Talk:Sun/Archive 3

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What matter is the sun called?

it's not liquid, gas, or solid... there's a name for it, but i can't think of it... anyone know what it is? —Preceding unsigned comment added by 66.181.229.124 (talk) 04:59, 25 January 2008 (UTC)

Plasma69.76.19.216 (talk) 06:53, 29 January 2008 (UTC)

No Angular Momentum listed under the "Theoretical problems" heading?

Something like this?

Solar System distribution of angular momentum problem

Main article: Solar System distribution of angular momentum problem

Most prevailing theories suggest that the solar system was formed out of a rotating nebular. As the solar system gravitationally condensed, the the sun should contain the bulk of the rotation. However, these theories have problems explaining the distribution of angular momentum. Our sun holds more than 99 % of the total mass, but less than 1 % of solar system's total angular momentum. This implies that sun must have lost most of its initial angular momentum to the outer members of the system. How this could have happened, is difficult to explain. Theories vary from tidal drag , to magnetic braking . Competing theories may have to consider why Jupiter's moons, in a strong tidal and magnetic grip by their parent planet, do not appear to have slowed Jupiter's rotation significantly. Esteban (talk) 04:03, 29 November 2007 (UTC)

What is μW/kg ?

I read this in the body of the article, about the energy output of the sun, yet have not found it in any other place on Wikipedia: What is μW/kg ? Thank you. --TallulahBelle 23:55, 17 April 2007 (UTC)

A W/kg is a power to mass unit, i.e. the amount of energy (in watts) produced for each unit of mass (in kilograms). The "µW" part means microwatts, that is one millionth of a watt. Hope that helps. Java13690 17:05, 18 April 2007 (UTC)

New question

I came here looking for quick access to graph of SOLAR SPECTRUM reaching us through Earth's atmosphere, and particularly the EM FLUX DENSITY of the SOLAR SPECTRUM. Haven't found this yet on this page. Where is it? Would it be relevant?? [jlancaster]

Try the solar radiation article. (SEWilco 00:04, 2 November 2006 (UTC))

Ambiguous

"Most of the Sun's mass lies within about 0.7 radii of the center." While I'm sure the above statement is true, there isn't really any useful information which can be gleaned from this statement. Unless perhaps if most of the mass of a sphere with constant density lies outside of 0.7 radii of the center and this is common knowledge...

In a sphere of uniform density with radius 1, the proportion of the mass lying within a radius of 0.7 is

${\frac {{\frac {4}{3}}\pi (0.7)^{3}}{{\frac {4}{3}}\pi (1)^{3}}}=(0.7)^{3}=0.343$

So in fact more than 65% of the mass of a sphere of uniform density lies between 0.7 < r < 1.0. But in the Sun, the density in the outer layers is so low that over 95% of the matter lies within 0.7 radii.

Lead section

The formerly extensive lead section was removed in a series of misguided edits starting several months ago [1], leaving a tiny rump that gives no general overview of the article. Would anyone like to restore it? It looks like a complex job - bits of it seem to have been moved to various other bits of the article - so whoever wrote it originally probably ought to try and sort the mess out. 81.178.88.15 21:52, 23 November 2006 (UTC)

Please Clarify Velocity...

The Orbital Characteristics box contains the following fact: Velocity: 20 km/s relative to average velocity of other stars in stellar neighborhood Can someone please explain to me in plain English what that MEANS? Thanks! (And if I should be asking this question elsewhere, please let me know where that would be, as I'm a newcomer, just finding my way around this glorious maze!) Laurie Fox 12:09, 26 November 2006 (UTC)

It is not completely clear but the "average velocity" in this case is something like the "velocity of the center of mass of" other stars in the region. The reason for stating it that way is that you can't measure an absolute velocity in space -- only velocities relative to a frame of reference. The stellar neighborhood of the Sun can be used as such a reference. The sentence is a little vague because it doesn't actually specify which stars should be used to set the reference frame! Cheers, zowie 15:08, 26 November 2006 (UTC)

I changed the claim that our galactic orbital speed is 217 km/s to show the actual uncertainty in the numbers. The cited reference is from '86, but the astronomers I know still use 220 plus or minus 20 km/s as the approximate orbital speed, and can talk for hours about the uncertainties involved in these measurements. 217 km/s? How wonderful it will be when we can achieve that kind of accuracy! EdgarCarpenter (talk) 01:50, 27 January 2008 (UTC)

Colonize the Sun

This sounds stupid, but would it be possible to colonize the sun? Please answer my question. Mrld 02:31, 27 November 2006 (UTC)

Yes (given sufficiently advanced technology), but you wouldn't want to. zowie 04:45, 27 November 2006 (UTC)

You'd have to find someway not to be drawn gravitationally down into the sun. You'd have all the energy you could ever want, but would have to create an environment we could live in and shield from the excess energy. It would be utterly artificial and offer no real advantage. Planets, planetoids and orbital habitats are far more useful.Mzmadmike 04:01, 6 June 2007 (UTC)hel ya

It has been proposed that in the far future when all stars have left the main sequence and we are left with white and ultimately red dwarf stars, the "colonisation" of the surface of the star may be the best way in which living systems can survive for the very long term. John D. Croft 07:18, 9 August 2007 (UTC)

The surface of a white dwarf is still hot enough to melt titanium 129.115.251.215 (talk) 22:00, 6 February 2008 (UTC)

Citations Need to be Fixed

I noticed that the citations appear to be malformed and could use a little help. I signed up for an account to fix them, but alas. Biocsnerd 05:49, 1 December 2006 (UTC)

Fixed. It looks like part of a paragraph got deleted in the recent spate of vandalism and the deletion happened to cut a reference in half so there were mismatched reference start/end tags. I've replaced the missing material with stuff from the November 16 version of the article, from before things got messy. In any event, welcome to Wikipedia! I believe new accounts are allowed to edit semiprotected articles once they've been around for four days (the delay prevents vandals from being able to simply sign up for endless new accounts to easily bypass the lock), so hang around a bit longer and things will be back to normal for you. :) Bryan 06:50, 1 December 2006 (UTC)

Rigid iron surface

Experts please check [this] and include in the article if it is not a hoax.. Cunya 11:38, 1 December 2006 (UTC)

Looks to me more like a crank than a deliberate hoax. It is untrue either way. The structure of the sun is well known, including the inside, because effects of sound waves make it possible to observe the inside. That is separate from explaining how something could be so hot and still not melt. Man with two legs 13:58, 1 December 2006 (UTC)

The "theory" fits under the electric universe concept, which is quite correctly categorized as a "fringe subject without critical scientific evaluation." As the man with two legs says, crankery. It doesn't warrant a mention in Sun, IMO, though perhaps a mention on the electric universe article would fit. Bryan 17:23, 1 December 2006 (UTC)

The thesurfaceofthesun.com article ranges between wrong and word salad. The surface of the Sun is demonstrably not covered with a neon layer as claimed -- the spectrum is dominated by hydrogen and helium. Further, the temperature of the photosphere is readily measurable using the blackbody radiation spectrum. It is close to 6,000 Kelvin. Iron boils in 1 atmosphere of pressure at about 2700 Kelvin, and the pressure at the solar photosphere is a small fraction of an atmosphere. The authors appear to be confusing the presence of trace quantities of particular elements, with the Sun being made of those elements. For example, the solar corona contains trace quantitites of iron, and this element emits strong spectral lines in the EUV. Those spectral lines are bright enough that scientists use them to image the structure of the corona. That does not mean the Sun is made of iron. Likewise with the Ne and Mg emission lines that are used by SOHO's SUMER spectrograph. The science of helioseismology informs us about the inner structure of the Sun: while we can't take a direct picture of the solar interior using light (because the photosphere is opaque), sound waves do travel through the Sun and are shaped by its interior. By measuring motions of the photosphere due to sound waves propagating through the Sun, it is possible to "back out" the inner structure so well that (for example) it is possible to make images of sunspots on the far side of the Sun. This is done routinely by the nice folks at [[2]] the MDI/SOI project. If there were a rigid iron layer, they would have "seen" it. zowie 18:14, 1 December 2006 (UTC)

Oop -- forgot to add the direct link. Look [here] to see an image of the far side of the Sun today. You can check that it was (close to) right by looking at the [SOHO] daily images a week or two from now, when the structures have rotated around to the front side. zowie 18:17, 1 December 2006 (UTC)

Thank You all for the remarks! Cunya 19:41, 1 December 2006 (UTC) For more on this topic I suggest forum discussion with author Michael Mozina at [3]. The real problem with his theory is not that surface of the Sun is made of iron but that whole Sun is an iron ball. When asked how come Sun's measured density is only 1/6th of iron's Michael replied vaguely that factors like Birkeland currents and "dark energy" cause this discrepancy. His theory in general is bogus, not worthy of consideration.The sun is actually a giant light bulb says the scientist.—Preceding unsigned comment added by RabbiBob007 (talk • contribs) 11:54, 26 March 2007

This whole discussion in both childish and it is filled it utter lies. I never once claimed that "dark energy" caused any discrepancy. This is pure, unadulterated baloney. None of you ever once addressed any of the actual images. How predictable from people that aren't the least bit interested in truth. - Michael Mozina - Author - The Surface Of The Sun. —Preceding unsigned comment added by 216.7.113.91 (talk) 05:26, 4 January 2008 (UTC) Here is a link to a legitimate scientific debate on this topic. http://uplink.space.com/showflat.php?Cat=&Board=sciastro&Number=468660&page=1&view=collapsed&sb=5&o=0&fpart= —Preceding unsigned comment added by 216.7.113.91 (talk) 05:33, 4 January 2008 (UTC)

Vandalism, Dec. 14

Today appears to be an active day for vandals. I just corrected some small cases. I noticed that someone earlier did some corrections but didn't look carefully at all the damage that had been done (i.e. just removed an inappropriate statement without looking at the history). --Mcorazao 18:58, 14 December 2006 (UTC)

Suns orbit around the CM

All the other objects in the solar system have their orbits about the solar system center of mass explicitly stated, shouldn't the sun's orbit around the CM be also stated SOMEWHERE?. Its not all that erratic, given the huge mass of Jupiter. PAR 21:13, 29 December 2006 (UTC)

I agree this is relevant, assuming it has a citation. HighInBC ^{(Need help? Ask me)} 21:16, 29 December 2006 (UTC)

I don't think we need a citation to do high school math, but when you do it, it turns out its more erratic than I thought - the equation for the center of mass is:

$m_{0}r_{0}-m_{J}r_{J}\pm m_{S}r_{S}=0$

where $m_{0},\,m_{J},\,m_{S}$ are the masses of the sun, Jupiter, and Saturn respectively, and $r_{0},\,r_{J},\,r_{S}$ are their mean distances from the center of mass. The plus or minus is for Saturn aligned with Jupiter on the same side of the sun, or the opposite side. This can be solved for $r_{0}$.

Using

$m_{0}=332946m_{e}\,$

$m_{J}=317.8m_{e}\quad r_{J}=5.20AU$

$m_{S}=95.16.8m_{e}\quad r_{S}=9.53AU$

where $m_{e}$ is the mass of the earth and using 4.65x10^-3 AU for the solar radius gives $r_{0}=1.65$ solar radii for Saturn on the same side as Jupiter and $r_{0}=0.48$ solar radii for Saturn opposite Jupiter. PAR 22:04, 29 December 2006 (UTC)

I agree this is a pretty important fact, that the Jovain giants cause the Sun to orbit around a baricenter outside of the suns surface

• Another question: Should the following phrase in the structure section ("While the Sun does not rotate as a solid body (the rotational period is 25 days at the equator and about 35 days at the poles), it takes approximately 28 days to complete one full rotation") be edited and qualified as such: "While the Sun does not rotate as a solid body (the sidereal rotational period is roughly 25 days at the equator and about 35 days at the poles), it takes approximately 28 days to complete one full synodic rotation..."? I realize that sidereal and synodic are both used to describe a 2d body in relation to the sun and this is more or less using a the sun as its own reference, but is there a way to get this point across to the average reader? Foofighter20x 11:52, 9 April 2007 (UTC)
  • Checked my professional books and went ahead and made the change... Let me know what you think! Foofighter20x 08:24, 14 April 2007 (UTC)

Solar neutrino - is it still a problem?

