What If The Sun Was To Go Out?

MadSci Network ^ | February 24, 1997 | Joseph Spitale, Grad student Planetary Science/Applied Math, Lunar and Planetary Laboratory

[SamAdams76]

...The short answer to your question is that no one knows the answer. I have come across some interesting information, though, and I will try to give you my thoughts on the matter from a physicist's point of view, but you might also want to resubmit the question with my answer attached and see if you can get further input from a biologist.

First, let's consider how long the planet could support large land animals like ourselves. Just think about the temperature difference between night and day and it should be pretty clear that the atmosphere (at least the troposphere, where we live) cools quite rapidly by radiation. It should only be a matter of days before the surface temperature drops below freezing everywhere on the planet. In, fact in six months to a year, the temperature should drop to less than 150 Kelvin, half its current value. I would not expect any biological activity to remain at this temperature. However, there may be organisms which could survive in a suspended state if they were to freeze before they starved. That's something a biologist would have to comment on. So I would say that an upper bound for the survival of large land animals would be less than six months, just based on temperature. However, it should be much less than this since the food chain, which starts with sunlight (which plants use), would break down almost immediately.

What would happen with the oceans? Well, there's a tremendous amount of latent heat in the oceans, which would help to warm the atmosphere. However, once the surface of the ocean began to freeze, it would become more and more insulated by the cover of ice. Thus, it appears that the transfer of heat from the ocean to the atmosphere could be significant only in the early stages of the cooling. However, the insulating effect of the ice would allow the oceans to stay above freezing for quite a while, though once again, the food chain would break down radidly, and the supply of oxygen would be cut off.

Now, there is another energy source which is significant - geothermal heat. There are organisms which live on the seafloor near geothermal vents - fissures from which superheated water laden with various gases and nutrients are expelled. The question is - are these organisms dependent only on the nutrients and heat that they recieve from the vents, or are they connected to the rest of the food chain? There are many more qualified to answer this than I. I wouldn't be surprised if they were dependent on the oxygen generated by photosynthesis, and thus vulnerable.

I have also seen mention of organisms found in core samples from quite deep in the Earth's crust which may depend only on geothermal heat, but I don't know how credible this is.

Of course, it's possible that technology would allow a very small population of humans to survive, just as they might on a lunar base. However, if such a facility does not already exist, it is doubtful whether one could be constructed before the atmosphere froze out onto the ground, especially since it would probably take more people to construct it than it would be able to support. It might be possible to modify a bomb shelter to serve such a purpose, but it would need to be able to generate breathable air, and there would need to be a way of obtaining fuel. With no solar energy, you would need to use nuclear energy, fossil fuel, or geothernal energy.

In short, we wouldn't last long, but there may be organisms which could survive indefinitely, either by freezing before they starve, or because they don't depend on solar energy at all. I would definitely recommend submitting this to a biologist for further comment.

[Interesting Times]

I am not a physicist, but it's my uneducated opinion that the sun can't just "go out". I mean, it's a nuclear reaction, right? What would it take to stop the fusion process?

That's a very good point, and we appreciate the additional rigor you have brought to the discussion. The question should therefore be re-phrased as "What if the sun went away?"

[ClearBlueSky]

Hey, wait! If the cute guy on the Tauntaun comes with it, I'll take that vacation!

[FreedomCalls]

Women and minorities to suffer most.

You are prescient. This is the headline from an AP news story today December 15th:

Women more at risk from climate change: Canadian at UN conference

BUENOS AIRES, Argentina (AP) - Severe weather caused by global warming can pose greater physical danger to women than men, a Canadian attending a UN conference on climate change said Friday.

"For instance, often women don't know how to swim, so in a flood situation that can lead to a higher instance of death or injury," Angie Daze, a program manager with a Canadian group called Reducing Vulnerability to Climate Change, said.

Plans for international co-operation to fight global warming beyond the end of the Kyoto Protocol dominated the United Nations conference on climate change.

[PoorMuttly]

What makes the elephant charge his tusk...what makes the muskrat guard his musk...who put the hot in Hottentot, wha'da they got that I ain't got....

COURAGE !