laws of probability dictate that all planets would have been ejected from their orbits by the gravity of passing stars within one quadrillion years, which is far before the time Hawking mentioned. I don't have a copy with me, but if someone wants to check it, that would be good. Serendi^podous 07:53, 27 March 2008 (UTC)

Earth's fate

Ove years Earth fate is still vague. First sun is thouhgt to get to 0.9 AU and Earth will just stay in the same orbit and just be semi-molten. Then a little later, Earth was thought because sun will lose 40% of gravitation pull Earth might escape to 1.6 AU when sun gets to almost 1 AU. Now we say because sun will get about 280 times raii; this bulges sun to 1.3 AU. I thought Earth will be able to escpae a little bit but the strong gravitation pull will still be too strong Earth may not be able to escape soon enough to avoid engulfment. Previously we thouhgt Earth might be able to escape fast enough avoiding engulfment. But now Earth's hope to survive is not to big to my display. Earth now has about a 70% to be swallow up. Now we will just have to say Earth will possibly be swallow up when sun dies. Anyways what is an Roche limit between sun and Earth. I thouhgt is due to expansion. Anyways Mercury and Venus is almost certainly swallow up at this time.--Freewayguy (Webmail) 22:38, 27 March 2008 (UTC)

GA nomination readiness

In response to Serendipodous' question to me about whether this article is ready to re-nominate for good article, here are my comments.

In summary, I think it's close to ready for nomination (and not terribly far from FA) but has a few outstanding issues. I carefully read through sections 1 and 2, but not further. The article is well written and mostly well organized (but see below). I did a bunch of copy-editing as I went.

• I might limit the table of contents; it's rather long and this article has a ton of short subsections which I'm not sure need to be in the TOC.

• I don't think the estimation of age warrants its own section; it could probably be worked into the pre-solar nebula section.

• Ref 1 (Cracraft 1982): A topical reference primarily about the solar system might be better than "Scientific responses to creationism"

• Reference issues (with the caveat that I am probably on the persnickety side about reference formatting and reliability.):

• Several references (e. g. #29, Malhotra 1995) list the author's institution as the publisher; the journal or 'self-published' should be listed instead. (Of the ones I've checked, many actually are published papers, so they are simply poorly cited reliable sources, but personal web pages should be replaced if practical.)

• There are also a good number of references with no author listed.

• At least one reference (#5, Hester 2004) links to a Universe Today article by a different author. Finding the original paper by Hester would be an improvement.

• Ref 14 (Goldreich & Ward 1973) has a dead link and no citation information; it's probably an ApJ article.

• Nebular hypothesis: I'd slightly expand the opening paragraph to give some idea what it is, rather than just where it came from. The expansion needn't be long, given that the details are right below and there's a main article link.

• The section on moons feels a bit short and lacking in detail.

That's as far as I read for now. I'll try to help with some of my suggestions if I can. ASHill (talk) 21:40, 28 March 2008 (UTC)

Refs reorganized

I reorganized the refs a bit. The "General references" section has what I think are good general references on the topic (a textbook and a professional conference proceedings article with a good, broad introduction). The "Further reading" section has the papers that were cited separately before. They're all relatively narrow in focus, and I think they should either be folded in as footnotes for specific facts or removed. (I moved one of them into a footnote.) Then the footnotes are in the "Notes" section. Feel free to hack away at the organization if you have a better idea. ASHill (talk) 03:20, 31 March 2008 (UTC)

I've had a go. Looks tidier now. Serendi^podous 07:41, 31 March 2008 (UTC)

Other hypotheses?

Is the nebular hypothesis the only current hypothesis about the formation of the solar system? If not, what are some of the others, even if they are not generally accepted? Applejuicefool (talk) 15:49, 2 April 2008 (UTC)

See the "Other theories" section. However, the nebular hypothesis is really a very broad umbrella; there are a lot of details that vary from model to model that still have the basic idea of a molecular cloud collapsing to form the Sun, with a bit of leftover material that forms the planets and the rest of the junk. There's very little doubt about that broad picture; that's how we see star formation all over the place. ASHill (talk) 15:58, 2 April 2008 (UTC)