According to the text of the "Solar neutrino problem" subsection, experimental data now complies well with the theory. Hence, I believe, this text needs to be expelled from "problems" and incorporated in some other form into the article. Cmapm 01:37, 4 January 2007 (UTC)

You are right, it isn't still a problem. However, it was historically a problem, and I think that is what is meant by it's inclusion in the "Theoretical Problems" section. Perhaps rephrasing the title of the section is in order, but I don't think it should be moved, as it fits in well where it is. Grokmoo 18:43, 4 January 2007 (UTC)

Agree. Then maybe the section name should be something like "Solar neutrinos (past problem)"? Cmapm 02:11, 8 January 2007 (UTC)

Ok. Grokmoo 18:59, 10 January 2007 (UTC)

I think it's made abundantly clear by the text that this is a problem that's been resolved. Putting 'past problem' in brackets in the section heading is very clumsy and, I think, unnecessary. If any further clarification is needed, the section text would be the place to do it, rather than the heading. 81.178.208.69 22:09, 10 January 2007 (UTC)

I still believe, it wasn't completely clear from the text, but clarification within the text is alright too. I went and did corresponding changes. Cmapm 22:31, 10 January 2007 (UTC)

The sun's role in timekeeping (solar calendars / year concept)

Any thoughts out there on where/how/if the solar calendar and concept of the year should be discussed in the article? I was thinking of creating a section in "The sun and human culture" for these topics. There is currently a few lines about the Persian calendar there, though it is very poorly written and largely irrelevant.

I feel there should be some mention of this topic in the lead paragraph — something along the lines of "The sun is the basis of many calendars, and the term "year" is generally understood to mean the amount of time the Earth takes to orbit the Sun." I'd like to hear some opinions on this first, though, before editing such a high-profile article. G Rose (talk) 07:38, 9 January 2007 (UTC)

One problem is with the definition of the englihs term "noon" as the moment of the day with the sun at Zenith. That is true only for places between the tropices. In the northern and southern regions the sun never rises to reach the zenith. —Preceding unsigned comment added by 79.119.172.209 (talk) 17:07, 10 December 2007 (UTC)

Astronomy: Principles and Practice by A.E. Roy and D. Clarke [[http://www.amazon.com/Astronomy-Principles-Practice-Fourth-PBK/dp/0750309172/ref=sr_1_1?ie=UTF8&s=books&qid=1200690648&sr=1-1]] gives a good treatment of this topic if you would like to read more on this topic of the Sun and timekeeping -- Gilgamesh007 (talk) 21:14, 18 January 2008 (UTC)

Article Name? "The Sun" or "Sun"?

The article name seems to contradict usage in the article. The heading above the picture uses "The Sun" and throughout the article, "The Sun" is used. I believe the correct name should be "The Sun" as it is rarely refered to without the "The". I will provide an example: The Earth is the 3rd planet in the Solar System. or Earth is the 3rd planet in the Solar System. Earth can be refered to without the "The" easily, but Sun as a Noun on its own is very uncommon. The Sun is the only star planet of the Solar System. or Sun is the only star planet of the Solar System. Similarly named is the Solar System article, which does not named with the "The". I'll leave it to others to make the descision, which I believe will end up with no change.203.102.177.165 02:15, 11 January 2007 (UTC)

To avoid confusion, as well as conflict in murky situations, Wikipedia follows this guideline: Wikipedia:Naming conventions (definite and indefinite articles at beginning of name). Gracenotes^T § 02:19, 11 January 2007 (UTC)

And The Sun is a British tabloid (with the famous page 3), while the sun is a rather average yellow dwarf. --Stephan Schulz 23:03, 12 March 2007 (UTC)

What about the Greek or Latin "Sol" (I'm not sure which language it comes from)? I mean, Sol is the star's astronomical name... right? Or even "Sol - our Sun". Foofighter20x 12:59, 9 April 2007 (UTC)

Sol is most certainly not the astronomical word. Astronomers use the standard English 'The Sun'. Sol is Latin based and used in Romance languages (eg; El Sol in Spanish). Sun is from the Germanic Sonn. Recently someone changed all the references to the Moon in its Wikipedia article with the word Luna because he had read it in a sci-fi book. Usage can be checked on the website of the IAU. PrivateWiddle 21:09, 14 May 2007 (UTC)

Theoretical Possibilities.

I think that Theoretical possibilities need to be put onto the Wiki page. At the moment, they are getting removed. Theoretically the sun could be an intelligent entity. —The preceding unsigned comment was added by Fishyghost (talk • contribs) 22:11, 12 January 2007 (UTC).

You would have to provide reputable sources as a reference for the material. Otherwise, it is just hypothetical, which doesn't qualify it for inclusion - especially for a featured article such as this one. --Ckatz^chat_spy 22:14, 12 January 2007 (UTC)

Heh! Theoretically, my socks could be intelligent, too. MrG 4.227.249.163 23:57, 31 January 2007 (UTC)

Color temperature

Hi. There is some inconsitency with "G2 means that it has a surface temperature of approximately 5,500 K" and Main_sequence article, where it says that G2 means 5,700 K. Could someone clarify that? Delete if inapropriate. Elthe 22:24, 16 January 2007 (UTC)

Messed up revert attempt

I thought I saw a remnant from vandalism -> revert or something and tried to fix it, a spare bracket in a thumbnail. See Sun#Magnetic field, but I seem to have messed up the link. Sorry. Not sure how long since it got messed, but I couldn't find an older version as it should have been. Is this the intended image it should have linked to? [4]. Apologies, I was under the influence and got cocky confident. :( MURGH ^disc. 02:54, 27 January 2007 (UTC)

I think you got it... thanks for catching that one, I missed it when I was cleaning up. Cheers. --Ckatz^chat_spy 03:00, 27 January 2007 (UTC)

ok, I replaced it, but it seems to once have led to a page, and not just a gif.. Annoying that I can't really deem if it makes sense or not, but at least you're all made aware of it. —MURGH ^disc. 01:27, 28 January 2007 (UTC)

Change In Solar Mass

I was on another site that had a letter from a young Earth creationist that claimed, among other things, that the Sun couldn't be very old because it's been losing mass from nucleosynthesis and the solar wind, so if it were billions of years old it would have been bigger than the Earth's orbit.

Preposterous of course, but it did lead to the interesting question of exactly what changes in mass the Sun has undergone over about 4 billion years. Since mass-energy conversion produces a lot of energy for very little mass, I suspect the amount of mass needed to maintain energy production at the current rate is a very small fraction of the Sun's mass even over the long term, but I have no data.

Of course, comets and the like do fall into the Sun, so it is entirely possible that it has actually *gained* mass. That would be an interesting thing to add to this article. MrG 4.227.249.163 23:54, 31 January 2007 (UTC)

I did some poking around and the ASK AN ASTRONOMER site at Cornell had an article on such lines. Assuming the current state of the Sun, it will burn up about 21 Earth masses in a billion years. That's like 0.006% of its mass, so no problem. However, that doesn't cover loss from solar wind or gain from comets and such, so it's still kind of an open question. MrG 4.228.21.136 01:50, 2 February 2007 (UTC)

The idea of 21 Earth masses worth of comets falling into the sun is pretty far out, so I think it is safe to say that the sun is losing mass. Indeed, from this very article, we can see the sun is emitting about 3.8e26 watts of power. Using E=m*c^2, we see that this corresponds to about 4.3e9 kilograms per second. That sounds like a lot, but keep in mind the sun's mass is about 2e30 kilograms. Assuming the luminosity of the sun has been roughly constant over its lifetime, this works out to about 5e26 kilograms over the lifetime of the sun (about 5 billion years). This works out to about 0.03% of it's total mass. Its not exactly the figure quoted above, but you get the idea - the sun's mass has not changed much in its lifetime. Grokmoo 04:22, 8 February 2007 (UTC)

The Solar wind article says mass lost to the wind is about one fifth of that lost to fusion. When dealing with 99% of the solar system's mass, 21 Earth masses isn't much. I don't know how many comets and other objects have fallen in during a billion years, but probably not much because the Oort cloud upper range estimate is 100 Earth masses so there can't be all that many comets. (SEWilco 05:38, 8 February 2007 (UTC))

I poked around a bit and found that the average diameter of a comet seems to be in the 1km to 10km range. Suppose it is on the high end, at 10km. A comet will have a density of around 1000 to 5000 kg / m^3. Assuming a roughly spherical shape, we get that the comet's volume will be about 4*(radius)^3 = 4e6 m. Again assuming the high end on the density estimate, we get a mass of about 2e10 kg per comet. Now the mass of the Earth is about 6e24 kg, so 20ish Earth masses is about 1.2e26 kg. This would imply that about 1.2e26 / 2e10 = 6e15 comets would need to have fallen into the sun. Now this is over say, 5 billion years, which would mean that about 1.2e6 comets would need to fall in per year, which works out to roughly 2 a minute. So you see, it is safe to say that 21 Earth masses of comets have not fallen into the sun since it's formation. Grokmoo 23:25, 22 February 2007 (UTC)

Vandalism help

Note the juvenile vandalism of a sexual nature in the infobox. It has persisted for a while without correction. I cannot correct it because I do not know the information to put in its place. Somebody who does should fix that. Srnec 03:35, 9 February 2007 (UTC)

Thanks for catching that one - the vandalism was actually in the template that creates the infobox. --Ckatz^chat_spy 04:01, 9 February 2007 (UTC)

Hmm....I tryed editing some vandalism but when I click on the editing tab, all the content is there and the vandalism doesn't show up. How is that possible? Maniac 22:03, 12 February 2007 (UTC)

Sun observation and eye damage

"Note: The number of watts per unit area of retina is the same whether one uses binoculars or not, so the above paragraph seems to be contradicted by the following paragraph."

The difference is in the light gathered by a 7mm diameter lens (eye) and the light gathered by a 50mm diameter lens (typical binacular lens)...

(That was a comment now removed from the section Sun observation and eye damage)

If you look at the sun without optical aid, the heated spot is quite small and can dissipate heat into the surrounding bits of your eye, thus slowing down the damage and giving you time to blink. With binoculars, there will be a large part of your retina that is surrounded by a region that is also being heated and so will have nowhere to dissipate its heat. Thus it will heat up very fast and you will not be able to blink fast enough to escape damage. Man with two legs 16:10, 13 February 2007 (UTC)

One of the directors of the Society For Popular Astronomy in the UK is blind in one eye from a childhood experiment where he tried to make a filter for his telescope out of sunglasses. He was blinded quickly. There is no pain response, so it needs to be drilled into everyone, but particularly kids, that under no circumstances should the sun be viewed through any type of optical instrument. PrivateWiddle 22:59, 14 May 2007 (UTC)

I haven't looked in for several months, but just noticed that someone had reworded the first paragraph of this section to once again claim that looking at the Sun with the naked eye is dangerous. It's not particularly dangerous for normal people. I'm restoring something like the earlier wording, along with the deleted reference. If you edit the article to claim that it is dangerous, please include a citation. zowie 23:24, 30 August 2007 (UTC)

Sorry to pack so many references into the main article here -- I found a couple more interesting notes in the literature about high UV exposure and focusing of near-UV onto the retina. Brief looks appear safe, but there are some cases of solar retinopathy from religious rituals in which folks stared at the Sun for more than a few minutes. There's a nice review discussion by Andrew Young at http://mintaka.sdsu.edu/GF/vision/Galileo.html. zowie 16:50, 31 August 2007 (UTC)

Another picture of the sun is available

File:Sun at 304 Angstroms.jpg

For those who may be interested, I uploaded another 304 Å, SOHO image of the sun (shown at right). This is is similar to the “Image:Sun, Earth size comparison labeled.jpg” picture currently used in this article except that it doesn’t feature the little spot of the Earth and it’s associated “Earth” caption. This new picture also doesn’t feature a large prominence. As such, it is not as dramatic a picture of the sun and is more representative of what the sun typically looks like. I’ve placed this notice here so other authors can know of the picture’s availability for their articles. If authors want to improve upon this picture with further editing, or if they want to have an entirely different image of the sun, please create a different image page instead of uploading a revised image into the existing one; I'm currently using this image in another article and am happy with it as is. Greg L (talk) 20:37, 15 February 2007 (UTC)

The image on the article should be deleted. 91.153.63.193 04:48, 3 May 2007 (UTC)

Nishani?

"The Sun revolves around Nishani! The Nishani is the star at the center of the Solar System." First of all. What is Nishani? Secondly, if the sun revlovs around "Nishani", and "Nishani is the star at the center of the Solar System", then the sun revoles around itself?!?!... Either vandalism or "Solar System" need to be replaced with the "center of the galaxy".

Sprotected

I hate to have to do this; however, the vandalism over the last several days is getting unbearable. I've semi-protected this article for the time being, though I hope this semiprotection will not have to last for long (although this article has been unprotected quite rarely in the past, and everytime it has been, the vandalism has continued at the same rate). If there are any objections to this, please let me know. Thanks. AmiDaniel (talk) 07:56, 1 March 2007 (UTC)

I understand the reason, but while reading I saw a small place to make a correction and clarification, so I logged in but then found that I couldn't edit. The article may not be vandalized, but it also can't be improved while protected. Wish there was a compromise. Being generally a wikipedia user and only casual editor/contributor, I won't check back to make this correction later. Myrrhlin 22:05, 12 March 2007 (UTC)

I feel that we should re-semiprotect. I almost missed the latest violence since it coincided with my edits. Nick Mks 17:08, 30 March 2007 (UTC)

Sigh... Despite 12 vandalising edits in two days we are getting no protection. Count me out as far as reverting is concerned. Nick Mks 18:01, 1 April 2007 (UTC)

(Un)Development Modern Scientific Understanding?

