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This article has changed immensely since it was designated an FA. The lead, in particular, has gotten thick to the point of near-unreadability by the average person. There's simply too much detail for a lead. And yet, the lead also seems to be missing some stuff that it needs per the WP:LEAD requirement to be a summary of the whole article. I'm going to see what I can do in the next hour, but I doubt I can finish it in that time. Un sch ool 03:19, 28 October 2009 (UTC)

Okay, I've removed some detail that would be better left in the body (and, I'm guessing, is already there, though I have to go back and put it in the body if it is now missing), and I've really cut down on the numbers. This lead is supposed to be easily accessible, readable, to the average joe, and the numbers were simply unnecessary to convey the concepts, which is what the lead needs to do. Un sch ool 04:27, 28 October 2009 (UTC)

The article gives some fairly precise detail on the chemical composition of the photosphere and some sketch information about the chemical composition of the core of the sun, but it would be nice to also include some information on the _overall_ chemical composition of the sun. I have no access to either journals or textbooks, but this NASA source suggests some values: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/961112a.html. Perhaps someone could compare with some published authoritative source and add the information.

— Preceding unsigned comment added by 81.107.38.136 ( talk) 12:02, 13 October 2009 (UTC)

It is unclear whether the distance from the sun to the earth (149.6 units) is taken from the center of the sun or the surface of the sun. If from the center, the distance from the surface would be 148.9 units since the sun radius is 0.7 units. If from the surface, then one would have to add 0.7 to 149.6 yielding 150.4 units. This matter affects all planetary distances, not just earth-sun, but it needs to be clarified somewhere. 69.108.2.81 ( talk) 21:19, 13 November 2009 (UTC)

A moderately interesting theorem that computes how far Sol's light dominion spreads out into the universe in a spherical formation, is to be found on these links [1] [2]. My two cents of new wiki stuff for this morning, if you like to add it to the wiki page. Cheers to all.

That is a v.interesting theorem! —Preceding unsigned comment added by 81.107.117.27 ( talk) 20:09, 29 November 2009 (UTC)

The sun's radius is introduced indirectly a long way into the article with the phrase "200,000 km or 70% of the solar radius." If the solar radius is 280,000 km the article should say so early on.

Bukovets ( talk) 12:47, 3 November 2009 (UTC)

Shouldn't this article be named Sol or Sol (star)? UNIT A4B1 ( talk) 02:41, 20 November 2009 (UTC)

Short version, no. "Sol" is the proper Latin name, while "Sun" is the proper name in English (per the IAU). "Sol" is used in science fiction, but not in real-world applications. Similarly, the Latin "Luna" is not the proper English name for the Moon. For more on the Sun-Sol issue, search through the talk page archives, as it has come up repeatedly. -- Ckatz ^chat _spy 04:47, 20 November 2009 (UTC)

If you're interested in the Latin, you can read the Latin version of this article here. The Latin article is at "Sol", but the English should be at "Sun" for the reasons mentioned above. 84.92.117.93 ( talk) 00:48, 6 December 2009 (UTC)

In the November 2009 issue of Scientific American, Zwart (a theoretical astrophysicist) lists the sun's orbital parameters differently. I don't know where the ones in this Wiki article came from, so I can't vouch for their accuracy. Should we upgrade to the following numbers?

The relevant passage:
"At the moment, we are located about 30,000 light-years from the center and about 15 light-years above the plane of the disk [of the galaxy], orbiting at a speed of 234 kilometers per second. At this rate, the sun has done 27 circuits since its formation."

APA citation:
Zwart, S. F. P (2009, November). The Long-Lost Sibliings of the Sun. Scientific American. —Preceding unsigned comment added by 76.120.250.205 ( talk) 18:26, 24 December 2009 (UTC)

{{editsemiprotected}}

I have trouble reading the Corona section of page http://en.wikipedia.org/wiki/Sun. There may be a numeric error by a factor of 10 or others smaller. And a sentence with arithmetic seem out of order. Here is a replica of some of the text with my comments imbeded in square brackets. … the Sun releases energy at the matter–energy conversion rate of 4.26 million metric tons per second… Power density is about 194 µW/kg of matter, though since most fusion occurs in the relatively small core the plasma power density there is about 150 times bigger. [Last phrase not clear. Why is the arithmetic done a sentence later, or is it?] For comparison, the human body produces heat at approximately the rate 1.3 W/kg, roughly 600 times greater per unit mass. [But 1.3/194µ = 6701, not 600] [per unit mass of the sun as a whole or of the core?] Assuming core density 150 times higher than average, this corresponds to a surprisingly low rate of energy production in the Sun's core—about 0.272 W/m3. [But 150(194 µW/kg) = 0.029 not 0.272] This power is much less than generated by a single candle... Edtakken ( talk) 02:56, 29 December 2009 (UTC)

Done Welcome and thanks for contributing. That portion appears to be a pseudo-scientific editorial against fusion power. The cited NASA source does not contain those numbers, nor does the paper characterizing a candle include that figure for power. All of the fusion occurs in the dense core yet the figures try to distribute the power across the entire mass, with a nod to "the plasma power density [in the core] is about 150 times bigger". Thanks again, Celestra ( talk) 16:41, 29 December 2009 (UTC)

The page is inconsistent. Kilometers is used five times. Kilometres is used once. Ckatz undid my change toward consistency and I'm changing it back to consistent. If someone wants to give me evidence that kilometres is the correct wiki standard, I'll change them all to kilometres but for now, I'm going with the majority standard inside THIS article. Friedlad ( talk) 04:07, 7 January 2010 (UTC)

WP:ENGVAR#Consistency within articles agrees that the article needs to be consistent in its use of national varieties of English. The guideline that seems right to use here is WP:RETAIN. Whichever variety of English the article originally used should be the standard with which we are consistent. I'll go check. Celestra ( talk) 05:43, 7 January 2010 (UTC)

The original (2002) did not have any words which are specific to a national variety. Until this edit last November, all of the national variations were American English (color instead of colour, kilometer instead of kilometre,...) It seems that Friedlad is correct to revert. Is there a option for the convert template to use the American spelling? Celestra ( talk) 06:02, 7 January 2010 (UTC)

While reviewing this article, I noticed that the diagram "Motion of Barycenter of solar system relative to the Sun" was a relatively poor quality gif file, the source URL was to a PhotoBucket account that is now disabled, and it was for the years 1945-1996. Therefore I created two new diagrams and uploaded them to Wikimedia for you: 1) File:Solar System Barycenter 1944-1997.png is a complete recreation of the diagram in the article with the same years and path to verify validity of my algorithms, and 2) File:Solar System Barycenter 2000-2050.png which is a more "current" diagram for the years 2000-2050. Feel free to use one or both of these public domain png files if you want to replace the older diagram. Larry McNish, Calgary Centre of the Royal Astronomical Society of Canada. http://commons.wikimedia.org/wiki/File:Solar_System_Barycenter_2000-2050.png http://commons.wikimedia.org/wiki/File:Solar_System_Barycenter_1944-1997.png 68.144.133.105 ( talk) 12:51, 8 January 2010 (UTC)

The title, Theoretical problems, strikes me as very strange. They're more like inconsistencies; the theories are wrong, the sun is right. Any ideas for changing the title? Friedlad ( talk) 13:58, 12 January 2010 (UTC)

'Theoretical incongruencies' seems appropriate. It suggests the disagreement between theory and reality. 'Inconsistencies' strikes me as just as strange as 'problems.' —Preceding unsigned comment added by 216.85.157.42 ( talk) 16:25, 18 January 2010 (UTC)

The article is unclear as to the source of visible light emitted from the Sun. In the subheading Core, it states "After a final trip through the convective outer layer to the transparent "surface" of the photosphere, the photons escape as visible light. Each gamma ray in the Sun's core is converted into several million visible light photons before escaping into space."

