Talk:Venus

why ? ONaNcle 12:24, 15 November 2007 (UTC)

(diff) (hist) . . m Venus (planet)‎; 12:21 . . (+16) . . Barliner (Talk | changes) (Reverted edits by ONaNcle (talk) to last version by 84.55.6.110)

I have a note on your talk page. In the original language the three article which you removed this template from are still showing as FA, and therefore qualify to have this template on SEWP -- Barliner  talk  12:27, 15 November 2007 (UTC)

shrek is not dreck

GREENHOUSE EFFECT on VENUS NOT SUBSTANTIATED by VALID PHYSICS

It cannot be substantiated with standard physics that the surface of Venus is kept hot by radiation from the colder carbon dioxide atmosphere. The small solid core of Uranus (55% the mass of Earth) has a surface temperature several times that of the Venus surface, and yet only about as much methane as Earth has water vapor. Uranus is nearly 30 times further from the Sun than Earth is, and thus receives little more than 0.1% of incident solar radiation.

In fact the surface temperature of Venus rises by about 5 degrees (from 732K to 737K) during the four-month-long day and so this requires an input of thermal energy, which cannot be coming by way of radiation from the colder atmosphere because, if it were, entropy would be decreasing.

Venus cools by 5 degrees at night, and so it could easily have cooled right down over the life of the planet if the Sun provided no insolation. So we can deduce that it is energy from the Sun which is gradually raising the temperature of the Venus surface during those four months of Earth time. But less than 20 watts per square meter of solar radiation gets through to the surface because carbon dioxide actually absorbs incident solar radiation.

If one tries to explain the 5 degree difference with Stefan-Boltzmann calculations for radiation, there is a difference of about 450 watts per square meter just between the two temperatures 732K and 737K, and so this is not supplied from the direct solar radiation which is only about one tenth of that which reaches Earth's surface.

Hence there is no scientific basis for assuming that direct radiation to the surface is the cause of the high surface temperatures on Venus, and thus there is no "runaway greenhouse effect."

Douglas Cotton (talk) 02:18, 1 April 2014 (UTC)

Indeed the notion that atmospheric heat transfer is mostly by radiation is an odd one, an alternative to the usual view that circulation is the main way for Venus. However, any effort you may make here to discount the greenhouse theory by disproving the convection part is surely in vain, as Simple Wikipedia is very much the wrong venue. Jim.henderson (talk) 14:16, 7 April 2014 (UTC)

Yes. Regarding the cited references, [11] does not link to anything and [12] states "As sunlight heats Venus' surface" which is incorrect, because that "sunlight" is less than a mean of 20 watts per square meter, whereas Stefan-Boltzmann calculations require an input of 14,000 to 16,000 watts per square meter assuming absorptivity between 0.85 and 0.95. All reference to a greenhouse effect should be removed as there has been a lack of due diligence in claiming any such phenomenon on Venus, runaway or otherwise.

Douglas Cotton (talk) 03:12, 8 April 2014 (UTC)

• We should, and must go with En wiki. For one thing, they have qualified astronomers contributing to their pages, and we (generally speaking) don't. For another, their sources support the view that Venus's atmospheric temperature is caused by "the strongest greenhouse effect in the solar System". We do not innovate in science (or anything else). Our job is to reflect the standard views on a topic in (fairly) simple English. It is not to be creative on subject-matter, or to represent minority views as if they were mainstream. Macdonald-ross (talk) 07:36, 12 September 2021 (UTC)

• I need to explain that the key sentence "Scientists believe that billions of years ago, the atmosphere of Venus could have been like Earth's atmosphere" is ambiguous. The Earth's original atmosphere was mainly CO₂ and there was water in abundance. Life on Earth originated in water under a CO₂ atmosphere. After the Great Oxygenation Event, the main atmospheric gas was oxygen. I will try and decipher the En wiki page. Macdonald-ross (talk) 08:15, 12 September 2021 (UTC)

  @Macdonald-ross this conversation was made 7 years ago... Ely - Talk 09:38, 12 September 2021 (UTC)

• Of course I know that. The point is that it should have been challenged, for the sake of readers who might not realise.

NO QUICK DELETE

NO QUICK DELETE! Look at the way they do it on En:WP, I linked Venus to Venus Planet and then there I put a link to Venus (disambiguation) which by the way I moved from here. Please don't delete. I did the same for Jupiter if you look. The Flying Spaghetti Monster! 09:28, 19 August 2008 (UTC)

Um... the EnWP article is located at Venus, not Venus (planet). —Giggy 09:47, 19 August 2008 (UTC)

Oh well that issue is resolved now anyway, just a misunderstanding by Minor Contributer. The Flying Spaghetti Monster! 10:55, 19 August 2008 (UTC)

Transit of Venus

This phrase "every 243 years, then every 8 years." makes no sense even if you know what it is supposed to be talking about. The linked section does a better job of explaining the subject, and probably should just be incorporated here.