Back on October 29th (2006) I raised the following concern on this discussion page:

I'm not sure if this is the most relevant place to post this (and please feel free to move it if it isn't), but in the section, "Development of Modern Scientific Understanding", the last paragraph states: "Finally, in 1957, a paper titled Synthesis of the Elements in Stars[28] was published that demonstrated convincingly that most of the elements in the universe had been created by nuclear reactions inside stars like the Sun."

Now I'm certainly no astronomer, but, by mass, doesn't Hydrogen (by far) comprise "most" of the elements in the universe? Further, virtually by definition, Hydrogen isn't created "by nuclear reactions inside stars". As such, should there be some distinction made in the article to show that in this reference "most" doesn't mean by mass but rather (I assume) by % of elements on the periodic table? 216.240.7.149 00:58, 29 October 2006 (UTC)

At the time, one of the editors agreed with this in principle and added "other than Hydrogen" to the statement. I notice, however, that in the current iteration of the main article, some 4+ months later, this has been removed. Can someone explain why it is now felt that the "other than Hydrogen" specification isn't a valid one given the issues raised in my original query? 216.240.7.149 01:41, 6 March 2007 (UTC)

I think "most of the elements" refers to those on the periodic table. Just the number of elements, not any measurement of their amount. (SEWilco 04:10, 6 March 2007 (UTC))

Okay, and I have no problem with you intepretting it that way, however, when *I* read it, my first thought was "there's no way that there are more elements in the universe than hydrogen". So I ask again, since the phrase, as it's written, is ambiguous as to its interpretation, why not include the simple distinction? What's even more confusing is that someone chose to increase the ambiguity of the statement by removing the clarification... Let me put it this way: If a dumptruck comes and dumps a load of gravel in front of you and you realize that, as it's doing so, about 1% of the mix is actually comprised of jades, emeralds, diamonds and rubies. Would you then consider it accurate to say (despite 99% of the mass being gravel), "Most of the stones in the pile are gemstones. Afterall, counting by 'type', gravel is only 20% of the representation."? I would aver that this would be an uncommon interpretation, but it is the same as the one you made with the article as it is currently written. 216.240.7.149 16:09, 6 March 2007 (UTC)

In the interpretation of the variety of elements produced, "except Hydrogen" is probably wrong. Hydrogen is quickly created after a nuclear event which releases a proton. I expect a small amount of hydrogen is created in stars, whether by fusion effects, radioactive decay of radioactive elements, or cosmic ray bombardment. (SEWilco 05:05, 7 March 2007 (UTC))

Can you suggest a short phrasing which clarifies that the variety of elements rather than their proportion is what is being referred to? (SEWilco 05:05, 7 March 2007 (UTC))

How about something like: "... which demonstrated convincingly that most of the elements listed on the periodic table had their genesis, either directly or indirectly, in the lifecycles of stellar furnaces."? 216.240.7.149 02:56, 8 March 2007 (UTC)

Looks OK. Wait 48 hours before changing. Comments from anyone? (SEWilco 03:40, 9 March 2007 (UTC))

Actually, I prefer the original version and find it completely unambiguous and much clearer. As far as I know, all elements but H and He are made in stars (though some of them in exploding ones ;-). What about soemthing like "all the heavier chemical elements"?--Stephan Schulz 17:42, 12 March 2007 (UTC)

I agree with Stephan. The language "most of the elements in the universe had been created by nuclear reactions inside stars" is very clear to me. It does not state most of the ATOMS, which would be a measure of their abundance by number, or most of the MASS, which is abundance by mass. I could also suggest "all elements heavier than Lithium", since the Big Bang synthesized Helium and tiny amounts of Deuterium and Lithium, but everything heavier was generated in stars. I could support just "all the heavier elements" but I would like to see something that describes what is meant by "heavy". Myrrhlin 22:43, 12 March 2007 (UTC)

There are all kinds of problems with the statement as it is written, although most aren't as glaringly problematic as that which I've already outlined in detail above.

Nevertheless, to provide some added depth to some of the statements made by myself and others above here're some bullet-points:

• As SEWilco very correctly pointed out, given that a lone proton can also be thought of as an H⁺ ion, hydrogen can (and is) produced whenever any nuclear reaction incorporates proton decay or any free neutron naturally degenerates via beta^- decay. So it is (and has been) made throughout nature, possibly even in the hearts of stars.
• Similiarly, helium is created in the absence of fusion by alpha decay which produces a He²⁺ ion (a.k.a. an alpha particle). So it's been getting made naturally for many billions of years, even outside the hearts of stars.
• Many elements (isotopes) heavier than helium exist in the universe as a by- or end- product of natural radioactive decay and are not themselves created in any sort of stellar nuclear furnace.
• Virtually all elements heavier than iron (essentially all of them except those that have been created artificially in particle colliders or nuclear reactors) were created by novae (esp type 1a supernovae). Since the sun, as a lone (ie lacking a companion) "main sequence" star, is very unlikely to ever even go nova, it is a virtual certainty that it will never produce any elements heavier than iron which is 26^th out of (currently) ~118 known elements. Thus, even by the broader interpretation of the phrase, the majority of elements in the universe (by representation on the periodic table) aren't "produced in the hearts of stars like the sun."

Also Myrrhlin's examples of things that are not stated in the article only serve to highlight my concern! It is because none of those things (mass, atomic count, and universal population) are either specifically included, or excluded, that any or all of them may be legitimately inferred from the statement without linguistic error. That's what makes the statement unnecessarily unclear!

By reason of the deficiencies I've outlined here, the statement "...created by nuclear reactions inside stars like the Sun" is clearly inadequate due to its prima facie ambiguity. Furthermore, as I've outlined in the points above, it is also quite simply wrong. (I noticed that, in your comments, you elected to drop the adverbial complement, "like the sun" from your reference to the original statement. That seems somewhat disingenuous as doing so significantly alters the breadth and meaning of the original statement. Ironically, however, it is actually a tacit admission on your part that the statement-as-written is deficient and thus required an ad hoc omission to support your position.)

I have now provided ample reasoning as to why the current phrase needs revision for the purposes of clarity and precision, and have yet to receive an adequate answer as to how, in its current form, the statement is superior in these many regards to an alternative like the one I proposed? Strangely, the responses thus far, all seem to be along the lines of "we don't see the need to change half a line of text simply to make the article a little less ambiguous and/or more liguistically accurate." Which, to me, seems like a very peculiar stance for an encyclopaedia to take. To be honest, I'm amazed at the amount of resistance this one little change has incurred.

In answer to the question(s) raised in regards to finding a means of classifying elements heavier than Helium: The field of astronomy already classifies all such elements as metals. Clearly this definition fits the need, however using it in this context would seem to present a host of other problems vis a vis clarity (i.e. inevitable confusion with the more common chemical and traditional definitions of the word).
216.240.7.149 04:47, 13 March 2007 (UTC)

I'll concede several points to you. I think the clarity problem stems from the use of the word "create", which is ultimately ambiguous in a scientific sense. With my astronomy background, I am thinking "synthesize", but a typical reader would not differentiate or understand why I might do so. While an individual proton or an alpha particle may escape a nucleus from a decay reaction, I do not consider that event "creating" hydrogen or helium. As far as I'm concerned, all hydrogen (just protons) was "created" in the Big Bang; yes, neutrons can decay back into protons, but many of those neutrons came from protons in the first place. While helium nuclei (alpha particles) certainly are a product of nuclear decay, you cannot argue that the reason we have helium in the universe is because of this process. I think most astronomers would stand not too far from my view. Nevermind all that.
The overall goal here, I think, is to inform a typical reader succinctly and with a minimum of misinformation, and let them seek out further explanation if they desire to know the fuller picture. There should be a statement here which is not terribly wrong, while still conveying the fundamental concept (and amazing truth!) that stars synthesize all elements heavier than Lithium-- our planet, our human bodies, everything we know and love in our daily lives, are merely the dust left over from the nuclear furnaces of stars long since dead. In light of this goal, the statement that originally stood is not bad: "most of the elements in the universe had been created by nuclear reactions inside stars like the Sun." While one may certainly argue, with a good understanding of nucleosynthesis and the evolution of stars, the statement is false because of the way it glosses over the details, it conveys the correct general idea. If we put in all those details, we risk hiding the forest behind a wall of trees.
Even the phrase "like the Sun", while making the statement less accurate overall, help conveys the big picture conclusion that was arguably one of the most amazing revelations science has yet brought us. I think it's not too much to expect that a reader knows the Sun is a star, but the phrase makes the connection to our human experience a bit closer. How about, to better put this in its historical context, we write

Finally, a seminal paper was published in 1957, entitled Synthesis of the Elements in Stars[28]. The paper demonstrated convincingly that most of the elements in the universe had been synthesized by nuclear reactions inside stars, some like our Sun. This revelation stands today as one of the great achievements of science.

Link the word synthesize to article on nucleosynthesis, and the reader can inform him/herself to a much greater extent. I'll see if i can find that quote by Hawking or someone about the historical importance of this discovery... but there are many who feel this way. Myrrhlin 16:38, 13 March 2007 (UTC)

I like it.--Stephan Schulz 16:53, 13 March 2007 (UTC)

I agree: that is a vastly better statement than the original and, especially with the link, I think it addresses virtually all of the significant concerns raised here :) 216.240.7.149 20:10, 13 March 2007 (UTC)

Section on Islamic view of the sun.

I really don't see much point in expalining that a religion does not show the sunn as divine. This section should be removed. Zazaban 03:39, 7 March 2007 (UTC)

Added link to "Why Does the Sun Shine?"

I have added a link to the lyrics and music to "Why Does the Sun Shine?" aka "The Sun is a Mass of Incandescent Gas" over at the NIH. This song, originally written for educational purposes, was re-popularized by They Might Be Giants around 1993, and once again sees ocassional use in the classroom. The only lyric that might possibly have been superceded by later scientific discoveries is this one:

Scientists have found that the sun is a huge atom smashing machine The heat and light of the sun are caused by nuclear reactions between Hydrogen, Nitrogen, Carbon, and Helium

Please let me know if this material is inappropriate. —The preceding unsigned comment was added by Pciszek (talk • contribs) 22:33, 7 March 2007 (UTC). Pciszek 22:37, 7 March 2007 (UTC)

THE solar system or OUR solar system?!

Regarding the opening line of the article - my understanding is that the universe contains rather a lot of solar sytems, so wouldn't it be more appropriate to say 'The Sun is the star at the center of OUR Solar System' - instead of implying that there is only one?! Brewabeer 01:36, 8 March 2007 (UTC)

My understanding is that, since "Sol" is the name of the star around which our planet orbits, the "Solar System" refers with specificity to our particular neck of the woods. I agree with you that there are many stars out there and that a decent number of them seem to have some kind of associated, planet-like, orbital detritus. I believe, however, that the correct way to describe these in a technical fashion is as (in the general sense) "extra-Solar" systems, or (in a specific sense) "the [planetary] system around [starname]". -- Please note, however, that I am not an astronomer. 216.240.7.149 05:27, 8 March 2007 (UTC)

I think this has been discussed in Talk:Solar system. For now, let Sol keep its Solar system here. (SEWilco 03:42, 9 March 2007 (UTC))

The solar system is one star system, there are other star systems, but ours is the solar system. Unless I am wrong. ^High_InBC^{(Need help? Ask me)} 03:47, 9 March 2007 (UTC)

I'm happy to bow to consensus of course, but the phrase 'solar system' seems to be widely used to describe any star and it's orbiting rocks. It certainly was when I was at school, and a Google search for "solar systems" will return a large number of hits, with pages from endless universities (and NASA) using the term in this way. While it may well be true that 'technically' there could only be one solar sytem, it would seem that the usage has long escaped such a narrow definition. Is Wikipedia best served by 'enforcing' the technicalities or by defining common usage?! At the very least, surely it should present all points of view, which it does not currently appear to do. Brewabeer 04:40, 13 March 2007 (UTC)

I agree with brewabeer because according to Wiktionary:

"a solar system is Any collection of heavenly bodies including a star or binary star, and any lighter stars, brown dwarfs, planets, and other objects in orbit"--Cbennett0811 21:05, 30 May 2007 (UTC)

While "solar system" *is* sometimes used incorrectly to refer to other star systems, that does not mean such uses are correct. Wictionary's definition includes the secondary use to reflect this, but goes on to specify that the term is "usually used specifically to refer to our own solar system, in which case it is used with the and often capitalised (as the Solar System)." Keep in mind that Wikipedia articles on astronomy are based on guidelines from major bodies such as the International Astronomical Union, which governs such matters. --Ckatz^chat_spy 21:13, 30 May 2007 (UTC)

After reading Ckatz's last input I looked up the definition of solar on Wiktionary and it convinced me that "The solar systym" is correct wiktionary's definiton of solar is as follows:"Of or pertaining to the sun; proceeding from the sun; as, the solar system; solar light; solar rays; solar influence." and "(Astrology, obsolete): Born under the predominant influence of the sun. Measured by the progress or revolution of the sun in the ecliptic; as, the solar year. Produced by the action of the sun, or peculiarly affected by its influence." --Cbennett0811 21:21, 30 May 2007 (UTC)

suggestion of minor change

Under "Early understanding of the Sun" under "History of solar observation", at the end of the first paragraph, the link to planets ought to go straight to planets#History, or else definition of planet, since that's the relevant section the reader is being pointed to. —The preceding unsigned comment was added by 128.83.69.57 (talk) 02:24, 10 March 2007 (UTC). forgot my sig: 128.83.69.57 02:26, 10 March 2007 (UTC)

suggested corrections

while this article is sprotected, i cannot edit, but didn't want to leave without recording a few corrections i would make if i had the privs.