However, in the Photosphere section, it says "The visible surface of the Sun, the photosphere, is the layer below which the Sun becomes opaque to visible light.[45] Above the photosphere visible sunlight is free to propagate into space, and its energy escapes the Sun entirely. The change in opacity is due to the decreasing amount of H− ions, which absorb visible light easily.[45] Conversely, the visible light we see is produced as electrons react with hydrogen atoms to produce H− ions.[46][47]"

The way I understand it, heat is transferred from the core to the photosphere, where the temperature is 5700K. The resulting blackbody spectrum at this temperature results in the visible light we see. How does the gamma rays get converted into visible photons (I'm guessing they are absorbed/knock off electrons and transfer heat that way), and how do "electrons react with hydrogen atoms to produce H− ions."? Can someone who knows this topic clear this up? —Preceding unsigned comment added by Kykw ( talk • contribs) 06:15, 20 January 2010 (UTC)

Under Life Cycle, it is noted "the Sun is gradually becoming more luminous (about 10% every 1 billion years), and its surface temperature is slowly rising. The Sun used to be fainter in the past, which is possibly the reason why life on Earth has only existed for about 1 billion years on land."

I am having some troubles understanding this...

As far as I can tell, for the most recent 4 billion years or so, the sun's luminosity has been fairly constant, and the earth's surface temperature has either been relatively stable, or slowly cooling.

So, if this is a predicted change from a past steady state to future warming trends, it should be noted as such.-- Keelec ( talk) 08:42, 21 January 2010 (UTC)

This is not a change from a past steady state. According to models, the Sun's luminosity has been increasing steadily for the past few billion years, and this will continue into the future. See e.g. Table 2, Sackmann et al., The Astrophysical Journal 418, 457–468 ( Bibcode: 1993ApJ...418..457S). Spacepotato ( talk) 02:39, 23 January 2010 (UTC)

The issue over where The Sun should redirect has been reopened. The original discussion in July 2009 led to a consensus to redirect The Sun to Sun. The new discussion can be found here. -- Ckatz ^chat _spy 21:08, 26 January 2010 (UTC)

...with this bit at least.

The apparent magnitude of the Sun as seen from Earth is –26.74, which is of course the brightest object in the sky. The Sun is what lights up the daytime sky. ^{citation needed} Although the absolute magnitude of the Sun, which is the apparent magnitude as it is viewed from 10 parsecs away is +4.83.

Deleting the whole lot seems simplest (as both magnitudes are mentioned in the infobox), but most articles of bright or important Solar System objects indicate apparent magnitudes somewhere else as well. In my admittedly exceedingly humble opinion the Sun, on any Solar System scale, qualifies as both bright and important. The bit about absolute magnitude might also be worth keeping, as it helps in comparing the Sun with other stars.

I think this should be moved to the Observation and effects section after heavy rephrasing, but figured I'd seek consensus (and someone courageous enough to approach that mess and put it into words more neatly). Sideways713 ( talk) 20:49, 28 January 2010 (UTC)

What about reversing the order as follows:

"The absolute magnitude of the Sun is +4.83. However, as the closest star to Earth, the Sun is the brightest object in the sky with an apparent magnitude of –26.74.

Thoughts? -- Ckatz ^chat _spy 21:12, 28 January 2010 (UTC)

Heaps better, so I put it in (with some slight modifications). Probably mostly due to my achy sleepy head I still see some problems with it though:

• It still just plain old doesn't sound good. If I was an author, and this sentence was trying to creep into my book... well, considering the standards of authors these days, I'd probably let it.
• It doesn't really fit either at the beginning of O&E or its current position.
• It goes on and on about Earth while ignoring all other objects orbiting the Sun. (OK, there are many very good reasons for that. To begin with, Earth is the only place we know of that has anyone concerned about apparent magnitudes on it. This therefore probably shouldn't be touched, unless you think however, due to its proximity, the Sun is the brightest object in the Earth sky usw. would work better.)

Now this is getting just petty... Perhaps I should get a life. Sideways713 ( talk) 19:29, 29 January 2010 (UTC)

Matter is loosely defined, but often thought of as fermionic particles like electrons and quarks. Almost everyone, by contrast, agrees that photons and other guage bosons are not "matter." Using this definition, matter can be converted to non-matter, or energy in the form of photons (such as electron-positron annihilation producing two gamma photons). Also, kinetic energy can be converted to pairs of stable particles, as happens in accelerators.

Alas! This fact has caused some people to misunderstand E=mc² to think that MASS can be converted to energy in the same way. It can't. You can get rid of "matter" but not mass. Mass is not "converted". It is conserved, just like energy, because the two are the same thing, and neither appears without the other. Thus, matter is converted to light in the Sun, but MASS is not. The light has the same mass-- it's just mass moving away. One kind of energy is converted to another, and one kind of mass is converted to another. But both are separately conserved. There is no conversion for any given observer. Loss of either mass or energy only means they left the system and you didn't keep track.

Incidentally, even in the Sun, "matter" is not converted to energy in the sense of some "matter" as fermions disappearing and reappearing as photons. The "matter" destroyed in the sun is not atoms, baryons, or even fermions like quarks, but rather nuclear fields. It has mass, but that 4 million tons is not "real particles" (as field it is virtual pions or something). So although matter can be "converted" to energy, that's not what's happening in the Sun, either, unless you're talking about the part of "matter" which isn't identifiable real particles. So let us avoid the word "converted," unless to say that rest mass is "converted" to the mass of a system of moving massless particles (here photons). The mass and energy move from the Sun out into space, but that's all. The mass stays the same if you consider the whole system. S B H arris 02:03, 18 February 2010 (UTC)

I have two problems with your changes to avoid the word conversion: first, the source does not talk of an "equivalence rate", it talks of a "conversion rate"; second, the word conversion includes the concept of movement between two forms of a thing as in potential energy being converted to kinetic energy as a thing falls. I'm fine with dropping converted from the second sentence, but I think the phrase "carried away as energy" makes it clearer that the mass and energy are different forms of the same thing. "Carried away with (or worse, by) the energy" seemed to convey that the energy apeared out of nowhere and carried away the mass. The current "in the radiated energy" can be read both ways, I think, so I'm fine with your version. Celestra ( talk) 03:38, 18 February 2010 (UTC)

Okay, good. The various types of energy can be converted to each other, and mass never changes during this, since obviously mass never appears without energy accompanying it, and vice versa. I would make the "mass in the energy" even stronger if I could. It's the mass OF the energy. Mass and energy are even more than different forms of the same thing (you make them sound like ice and liquid water). Even more, mass and energy always appear together. All energy HAS mass. All mass HAS energy. So it's not just that the mass is carried away AS light; rather the mass is a property of the light. The light has mass. First, this mass is in the Sun, THEN the mass moves off (leaving the sun lighter, but leaving whatever the light is absorbed by, heavier). It always stays mass. It always has a gravitational field, even after it is transformed to light. Mass is conserved over time, as seen by any single observer, period, end, full stop. YOu can't get rid of it, any more than you can get rid of energy.

Oh, and BTW, the source talking about "conversion" may simply be wrong. I think E = mc² is the most well-known equation in physics, and probably the most popularly misunderstood. You'll find endless sources that tell you it means mass can be converted to energy, and they're all wrong! A good physics text on special relativity like Taylor and Wheeler puts it straight. S B H arris 17:42, 18 February 2010 (UTC)

If someone puts in 'The Sun' into the search box, they are more likely to be looking for the newspaper of that name not the celestial body. Sam Blacketer ( talk) 15:51, 14 November 2009 (UTC)

You mean we should redirect The Sun to The Sun (newspaper)? I think it is better to create a dab. Ruslik_ Zero 16:39, 14 November 2009 (UTC)

This was extensively debated in late July, with the consensus being to move the newspaper's article to The Sun (newspaper), redirect "The Sun" to "Sun", and use the " Sun (disambiguation)" hatnote at the top of the page. -- Ckatz ^chat _spy 21:48, 14 November 2009 (UTC)

Well, that debate came to the wrong decision. WP:THE is the guiding page and its application here is clear. I also dispute that the closer of the debate correctly determined consensus - certainly not on a pure vote count, and definitely not if established naming convention is given the greater weight appropriate. Sam Blacketer ( talk) 22:54, 14 November 2009 (UTC)

