How long would earth be warm if...

[herpguy]

I know this is impossible, but if the sun were to spontaneously dissapear and no heat or any other form of energy from it remained, how long would earth be at livable temperature? Would Venus' heat drop significantly slower due to its dense atsmosphere and abundance of greenhouse gases? I heard somewhere that Jupiter gets only 1/5 of its heat from the sun. Would the planet's temperature be affected as much as it would for the other planets by the event?

 

Sorry, I really don't know much about this...

 

Thanks.

[insane_alien]

i reckon earth(at least its surface) would get very cold very fast unless its near an ocean where there would be a delay of a few weeks maybe. The sahara can drop from 40+degrees C in the day to below freezing at night. i imagine the rest of the world would cool at a similar rate.

[Sisyphus]

Yeah, just considering how much cooler it gets at night, the oceans would all be frozen over within a couple weeks. Why.... what are you planning?!?!?

[insane_alien]

if it involve making 2*10^30kg disapear we can only assume that involves antimatter in which case we will be cooked by gamma rays and it won't matter anyway. the earth would be vapourised though so his question is moot

[J.C.MacSwell]

if it involve making 2*10^30kg disapear we can only assume that involves antimatter in which case we will be cooked by gamma rays and it won't matter anyway. [b']the earth would be vapourised though so his question is moot[/b]

 

This is for those that didn't think the Sun disappearing question was moot to begin with.

[Martin]

... the oceans would all be frozen over within a couple weeks...

 

that is a good way to make the question precise. HOW LONG before all the ocean was frozen over?

 

Would it be a couple of weeks?

Or would it be a few years?

 

I don't know the answer but it should be possible to estimate. The key thing would be to google the earth's ENERGY BALANCE or heat balance and get a figure for the overall wattage that the earth radiates into space.

 

then one would estimate the amount of heat you need to remove, to make oceans freeze over

 

My guess is the earth radiates a couple of hundred watts per sq. meter surface area-----radiates off into space.

I dont mean reflection from cloud tops, of sunlight that never got down to the surface. I mean loss into space from the surface.

 

It should be possible to calculate.

==================================

 

As for the MOOTNESS suppose aliens come and orbit a large mirror at the Lagrange point between us and the sun. they want to freeze us before they invade, or something. or maybe it is their idea of a practical joke.

 

so suddenly the earth is in total shadow----this mirror is reflecting the sunlight that would have come to us back towards the sun instead. The sun doesnt know the difference because it is just a small amount of sunlight---a planet's worth.

 

so the earth is suddenly in darkness and how long does it take to freeze?

not a completely silly question

[J.C.MacSwell]

that is a good way to make the question precise. HOW LONG before all the ocean was frozen over?

 

Would it be a couple of weeks?

Or would it be a few years?

 

I don't know the answer but it should be possible to estimate. The key thing would be to google the earth's ENERGY BALANCE or heat balance and get a figure for the overall wattage that the earth radiates into space.

 

then one would estimate the amount of heat you need to remove' date=' to make oceans freeze over

 

My guess is the earth radiates a couple of hundred watts per sq. meter surface area-----radiates off into space.

I dont mean reflection from cloud tops, of sunlight that never got down to the surface. I mean loss into space from the surface.

 

[b']It should be possible to calculate.[/b]

==================================

 

As for the MOOTNESS suppose aliens come and orbit a large mirror at the Lagrange point between us and the sun. they want to freeze us before they invade, or something. or maybe it is their idea of a practical joke.

 

so suddenly the earth is in total shadow----this mirror is reflecting the sunlight that would have come to us back towards the sun instead. The sun doesnt know the difference because it is just a small amount of sunlight---a planet's worth.

 

so the earth is suddenly in darkness and how long does it take to freeze?

not a completely silly question

 

I think we looked at this before and it should be presently very close to what the earth receives from the sun as you are implying. This would drop as it cools though.

[insane_alien]

yeah it would drop but we can calculate how much it would drop. the energy output is proportional to T^4

[YT2095]

as far as I can see, you`de need to calculate the mass of the Earth and latent heat energy contained therein, along with rate of emission (it would decline on a non linear scale), as the temp dropped in literaly Days, there would be no cloud cover either (works a little like an IR blanket), and so the temp would be lost at a greater rate etc...

the Oceans would take a Very long time to freeze, even enough to walk across from the UK to Canada for example, or pole to pole. probably in the order of several months (prividing that we maintained our orbit around this dark sun)

this would NOT be the case if the Sol suddenly vanished!

a moving object will maintain its course unless acted upon bt another force. and so the second Sol vanished, the earth would continue off into space, and more than likely hit something that would generate Plenty of heat! long before you`re all dead!

[darkangel199]

heh, i saw this on "The Twlight Zone" their time frame was about a week and the earth was completely frozen, but the sun came back, according to the Twlight Zone, our solar system passed through a nebula of "dark matter" which blotted out the sun as we passed through it. lol i suppose its a good enough theory for the tv show considering no one really knows what the hell it is, some scientist guy cant say it couldnt happen...right...? maybe?...possibly?