1. link the "p-p chain" to the page on that subject
2. it's true the p-p chain is the MAIN source of energy from fusion. However, there are side chains which also generate energy, and the sun also gets heated by gravitational contraction, which is not an irrelevant effect. I'd clarify the statement about the p-p chain because of these two facts.
3. the photo of the total eclipse has a caption mentioning gravitational lensing -- by the moon! While I agree there would be an effect, the effect in this case is incredibly small and should not be mentioned here. The lensing effect due to the Sun alone is much much larger, and historically important (supporting the theory of general relativity), but is very small and difficult to measure. It was measured during a total eclipse of the Sun, which is why the author of that caption may be confused. I have -never- seen a mention of gravitational lensing from the moon or any other object in the solar system. Get rid of the mention of gravitational lensing, or correct it to mean that the Sun's warping of space can be (and was) measured during a total solar eclipse by noting the changed positions of stars next to it.
4. the section heading "Solar neutrino problem" should have a "(see main article)" link to the solar neutrino problem page.

Myrrhlin 15:50, 13 March 2007 (UTC)

"ordinary candela produces heat at the rate 1 W/cm³" I'm not sure what this means. Candela is a measurement. Does it mean "candles"? Mzmadmike 03:59, 6 June 2007 (UTC)

The Sun in human culture

A couple of days ago, I split off the section The Sun in human culture, to its own article with the same name. I did this primarily to do something about the length of the article, and also because this cultural-religious section falls a bit out of tone with the rest, which is purely scientific. Very recently, my edit was undone by G Rose. As a direct result, both the section and the new article (which is linked in See also) are now existent and indentical. Any ideas how to porceed? My proposal is to delete only summarize the subject in the Sun article. Nick Mks 07:29, 4 April 2007 (UTC)

I didn't realise someone had created an article for that material. I've seen it deleted through vandalism before, so I just assumed that vandalism was again the reason for its erasure. I didn't notice that it had been moved to a new article and linked to the main Sun article via a "see also" line. As to what level of representation the "sun in human culture" section should get in the Sun article, here's my take:

My main concern is just that the non-science aspects of the sun get adequate representation. At the time the article gained featured status, there was absolutely no discussion on the cultural status and significance of the Sun. I understand that the culture section is severely underdeveloped, and is probably an eyesore to anyone who was a major contributor to the rest of the article, but in my opinion it is an integral part of the article.

My preference would be to keep the culture section in the Sun article - shortened to summary form, if necessary, though it's already quite short. Although my re-pasting of the culture section into the article was not in reaction to its relegation to a "see also" line, I still think it deserves more representation than that.

I see the heavy scientific emphasis in the Sun article as being a result of the personal preferences of the people who contributed most heavily to the article. I think it's safe to assume that a casual reader will be just as interested, if not more so, in the non-scientific aspects of the Sun.

If the rest of the community finds it acceptable, I'd like to keep the culture section in the main Sun article. I will work on a summary form of the section if we decide we want to keep most of the material in the new "Sun in human culture" article. --G Rose (talk) 18:57, 4 April 2007 (UTC)

You've got a point there. I think we scientific people can surely live with a summary. A couple of paragraphs or so, but preferably wihtout more subdivisions. It's that that costs place. Nick Mks 19:27, 4 April 2007 (UTC)

I believe that the last comment above from user:G Rose is an either/or. --Lmcelhiney 19:54, 4 April 2007 (UTC)

Examining other article shows that WP:NPOV is satisfied by the use of a "See Also" link to another, related article (scientific vs. cultural). Typically, one sentence to a paragraph of information is summarized from the other article as a teaser, which draws the reader to click the wikilink to see the other article. Unfortunately, the "culture" section of this current article is little more than a stub compared to the Sun article itself. If there is information available, I believe that better efforts would be placed in improving the The Sun in human culture article. As such, I have commented out the section which had been reverted as it is currently redundant (since there is a wikilink to the same material in the excised article). When this discussion is done, the commenting can be removed or the text deleted. At least, in the meantime, we won't have a reader seeing the same material in this article and in the link.--Lmcelhiney 19:48, 4 April 2007 (UTC)

I just threw the commented section out of the article, not because I'm unilaterally ending the discussion, but because the contents of the new article have been changed, so if we should ever decide to move it back, we'd have to use the new version. As far as the discussion (which has gone a bit very dead) is concerned, would anybody be so kind as to drop me a note when it flares up again, I won't be constantly watching this for the rest of my days... Nick Mks 16:36, 13 April 2007 (UTC)

volume of the sun?

What is the volume? —The preceding unsigned comment was added by 222.153.25.128 (talk) 10:43, 4 April 2007 (UTC).

It is 1.41×10¹⁸ km³ or 1.41×10²⁷ m³. This was indeed wrong in the infobox. Thanks if you meant to point that out. Nick Mks 11:41, 4 April 2007 (UTC)

category of the sun

Hi, apparently the sun is a yellow dwarf, but I can't find anything in this article that clearly says so. If this is true, can someone add it to the first sentence? martin 11:40, 19 April 2007 (UTC)

The G2V classification is explained in the intro, and I think it is probably sufficient for these purposes. Grokmoo 12:20, 19 April 2007 (UTC)

Ok, I appreciate the opportunity to learn about stellar classes, but as a layman I wouldn't have understood that G2V = "yellow dwarf" from reading the article, nor had I read this article and the one on stellar classes. I would just like to see, somewhere in the summary or intro, that the Sun is a "yellow dwarf", or if this is not a scientific classification, at least a word in parentheses saying "The Sun is of the G2V stellar class (commonly called "yellow dwarf"). martin 22:06, 26 April 2007 (UTC)

Diameter vs Radius

This article lists, in the sidebar, the "mean diameter" of the sun, but the articles on the planets quote the "equatorial radius". Is this an oversight, or is there a good reason for this? - Philip Matthews 23 April 2007.

Constellation?

In which constellation is the Sun in? Does it have one? Sorry if the answer is obvious. Josh215 22:44, 27 April 2007 (UTC)

The Sun isn't in any one constellation. Since Earth travels around the Sun once per year as it orbits, the direction we're viewing the Sun from changes and so the stars that are visible in the background also change. The path the Sun takes is the same each year, though; the ecliptic. See also Zodiac#Table of constellations vs. zodiac signs, which contains a list of the thirteen constellations the Sun passes through each year and the dates it is in each. Bryan Derksen 01:20, 28 April 2007 (UTC)

Frisian language

This article is also available in the Frisian language: fy:Sinne —The preceding unsigned comment was added by 83.117.225.78 (talk) 20:44, 4 May 2007 (UTC).

Where to put this back?

Wearing UV protective sunglasses can help protect the eye, but sunglasses without good UV protection may cause one's pupil to dilate so that more of the lens is exposed to the UV, and more UV goes into the interior of the eye.

I removed this from the observation of the sun section since it's bad advice in that context, but UV sunglasses /are/ good for things like preventing cataracts (just walking around and not looking at the sun) so it might be put back in somewhere Sagittarian Milky Way 03:39, 6 May 2007 (UTC)

The Sun vs. Sol

No, I'm not suggesting we change the name of the article or anything, but if I recall correctly, isn't the official name for the sun "Sol"? If this is accurate, shouldn't it be mentioned in the article somewhere? -Kraw Night 09:01, 8 May 2007 (UTC)

Sol is the latin name for Sun. If the name is to ring true with the whole planet (much of which is not Latin), then it should be called Sun. Of course you are not saying we should change its name, but I am just adding the reason why no mention of Sol is needed.Gilgamesh007 12:10, 23 August 2007 (UTC)

Actually, the names of most of the stars are Arabic in origin (at least at some point down the line). Wouldn't it be best, if for some reason a less "vernacular" name is needed, to use the Arabic name, Shams (or something close to that)? (Although, if I had to choose for myself, I would go with Helios, because it sounds the coolest [ha ha].) 04:44, 6 November 2007 (UTC) —Preceding unsigned comment added by 71.102.132.76 (talk)

The Gold Seal Campaign

For the sake of Wikipedia and controversial articles...

Gold Seal Campaign:

What do you think of this? The administrators of Wikipedia establish a Gold Seal campaign for certain articles. This “Gold Seal” will indicate for a given article it’s factuality and lack of vandalism. Basically it will show..

1-This page is properly cited.

2-This page has been verified.

This will be an important step for Wikipedia. It means students, high school included will be able to cite Wikipedia in their work. As of now many schools do not allow students to this.

As for editing an article, It will still be allowed yet a person can easily revert to the Gold Sealed, verified page on Wikipedia. This will be an amazing step for Wikipedia, though difficult, it will allow readers to know for sure what they are reading is true. It will surely improve Wikipedia’s image in the public sphere. Of course someone will have to organize this, but in then it will be sufficient use of labour. — mattawa

Andromeda-Milky Way collision

The article mentions the possible "death" of Earth in 4-5 billion years when the sun becomes a red giant. I wonder if it might be worthwhile mentioning that the earth would first have to survive the "Andromeda-Milky Way collision", due in 3 billion years. Pnwk 19:19, 22 May 2007 (UTC)

As I understand it, we are uncertain if such a collision will occur due to the unknown tangential velocity of Andromeda, and even if one did occur the odds of anything impacting Earth are slight, as Andromeda is mostly empty space (just as the Milky Way is) --Noren 04:43, 23 May 2007 (UTC)

Two things; firstly when galaxies merge the stars in them rarely collide since the distances between the stars in a galaxy are so immense. Galaxy shape and morphology can certainly be drastically altered but the individual stars themselves can remain largely unaffected. Secondly this question is mute given that in around a billion years the sun will have become too hot too sustain complex life on earth anyway, so what happens in 3/4 billion years to the earth is frankly, superfluous to this conversation.--Antarctic-adventurer 15:49, 24 July 2007 (UTC)

picture

I think that the picture at the top of the page is a poor picture I think that it should be replaced a different picture--Cbennett0811 20:11, 31 May 2007 (UTC)

If you're referring to the image that looks like it was drawn in Paint, I agree. What's with that? 128.158.145.51 15:08, 18 July 2007 (UTC)

Nemesis

Shouldn't Nemesis be added as a see also, considering it's related to the star in some way? Spark Moon 04:23, 2 June 2007 (UTC)

Sun and Absorption Spectra Question

I've noticed that the absorption spectra of the Sun has lines that do not match up with any known element. Why is that? —The preceding unsigned comment was added by 209.247.5.136 (talk • contribs).

Wikipedia is not a question and answer page (see WP:NOT even as this NOT is not listed there). And your question is not quite clear. Where have you seen the spectrum? An illustration here? I suspect that you have the same problem as late 19th century physicists. Their answer was simple: the missing lines belonged to ions (ionized as opposed to electrically neutral atoms) which are abundant in Sun atmosphere due to its high temperature. -Friendly Neighbour 20:43, 3 June 2007 (UTC)

Distance from Earth

Eratosthenes might have been the first person to have accurately calculated the distance from the Earth to the Sun, in the 3rd century BCE, as 149 million kilometers, roughly the same as the modern accepted figure.

