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How long would we live without the sun

 
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Aug21-07, 08:16 PM   #18
 
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How long would we live without the sun


You didn't really specify exactly what stages you're talking about, though. I thought you were simply talking about its gradual expansion.

The Sun will indeed go through a series of pulsations, shedding mass each time. These will occur very late in its life, though, on its way to becoming a so-call planetary nebula. The Earth will be completely gone (absorbed into its outer layers) long before these pulsations even begin to occur.

Also, the solid angle of the Earth as seen from the Sun is so small that only a miniscule fraction of any ejected mass is going to actually impact the Earth. I cannot personally say what effect it would or would not have on the Earth if it miraculously still existed then; perhaps a more educated planetary physicist could say.

- Warren
Aug21-07, 08:26 PM   #19
 
Sorry, I was talking about the first red giant phase ( when it depletes hydrogen). With very strong solar winds it will lose quater of its mass in the course of a few million years, that in turn will result in lower central gravity in the solar system, and planets in response will move outwards of their original orbits.......
Aug22-07, 07:34 AM   #20
 
Mentor
Hmm - I'd never heard that before, but that's what wik says:
The Sun is expected to become a red giant in about five billion years. It is calculated that the Sun will become sufficiently large to engulf the current orbits of some of the solar system's inner planets, including Earth.[6][7][8] However, the gravitational pull of the Sun will have weakened by then due to its loss of mass, and all planets but Mercury will escape to a wider orbit. That said, Earth's biosphere will be destroyed as the Sun gets brighter while its hydrogen supply becomes depleted. The extra solar energy will cause the oceans to evaporate to space, causing Earth's atmosphere to become temporarily similar to that of Venus, before its atmosphere also gets driven off into space.[9] Venus will become a burnt out planet; its atmosphere having long been driven off, and its rock will melt.[1]
http://en.wikipedia.org/wiki/Red_giant
Aug22-07, 01:35 PM   #21
 
Horrible to read, although facinating :=\
Aug23-07, 04:33 PM   #22
 
http://deneb.astro.warwick.ac.uk/phs...SDSS1228+1040/

A pretty good diagram with explanations of the different stages of such an event...
Sep10-07, 02:54 AM   #23
 
Quote by Alex Nesh View Post
I was trying to come up with a solution to the timeline when hypothetically speaking the sun would stop shining ( or emitting radiation). Now, gravitational issues aside (the sun as a body still there), how long would it take for median temperature to drop beyond freezing point around the globe? How long would it take for the oceans to completely freeze, and how long would it take for the air to become liquid or solid?
I'm wondering if anybody did a research on this topic, I searched the internet but could not find anything about the subject.

Also, as the sun burning hydrogen in its core it becomes more efficient, therefore, gets hotter (as I understand). Somewhere I saw that it increasing its output about 10% in billion years. How long would animals have left on this planet, and how would it affect us humans in.... let's say 10,000-50,000 years from now.
Thank you very much


In a couple of billions of years, the oceans will start boiling, and that is when the life on Earth will end, do not worry about the Sun exploding in 4 billion years, life as we know it will end in 2
Sep10-07, 04:23 AM   #24
 
Quote by Alex Nesh View Post
do you think the earth would change its orbit as the sun becomes red giant, or would it be engulfed by the "surface" of the sun altogether?
it is hardly so that the earth will cahnge its orbit but there maybe some truth in it too. but most likely, the sun may die out before it can 'burn' our planet
(visit my blog!)
Sep10-07, 04:25 AM   #25
 
Quote by Duck1987 View Post
In a couple of billions of years, the oceans will start boiling, and that is when the life on Earth will end, do not worry about the Sun exploding in 4 billion years, life as we know it will end in 2
yea. it is true but we wont live to see it though. maybe scientist have found a way to this problem by then. but do you know that the earth itself is already dieing? changes may happen!
(visit my blog!)
Sep10-07, 09:58 AM   #26
 
Quote by kaisxuans View Post
yea. it is true but we wont live to see it though. maybe scientist have found a way to this problem by then. but do you know that the earth itself is already dieing? changes may happen!
(visit my blog!)
How exactly is the Earth dying? Do you mean that its rotation is gradualy stopping, or that the Moon is getting farther away? Or the Global warming? Or do you mean the tsunamis? or 2012?
Sep10-07, 11:15 AM   #27
 
Quote by cesiumfrog View Post
Assume earth is a black body radiator, calculate rate of energy loss. Multiply the latent heat of freezing water by the seven oceans.
7 oceans? I counted 5... Atlantic, Arctic, Indian, Pacific, and Southern oceans. Which other 2 oceans are you thinking of?
Sep11-07, 04:14 AM   #28
 
Quote by Duck1987 View Post
How exactly is the Earth dying? Do you mean that its rotation is gradualy stopping, or that the Moon is getting farther away? Or the Global warming? Or do you mean the tsunamis? or 2012?
there are a few factors that affect the earth's "health". but now the main factors i can think of is global warming and the thing about pollution and the hole in the atmosphere. global warming is making the earth hotter and hotter,causing drastic changes in our everyday life. pollution is kill us too! and so is the hole in the atmosphere. if there is already one,who says another 1 would not appear? it all holds and depend on the future people/genaration to solve these current problems. hopefully they will be solved...
(visit my blog! plz..)
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