Survey

WP:Good article usage is a survey of the language and style of Wikipedia editors in articles being reviewed for Good article nomination. It will help make the experience of writing Good Articles as non-threatening and satisfying as possible if all the participating editors would take a moment to answer a few questions for us, in this section please. Would you like any additional feedback on the writing style in this article? If you write a lot outside of Wikipedia, what kind of writing do you do? Is your writing style influenced by any particular WikiProject or other group on Wikipedia? At any point during this review, let us know if we recommend any edits, including markup, punctuation and language, that you feel don't fit with your writing style. Thanks for your time. - Dan Dank55 (talk) 16:02, 9 April 2008 (UTC)

P.S. The survey will end on April 30. - Dan Dank55 (talk) 20:39, 11 April 2008 (UTC)

GA review

Overall, I'd say this is a pretty good article! Very good in fact. It's a pretty long one, so it's taking me a while to read through it all in detail, so I'm going to stagger my suggestions. Since I'm not actually finished reviewing the article yet, I'll hold off on putting the article on hold, and will only do so once I am finished. So for now the article is still in the state of "being reviewed". And I know the below looks like alot of bullet points, but the article is pretty long, and alot of the bullet points are very minor fixes. So, without further ado, here's my suggestions/concerns so far:

1. Early on, the article mentions that the Nebular hypothesis is the currently accepted hypothesis, which begs the question: what are the other hypothesis? Basically, by basing the article entirely on the Nebular hypothesis, it only serves as a summarized version of the Nebular hypothesis article itself. I feel like alot more could be said about other hypothesis (scientific and otherwise), and maybe a little less about the nebular hypothesis. Right now the "Other theories" section is more of an afterthought then anything.
2. Along the same lines, I'm not sure what the point of the Issues with the nebular hypothesis section is. It seems to apply more to the hypothesis than the topic.
3. In general dashes used in between numbers (like "2 - 230") should be a medium dash without a space. So "2–230". The small dash is only used for hyphenated-words. And number words like "million" should have an   between the number and the word. So "230 million.
4. "Theories describing formation and evolution" is missing a "the", I believe.
5. "Main article: nebular hypothesis" Nebular should be capitalized.
6. In general, try and keep in-line citations to the end of the sentence, unless a particular phrase is so unbelievable it can't be avoided.
7. The last paragraph of the Pre-solar nebula section kind of comes out of nowhere. It doesn't seem to have anything to do with Pre-solar nebula, and though it's obviously important to mention the facts that it contains, I don't think that section is the appropriate place to do so.
8. I'm not sure what the point of the Solar System's Most Abundant Isotopes table is.
9. The last two paragraphs of the Formation of planets section are too small (2 and 1 sentence, respectively). I'd recommend either expanding them, rewording them, or combining them.
10. "US state of Arizona" awkwardly worded.
11. In the planetary migration section, it's a little awkward to keep referring to Neptune and Uranus as "the less massive planets." Why not just call them by name?
12. Protoplanetary disk needs a wikilink.
13. "Because planetary migration requires that the protoplanetary disc still be present, it must occur while the planets are still forming, within a few million years of the initial formation of the planet." This is a slightly awkward sentence because it stops talking about the actual formation of the solar system, and starts talking about the phenomenon of planetary migration. It's a valid point to make, but relate it to topic at hand. Broad explanations like that are probably better suited for the planetary migration article itself.
14. "However, a large number of KBOs" What is a KBO? Did I miss the explanation of this earlier in the article?
15. "circumplanetary discs" isn't explained, nor is it wikilinked (since an article doesn't exist). One or the other is needed, and since an article doesn't exist, I'd recommend giving a brief explanation of what it is.
16. "(These attributes are impossible to achieve via capture, while the gaseous nature of the primaries make formation from collision debris another impossibility.)" I don't see any reason for this sentence to be in parenthesis. Same with "(Alternatively, neither of these events may occur; the inherent chaos means only future possibilities can be determined.)"
17. "choking on the products of their nuclear reactions" is "choking" really the right word here? Drewcifer (talk) 05:20, 12 April 2008 (UTC)

P.S. I just noticed the suggestions hamiltonstone made above a few months ago. Some of his suggestions pertain to the concerns I have with the article (namely in its breadth), so take a look at all of his suggestions as well, since it doesn't appear all of his suggestions have been taken into account yet. In the meantime, I'm finished reviewing the article, so I'll put it's nomination on hold, a process that lasts about 7 days. I will have to either pass or fail the article once those 7 days are over. Let me know if you have any questions or concerns in the meantime. Drewcifer (talk) 07:44, 12 April 2008 (UTC)

Here are a few quick thoughts on the review. (Thank you, Drewcifer, for a thorough review.) I'm traveling, so I have limited time to make edits.