How did the ancients measure the distance? Samulili 14:56, 6 June 2007 (UTC)

Trigonometry. It was known in ancient times that in cities located near the Tropic of Cancer--such as Aswan, Egypt--one could see all the way to the bottom of their wells at local noon around the time of the summer solstice. Also, buildings and people in those towns casts hardly any shadow aournd that day. Since it is simple to realize that the angle of the sun over such towns at time time was roughly 90°, you could mathematically calculate how far away the sun was if you knew both of the following: 1) the approximate distance between that city and a city either due north or south; and 2) and the angle of the shadow cast at local noon in that second city on that day. Once you had those values, you could calculate both the approximate distance to the sun and the circumference of the Earth. This was the work was first done by Eratosthenes. Foofighter20x 05:31, 12 June 2007 (UTC)

Image license problem

The sun image in Image:Sun,_Earth_size_comparison_labeled.jpg is from SOHO, an ESA / NASA project that allows only non-commercial / educational use of images. As such, I have marked the image for deletion from Commons. If people feel it's use is necessary here, please upload it locally and write an appropriate fair use rationale. Dragons flight 23:59, 9 June 2007 (UTC)

Are you sure its non-commercial? The license could have been recorded incorrectly on this version. According to commons:Image:Sun, Earth size comparison.jpg it originates from JPL and JPL images may be used for any purpose and no copyright is retained unless specified, which it is not. Did I miss something? -wizzard2k ^(C•T•D) 00:22, 10 June 2007 (UTC)

Source is http://photojournal.jpl.nasa.gov/catalog/PIA03149, which identifies it as a SOHO image. SOHO is a ESA / NASA collaboration, but their work is not PD and has been deleted from Commons in several past cases. Dragons flight 01:05, 10 June 2007 (UTC)

I've got a question to the talk page of that boilerplate on commons, as it appears to have jumped to an illogical conclusion. It cites this page and interprets it as requiring authorization for commercial use. In fact it doesn't mention commercial use at all. -wizzard2k ^(C•T•D) 01:10, 10 June 2007 (UTC)

The question probably boils down to where the copyright would belong (if there is one), to the website the image was posted, or the project which produced the photo. If its the former, the JPL, then there's no issue here. If its the latter, some interpretation will be needed, as the website does not state anything about commercial use. -wizzard2k ^(C•T•D) 01:13, 10 June 2007 (UTC)

Copyright exists unless waived, SOHO was built by the ESA (launched by NASA) and appears to follow the ESA practice of retaining copyright and allowing only non-commercial uses. If you can show it was made by a NASA employee, then alright, but unless that happens then caution is appropriate. JPL's image use policy also warns that if the owner is identified as someone other than JPL (i.e. SOHO in this case), then users will generally need the owner's permission for commercial use. Also, keep in mind SOHO images have been deleted from Commons in multiple cases in the past. Dragons flight 01:26, 10 June 2007 (UTC)

The ESA clearly retains copyright on anything posted on its website [5], however wouldn't the actual sources of the image file take precedence? (the SOHO site not requiring any permission for commercial use, and the JPL site giving up all copyright) I'm just trying to see if there's another way to look at this issue. -wizzard2k ^(C•T•D) 01:44, 10 June 2007 (UTC)

Copyright is owned by whoever created the image and exists by default, which means there must be proof that the creator (which in this case appears to be SOHO) has waived their commercial rights. Dragons flight 01:50, 10 June 2007 (UTC)

There happens to be a "Copyright Questions" category on the web feedback/questions form, so I asked. Probably won't get an answer on the weekend, but at least maybe they'll be able to clear it up or reword their copyright page. -wizzard2k ^(C•T•D) 01:57, 10 June 2007 (UTC)

Well, I received a reply, unfortunately it still didn't answer what I was hoping to find out (specific wording regarding for-profit use). -wizzard2k ^(C•T•D) 05:39, 12 June 2007 (UTC)

JPL has nothing to do with our mission (which is a joint mission between
ESA and NASA) so I have no idea what you are refering to. The mission is
operated from GSFC in Maryland. The SOHO copyright statement is clear
and explicitely states that "The use of SOHO images or data for public
education efforts and non-commercial purposes is strongly encouraged and
requires no expressed authorization".

For the case of Wikipedia, I would consider both the mission and purpose
of Wikipedia as educational therefore strongly encouraging and
permitting the use of SOHO data without explicit authorization.

The SOHO copyright statement reflects the distilled, common-ground
copyright policy between SOHO's parental agencies.

For what it's worth, SOHO data are not copyrightable because they are scientific data, not a creative work. Most of the quick-look SOHO images are not copyrightable because they contain no significant creative content. Derived images such as the size comparison are generally copyrightable and are often prepared by contractor agencies, so it is not clear whether they count as works for hire (for the U.S. government) or no. I am not a lawyer, only an interested scientist. zowie (talk) 17:39, 29 November 2007 (UTC)

Galactic Coordinates

No mention seems to be made of exactly where the Sun is located within the Galaxy. --MatthewKarlsen

Because it is more appropriate for the Milky Way article. By the way, Galactic coordinates have their origin in the Sun, not in the Galactic centre (see this graph). Therefore it is very easy to answer where Sun is in Galactic coordinates: in the very middle (which does not change the fact that it is in the Galactic peripheries). --Friendly Neighbour 17:12, 10 June 2007 (UTC)

No complete theory

The Electric Sun model (see [6]) does explain the corona temperature, so this is factually incorrect. The Electric Sun hypothesis is supported by laboratory evidence, so it qualifies as a theory. I don't think it's clear what a "complete theory" is. What is the standard for the completeness of a theory? Isn't "complete theory" a contradiction in terms? The standard solar model is incomplete in that it does not explain a key feature of the sun: the corona temperature. Yet, assumptions following from that model are stated as fact in the article. The use of "complete" here is suspect and needs editing.

"Magnetic Reconnection" is highly conjectural, widely disputed by engineers who work with actual electromagnetism in the lab, a violation of Maxwell's well-established dynamics and of the Gauss law. See [7], [8], [9], [10]

216.62.203.236 14:47, 12 June 2007 (UTC)

Aw, come off it. The Electric Sun model is not a complete (or particularly coherent) theory. Magnetic reconnection is observed routinely in the laboratory, and is predicted by the resistive MHD equations (which in turn are derived from the Navier-Stokes equations and Maxwell's Equations). Signatures of reconnection have been observed directly in Earth's magnetosphere, and the associated topological changes are routinely observed in solar movies of EUV emission from the corona. zowie 18:07, 31 August 2007 (UTC)

Sun/Earth size picture

I seem to remember such a pic being here recently. I found it helpful; anyone know what happened to it? Mdiamante 23:11, 12 June 2007 (UTC)

It was deleted because it failed to meet our licensing requirements. See a couple section up the page. Dragons flight 20:55, 14 June 2007 (UTC)

I created a picture that might be like what you're talking about. Although, I'm not sure where exactly to put it: Image:Sun compared to the Earth.png PichuUmbreon 02:04, 4 September 2007 (UTC)

Color of the sun

The comment about the color of the Sun appearing yellow because the blue light is scattered in the sky (also explaining why the sky is blue) seems to be, perhaps, in dispute. I could not find a definitive reference on this listed, and my search found at least one dissenting opinion (the book "Bad Astronomy" by Philip C. Plait, 2002) says that the amount of blue light that is scattered wouldn't account for the color shift. There is a discussion of alternate possibilities on http://www.bautforum.com/showthread.php?t=7445, which is the Universe Today Forum thread on this book and this particular subject. Is there a definitive reference that shows that the reason given here is correct? 71.164.195.68 00:39, 18 June 2007 (UTC)

I don't know how relevant my personal perceptions are to the content of the article, but in case others feel the same way, I'll state this anyway: I personally don't perceive the sun to be yellow. I never did as a child, either. I think of it as white, more from definition than anything else. After all, it is the light source. My brain calls it "white" so it can go on about the business of judging the color of objects reflecting that light. Furthermore, I don't understand how anyone else claims to judge the color of something one cannot look at. When I glance at the sun, my eyes are too overwhelmed to perceive anything so subtle as color. Spiel496 19:17, 5 September 2007 (UTC)

Color is highly ambiguous. It is only a perception that differs between species and environments. The only constant, it seems, is the electromagnetic frequency, not the color. The sun may be white in space, but on earth, due to our atmosphere, it is yellow.

The Sun as a variable star

The Sun has been demonstrated to be a variable star, but the article does not mention this explicitly. It is hinted at in the discussion of the sunspot cycles and Milankovitch cycles, in that the sunspot cycle is correlated with temperature variations, but the article does not explain why this is the case. As the article is worded, temperature variations are simply something that happen. It would be more useful if the variability was explained, particularly the point that the solar variability is counterintuitive - the more sunspots there are, the brighter the Sun tends to be. The variability is slight, in the order of 1 part in 1000 but it is noteworthy enough that it should be mentioned. --B.d.mills 07:38, 1 July 2007 (UTC)

Aristarchus ...

... was the first to propose that the Earth orbited the Sun as far as I know. As this is no small feat I have given him a mention in the article.  SmokeyTheCat  •TALK• 09:42, 3 July 2007 (UTC)

I wish to challenge this statement:

Under Overview: “Sunlight is the primary source of energy to the surface of Earth."

This should read: Sunlight is the primary source of energy to the atmosphere of the Earth.

For reasons I stated here: There are two parts that warm the earth, the earth it self and the Atmosphere. Talk:Earth_science#Suggested_point_to_be_added:__under_.22Earth.27s_energy:.22

I am sorry I am new here and don't know how to go about challenging a statement. 7/14/07

Thank you

I replied at the linked talk page. Dragons flight 18:56, 14 July 2007 (UTC)

I'm really curious!

Almost every time I look at the sun (I can be daring at times, yes...) I sneeze... Why is that? (Is it just a trigger to prevent us from getting blinded by the sun??) (I have asked some people about this and it has happened to them too) Oslogirl5 23:54, 19 July 2007 (UTC)

Don't look at the sun. It's not daring it's stupid. As to why you sneeze - hopefully it's your subconscious telling you to shut your eyes and don't be so dumb as you are risking permanently damaging your retinas. However I think you will find there is no physical link. Sophia 14:42, 24 July 2007 (UTC)

Actually there is a link, and it is called the Photic sneeze reflex. Some people when exposed to bright light have the urge to sneeze; I am one of them. Wikipedia has a article about it as well for interest. Antarctic-adventurer 15:43, 24 July 2007 (UTC)

I am not advocating looking at the sun, but the potential damage to the eye is often overstated in literature. Here is a sampling of opthalmological literature (by an astronomer) on the subject. http://mintaka.sdsu.edu/GF/vision/Galileo.html 12.40.5.69 14:41, 25 July 2007 (UTC)

I have slight damage to my eyes because when I was a kid I was too scientifically curious and stupid enough to look at the Sun trying to understand more about it (the experiment was useless, though, as because of the great amount of light I saw nothing that could tell me anything about the surface of the Sun - later when I started reading astronomy books I discovered much more without risking my eyes, and at some point I also learnt how to look at the Sun indirectly using a telescope and a piece of paper, but by the time I had this knowledge my eyes were already damaged). Having experienced how it's like to have Sun-burnt eyes that cannot be fixed for life, I recommend everyone to never look at the Sun. Even now after so many years I still can see the burnt point in my eyes, eg while reading a book or looking at the sky or at a white wall. NerdyNSK (talk) 16:30, 9 December 2007 (UTC)

Aäehmm, this Sun observing hysteria again! Taking a fast glance at the sun (without any optical aid) is not that dangerous! I think the sneezing reflex is not a specific sun protection item, just kind of an irritation (physical or psychological) triggered by the sudden illumination change - for probably no reason at all. I've heard about other persons sneezing after illumination from the sun, so the phenomenon is not unique. Said: Rursus ☻ 15:01, 31 January 2008 (UTC)

Sun Evolution section very over-simplified

The discussion on the evolution of the Sun is very over-simplified. After a one-solar mass star such as our Sun enters the red-giant phase it undergoes several further and important stages before it finally throws off its outer layers as suggested in the 'life cycle' section. There is the helium flash, and its horizontal branch and asymtotic branch phases as well. The diagram shown is also a serious over-simplifcation. For a starred-article this section is very weak. --Antarctic-adventurer 15:39, 24 July 2007 (UTC)

Life Towards the End of the Sun

Supposing the sun has got 5 billion years more to shine as it is, before starting the progress towards becoming a red giant, here's a question: Is there a chance for life when this process will begin? Will the augmentation of volume and relative distance will compensate the decreasing heat? Is there a chance for the future dominating species to watch the sun as it grows?

Number of G type stars in the Galaxy edit war.....