If you feel that way, you can certainly ask for a review or a renewed discussion. However, it would not be appropriate to arbitrarily change the redirect without said discussion. I'd also point out that the earlier discussion did consider WP:THE, that the British paper (while certainly very popular) is not the only paper using that title, and that the original nominator actually changed his proposal in order to have "The Sun" redirect to "Sun". -- Ckatz ^chat _spy 23:09, 14 November 2009 (UTC)

I think it should be reopened per WP:CCC. The point about the naming guideline is that it ought to have far more weight in the issue; it's effectively up to those arguing a different outcome to contend why the guideline should be ignored on this occasion. The original proposer of the move actually made his proposal more extreme, given that he started by proposing The Sun as a disambiguation page. There might be a case for a separate disambiguation page for newspapers called The Sun given that there is no article on the former London evening paper (1792-1871). Sam Blacketer ( talk) 23:27, 14 November 2009 (UTC)

With regards to WP:CCC, yes, of course consensus can change - but that is usually considered in regards to long-standing matters when significant opposition arises, not relatively minor issues that were debated and concluded a short time ago. With regards to the guideline, the consideration was that in this case, "The Sun" was far more commonly thought to refer to the star rather than the other references, let alone to a single paper. In part, that reflects an international perspective. -- Ckatz ^chat _spy 23:46, 14 November 2009 (UTC)

If someone puts in 'The Sun' into the search box, they are more likely to be looking for the celestial body, not the newspaper. South Bay ( talk) 01:07, 17 November 2009 (UTC)

Obviously; it's odd that the OP thinks otherwise. -- 98.108.219.226 ( talk) 00:45, 24 February 2010 (UTC)

I read at topic: Present anomalies

Its magnetic field is at less than half strength compared to the minimum of 22 years ago. The entire heliosphere, which fills the Solar System, has shrunk as a result, resulting in an increase in the level of cosmic radiation striking the Earth and its atmosphere.

There is no reference ... sounds a bit bold, I would suppose the heliosphere keeps on expanding as long as the sun keeps shining? Michel_sharp ( talk) 21:42, 4 March 2010 (UTC)

Why cant I edit this page?I logged in. Easterndarksunrise ( talk) 02:39, 8 March 2010 (UTC)

This page is Semi-protected, so it can only be edited by users whose accounts are more than 4 days old and have 10 edits or more. -- The High Fin Sperm Whale 02:44, 8 March 2010 (UTC)

This here is information, for which i'am not so sure if it's included in the article, at least check the image http://science.nasa.gov/headlines/y2010/12mar_conveyorbelt.htm There is also a link to the report on Science. ThorX 11:02, 15 March 2010 (UTC) —Preceding unsigned comment added by ThorX13 ( talk • contribs)

Isaac Asimov wrote a book stating that our Sun is fourth- or fifth-generation. In other words, our Sun has gone nova, maybe even supernova once. Does that fit in the scope of the article? 75.243.68.250 ( talk) 06:19, 12 April 2010 (UTC)

In which book did Asimov say this? I doubt that Asimov meant that the sun had gone nova three times when he said it was fourth generation. Each generation is made from the discarded remnants of the previous generation. So a forth generation star would be made up of bits from third generation stars. The sun pretty well wouldn't exist if it had ever gone super-nova. -- Salocin-yel ( talk) 12:46, 14 April 2010 (UTC)

article indicates the age of the sun is 3.8-2.5billion years old. Recent Data suggests it is closer to 4.6billion years which is consistent with other measurements on the earth,moon,and meteorites. See "Standard Solar Model" wiki which references "^ Sackmann, I.-Juliana; Boothroyd, Arnold I.; Kraemer, Kathleen E. (November 1993). "Our Sun. III. Present and Future". Astrophysical Journal 418: 457–468. doi:10.1086/173407." —Preceding unsigned comment added by 70.138.186.72 ( talk) 00:49, 16 January 2010 (UTC)

Noticed while reviewing, that the density given for the top of the Convective zone (Photosphere) of 0.2 g/cm³ and the following parathetical statement(1/10000 of sea level density) didn't jive. These values are not equal. Checked reference (NASA1) and made minor correction. GeoPopID ( talk) 13:46, 28 March 2010 (UTC)

Note that our unit is g/m³, which gives us the 6 extra zeros. Density of air is 1.2 kg/m³, which is (to 1 significant digit, and with a wince) 10000 times more. -- Stephan Schulz ( talk) 16:00, 28 March 2010 (UTC)

My mistake. Gram per cubic meter (g/m³) is a funny unit, and it got me! If I were God I would make the SI Committee change the name for the base unit of mass to something you can use the prefixes with. That would ameliorate a lot of these kind of errors. GeoPopID ( talk) 19:18, 29 March 2010 (UTC)

The second paragraph currently [3] says "and is informally designated a yellow star, because the majority of its radiation is in the yellow-green portion of the visible spectrum.[12]", where 12 is [4]. No. Well, "informally" is border line, because stellar classification isn't, and G class is often called "yellow". But definitely not "because the majority" (cite supports "majority" but not "because") - it's yellow relative to the blue spectroscopic reference star Vega (see stellar classification#Conventional_and_apparent_colors, currently [5] ok, though the table with colors above it has become variously bogus). The article is now semi-protected, so fyi. (The Sun is also yellow relative to the blue non-reference muppet Cookie Monster, but that isn't causal. And is blue relative to yellow Big Bird, purple relative to green frog Kermit, and green relative to purple dinosaur Barney.) 98.216.110.149 ( talk) 20:12, 8 March 2010 (UTC)

The sun is not yellow from space it is white. The blue-green ultra-violet rays make the sun appear yellow from earth when they hit it from behind. Given the fact that it has a yellow glow omitted from it can be possible in distant space. From Space it is white, never changing, always the same. Only a stupid hominid would complain about that. A Cold Green absorbs light, do i see green stars in space?

http://www.acclaimimages.com/_gallery/_free_images/0124-0610-2618-0055_setting_sun_and_earths_horizon_from_space_o.jpg Sun from space

http://www.edge.org/documents/images/newrings_cassini1000.gif Saturn and the Sun

http://i.dailymail.co.uk/i/pix/2009/11/26/article-1231118-0755BEBD000005DC-829_964x641.jpg Sun from space again

http://www.windows.ucar.edu/sun/images/Space_sun_Eclipse.gif Sun from space during an eclipse. Green-blue hits white making yellow.

No photoshop.

The sun is a few trillion years old. The sun's age was last checked during the great cataclysm of the tertiary period, 120 million years ago when it was 14 years old. Now it is 30. The sun is still white and these rays you speak of is called our god Krishna. Last time I checked our sun wasnt dying out. -- Murriemir ( talk) 16:36, 16 April 2010 (UTC)

The temperature at the core is listed as 15.7x10^6. Shouldn't this be written 1.57x10^7? Thanks. Rhcathal ( talk) 11:13, 17 March 2010 (UTC)

Technically it should. It was probably written the other way because people think in millions. It would have been even better to write it as 15.7 million kelvins. BTW, no degree sign is needed for a kelvin. S B H arris 17:14, 16 April 2010 (UTC)

Is our sun part of a binary, where the other has since died? —Preceding unsigned comment added by 82.132.136.203 ( talk) 11:18, 9 October 2009 (UTC)

An interesting hypothesis. It may also be possible that our solar system is binary, however we are too far away from the other star to notice it.-- 24.171.1.195 ( talk) 01:39, 13 December 2009 (UTC)

It is a hypotheses that is debated very seriously in the scientific community and there are a couple of major star surveys underway working to resolve the issue (most stars in our neighborhood have never had their distance from the Sun calculated, because this previously required labor-intensive parallax measurements). However newer technology is speeding this up and the search for the Sun's possible companion star is now underway through a couple of major star studies. See the Wikipedia article Nemesis (star) for more details.

By the way, the prospect of the Sun possibly having a small companion star in co-orbit around it (a Red or Brown Dwarf) is taken seriously enough in the scientific community that a small section on the theory merits addition to this article. The fact that two major astronomical star surveys are currently underway to prove or disprove the theory certainly rates at least a mention in this article.