• Regarding the Nebular hypothesis: The Nebular hypothesis is a very broad umbrella which is, in some form, so broadly accepted that the other theories only merit the afterthought mention they get. However, it is a scientific theory and there's enough uncertainty about the formation of the Solar System that I'd prefer to keep the current wording.
• Details here vs. in nebular hypothesis article: I think it's best to keep the formation details here because the nebular hypothesis is the name for the processes by which the Solar System is thought to have formed. The nebular hypothesis is more broad and does not only apply to the Solar System. However, I do think that some of the discussion here of extrasolar planets and extrasolar planetary system formation could be trimmed unless it explicitly informs our understanding of how the Solar System formed.
• I'm not sure which of hamiltonstone's suggestions haven't been implemented; we have certainly made a fairly thorough (I think) attempt to address all of them, including a significant restructuring of the article. However, it's certainly possible that the restructuring has still left hamiltonstone's concerns present.

I think that renaming the sections so they're less explicitly based on the nebular hypothesis might help with the impression that there are other hypotheses that merit further attention. In particular, perhaps we should rename the Issues section something like "Remaining unresolved issues with the formation and evolution of the Solar System"? (That wording is terrible and should not be used, but something along those lines....) ASHill (talk) 03:18, 15 April 2008 (UTC)

Hey Ashill, thanks for your work on the article so far and your response. My main concern with the article (that I think was something hamiltonstone brought up earlier) is the scope of the article. Specifically, it concentrates far too much on a single (scientific) hypothesis, while not even mentioning the cornocopia of other theories, scientific, historical, religious, cultural, and the like. I just did my best to prove this exact point on Serendipodous's talk page, so please see my full argument here. I realize the intent of the article (and the Solar System Wikiproject and those that wrote the majority of this article) was to do a scientific overview of the topic, and it does that very very well, but unlike many other solar-system articles (like Molecular cloud for instance), there's alot that's not being said here. For a god example of what I mean, take a look at Solar eclipse or Comet. Drewcifer (talk) 03:31, 15 April 2008 (UTC)

The problem with mentioning earlier hypotheses, such as religious beliefs, is that to apply the term "Solar system" to those periods is anachronistic in the extreme. The Bible makes no mention of other planets in its creation myth, and tells the story of creation from a geocentric point of view. You can't speak of a "solar system" until the heliocentric view became predominant, which didn't happen until the late 17th century. The term "solar system" isn't recorded until 1704. Even then, we aren't strictly talking about a "solar system"; what we now call the Solar System was still considered the entire universe. The idea of a "solar system" didn't really stick until the 19th century, when Father Angelo Secchi discovered that the Sun was a star. Such early ideas belong in an article about the creation of the universe or the creation of the world, but the Solar System, being a purely modern concept, should be discussed in purely modern terms. Serendi^podous 07:00, 15 April 2008 (UTC)

I have to agree with Serendipodous. The "Solar System" with big spherical rocks wandering around a central-nuclear-non-deity is a recent concept. Where as eclipses and comets have been seen since the beginning of time and thus have many religious concepts. -- Kheider (talk) 12:39, 15 April 2008 (UTC)

I see. Good points. Although this sounds roughly like semantics, I will defer to your superior knowledge on the subject. That said, since Wikipedia should be written for the average Joe such as myself (and not written for someone who already knows all of this stuff), I would suggest that the article makes note of the same line of reasoning you guys just presented. So, here is my latest suggestion (which is definitely easier to accomplish then my last): start the article off with a small pre-nebular hypothesis section. Explain the concept of the solar system, explain when the concept arose, who invented the concept, etc. I would imagine you could do so in three of four sentences easily. Then, probably in a new paragraph, mention some early solar system hypotheses, perhaps cut+paste the two paragraphs later on in the article that are already there. Then mention the nebular hypothesis, when it was created, who created it, and why it has come to scientific prominence (ie what it offered that previous hypothesis didn't). So in all, I'm suggesting an introductory section that would probably be around four paragraphs. Two of which are already in the article. Lastly, I still have a problem with the problems of the nebular hypothesis section. If you're going to base the article on the hypothesis, which it seems is a reasonable thing to do, then getting into the scientific nitty gritty of the actual hypothesis seems somewhat unrelated. Especially since, as has been pointed out, the nebular hypothesis isn't an exclusive phenomenon to our solar system. Hope all of this sounds a bit more reasonable. Let me know what you think. Drewcifer (talk) 20:27, 15 April 2008 (UTC)

I think that this article is best if it acts essentially as a detailed sub-page of the summary style Solar System article. I think talking about the history of knowledge of the Solar System is better left in the main article to keep this article narrowly focused on the formation and evolution of the Solar System.