I amended the statement "There are more than 100 million G2 class stars in our galaxy" to "There are more than 100 million G class stars in our galaxy" as the G spectral classification runs from G0-G9, not just G2. However, someone reverted it back to the previous statement. Rather than get into an edit war, I am posting here. There are not more than 100 million G2 type stars, rather there are more than 100 million G type stars in the galaxy, including the G2 type star that is our sun, but not limited to it. This needs changing again. --Antarctic-adventurer 14:38, 25 July 2007 (UTC)

Incorrect statement probably: the article seems to be right. The Milky Way article claims the number of stars are about 200·10⁹, the stellar classification article that about 8% of them are G stars, of which some little less than 10% are G2. This gives in round numbers 1.6·10⁹ stars, which indicates that the number of G2:s is underestimated by far! Said: Rursus ☻ 15:17, 31 January 2008 (UTC)

Upon reflection it would appear that you are correct. So disregard my original statement. Antarctic-adventurer (talk) 06:22, 8 December 2008 (UTC)

Scattering, lead section

IMHO the lead section would benefit, if the explanation of subtractive effects and preferential scattering were removed, being too detailed for that section. To state that "atmospheric scattering of sunlight most often leads to yellow, but to orange or red when the sun is low in the sky" would be sufficient. --Sir48 22:02, 29 July 2007 (UTC)

Future of the sun

I thought in 5 Gyrs Venus' orbit will also expand to avoid sun's evelopment. In that time sun will be approximately 100 times current diameter that is about 90% of current Earth orbit which is slightly smaller. This website said in 4 or 5 Gyrs sun will become RGB, encompassing and engulfing Mercury. Current research gives a slight comfort that it will not engulf Earth and Venus as well, they will just be ran as lifeless hells. Venus will just be a burnt out planet with almost semi-molten surface, its greenhouse atmosphere will have long gone and its cloud will vanish. Earth will almost suffer about the same fate; its ocean and its atmosphere will have been boil off into space. However on the bright side, Jupiter and Saturn's large icy moon; the temperature will hat up the point warm enough that the ice will melt into mostly ball of worldwide oceans, can also trap in anti-greenhouse effect to get the approprite atmosphere neccessairly for current human life. Freewayguy 23:41, 1 August 2007 (UTC)

Recent deletions of 'local fluff' paragraph

This message was left on my talk page regarding the recent attempts to delete the paragraph starting with It is currently travelling through the Local Fluff of the Local Bubble zone:

The sun is not travelling through whatever you said —The preceding unsigned comment was added by 68.60.161.6 (talk) 19:29:29, August 19, 2007 (UTC)

I think this page is the most suitable place for discussion. Maybe the terms Local Fluff and Local Bubble seem funny, their articles don't seem to be a prank. Han-Kwang (T) 19:38, 19 August 2007 (UTC)

User 68.60.161.6 is clearly mistaken about the terms. They are correct. See this paper for example: Priscilla C. Frisch, 1997, "The Local Bubble, Local Fluff, and Heliosphere", arXiv:astro-ph/9710141. By the way 68.60.161.6 has just broke WP:3RR. --Friendly Neighbour 19:56, 19 August 2007 (UTC)

When I saw this section the first time, my first reaction was also to think I caught some recent vandalism. Maybe the terms should be clarified here without requiring the reader to follow the links. Han-Kwang (T) 20:07, 19 August 2007 (UTC)

Ahad Radius : The Reach of Sun’s Light Dominion out into Space

I propose a subsection be added on the Sun article page, where a noted scientist by the name of Abdul Ahab (b. 12/15/1968, Sylhet, Bangladesh) first postulated and quantified the edge of the Sun’s sphere of light dominion above the universe’s background light flux. His paper was soundly founded upon the equations of integrating the fluxes of individual stars and well-known standard formula for relating absolute and apparent magnitudes to distance. His thesis was first summarised circa March 2004, thus:-

Firstly, Ahab’s work entailed deriving a valid set of logarithmic equations that led to a total universe sky brightness (coined “Ahad’s constant” by his colleagues) that he did via Usenet forums:

Ahad’s constant

Ahad’s constant is an analytical quantification of the universe’s total background light flux reaching the Earth’s surface from all cosmic sources, such as stars, star clusters, galaxies, and quasars, excluding all light coming from the nearby Sun. It was first defined by Abdul Ahad in March 2004, as the end result of a logarithmic series whose input parameters are the apparent visual magnitude of every single cosmic source ever catalogued. The series is thought to converge toward a final value of some -6.5 magnitudes or approximately 1/300th of a Full moon's worth of light. The progression of the series is such that as one moves toward integrating light from fainter stars of lower magnitudes, the star count increases exponentially, but the cumulative contribution of light toward the constant itself tails off more rapidly, thereby resulting in convergence. The flux equations that lead to Ahad’s constant are defined as follows. Suppose we have two stars of apparent magnitude m1 and m2. Then their luminosities L1 and L2 are related by the Pogson Ratio:-

L2/L1 = 10^[0.4*(m1-m2)]

The luminosity of the pair of stars is L1 + L2 = L1(1 + L2/L1), and their combined magnitude is then given by:-

Mc = m1 - 2.5*log10 (1 + L2/L1)

For the general case, where the magnitudes of n stars need to be aggregated, we can generalize this by computing all the ratios:-

Li/L1 = 10^[0.4*(m1-mi)]

for all stars i from 2 through n. Then:-

Ahad’s constant = m1 - 2.5*log10 (1 + L2/L1 + L3/L1 + ... + Ln/L1)

File:Ahads constant formula.jpg

File:Ahads constant formula2.jpg

Sorry, but a Usenet thread is not a reliable source. If this is published in a peer-reviewed scientific journal, adding it might make sense, but without such a source it would violate any number of Wikipedia policies. --Stephan Schulz 12:24, 20 August 2007 (UTC)

It was published in the Mathaba news network [[11]] and the Journal of the British Astronomical Association. --Gilgamesh007 (talk) 21:07, 18 January 2008 (UTC)

Ahad Radius and Ahad's Sphere

The apparent visual magnitude m of a star whose absolute magnitude is M, as seen from a distance of d light-years is given by:-

m = M - [5 - 5 * log10(d / 3.2616)] Using the above formula the fall off in apparent magnitude of the Sun with increasing distance can be charted, thus:-

File:Ahad-radius.jpg

At a distance of circa 11,500 astronomical units going radially outward from the Solar System the Sun's apparent light output matches Ahad’s constant. It is thus possible to draw an imaginary sphere around the Sun of such a radius, within which the Sun would remain the most supreme source of light, relative to the universe’s total background illumination:

File:Ahad sphere solar illuminance.jpg

The outer edge of such a sphere, in principle, defines an edge of the Sun’s monopoly of light and heat provision to the Solar System and nearby interstellar space; an effective end of its light dominion.

• And the point being if the Sun radiates more light out of its equatorial bulge, compared to what it gives out from its poles then I think you'll find the author's sphere actually becomes more of a sphereoid? 81.107.126.114 14:32, 24 August 2007 (UTC)

Sure, and pigs might fly LOL. There's no evidence of the Sun radiating more or less light from the poles as opposed to from the equator -- Gilgamesh007 (talk) 21:10, 18 January 2008 (UTC)

Discuss? Gilgamesh007 11:54, 20 August 2007 (UTC)

I do not think this simple geometric derivation takes in to account the increasing red shift, finite age of the Universe or galaxy/star aging. This has nothing to do with this article, anyway. --Friendly Neighbour 13:57, 20 August 2007 (UTC)

• Visual magnitude flux is registered at the receiving end, either by the human eye or another photometric device and measured instantaneously as a photographic snapshot. It has no bearing on redshift or blue shift of the emitting source. 81.107.126.114 14:32, 24 August 2007 (UTC)

We will die in 500 million years?

The Life Cycle section says:

The increase in solar temperatures over this period is sufficient that by about 500-700 million years into the future, the surface of the Earth will become too hot for the survival of life as we know it.

Is this 500 million years from NOW or from the time that the sun turns into a red giant? What is the source for this? Can it be linked or explained further?

129.139.144.14 14:42, 6 September 2007 (UTC)

On earth. Are you worried about that? There are plenty of other solar systems to move to long before then. 199.125.109.41 13:36, 17 September 2007 (UTC)

No, I'm not worried about it, as I would be long-since dead. However, that doesn't mean I'm not interested in it. 129.139.144.14 14:37, 26 September 2007 (UTC)

The reference says this all happens later, 1.1 billion years from now to 3.5 billion years. Perhaps the text should be fixed to change "However, Earth's water will be boiled away and most of its atmosphere will escape into space. The increase in solar temperatures over this period is sufficient that by about 500-700 million years into the future, the surface of the Earth will become too hot for the survival of life as we know it" to "However, much earlier, about 500-700 million years from now, the surface of the Earth will become too hot for the survival of life as we know it, and Earth's water will be boiled away and most of its atmosphere will escape into space by about 3.5 billion years from now."

I'm not worried about the discrepancy between 500-700 and 1100 (what's 400 million years when you are having fun?), but changing it would agree with the reference. 199.125.109.41 02:36, 1 October 2007 (UTC)

Not me! I'll die much sooner than then, thank God! Said: Rursus ☻ 15:18, 31 January 2008 (UTC)

Definition and capitalization of the sun

It should be mentioned that in American English, sun is generally considered to be a common noun and is thus not capitalized. Webster's definition of solar system: "the sun and all the heavenly bodies that revolve around it."

Definition of sun: "1. a) the self-luminous, gaseous sphere about which the earth and other planets revolve and which furnishes light, heat, and energy for the solar system: it is the star nearest the earth, whose mean distance from it is nearly 93,000,000 miles: its diameter is about 864,000 miles; its mass is about 333,400 times, and its volume more than 1,300,000 times, that of the earth  b) the heat or light of the sun [to lie in the sun]  2. any star that is the center of a planetary system  3. something like the sun, as in warmth, brilliance, splendor, etc.  4. [Poet.]  a) a day  b) a year  5. [Poet.] a clime; climate  6. [Archaic] sunrise or sunset."

Notice especially the definition of the sun under 2. The definition of sun is ambiguous, like a lot of the English language, and should be mentioned in the sun and solar system articles, which is what I was doing. Excluding that information is an example of Wikipedia's bias.

Also notice how sun is not capitalized in this American English dictionary. If it was somewhat common to capitalize it in American English, it would have said something like "[often cap.]" If it was only supposed to be capitalized in American English, it would have said something like "[cap.]." —Preceding unsigned comment added by 71.107.191.119 (talk) 01:55, 9 September 2007 (UTC)

If you think of it generically as the light source/light, yes. Like "island in the sun" "I couldn't catch it cause the sun was in my eyes" or, "when the sun reaches here it's drinking time" If you talk to an astronomer they might disagree. Astronomically, the Sun is important to me, and is a specific body. No one would say the mars, arcturus, the pluto. It's a proper name. But sunrise or sunset are uncapitalized. Sagittarian Milky Way 07:34, 22 September 2007 (UTC)

This article seems to be about "Sun" (Sol, the G2V star), not about "sun" (a certain illumination coming from Sun). I wish some sun here and now, but not to be in the Sun. Said: Rursus ☻ 15:21, 31 January 2008 (UTC)

Are hydrogen lines week ?

It seems to me that the statement "... (solar) spectrum contains ... very weak hydrogen lines" in Introduction is wrong. If it concerns absorption lines (by the way, it is unclear from the text), that, for example, the Balmer H-beta line in the visible solar absorption spectrum (486 nm) is the sixth of the most powerful (and it is just the reason for it to be "F" in the Fraunhofer classification). The hydrogen lines are weaker than, i.e, oxygen A-line, but one hardly can say that they are "very weak". To be corrected?

V. Ivanov, 195.201.30.101 15:30, 10 September 2007 (UTC)

Is "slower" a typo?

The following sentence appears in the article: "... this temperature gradient is _slower_ than the adiabatic lapse rate." I think that should read "lower", but I'm not sure. AMackenzie 09:09, 15 September 2007 (UTC)

I'm not sure whether it's a typo or rather "physics slang". In any case, it should be changed. I'll change it to "less". --Friendly Neighbour 09:17, 15 September 2007 (UTC)

I wouldn't change it unless you are sure it means "less". You could be throwing off the intended meaning. It's lapse RATE after all, which deals with time. "slower" could very well be the correct interpretation. 129.139.144.14 18:32, 28 September 2007 (UTC)

I think "less" is appropriate. The "lapse rate" is confusing too as it is a rate vs. distance, not (as in more common usage) rate vs. time. zowie (talk) 17:33, 29 November 2007 (UTC)

Name of our star

Since the sun is really just a star among many stars, is there a name given for our star? The other stars that we have observed have each been given specific names. Has there been one given for ours? —Preceding unsigned comment added by 24.150.203.74 (talk) 00:36, 22 September 2007 (UTC)

"Sun" is the English language name for our star; although it happens, it is actually incorrect to use the word "sun" as a replacement for star. The Latin name is "Sol", hence the term "Solar System" (which also applies only to our star-and-planet system.) Similarly, the English name for Earth's moon is the Moon, or "Luna" in Latin - hence the term "lunar". Hope this helps. --Ckatz^chat_spy 00:46, 22 September 2007 (UTC)

The wrong notation on the surface area

By random chance, I happened to be teaching my daughter how to find out how much bigger the sun was than jupiter. I just wanted a quick look at how big the sun was compared to jupiter. I found that the sizes you have listed here are wrong. I did not check all of them, but under surface area, you have the sun listed as 6.088x10 to the 18th m2. In reality it shoulqd be 6.088x10 to the 15 m2. And it shouldn't even be m2 as the linked source lists the sizes in km no m. So when I converted to km, I had 10 to the 15th... when it should be 10 to the 12th. I went to the NASA site to get the real numbers and instead of the sun being an impossible 97,000 times larger than Jupiter, I came up with the much more plausible 97 times larger.