[[Tycho?]]

as far as I can see' date=' you`de need to calculate the mass of the Earth and latent heat energy contained therein, along with rate of emission (it would decline on a non linear scale), as the temp dropped in literaly Days, there would be no cloud cover either (works a little like an IR blanket), and so the temp would be lost at a greater rate etc...

the Oceans would take a Very long time to freeze, even enough to walk across from the UK to Canada for example, or pole to pole. probably in the order of several months (prividing that we maintained our orbit around this dark sun)

this would NOT be the case if the Sol suddenly vanished!

a moving object will maintain its course unless acted upon bt another force. and so the second Sol vanished, the earth would continue off into space, and more than likely hit something that would generate Plenty of heat! long before you`re all dead! [/quote']

 

Pshh, hit something? What would the earth hit? It would fly off into void.

 

But yeah, as has been mentioned, the atmosphere would go below freezing after a few days. Ocean would take much longer. With the large difference in temperature between the water and the air you'd pretty much cover the earth in fog, which might provide a bit of insulation (well... probably not enough to make a difference). The tides would also keep water moving and delay the freezing. The deep oceans would stay liquid for thousands of years, perhaps indefinately. You have tidal actions, as well as geothermal output.

[ecoli]

Well, you would definately have at least 8 mintues, because you'd still have sun rays, even after it disappeared, for that long.

[chitrangda]

it wil start droping after 8 mints.

day wil be no more life will be destroyed.

[chitrangda]

venus will not take much time to drop ot its temp

even though it has huge no of greenhouse gases

venus will be cold planet within few mints only not days or years.

[chitrangda]

hope that works.

[YT2095]

'']Pshh, hit something? What would the earth hit? It would fly off into void.

 

how about the Asteroid belt? or any one of inumerable objects out there, that we don`t even know about.

[insane_alien]

YT, the asteroid belt will be expanding and becoming even more diffuse than it already is. the distances between the asteroids are more than capable of allowing a fair sized planet like earth through the belt. we would probably be fine.

[[Tycho?]]

how about the Asteroid belt? or any one of inumerable objects out there, that we don`t even know about.

 

Well the asteriod belt would by flying off into space as well.

 

And has been mentioned, it probably wouldn't matter anyway. The asteriod belt isn't like how its portrayed in movies, with rocks constantly smashing into eachother, providing a daring challenge to any space craft flying through. Its mostly empty in real life. When one of the voyager probes was passing through the asterioid belt, they had to alter its course to get it close enough to an asteroid to study it.

[[Tycho?]]

venus will not take much time to drop ot its temp

even though it has huge no of greenhouse gases

venus will be cold planet within few mints only not days or years.

 

Uh, is english your native language? Cause it could use some work.

 

I assume "mints" means minutes. And with Venus's greenhouse effect and extremely thick atmosphere it would take longer than earth to cool down significantly

[CPL.Luke]

venus also has alot less mass so there would be less heat present.

 

 

as for the earth, if you believe the theories about a uranium core at the center producing the heat necessary to keep the core spinning, then we could still use geothermal energy to keep ourselves alive with or without the sun.

[insane_alien]

CPL: its actuall potassium and leftover heat from the earths formation. the heat isn't what keeps the core spinning. its angular momentum at its finest.

[[Tycho?]]

venus also has alot less mass so there would be less heat present.

 

 

as for the earth' date=' if you believe the theories about a uranium core at the center producing the heat necessary to keep the core spinning, then we could still use geothermal energy to keep ourselves alive with or without the sun.[/quote']

 

Venus's atmosphere has significantly more mass than that of Earth.

 

I dont think its uranium keeping the core molten. But even if its not, geothermal will remain viable for a long, long time regardless of what the sun does.

[YT2095]

I`m still not convinced that the sudden Jolt wouldn`t interupt ordinary orbital objects (and we only know of a small percentage of them) on a potential collision with us.

 

Anyway, another thought, the seas and Oceans would freeze perhaps alot faster than I 1`st thought, think about it, the Tidal movement would be very diminished also, and movement in the water will slow it`s freezing, without that, then it`ll freeze much faster.

[insane_alien]

isn't the moon the primary cause of the tides with the sun only providing a small fraction of the effect. the moon would still be there.

[CPL.Luke]

insane alien, without the heat the core would cool and both A: slow down (it currently spins faster than the earth rotates), and B: become less conductive this would have the total result of removing the earth's magnetic field. It still hasn't been determined why the earth's magnetic field has remained intact whilst mars's died out hundreds of millions (if not billions) of years ago.

 

 

I forget if venus and mercury still have there's but its a good bet as they still have their atmosphere.

 

there is some circumstantial evidence for the earth having a uranium core a few miles wide at its center based on asteroid composition and the continued existance of a hot molten core.

 

besides if there was alot of uranium around when the earth first formed it would be logical that a significant portion would sink to the center of the earth along with most of the iron.

 

 

Yt while the earth technically orbits around the center of mass of the solar system, and not the sun, the sudden removal of that much mass would make the earth run off at a near tangential path to its current orbit for a very long period of time, (all the orbits would be extended by billions of miles)