75.166.179.110 ( talk) 18:44, 21 March 2010 (UTC)

I disagree. Until there is greater evidence than there is now that a companion star exists in the Solar System there is no need to mention it in a encyclopedia article like this. We are presenting verifiable, referenced facts, not the speculative possibilities of science fiction.

Anyway, there is some real trouble with that hypothesis: first of all, in order to define this as a binary star system, the companion by definition would have to be a star. That eliminates brown dwarfs or substars like that from consideration. Such a body in orbit around the Sun would be considered a planet, if not, any of the four gas-giant planets, Jupiter, Saturn, Uranus, or Neptune could be considered a "companion star" of a multi-system.

Second, in order for a companion to be "stellar" it would necessitate a large mass, again by definition. The smallest know "normal" star is 93 times as massive as Jupiter (see Wikipedia article, "Star", under subsection "Mass"). Again, if the body was much smaller, so that it couldn't sustain nuclear fusion, it would be considered a planet. It is a bit hard to imagine a star as massive as that, located, say, within 0.5 - 1.0 parsec distance (where it wouldn't be perterbed away by nearby systems) having not already been discovered. Remember, the search for additional planets has been going on for centuries. Since the orbital barycenter of the Sun lies under its surface and much of this perturbation is explained by the existance of the known planets, it is hard to believe something else is out there.

Third, a main-sequence star, no matter how dim of a red dwarf, that close must have already of been detected. A more exotic object even if invisible in the visible light would likely radiate at other wavelengths. Even if it didn't radiate at all, seems to me its mass would have been detected by its gravitational effects.

I don't mean to take away from the research being made to verify this one way or the other, but obviously there is nothing to report yet. I see no need to publish it. GeoPopID ( talk) 15:58, 28 March 2010 (UTC)

I gave up formal academic study of astronomy some time ago but try to keep up a lay currency in it, and I think you are flat wrong about this, GeoPopID. Although I'm not inclined at this time of night to start crunching the numbers or digging for references, my firm understanding is that the smallest and dimmest stars proper are still so difficult to detect even at distances under a light year that a solar companion could well not have been detected yet: gravitation is far too weak for this purpose (inverse square law), and a distant companion's mutual orbit would be so long that orbital perturbations would be unnoticeable. The problem is not merely seeing such a star - it might well ready be in our catalogues already - but measuring the distances and space velocities of all the possible candidates to distinguish one close dim star from all the brighter but more distant ones. In the case of the planets most searches were confined to the region of the ecliptic - a small fraction of the total sky - and all depended on spotting proper motions orders of magnitude larger than would be the case here.

I agree that this article needs only a brief mention, with a link to Nemesis, but that mention ought to be included. I also think your tag of "science fiction" (of which I'm also a fan and collector) is inappropriate to something that is unconfirmed but uncontroversially possible without bending or extending any existing theories. 87.81.230.195 ( talk) 21:53, 23 April 2010 (UTC)

The second sentence of the first paragraph reads "It has a diameter of about 1,392,000 kilometers (865,000 mi) (about 109 Earths), and its mass (about 2 × 1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the Solar System's;..." and I find this a bit confusing. I feel it would be better to reword it to read "... and its mass accounts for about 99.86% of the Solar System's total mass; ..." or "... its mass accounts for about 99.86% of the Solar System ..." The reason that I find this confusing is it makes me ask "Solar System's what?" when I get to the semicolon. 74.131.104.227 ( talk) 15:19, 18 April 2010 (UTC)

These two lines are in the text right now not cited. there is obviously a big discrepency between 4 and 430-600....

• In its core, the sun fuses 430–600 million tons of hydrogen each second
• Each second, more than four million metric tons of matter are converted into energy within the Sun's core, producing neutrinos and solar radiation

Smitty1337 ( talk) 04:41, 6 May 2010 (UTC)

The efficiency of hydrogen fusion is only 0.7%. So, fusing ~620 million tons of hydrogen only yields ~4.3 million tons' worth of energy. The remaining ~616 million tons of mass are left as helium. Spacepotato ( talk) 04:48, 6 May 2010 (UTC)

Replace http://en.wikipedia.org/wiki/File:Yohkohimage.gif with http://commons.wikimedia.org/wiki/File:TheSun.png —Preceding unsigned comment added by Rgnort4guort ( talk • contribs) 20:29, 5 June 2010 (UTC)

A request for comments has been filed concerning the conduct of Jagged 85 ( talk · contribs). That's an old and archived RfC, but the point is still valid. Jagged 85 is one of the main contributors to Wikipedia (over 67,000 edits, he's ranked 198 in the number of edits), and practically all of his edits have to do with Islamic science, technology and philosophy. This editor has persistently misused sources here over several years. This editor's contributions are always well provided with citations, but examination of these sources often reveals either a blatant misrepresentation of those sources or a selective interpretation, going beyond any reasonable interpretation of the authors' intent. I searched the page history, and found 7 edits by Jagged 85 in June 2009 and 12 more edits in March 2010. Tobby72 ( talk) 21:15, 11 June 2010 (UTC)

The Sun is shining today with an Orange glow instead of its usual White. What does this mean? -- Arima ( talk) 23:37, 1 August 2010 (UTC)

That there's lots of crap in the air between you and it. Hold your breath. S B H arris 23:40, 1 August 2010 (UTC)

Maybe the article could use something like this? -- 82.171.70.54 ( talk) 14:03, 2 August 2010 (UTC)

Mirror of that image here. -- 82.171.70.54 ( talk) 02:53, 15 August 2010 (UTC)

It's nice, but somebody who made it, has to upload it to COMMONS or Wikipedia with a license to use it. S B H arris 03:05, 15 August 2010 (UTC)

The articles says the density is 0.2 g/m^3, which is 1/6,000 that of Earth at 1200 g/m^3, not 1/10,000. I've changed it. Later this is said to represent 10^23 particles per m^3 which would be about 1/6th mole/m^3. For Earth at 25 C, the molar density is about 1200 g/m^3/29 g/mole = 41 moles/m^3, so the molar ratio here is 1/240th, and the implied mean molar mass in the photosphere is 29/240 = 0.12 g/mole. This isn't quite right, as even H plasma is 0.5 g/mole. However, the factor of 0.5/.12 = 4 is the right order of magnitude. The particle density at sea level on Earth is 41 moles/m^3 x 6e23 particles/mole = 2.46e25 particles/m^3. A figure of 1% of this would be 2.4 e 23 particles/m^3, so this comes out about right. If the photosphere is H, it's 0.5% of the particles/volume, and if H plasma, very close to 1%. As in the edit note, the easy way to estimate this is 1/6000th of the density of Earth air, multiplied by particle mean mass ratio of 58 (assuming air at 29 and H plasma at 0.5). Multiplying one by the other gives a ratio of particle densities of 58/6000 = about .01 = 1%. S B H arris 22:41, 16 August 2010 (UTC)

The article shows it for: 1H (74.9%), 2He (23.8%), 6C (0.3%0, 10Ne (0.2%), and 26Fe (0.2%), and goes on to say that internally, the 2He constituency rises to 60%. Does that mean that there can't be any significant amount of Deuterium (1H2 or 1D2) within the sun? WFPM ( talk) 20:51, 7 October 2010 (UTC)

Primordial levels of deuterium are low, and deuterium is destroyed quickly in the core of the Sun by being fused into helium, so there is very little deuterium in the Sun. This is not mentioned in the article, which doesn't discuss the isotopic composition of the Sun. Spacepotato ( talk) 20:57, 7 October 2010 (UTC)

Besides the 6C12, is the Sun supposed to have (fusion) created the 10Ne and 26Fe? Or merely accumulated it? And the Nucleosynthesis article shows the existence of 3Li and 5B as fusion created by Nucleosynthesis. WFPM ( talk) 05:32, 8 October 2010 (UTC) Also see Solar surface fusion re surface 1D2 production in the Sun. WFPM ( talk) 05:50, 8 October 2010 (UTC)

Shouldn't the Sun be categorized with other similar yellow stars in a category with that name? -- Zaurus ( talk) 10:10, 14 October 2010 (UTC)