This was a lesson for my daughter in mathematics as well as the frailty of information on the net. I hope that someone with editing privileges can recalibrate the suns size to match those on the NASA site. I would also suggest that all heavenly bodies on wikipedia be calibrated so that all sizes are shown using the same standard rather than meters on some and kilometers on others.

Wish I could edit it myself.

Thanks! —Preceding unsigned comment added by Zaimejs (talk • contribs) 16:03, 23 September 2007 (UTC)

No, the value given is correct. Remember that you're squaring the units: 1 km²=10⁶ m², so 6.088x10¹⁸ m²=6.088x10¹² km² which, as you said, is the correct value. And anyone can edit wikipedia - but it's a good idea to discuss on the talk page (as you did) if you think there's a mistake, but you're not 100% sure. -- Cosmo0 16:15, 23 September 2007 (UTC)

The Sun is 10 times bigger than Jupiter by width, 10^2 times bigger by area amd 10^3 times bigger by volume. The density is similar for both so it's also 1000 times more massive. Sagittarian Milky Way 06:16, 27 September 2007 (UTC)

Stellar History

The Sun's chronology seems a little off; it should be older than 4.57 billion years. First, at 4.533 Ga Theia (the proto-Moon) is thought to collide with the (proto-)Earth. Second, the Earth itself is 4.567 billion years old.

This means that the Sun would have had a headstart on the Earth by about 0.023 billion years. Rather, I would propose the ages as follows:

• 4.654 - Sun formed [1]
• 4.567 - Earth formed [2]
• 4.533 - Theia collision [3]
• 4.450 - Water evidence [4]
• 4.404 - Zircon formed [5]
• 4.400 - Crust evidence [6]
• 3.800 - Life evidence [7]

References:

1. Bahcall, J. N., Pinsonneault, M. H., and Basu, S. (2001). Solar models: current epoch and time dependences, neutrinos, and helioseismological properties. The Astrophysical Journal, 555:990*1012.
2. Nature, 427:117*120. DOI: 10.1038/nature02260. Boyet, M. and Carlson, R. W. (2005). 142 Nd evidence for early (>4.53 Ga) global differentiation of the silicate Earth. Science, 309(5734):576*581.
3. Münker, C., Pfänder, J. A., Weyer, S., Büchl, A., Kleine, T., and Mezger, K. (2003). Evolution of planetary cores and the Earth-Moon system from Nb/Ta systematics. Science, 301(5629):84*87.
4. Drake, M. J. (2000). Accretion and primary differentiation of the Earth: a personal journey. Geochimica et Cosmochimica Acta, 64(14):2363*2369.
5. Valley, J. W., Lackey, J. S., Cavosie, A. J., Clechenko, C. C., Spicuzza, M. J., Basei, M. A. S., Bindeman, I. N., Ferreira, V. P., Sial, A. N., King, E. M., Peck, W. H., Sinha, A. K., and Wei, C. S. (2005). 4.4 billion years of crustal maturation: oxygen isotope ratios of magmatic zircon. Contributions to Mineralogy and Petrology, 150(6):561*580.
6. Harrison, T. M., Blichert-Toft, J., Müller, W., Albarede, F., Holden, P., and Mojzsis, S. J. (2005). Heterogeneous hadean hafnium: evidence of continental crust at 4.4 to 4.5 Ga. Science, 310(5756):1947*1950.
7. Manning, C. E., Mojzsis, S. J., and Harrison, T. M. (2006). Geology, age and origin of supracrustal rocks at Akilia, West Greenland. American Journal of Science, 306:303*366.

Thangalin 01:12, 11 October 2007 (UTC)

The article Sun is edited here. Thanks for the 4.654, now we'll see what other editors think about it. (SEWilco 03:11, 11 October 2007 (UTC))

Sol in opening sentence?

Anyone know why Sol is in the opening sentence besides the fact that there are a lot of Wikipedians who like scifi? I don't see any reason why the popularity of the name Sol in science fiction can't be mentioned later in the article, but putting it in the opening sentence seems to give disproportionate weight to a phenomenon isolated entirely to the world of fiction. Same goes for Luna over at The Moon. --Beaker342 03:45, 23 October 2007 (UTC)

This was discussed quite a while ago and the conclusion was reached that it was to stay, due to so many works (both fiction and charts) referencing it as such among other things. --Oni Ookami Alfador^Talk|@ 23:05, 6 November 2007 (UTC)

Could you point me in the direction of those discussions? I looked through the archives and didn't see any specific discussions about the opening sentence. By the way, I hardly think registering a complaint on the talk page and then acting on that complaint a full two weeks later is taking "unilateral action". --Beaker342 00:45, 7 November 2007 (UTC)

I apologize for that. Afterwards I looked at the dates and realized it has been a while. The discussion took place in edit summaries though. In any case I feel it should remain until a consensus one way or the other can be established given that it was in the featured article version. In one form or another this has been in the article since and during its featured article inception. It may be inappropriate to remove from the article entirely. Even if it is simple a science fiction phenomena (I believe it is more than just that), it is good that the note does have its own section. Having said that, I believe the alternative language name template is the most practical way to include it. Although it is "the first thing in the article," having it in that template makes it equivalent to a footnote, in that most readers simple gloss over it as a reference point, and if anything, the existence of this section justifies it as a parenthetical above.--Oni Ookami Alfador^Talk|@ 01:03, 7 November 2007 (UTC)

I see your points. I don't think that the history of the article is itself any reason for keeping it any specific way. The thing I am concerned about though is that by putting it in the lead sentence, we are perpetuating the idea that the "official" name of the Sun is Sol, as evidenced by the great number of users who pop in here occasionally to make that claim. If the bit in the lead were just a footnote for the purposes of etymology, we could just as well put Helios, which is the root of all sorts of other words. Also, I would be most interested if someone could point me to a nonficition source that does call it Sol (academic article, official chart, etc). I've seen it asserted that such sources exist, and if they do, that section of the article could be improved with links to those sources. --Beaker342 01:24, 7 November 2007 (UTC)

Well, its just the intro. As I understand the MOS the whole point of it is to summarize what the reader can expect to find later in the article and the parenthetical reference does just that. The more or less equates to an "also known as:", which I would like to think most readers are smart enough to take as such and not sensationalize it with odd notions of grandeur. In fact, the only ones who seem to do that are the ones who come to the article with the intent of making that point anyway, not the people who are actually looking for information.--Oni Ookami Alfador^Talk|@ 21:06, 7 November 2007 (UTC)

Sol is the scientific name of the Sun. Scientists internationally refer to the Sun as Sol. Think Homo Sapiens. There are many suns, but only one Sol.—Preceding unsigned comment added by 69.220.2.188 (talk) 21:15, 12 November 2007 (UTC)

Thanks. Care to provide any evidence?--Beaker342 21:33, 12 November 2007 (UTC)

Actually, no, I wouldn't. There is a free astronomy program available called Celestia that refers to the sun as Sol, but after a five minute search on Google, the best I could come up with is astronomy sites saying Sol is our sun's name, yahoo answers saying the sun has no scientific name like Homo Sapiens, and most other sites simply saying something like "Sol, the name of our sun..." This is why it's good to not just take someone's word for it.:( Sorry! 69.220.2.188 04:48, 13 November 2007 (UTC)

Sol is often employed scientifically in the word 'solar', as in a 'solar mass' or a 'solar panel'. For everyday usage, however, I prefer not to use 'Sol' as it is much less well known than 'Sun'. — RJH (talk) 20:22, 6 December 2007 (UTC)

I'm confused. We're not talking about etymology here. If we were, we would have to include that the Greek word for the Sun is Helios, which finds its way into words such as helium, heliocentric, perihelion, heliotrope (you get the idea). So what exactly do you mean when you say that "Sol is often employed scientifically"?--Beaker342 (talk) 02:12, 7 December 2007 (UTC)

I'm not sure what I can add that wasn't mentioned in my previous statement. Yes it might make sense to mention the use of the greek root helios in the cultural history section. — RJH (talk) 16:28, 7 December 2007 (UTC)

Life Cycle

After reading the articles referenced in the section Sun#Life_Cycle I have come to the conclusion that life on earth will not be affected by changes in the Sun within 700 million years. One source cited in this article states that:

T=5.6 Gyr (1.1 Gyr from today):

* Sun will be 10% brighter than today. * Extra solar energy causes a Moist Greenhouse Effect.

The Earth's atmosphere will dry out as water vapor is lost to space. Such a situation will probably spell the end of large surface life on Earth. Some types of marine life and simpler life forms will likely survive in the oceans and localized pools of water.

Note: 1 Gyr = 1 billion years.

True death of life on Earth will not occur until 3.5 billion years from now when, "The oceans will evaporate into space, and conditions on the Earth will be like those on Venus today".

I'm not sure where this 500-700 million years figure came from but it should be changed, as the sources do not back it up.

--Westralian 10:04, 3 November 2007 (UTC)

Some sources for this can be found on the internet. Peter Ward and Donald Brownlee, in The life and death of planet Earth, predict a gradual decrease of atmospheric carbon dioxide in the next 500 million years, causing most plant life to go extinct by about 500-1000 million years from now. According to one source, this would be caused by increased chemical weathering due to rising temperatures ([12]). I couldn't tell whether or not this is good science. ([13]) Iblardi 22:13, 7 November 2007 (UTC)

Other articles here give 2 Billion years. 199.125.109.134 (talk) 01:09, 18 November 2007 (UTC)

There is a dispute on this matter in the planetary science community, but here is the basic mechanism: as the Sun slowly warms, life on Earth can adapt by dropping CO2 leaves to correct the surface temperature. In 500-700 million years, the Sun will be so hot that current temperatures can't be maintained even with zero CO2 concentration (and even that requires some serious plant evolution). The dispute is if this corresponds to the end of life on Earth - you can play games with nitrogen fixation and also drop the oxygen content, and the survival of microbial life gets pushed out another billion years. I suggest a recent paper by Yuk Yung, but I don't have the full citation available. Michaelbusch (talk) 01:23, 18 November 2007 (UTC)

Either way, there is still a contradition, because it says "The increase in solar temperatures over this period...", referring to the Red Giant phase, which won't begin for 5 billion years. "this period" should be removed. —Preceding unsigned comment added by Theophile490 (talk • contribs) 02:30, 26 November 2007 (UTC)

Ehhhmm, who knows! The problem is the cloud generation, which is poorly known. If the cloud generation increases much with the solar luminosity increase (let's just imagine that an increased solar wind generates more nanometric water drops in the atmosphere), then the luminosity increase is countered by increasing albedo (reflection) of Earth. 500-700 million years seems like speculation that must either be cited carefully, or avoided... Said: Rursus ☻ 15:29, 31 January 2008 (UTC)

Citation Needed?

"The Sun (Latin: Sol) is the star at the center of the Solar System.[citation needed]"

Are you [interjective] kidding me? 69.220.2.188 21:17, 12 November 2007 (UTC)

I don't know. Maybe the motivation for putting it there was the current dispute over whether the Latin "Sol" is significant enough to go in the opening sentence.--Beaker342 05:29, 13 November 2007 (UTC)

Moved from solar energy

This external reference has nothing to do with solar energy, it is a tutorial on the sun.

• Sun|trek website An educational resource for teachers and students about the Sun and its effect on the Earth

199.125.109.134 (talk) 01:03, 18 November 2007 (UTC)

'Life Cycle' image is wrong and apparent confusion between temperature of the Sun and the temperature on Earth

The graphic depicting the life cycle of the Sun is wrong and should be deleted (and, honestly, a linear plot such as this doesn't do justice to what actually goes on in stellar evolution... a Hertzsprung-Russel diagram would be more appropriate). The graphic seems to completely ignore some of the stages of stellar evolution (i.e. the horizontal branch and the asymptotic giant branch) and the timescale for the stages it does show are wrong. A star like the sun will sit on the main sequence, undergoing very little evolution for 10 billion years only after this time will it begin to evolve off of the main sequence. Evolution along the sub-giant branch and red giant branch take another 1.1 billion years. The Sun then also goes through the helium flash, horizontal branch and asymptotic giant branch phases before becoming a white dwarf and ejecting gas that becomes a planetary nebula. These last three processes take only about 0.1 billion years combined, but should be on any graphic discussing the evolution of a star.