I agree that the presentation of Issues with the nebular hypothesis section good be better presented because what we really care about here are issues with our understanding of the formation and evolution of the Solar System. I'll try to work on that, but any suggestions or help would be most welcome. ASHill (talk) 22:53, 15 April 2008 (UTC)

My suggestion to add some context to the article is to avoid misunderstandings (with the common reader) like the one I experience in this review: "Well, what about everything else? I've never even heard of the nebular hypothesis. This article sucks! It's totally incomplete!" Semantics play an important role in explaining this, as does an explanation of the general progression of our knowledge. To the average reader, I would stipulate that the article's unflinching focus on the nebular hypothesis seems odd and incomplete. Let me put it this way: everything you've explained to me makes sense, but it serves no purpose here on the talk page. I would guess that my concerns would echo the average reader, so why not be upfront about the method to your madness, and provide it to every reader, not just me? Remember, we're not writing a scientific journal here, we're writing an encyclopedia for everyone. Drewcifer (talk) 23:08, 15 April 2008 (UTC)

Re point 7: I've reworded the paragraph and the proceeding one a bit; I think it flows better now and it's more obvious why the point is relevant there. ASHill (talk) 20:18, 16 April 2008 (UTC)

For accounting, I believe that points 5, 7, 8, 9, 10, 11, 12, 14, and 16 have been addressed. (More may have been; I haven't checked all points.) Points 1 and 2 (the biggies) are on their way with the revision currently underway (mostly by Serendip). ASHill (talk) 20:32, 16 April 2008 (UTC)

I fixed points 4, 13 and 15 (if I didn't do a good enough job, let me know). Point 3 can be addressed by running Brightorange's program when the article is finished. As regards point 6, I tend to disagree with that philosophy, because in my experience, there is no point anyone can make that someone else will not find ludicrous or objectionable. Point 17 will need either a better metaphor (I can't think of one) or a rework by a more literally minded person than myself. Serendi^podous 20:53, 16 April 2008 (UTC)

Re point 6: I concur. When a citation is used for a specific point within a sentence, it's easiest to identify if the footnote is right there rather than at the end of a sentence. I'll check and try to move any mid-sentence footnotes that aren't used for very specific facts to the end of the sentence. ASHill (talk) 22:13, 16 April 2008 (UTC)

Re point 17: I deleted the choking clause; in addition to being awkward, it's wrong (or at least not true for all red giants). Is a further expansion of the Evolution hypotheses section in the works? If not, I'd delete the section. ASHill (talk) 22:17, 16 April 2008 (UTC)

I have a number of books on reserve in the British Library to deal with that. However they are on a 48 hr + waiting list, and so won't be available until at least Friday. Serendi^podous 06:37, 17 April 2008 (UTC)

WOW! Awesome work you guys! That History section is great, and I hope you agree it adds a layman's touch to the article. I know the section isn't complete yet, but since the 7 days for the review hold are up, I'm just going to go ahead and pass the article regardless. I'm glad to hear that you've got some books on the way to add a bit more to the Evolution hypothesis, but in the meantime I don't see any reason to hold up the article's nomination because the British Library is being slow. It's clearly GA status now, and on the verge of FA greatness. Before taking that last big step, my only further recommendations would be to round out the History section a bit more, and to move it to the beginning of the article rather then the back. At the end it feels a bit like an afterthought, and it just seems to make a better logical progression if you start out with a historical view (as the lead does already). Also, the prose needs a bit of a copyedit before it can be called perfect. It's all brand new prose, so it's still a little rough around the edges. If and when the article is nominated at FAC, please drop me a line and I'll be happy to support its nomination. Drewcifer (talk) 10:44, 17 April 2008 (UTC)