The value of the metallicity give in the table on the right is wrong. I dont mean that the source cited is false, but the value depicted is not the metallicity (Z) but the ratio Z/X which is not the metals mass fraction over total mass (definition of Z) but the metals mass fraction over the hydrogens mass fraction! The value given by the article that's cited is 0.0133. 90.40.241.68 ( talk) 20:46, 4 January 2011 (UTC)Panos_Strasbg

I changed the infobox to cite Z=0.0122 from Asplund et al. (2006). Unfortunately, this is not consistent with the elemental abundances at the bottom of the box. New 3-D models of the Sun's atmosphere have lowered estimates of Z which perhaps led to confusion. Spacepotato ( talk) 21:39, 4 January 2011 (UTC)

This word is used nine times in the lead (and fifty seven times in the article), can anything be done to cut a few of them out?-- NYMFan69-86 ( talk) 05:35, 15 January 2011 (UTC) you all know maybe a lies —Preceding unsigned comment added by 72.218.241.208 ( talk) 20:38, 15 January 2011 (UTC)

It would be great if someone has time to add a section on the solar abundance problem which, I think it is fair to say, has replaced the neutrino problem as THE unsolved problem in solar physics. Timb66 ( talk) 12:11, 7 February 2011 (UTC)

Important info needs to be added in that the Sun's surface has finally been mapped. No CGI here. How as well. Simply south.... .. 12:35, 7 February 2011 (UTC)

I have removed the out-of-date tag. Please give more details and sources for your assertion. Timb66 ( talk) 19:37, 7 February 2011 (UTC)

Recent reports on two space probes orientating around the sun have mapped out what the sun's surface has looked like. Maybe not quite the right tag to use. See here and here. Simply south.... .. 19:52, 7 February 2011 (UTC)

OK, thanks. Yes, the results from the Stereo spacecraft are noteworthy, but note they are the latest in a succession of spacecraft dedicated to studying the Sun, such as SOHO, TRACE, Ulysses. I don't think the out-of-date tag was justified here. Better to add some links. Timb66 ( talk) 23:04, 7 February 2011 (UTC)

I really think its important that we focus on these two things a bit more in the article. Not that I think sections need to be erected, but that certain wordings need to be altered.

First of all, I don't believe that 'white' is a color. Black and white are essentially the 'off' and 'on' state of rods and cones. Black is the lack of light and white is a perception overflow of light. Open and closed, they are only the representation of light & according to modern physics, photons are not color. Photons become entangled with other particles and CARRY the color along with them. Therefore, 'white' isn't a 'color' and the sun is actually YELLOW - GREEN 7 NOT WHITE.

Secondly, I do not believe there is enough emphasis put on the fact that the surface observations of the sun are not advanced enough to determine what lies beneath. If the sun emits photons, it is entirely possible that the photons generate the heat observed from the sun and the fusion is actually cold. We speak of the sun as though it is a burning ball of fire, but the oxygen content is lacking, thought it could be that it is burnt away, it still doesn't change the fact that you would need to penetrate the corona in order to get accurate readings. It very well could be that underneath a fusion layer we could find an condensate ocean, surrounding a ball of ice, that encases a super cooled gas sphere. But, we can not know this for sure, and that is my point. Lawstubes ( talk) 02:05, 2 January 2011 (UTC)

Please read white#light. For your second bit, we use reliable sources to determine "emphasis" or whatever - and please read WP:NOTAFORUM. Vsmith ( talk) 03:16, 2 January 2011 (UTC)

As Sheldon Cooper reminds us, it could be that inside every black hole there's a little man with a flashlight looking for a circuit breaker. But unlikely. S B H arris 18:41, 15 February 2011 (UTC)

Re:"We speak of the sun as though it is a burning ball of fire, but the oxygen content is lacking, thought it could be that it is burnt away,". Erm, the "burning" is nuclear fusion, not oxidation - there isn't, and never was, any oxygen involved. -- Boing! said Zebedee ( talk) 18:44, 15 February 2011 (UTC)

The sound wave and neutrino observations show that the temperature inside the Sun increases from the surface to the core. That would indicate there is not any condensed material deep in the Sun. —Preceding unsigned comment added by 128.183.170.189 ( talk) 17:40, 18 March 2011 (UTC)

I've removed the parenthesised remark

even though the power per unit area of image on the retina is the same, the heat cannot dissipate fast enough because the image is larger

from the paragraph on observation with optical assistance in the interests of accuracy. The difference in illuminance between binoculars and unassisted viewing is highly variable, but the maximum would be e.g. 7x50s and fully dilated pupils where they are approximately equal. In daylight, or with higher power, or with smaller aperture, the illuminance is always going to be lower than the unassisted view.

I've also commented out the Marsh quote from JBAA. That is a very relevant paper to this article but it does not actually make the point that it is supposed to be reinforcing - it does not even mention binoculars for example. I've only commented it out because hopefully a new home can be found for it but its current placement is misleading. Crispmuncher ( talk) 11:05, 19 March 2011 (UTC)

the numbers on the diffusion time of photons within the solar radiative zone are wrong.

they were derived from a wrong assumption.

yes that even happens in physics.

have a look to the references and to

http://www.springerlink.com/content/l256u14247171u67/

someone with the authority, please change it.

thanks

morten

132.230.90.122 ( talk) 18:04, 31 March 2011 (UTC)

Thanks for pointing out this interesting article ( doi: 10.1023/A:1022952621810). However, the article does not say that the usual numbers for the diffusion time scale of photons are wrong, but that they do not reflect the time scale of energy transfer in the Sun, which is governed by the longer Kelvin-Helmholtz time scale. Spacepotato ( talk) 23:39, 4 April 2011 (UTC)

thats correct let me rephrase my statement:

even though the photon diffusion time within the solar radiation zone is of the order of 10^5 years this can not be considered as the time a photon needs to travel through the solar radiation zone (SRZ). in the SRZ photons are in thermodynamic equilibrium with the plasma. hence they diffuse (travel) on a thermal (Kelvin – Helmholtz) time scale to the bottom of the convection zone.

in the wikipedia article it is stated:

"Therefore it takes a long time for radiation to reach the Sun's surface. Estimates of the photon travel time range between 10,000 and 170,000 years.[44]"

in my opinion this is at least missleading. see doi: 10.1023/A:1022952621810:

"According to the virial theorem, the total internal energy of a star in hydrostatic equilibrium is of the order of the absolute magnitude of the gravitational energy. As a consequence, the time scales obtained by dividing these two energies by the luminosity are approximately equal – the Kelvin–Helmholtz time. For the Sun the Kelvin–Helmholtz time scale is t_KH ≈ 3×10^7 years. This is the time needed by the star to settle to equilibrium after a thermal perturbation. Since in the solar interior energy is transported by radiation, the time scale associated with radiative transport should be of the same order."

"On the other hand, a photon-diffusion time scale has been estimated as t_d ≈ 1.7 × 10^5 years (Mitalas and Sills, 1992). This is the time photons would need to diffuse in a random walk through the Sun; it is short in comparison to the Kelvin–Helmholtz time. This short time scale could be mistaken for the time scale of energy transport in the Sun; indeed it has been discussed occasionally in the context of how the energy generated in the solar core gets out to the surface (e.g., Lang, 2001). It is the purpose of this note to point out that, due to the large heat capacity of the solar interior, energy transport in the solar interior is in fact governed by the Kelvin–Helmholtz time scale."

i still belive the numbers given in the article are not derived from the correct assumptions. as a compromise i propose something like the following:

Therefore it takes a long time for radiation to reach the Sun's surface. Estimates of the photon travel time range between 10,000 and 30,000,000 years depending on whether a random walk process or thermal diffusion is considered as the driving mechanism of energy transport.[44] & doi: 10.1023/A:1022952621810

thanks

morten

132.230.90.122 ( talk) 13:36, 14 April 2011 (UTC)

I think that the difference between the two different numbers is as follows. The photon diffusion time assumes that a single photon starts near the center of the Sun and scatters, without being absorbed or emitted, until it reaches the outer edge of the Sun, or, better, the convective zone (see Mitalas & Sills, Bibcode: 1992ApJ...401..759M.) In reality though energy transport does not conserve photon number, as one starts with gamma rays with energies on the order of MeV and ends up with much lower-energy photons. So, I don't disagree with the paper doi: 10.1023/A:1022952621810, but I think that the longer timescale is relevant to the collective process of energy transport, involving a large number of photons (and matter), and not to an individual photon. Therefore, I would suggest adding something like the following after the sentence in the article "Estimates of the photon travel time range between 10,000 and 170,000 years":