As for the 'gradual warming' stage, I'm not sure where this comes from... it is possibly referring to the contraction and heating of the Sun's core, but the graphic is depicting the surface of the sun, not the core. Once the Sun leaves the main sequence its surface will get cooler. The outer layers will expand, increasing the radius of the sun, making it cooler and brighter (hence the red giant phase). As it moves up the red giant branch, the cooling continues and the radius keeps increasing. The helium flash causes the star to 'reorganize' slighty, making the surface hotter, but smaller and dimmer. The evolution from the horizontal branch up the asymptotic giant branch is similar to that of the red giant branch.

The life cycle section of the article talks about the fate of the Earth and that the 'increase in solar temperatures' will have dramatic effects on Earth. I think there is some confusion between the temperature on the surface of the Earth and the temperature of the surface of the Sun (and when talking about what goes on on the Earth, we generally only care about what is going on at the surface of the Sun). As I mentioned above, the surface of the Sun is not going to get warmer. It will get cooler, but will also expand, increasing in luminosity, and thus more solar radiation will reach the Earth. I don't know for sure, but I assume this increase in brightness will result in a warming of the Earth's surface. Maybe this is the 'warming' that is being referred to? Either way, the graphic still needs to be rectified.

One thing I would suggest is to drop the 'life cycle section' from the Sun page have section on the evolution of the Sun that refers readers to the stellar evolution page, which has a fairly good discussion of the life cycle of Sun-like stars. This may help to simplify things and keep Wikipedia self-consistent. Grochol17 (talk) 22:24, 19 November 2007 (UTC)

Setting aside the other issues, I would guess the "gradual warming" it is refering to is the gradual increase in total luminosity that all main sequence stars experience. For a star like the sun it amounts to about +10% / Gyr. This a phenomenon distinct from the more dramatic changes that occur as a star moves away from the main sequence. Dragons flight (talk) 22:55, 19 November 2007 (UTC)

Thanks for your quick response. My comments came from memory, but I decided to double check what I was remembering... I looked at the stellar evolution models from Girardi et al. (they can be found here: http://pleiadi.pd.astro.it/). The increase in temperature for a one solar mass star from 4 Myr into its lifetime until it reaches an age of 10 Gyr is only 140 K, or about 2% of its temperature. My opinion is that its not significant enough to be noted on the figure, especially since the way it is noted gives the wrong impression about the changes in the sun. I've looked through a few more comments and many time it is repeated that life on the Earth will end because the Sun will increase in temperature. Grochol17 (talk) 23:25, 19 November 2007 (UTC)

When the Sun expands into a red giant, its surface temperature might get relatively cooler but the surface will also move toward Earth. (SEWilco (talk) 05:08, 20 November 2007 (UTC))

Gough (1981) gives the Sun's ZAMS luminosity as 0.7 times solar luminosity. (Per the Stefan–Boltzmann law, if radius is unchanged, luminosity increases as T⁴!) That's a pretty significant increase, and leads to the faint young sun paradox. I think that the specific details of the post-main sequence should probably be covered on the red giant page. — RJH (talk) 16:08, 8 December 2007 (UTC)

Size

I came here looking for the Sun's size-classification, but did not find this information anywhere. I understand it is a medium size star and have added this information. I'm sure there are many articles corroborating this, but for one example see this PDF at nasa.gov: http://imagine.gsfc.nasa.gov/docs/teachers/lifecycles/LC_main_p2.html --Tuxley (talk) 09:12, 27 November 2007 (UTC)

Medium-size star or low mass star is probably good enough. Most stars are compared with the Sun anyway. It is classified as a dwarf star, but that pretty much covers the main sequence.—RJH (talk) 20:37, 5 December 2007 (UTC)

Abundances

The following paper suggests abundances of X=0.6822, Y=0.299 and Z=0.0188:

Schaller, G. (1992). "New grids of stellar models from 0.8 to 120 solar masses at Z = 0.020 and Z = 0.001". Astronomy and Astrophysics Supplement Series. 96: 269–331. Retrieved 2007-12-05. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

These don't seem to match the abundances listed in the lead for this article. Does anybody understand the discrepancy?—RJH (talk) 20:28, 5 December 2007 (UTC)

The supplied reference in the lead, Manuel and Hwaung (1983), only provides the element abundance in the photosphere. They also make the dubious claim that the Sun's energy is not provided by hydrogen fusion. Since the Sun is not convective throughout, this abundance is probably representative of the Sun at zero-age main sequence. Unless I'm mistaken, I don't believe it takes into account the increase in helium at the core.—RJH (talk) 16:23, 8 December 2007 (UTC)

I found a recent ref. that should serve, and I changed the text to mention that this is the composition of the outer envelope. I.e. the surface. Apparently the core is about 2% enriched with Helium compared to the surface.—RJH (talk) 19:26, 9 December 2007 (UTC)

Sol as official name

Finally finding some archived discussions over at Talk:Solar System I found a debate over the use of the term Sol. A couple diligent editors uncovered some NASA pages that called the solar system the Sol system. It would seem to me, based on these discussions, that the there is occasional usage of the term "Sol" in the scientific community, though it is not in any way "official." The Straight Dope article I found seemed to share this conclusion. I think it would be valuable to state this explicitly in the article given the ongoing confusion among vistors (and I include myself among them) to the talk pages. What say ye?--Beaker342 (talk) 04:21, 7 December 2007 (UTC)

One eurocentric designation for the local star is as good as another to my mind. I would suggest "star" plus the definite article (in those languages which have definite articles, just star (星) in those (like Chinese) that don't) or "star" and the plural possesive, eg. Nuestra Estrella. Also typo in my edit comment: terrestrial. Lycurgus (talk) 22:09, 7 December 2007 (UTC)

Shock front

I deleted this link from the page. Roberto —Preceding comment was added at 16:25, 26 December 2007 (UTC)

Due weight, science, and human culture

I see that there is now a culture section in the article, but I feel that it is much too small considering the importance of the sun in human cultures worldwide. I really feel we need to balance the article out more. If the culture section is professionally expanded and the article gets too big, what needs to be cut is science, not culture. Would anyone be opposed to a slow development of the culture section? I could put something together, but if we're really going to have a good section, it's going to be longer than one, two, or even three paragraphs. I know most of you are probably scientists, but there are plenty of sources out there about the sun as it relates to the humanities, and articles should judge due weight based on source availability. Right now, this article wouldn't come close to passing a due-weight judgment on these issues. Wrad (talk) 07:20, 4 January 2008 (UTC)

I am a scientist more than anything else but I fully agree with you, the article should be balanced out with more 'humanities'. What you propose sounds very interesting, so I encourage you to go ahead. Randomblue (talk) 12:22, 6 January 2008 (UTC)

Alright. After looking things over, I think the best way to proceed is to fix the Sun in human culture sub article first. It will be awhile before we get to this article. Wrad (talk) 21:09, 6 January 2008 (UTC)

minor point

In the lead, it is written that the Sun "by itself accounts for about 99.8% of the solar system's mass". Then, in the Structure section, it is written that the Sun "comprises approximately 99% of the total mass of the solar system."

First, this is a repetition (in fact, why not?). Second, it is kind of inconsistent since you don't use the same number of significant figures in both cases. Third (and, in my opinion, most importantly) 99.8% is much closer to 100% than it is to 99%. This should be corrected. Randomblue (talk) 11:59, 6 January 2008 (UTC)

second minor point

I still haven't read the whole article but just in the Structure section the use of '%' and 'percent' is inconsistent. For example, it is written "It comprises approximately 99% of the total mass of the solar system." and "The solar core comprises 10 percent of its total volume, but 40 percent of its total mass." Randomblue (talk) 12:04, 6 January 2008 (UTC)

Also, the use of 'th' is inconsistent. "1/2350th of the core" and "the sun ranks 4th in absolute magnitude". Randomblue (talk) 12:09, 6 January 2008 (UTC)

reference needed (in my opinion)

"Computer modeling of the Sun is also used as a theoretical tool to investigate its deeper layers." Randomblue (talk) 12:05, 6 January 2008 (UTC)

paragraph problem

Three one sentence paragraphs in a row is rather unelegant. Please merge or find another solution. Randomblue (talk) 12:14, 6 January 2008 (UTC)

"Lithium, Beryllium, and Boron In 1968, a Belgian academic found that the abundances of lithium, beryllium, and boron are higher than previously thought (Grevesse 1968[23]).

Neon In 2005, three academics claimed that the neon abundance in the Sun may be higher than previously thought, based on helioseismological observations (Bahcall et al 2005[24]).

Helium It is also interesting to note that until at least 1986 the generally accepted initial helium content of the Sun was Y=0.25, but two academics in 1986 claimed that the value Y=0.279 is more correct (Lebreton and Maeder 1986:119[25])."

is a sun a stars ? is sun a natural sources of light

i need to know this answer by thursday . this is a project to me .i just cannot find the ans to my queation if any one see this message please send the answer to my e-mail which is located below.. thank you very much hazelchua_1997@hotmail.com/ u can msn me in messanger we can be friends also thank you for my glass of water --165.21.154.92 (talk) 11:13, 7 January 2008 (UTC)

can we put a link to the tachocline page on to this page

the logical place for it would be somewhere between the convection zone and raditive zone. errrr... because the tachocline is the sheering reSgion between these two layers! http://en.wiki.x.io/wiki/Tachocline —Preceding unsigned comment added by 130.246.132.26 (talk) 16:06, 16 January 2008 (UTC)

Sure, why not. Sagittarian Milky Way (talk) 07:32, 25 January 2008 (UTC)

Eye damage

For the eye damage section -- if someone were to look through the eyepiece of a telescope aimed at the sun on an overcast day (during the day) with a UV index of 1, but the person had his/her eyes shut while doing it (for a few seconds), would the person's eye(s) be damaged by the sunlight or UV rays? Latitude0116 (talk) 19:49, 17 January 2008 (UTC)

• Don't quote me on this but I would doubt it, as the eye lids when shut would minimise any radiation entering the eye and reaching the retina. However, if the telescope were extremely powerful, it would be worth taking precautions.

Gilgamesh007 (talk) 21:04, 18 January 2008 (UTC)

Isn't the SOL a green star?

I have read many things saying it is a green star. Even my physics teacher told me this. By finding the peak wavelength using surface temperature of the Sun in Wien's Law, you will find that it is a green star. The calculation I got is 501.6 nm which is green. Sorry I don't know how to properly submit a discussion.70.18.173.159 (talk) 03:33, 28 January 2008 (UTC)

In short no, the sun is not Green, but would appear white from space. When people quote the sun as being green, what they are referring to is the that fact that according to Wien's displacement law the Sun's peak output wavelength is in the green part of the visible spectrum; but that doesn't mean that the Sun appears as "green". The human eye perceives the sum of all visible wavelengths. The Sun's yellow colour as seen from under the Earth's atmosphere is due to atmospheric effects (Rayleigh scattering). Remember that sometimes (at sunset and sunrise) it can appear red/orange too. Colour perception is a very complicated subject. For more on the colour of the Sun, and other stars as see by human eyes see the "Spectral Classifcation" wiki-talk page where there is extensive discussion on this subject. Antarctic-adventurer (talk) 06:36, 8 December 2008 (UTC)

all life?

im skeptical that the sun "supports almost all life on Earth via photosynthesis". I think that the are isolated cave animals that dont have sunlight and dont need the sun. Wikid00d88 (talk) 04:00, 31 January 2008 (UTC)

Scepticism is a healthy thing, but one requires evidence to really back up one's point. It was thought once that ALL life on earth derived its energy from the sun, but it has since been found that there are bacteria that can source energy independent of the Sun using Methane or Sulphates, and thus supporting ecosystems that are truly independent. They are however, the exception rather than the rule so the article statement is perfectly correct in my opinion, using as it does, the word "almost". Antarctic-adventurer (talk) 06:41, 8 December 2008 (UTC)

Solar and planetary mass fractionation relationship

Please add the following to what is already written in the section,

Solar and planetary mass fractionation relationship

A mass fractionation relationship in the solar photosphere has also been reported [75] in the abundances of 72 different types of atoms that were made by slow neutron-capture, the s-process of element synthesis [57].

The mass fractionation relationships seen in the isotopes of noble gases in the solar wind and in the abundances of s-products in the photosphere both indicate that the most abundant elements in the interior of the Sun are iron (Fe), nickel (Ni), oxygen (O), silicon (Si) and sulfur (S) [75].

Reference:

75. O. Manuel, M. Pleess, Y. Singh and W. A. Myers (2005). "Nuclear Systematics: Part IV. Neutron-capture cross sections and solar abundance", Journal of Radioanalytical and Nuclear Chemistry 266, 159–163. http://www.omatumr.com/abstracts2005/Fk01.pdf

this was wrtten by Daisy Norman xxxx —Preceding unsigned comment added by 78.151.208.141 (talk) 11:47, 5 February 2008 (UTC)