Since energy transport in the Sun is a process which involves photons in thermodynamic equilibrium with matter, the time scale of energy transport in the Sun is longer, on the order of 30,000,000 years. This is the time it would take the Sun to return to a stable state if the rate of energy generation in its core were suddenly to be changed. (reference: doi: 10.1023/A:1022952621810)

Spacepotato ( talk) 22:40, 14 April 2011 (UTC)

It doesn't help that some people DEFINE "photon diffusion time" in the sun as total thermal energy in the sun, divided by luminosity (total energy output). A ratio that does give something like the Kelvin-Helmholtz time of 30 million years (and is something like how THEY derived it), but I do not think it automatically the mean time for diffusion of an average photon from core to photosphere. At best it gives the THERMAL ENERGY diffusion time, but that is given by the physical size of the Sun and something like the diffusivity-- a function of both thermal diffusion (whether by radiation or not) and heat capacity. The later is the limiting factor, as there's something like 1000 times more total "heat" (thermal energy) than light in the core of the sun (my back of the envelope calculations show something like 10^16 J/m^3 thermal energy at the core but only 10^13 J/m^3 from pure photon gas at 15 million K). So most of the Sun's energy is stored as kinetic energy of plasma particles, not photons. That vast heat capacity buffers any changes in energy output on a 30 million year time scale, so in a sense it doesn't matter how fast photons get out (even if they were the same photons, which as has been pointed out, they are not). S B H arris 05:57, 16 April 2011 (UTC)

"The most abundant metal is oxygen (1%)..." I thought the oxygen was not a metal. Witchunter ( talk) 17:17, 19 April 2011 (UTC)

To astrophysicists, all elements other than hydrogen and helium are metals. See Metallicity. Spacepotato ( talk) 01:33, 20 April 2011 (UTC)

Can we add in that this knowledge about the sun is only today's knowledge of astronomy and space and is not confirmed? There is no reason to get children scared about living in the current world and they shouldn't feel they are living on a ticking time bomb. The current knowledge of stellar evolution will more likely change over their lifetime. Sunshinekind ( talk) 03:24, 5 March 2011 (UTC)

Wikipedia is not going to qualify every statement of scientific understanding with "according to current consensus, which might change." (That is implicit.) Nor is Wikipedia written to avoid scaring kids - but if it was, we might first want to address, say, the article on Jeffrey Dahmer. A threat that's about 5.5 billion years in the future is just about the last thing that would need to be "softened." Jeh ( talk) 04:09, 5 March 2011 (UTC)

I understand that Wikipedia doesn't need to explain every scientific theory. But from what I know about science (I grew up in a family of scientists) you still need to mention it as a theory (eg Big Bang Theory) as it cannot been scientifically proven as fact. I'm not against all the work astrophysicists have done to try and solve the mystery, I just think the stellar evolution of the sun should be seen as current theory. Just remember once upon a time we used to 'know' the earth was flat - but we were clearly wrong. Sunshinekind ( talk) 09:34, 5 March 2011 (UTC)

Please can you give a credible source for your claim that scientists published the fact that earth is flat. -- Stone ( talk) 11:31, 5 March 2011 (UTC)

But we still don't need to explain science on every science-based article, and say stuff like "It's only a theory". If people want to learn about science in general - about how science works, what "theory" means in scientific terms (it doesn't mean "just an idea, not a fact" - gravity is still a "theory", but we're not all going to start floating away any time soon), etc, we have a bunch of more general articles covering all of that - Portal:Science is a good start. -- Boing! said Zebedee ( talk) 11:05, 5 March 2011 (UTC)

To Sunshinekind: Um, science never claims to have "scientifically proven as fact" anything. (Mathematics, yes. Not science.) Theories can be proven false, but not proven true; the best science ever does in that direction is to find more and more evidence that supports a theory and while finding none to reject it. Jeh ( talk) 17:07, 5 March 2011 (UTC)

Thanks for the input. I see where you are coming from - I guess I just struggle with the idea of the world not being here one day. Quite sad really, its very beautiful Sunshinekind ( talk) 01:40, 6 March 2011 (UTC)

Only at one time will anything in the universe be open to the title of 'fact' This is when or if a unified field theory paired with several thousand years of research yet to come, Reveal the infinite chain of cause and effect on the smallest and largest magnitudes of any perceived force, object or indeed concept. That is to say 'we know it inside and out' And fortunately I for one don't believe this is possible given our fallible, restricted perceptions bore down by our beautifully flawed biology. I'd rather wonder about the cosmos in all it's possibilities than tediously recite its details. peace. (TheGarden1988 07:57 30/5/2011) — Preceding unsigned comment added by TheGarden1988 ( talk • contribs) 06:56, 30 May 2011 (UTC)

Yes, only God knows the "true facts", but there is no reason why Wikipedia cannot state the best current theories for those of us who not only stand back in wonder and awe but also wish to understand some of the subtleties and complexities. Dbfirs 07:06, 30 May 2011 (UTC)

The sentence is meaningless as it stands, and has bad grammar to boot. It may be intended to state that there are a large number of absorption lines. If so, the sentence should read something like, "There are on the order of X absorption lines in the visible part of the Solar spectrum." —Preceding unsigned comment added by Cosmicjay ( talk • contribs) 00:25, 24 May 2011 (UTC)

I've removed the sentence and linked to the article on Fraunhofer lines. Feezo (send a signal | watch the sky) 20:28, 4 June 2011 (UTC)

Nothing is mentioned on the age of the Sun or when it is going to die —Preceding unsigned comment added by 124.184.255.157 ( talk) 02:03, 11 May 2011 (UTC)

It is in there. Re read the article's section "life cycle", http://en.wikipedia.org/wiki/Sun#Life_cycle. 98.112.76.201 ( talk) 14:36, 8 June 2011 (UTC)

Age of sun is left is only 4,24,969 years. as per cycle done . — Preceding unsigned comment added by 210.89.69.179 ( talk) 01:36, 17 June 2011 (UTC)

Refer to Template_talk:Solar_System_Infobox/Sun#Replaced_the_false_color_image_of_sun. talk section of info box . Dave3457 ( talk) 00:45, 16 June 2011 (UTC)

This is a false color image of the sun and is not what the sun looks like. The wavelength of light used is a single extreme ultraviolet wavelength.

This is what the sun actually looks..

There is, what I feel to be a very important debate going on about what the lede image of the sun should be in this article. The present image is very misleading. Please go to the above link and give your input. Dave3457 ( talk) 04:08, 17 June 2011 (UTC)

Debate? I don't see a debate. You answered yourself. Not much of a debate. In fact, neither image is true. Both are taken through filters, because you can't look at the Sun in true light. Serendi ^pod ous 06:32, 17 June 2011 (UTC)

Refer to above link for response. Dave3457 ( talk) 04:05, 18 June 2011 (UTC)

Please remove the erroneous final period from the image caption

Motion of barycenter of Solar System relative to the Sun.

in section Motion and location within the galaxy, in accordance with WP:CAPTIONS. Thank you! -- 213.168.116.136 ( talk) 21:05, 19 June 2011 (UTC)

(Also, while you're at it, you may want to improve the wording of the caption as well, maybe along the lines of

Motion of the barycenter of the Solar System relative to the Sun

-- 213.168.116.136 ( talk) 21:08, 19 June 2011 (UTC))

Period removed, the caption already contains the 2nd. Vsmith ( talk) 22:00, 19 June 2011 (UTC)

Thanks so far. On my second point (which is more of a personal suggestion), I think that omitting the "the"s as the current caption does is a bit awkward. Consider the current wording:

Motion of barycenter of Solar System relative to the Sun

versus my suggestion:

Motion of the barycenter of the Solar System relative to the Sun

If you think the former is better, feel free to leave it as is. (Just wanted to note the difference since you appear to have overlooked my suggested addition of two "the"s.) -- 84.44.228.41 ( talk) 15:09, 20 June 2011 (UTC)

Heh - seems I'm blind sometimes. Vsmith ( talk) 17:10, 20 June 2011 (UTC)

np. thanks a bunch! -- 84.44.228.41 ( talk) 17:31, 20 June 2011 (UTC)

User:Materialscientist you wrote "the value is way off and is of unclear relation to the lead of this article" [6]. Light particles part of SUN are traveling at 186,413.22 miles per second while sun is expanding. You can compare it to a balloon traveling while its blown. The edit made by me was well referenced "The velocity of sun by Sayan a thirteen century (died 1387) commentator of Rigveda cited to be 186,413.22 miles per second "tatha ca smaryate yojananam. sahasre dve dve sate dve ca yojane ekena nimishardhena kramaman" and its translation is "[O Sun,] bow to you, you who traverse 2,202 yojanas in half a nimes.". As per Prof Kak the velocity comes to "186,413.22 miles per second" http://www.ece.lsu.edu/kak/sayana.pdf, (accessed 15 Feb 2011), the referenced information is accessed from Indian Journal of History of Science, vol. 33, 1998, pp. 31-3". Please explain why you reverted the same? Ganesh J. Acharya ( talk) 04:51, 7 July 2011 (UTC)

(edit conflict) Apparently you are confusing velocity of the sun and speed of light, which is what Kak is writing about, and which is not relevant to the lead of this article. Materialscientist ( talk) 04:54, 7 July 2011 (UTC)

I am referring to what Sayan has cited, isn't it about the speed of SUN? Ganesh J. Acharya ( talk) 04:58, 7 July 2011 (UTC)

Please read again his article, and this article (the infobox gives a summary of velocities of the Sun). Materialscientist ( talk) 05:00, 7 July 2011 (UTC)

But, it does not inform about velocity of Sun while it is expanding. Sayan is citing about the Sun's expanding velocity. Ganesh J. Acharya ( talk) 05:11, 7 July 2011 (UTC)

The cited source doesn't say anything of the sort. It examines what Sayana might have meant - if he meant the speed of light, then according to one interpretation of the measurements used he was very close (perhaps by coincidence), but if he meant the speed of the Sun he was hopelessly wrong. There's no mention of any "expanding" in there -- Boing! said Zebedee ( talk) 05:28, 7 July 2011 (UTC)

"but if he meant the speed of the Sun he was hopelessly wrong", Does physics say velocity of expansion of Sun is not velocity of Sun? If a balloon is blown the outer diameter does that not travel? " Velocity" is the measurement of the rate and direction of change in the position of an object. So, does part (LIGHT) of SUN not change positions while they expand? So, when light (Particles of SUN) travels does not mean Sun travels (while expanding)? Ganesh J. Acharya ( talk) 05:47, 7 July 2011 (UTC)

Please quote the part of the cited source that talks about "expansion" - I've read it twice and I can't find any mention of it -- Boing! said Zebedee ( talk) 05:51, 7 July 2011 (UTC)

(PS: As an aside, the Sun has never expanded at anything remotely close to 186,000 miles per second - in fact, I don't know whether it has ever expanded at all, has it? -- Boing! said Zebedee ( talk) 05:54, 7 July 2011 (UTC))

Assuming balloon travels at X speed while it expands, can one reply the following when one is asked "Q. At what speed is the balloon traveling?"... "A. The balloon is traveling at X speed" Ganesh J. Acharya ( talk) 06:08, 7 July 2011 (UTC)

I repeat, again and for the last time, there is NOTHING about expansion in the cited source! -- Boing! said Zebedee ( talk) 06:19, 7 July 2011 (UTC)

Is it written that the following is cited by Sayan "[O Sun,] bow to you, you who traverse 2,202 yojanas in half a nimes." and this velocity comes to "186,413.22 miles per second" Ganesh J. Acharya ( talk) 06:25, 7 July 2011 (UTC)

And where in that sentence can you see the word "expand" or "expansion"? -- Boing! said Zebedee ( talk) 06:28, 7 July 2011 (UTC)

When you mention about Velocity of an object is that necessary to mention in what mode (weather expanding or not) is it traveling? Ganesh J. Acharya ( talk) 06:33, 7 July 2011 (UTC)

It says "traverse"! It does not say "expand"! Please, just tell us where you got this "expansion" business from? -- Boing! said Zebedee ( talk) 06:39, 7 July 2011 (UTC)

Do an object "traverse" while that expands? Ganesh J. Acharya ( talk) 06:41, 7 July 2011 (UTC)

No, traversal has got nothing to do with expansion, and there is no mention of expansion in the Kak paper -- Boing! said Zebedee ( talk) 06:50, 7 July 2011 (UTC)

"traversal has got nothing to do with expansion" it's scientifically an incorrect statement. Ganesh J. Acharya ( talk) 06:57, 7 July 2011 (UTC)

Sorry dude, but I'm not going to waste any more time arguing with you - there is no mention of expansion in the paper, traversal is not expansion, the idea that the Sun has ever expanded at 186,000 miles per second is simply nonsense - and that's all there is to it. I'll leave you to see if you can get a consensus to support your interpretation -- Boing! said Zebedee ( talk) 07:02, 7 July 2011 (UTC)

Arguments are for good aren't they? they help arriving at an appropriate "consensus" don't they? Ganesh J. Acharya ( talk) 07:30, 7 July 2011 (UTC)

I repeat what I wrote before and leave it for everyones consensus. Assuming balloon travels at X speed while it expands along the radius, can one reply the following when one is asked "Q. At what speed is the balloon traveling?"... "A. The balloon is traveling at X speed". In the same manner SUN is a mass of incandescent gas which is expanding while its rays are traversing indefinitely in the Universe. As with the expanding balloon for the question on velocity "Q. At what speed is the balloon traveling?" the answer can very much be "A. The balloon is traveling at X speed", even in case of Sun, the answer very much is "The Sun traverse 186,413.22 miles per second". Because sunlight (the other-most layer of SUN) is very much part of Sun as the outer most visible layer of the balloon is to the balloon. Ganesh J. Acharya ( talk) 09:22, 7 July 2011 (UTC)

And I'll repeat once more that there is no mention whatsoever of anything expanding in the cited source and that Sayana doesn't mention sunlight, so what you are saying is utterly irrelevant. I've looked back at your Talk page history, including your previous username, and it seems you've long had a problem with personal interpretation and analysis of primary sources. You really should have learned by now that the only thing that goes into Wikipedia articles is material that can be directly referenced to reliable sources, and not personal analysis or speculation - and certainly not your personal attempts to square Vedic sources with science. You are perfectly welcome to believe that Sayana was talking about the "expansion of light" from the sun if you want, but unless he specifically said that or there are reliable sources that make that argument, it simply does not belong on Wikipedia. -- Boing! said Zebedee ( talk) 09:36, 7 July 2011 (UTC)

I initially did not cite anything about expansion of sun at this talk page, I only cited about the speed of SUN being mentioned by Sayan and same being referred by Prof. Kak. It was you ("but if he meant the speed of the Sun he was hopelessly wrong") and Materialscientist ("Apparently you are confusing velocity of the sun and speed of light") having doubts over what was written. So, I needed to quiz you both if had considered about Sun's expansion while emitting light along it's radius to arrive at Sun's speed. Ganesh J. Acharya ( talk) 15:08, 7 July 2011 (UTC)

No, it was Dr Kak who was asking the question about whether Sayana was referring to the speed of the Sun or of its light, in the paper, not me, which is the only reason I raised it - it was not my speculation or uncertainty at all. As Kak points out, if Sayana meant the speed of the Sun itself as it traverses the sky, he was badly wrong (and that means it is not a useful source for this article at Wikipedia). If he meant the speed of light, he was very close, but that's not what the article is about, so again it is no use for us here. That is all. -- Boing! said Zebedee ( talk) 15:52, 7 July 2011 (UTC)

I know what Prof Kak wrote there, has Prof Kak not agreed that the verse is written with respect to sun? In those days or for that matter even today Sun is seen as a living soul. If you start illuminating by yourself like Sun and your parts (rays emitted) move at 186,413.22 miles per second which a Risi sees and admires with the above words would that be wrong? Ganesh J. Acharya ( talk) 03:17, 10 July 2011 (UTC)

It sounds like clutching at straws in trying to find a modern interpretation of obscure Sanscrit. By that interpretation, all objects that you can see must "traverse" at the speed of light. Which original word is translated "traverses"? Can it be translated "radiates"? Dbfirs 06:38, 10 July 2011 (UTC)

You're really not listening, are you Ganesh? If it *does not state something explicitly in a source* then it cannot go in a Wikipedia article. Nobody here is interested in your personal interpretation or speculation - and if you want to publish your own interpretations of Vedic sources, you'll have to go find somewhere else to do it -- Boing! said Zebedee ( talk) 11:27, 10 July 2011 (UTC)

What is Expansion Scientifically?

How would you explain "A Matter Expands" scientifically? Ganesh J. Acharya ( talk) 06:15, 7 July 2011 (UTC)

Look, here's what the abstract says...

"In his commentary on the Rigveda, the fourteenth century scholar Sa ̄yan.a mentions a specific speed for the sun which can be used to de- termine the distance to the sun. Vartak has interpreted this statement to stand for the speed of light but we cannot place that in any reason- able historical context. The distance to the sun implied by Sa ̄yan.a’s statement suggests that there was another astronomical tradition in India which is now lost."

And the quote from Sayana is...

"Thus it is remembered: [O Sun,] bow to you, you who traverse 2,202 yojanas in half a nimesa.'"

It's clearly talking about a *traversal* speed - ie the speed with which the Sun moves across the sky - and says nothing whatsoever about expansion. And if the actual traversal speed is known, the distance can be calculated. Unfortunately, Sayana produces a hopelessly incorrect value for the Sun's traversal speed and therefore for its distance too. Sayana's speed is close to the actual speed of light, and others have suggested that is what he meant, but Dr Kak's paper suggests that that is coincidence and Sayana simply got it wrong, basing his figures on some now-lost tradition. -- Boing! said Zebedee ( talk) 06:38, 7 July 2011 (UTC)

Yes, I think Sayana's claim belongs in an article about the history of India, not this article. Whether is is an amazingly accurate estimate of the "expansion" of light from the sun, or just a strange coincidence can be discussed there. Dbfirs 07:44, 7 July 2011 (UTC)

The concept of "expansion" is not even hinted at anywhere in the paper, so it really isn't anything to do with "expansion of light from the sun" at all -- Boing! said Zebedee ( talk) 08:43, 7 July 2011 (UTC)

I agree, I can't see how traversal can be interpreted to mean expansion, but I don't know any ancient Indian (Sanskrit?). Ancient texts can often be reinterpreted in the light of subsequent knowledge, but in any case the discussion (if there is one) should go in a History article. Dbfirs 16:00, 7 July 2011 (UTC)

It says the sun is 'almost perfectly spherical' is there a technical word to describe the suns shape for example the earth is geoid. — Preceding unsigned comment added by The Gaon ( talk • contribs) 10:59, 7 July 2011 (UTC)

Well, logically, it would be something like "soloid", but I wouldn't recommend using that neologism, partly because it has already been claimed in fringe "pseudo-science" pulsoid theory, partly because we have the term sphere that almost perfectly describes the shape, and partly because the deviations from perfect sphericity are variable. The earth's geoid (almost an oblate spheroid) is reasonably constant and easily measured. Dbfirs 06:30, 10 July 2011 (UTC)

The distance from earth is 1 AU (149.60×10^6 km) not 1.496×10^8 km. — Preceding unsigned comment added by 141.58.71.236 ( talk) 13:11, 14 July 2011 (UTC)

dear friends i appreciate your work but some very little bits of detail can be seen as deliberate identity attack specially in a featured article like this. Persians do not consider themselves as Arabs and you yourself in many of your articles have accepted it as a fact. to Persians Avicenna is a national hero and putting his name under Arab scientist here in Iran is observed as an insult. please correct it.

regards

behzad — Preceding unsigned comment added by 91.98.90.76 ( talk) 09:38, 28 August 2011 (UTC)

Yes, Iranians of my acquaintance would be most offended to be called Arabs. I'm sure the insult was not intended, but arose through confusion in some Western minds between "Arab" and "Islamic". I have split the paragraph to try to avoid the confusion, but please make further corrections to make the cultural origins clear. Dbfirs 16:21, 28 August 2011 (UTC)

thanks a lot; i appreciate that. i guess it was a great idea to split it, changing Arab to Islamic could also do.

i wish you success

behzad — Preceding unsigned comment added by 91.99.175.6 ( talk) 18:37, 29 August 2011 (UTC)

There is a typo in the first sentence. someone fix it, it doesnt make sense Glennnnelg ( talk) 17:31, 31 August 2011 (UTC)

Extra "painful" removed. Vsmith ( talk) 19:07, 31 August 2011 (UTC)

The article includes the sentence

During this era, known as the Maunder minimum or Little Ice Age, Europe experienced unusually cold temperatures.[84]

However, as the two linked articles make clear, the Maunder Minimum was a period of decades while the Little Ice Age lasted centuries. It's misleading to speak of these two historical periods as "an era."

I suggest removing the words, "or Little Ice Age."

Henrodon ( talk) 12:20, 30 September 2011 (UTC)

This section (or another) should include the fact that, because of his huge radius, photographs of the sun are not simultaneous on all of his points, as intuition should suggest. The center of the sun is 2 seconds light nearer to the camera than the borders, so a photograph shows the borders 2 second older than the center. — Preceding unsigned comment added by 190.137.14.198 ( talk) 22:52, 1 October 2011 (UTC)

I think this section ought to have the new visible light sunspot image taken by the NST at the Big Bear observatory featured here: http://www.spaceref.com/news/viewsr.html?pid=39004

The article begins by stating that "The Sun is the star at the center of the Solar System" — this is not true. The center of the Solar System lies somewhere outside the surface of the star. The Sun is not a fixed object in our star system, it too is affected by the gravity of the planets and it wobbles (orbits) around the center of the Solar System. I've changed the article to say "approximately at the center". -- Diego_pmc ^Talk 18:08, 3 October 2011 (UTC)

I've had to revert your change as it does not work in the lead sentence. Such a point would be better suited to the body of the article; in the lead, it will only confuse the average reader. -- Ckatz ^chat _spy 18:16, 3 October 2011 (UTC)

I still think it's better to try to rephrase that, that sentence is wrong as it is right now. Maybe we should remove any reference to the center of the Solar System in the first phrase? Maybe something like "The Sun is the only star in the Solar System." -- Diego_pmc ^Talk 19:37, 3 October 2011 (UTC)

Again, we have to look at this from the perspective of the average reader. From what I can find, the barycentre of the Solar System may sometimes be above the Sun's photosphere, but never outside of the corona. -- Ckatz ^chat _spy 02:22, 4 October 2011 (UTC)

How about "The Sun is the star at the approximate center of the Solar System." ? It's correct on all points, and it may intrigue the new student of this topic into reading further. Jeh ( talk) 02:30, 4 October 2011 (UTC)

Although it wobbles, averaged over time, it is at the center. I agree with Ckatz that, for the opening of the article, saying it is "at the center" is perfectly reasonable in conformance with the straightforward tone of the first paragraph. Similarly, the Observational Data says that light takes 8 minutes 19 seconds to reach the earth although, as pointed out elsewhere, this is also an average, with light from the edge taking longer due to its greater distance from the earth. Henrodon ( talk) 04:42, 4 October 2011 (UTC)

This section (or another) should include the fact that, because of his huge radius, photographs of the sun are not simultaneous on all of his points, as intuition should suggest. The center of the sun is 2 seconds light nearer to the camera than the borders, so a photograph shows the borders 2 second older than the center. — Preceding unsigned comment added by 190.137.14.198 ( talk) 22:52, 1 October 2011 (UTC)

I think this section ought to have the new visible light sunspot image taken by the NST at the Big Bear observatory featured here: http://www.spaceref.com/news/viewsr.html?pid=39004