So, I was watching that silly new Skittle commercial where the girl’s eating the yellow one, and the sun is bouncing along with her skittle, until she eats it and it suddenly becomes night, and it got me wondering:
How long would the Earth last if the sun went out? I’m not talking going super nova or collapsing into a black hole…it just, went out. Something with the same mass and density was there, so orbit isn’t offset, just no more heat and light. Would the Earth immediately freeze over, or would it wait till plant life started to die off before things got really bad?
I think the life that lives around deep sea hydrothermal vents would keep on going for quite a while, as they get their needs from the earths volcanism; the oceans might start to freeze over though.
There’s an old science fiction story I read as a kid where a “dark sun” passes by the solar system and drags the earth with it.
The survivors have to mine through the different layers of frozen atmospheric gases “snow” to get to the oxygen snow layer, the gases having frozen out one by one as the temperature fell, and take this back to their homemade shelter.(don’t know how credible this is)
Any one know who wrote this and what its tiltle is?
bunyip - the story is called “A Pail of Air” but I can’t remember the author.
My two cents - we know for sure the earth would be unaffected for eight minutes, because of our being eight light-minutes from the sun, but beyond that I’m not entirely sure. In the story mentioned above they use nuclear power to stay alive, but I’m also doubtful about the credibility of it.
There’s a very complex network of heat flows to take into account. My calculations suggest that despite the darkness and rapid death of all plants, and disregarding those pesky people who live on the crust, the Earth as a whole would cool very slowly.
According to [a href=“http://www.geocities.com/combusem/SOLAR.HTM”]this site[/a], the total amount of energy from the sun reaching the earth is 2.22E11 GW (2.22 x 10^20 joules/second). Working out the heat loss from this is rather complex, since the core is noticeably warmer than the crust. However, if the earth weighs 6x10^24 kg, and we assume the earth is currently (with the sun) in thermal equilibrium, homogenous, and made of iron (specific heat capacity 450 J/kg/K). Then the sun’s radiation would heat the entire earth by 7E-8 degrees K (or celsius) per second, meaning without the sun it would cool one degree celsius in 200 years.
However, in practice, the core gets a lot of its heat from radioactivity, and the crust would cool far faster, and all the plants would be dead anyhow. So disregard all the above.
Consider how much the temperature falls between daytime and nighttime. In temperate regions I would guess it is between 10 and 20 degrees celsius. That is in the time between peak sunlight (noon) and sunrise the next day, less than 18 hours in general. If it cools a conservative estimate of 10 degrees in 18 hours, then 3 - 5 days seems a pretty good estimate.
There’s also growing evidence that bacteria can live down to some depth in the actual rocks of the earths crust, and that if this is so the largest mass of living things could be beneath our feet not on the surface at all.
So even if all surface life died perhaps the majority, in terms of sheer mass, of life would go on as long as the earth’s heatflow and volcanism carried on.( But if all the surface water froze would enough be produced volcanically to support the rock dwellers?)
I’ve read that hydrothermal vent communities need oxygen, origionally produced by photosynthesis, so eventually these might suffer in their warm water pockets under the frozen oceans.
A year or two back, I was working on a novel where something like this happens (the sun goes out for a few days), and I asked a physicist friend of mind about how long the earth would last in these conditions – how long would it be until plants died, lakes and oceans started freezing over, etc. He said he wasn’t sure, but extrapolating from the temperature drop at night, he thought that even summer-area land temperatures would drop below freezing within 24-36 hours, which would obviously be bad for plants. He thougth ocean temperatures would take a bit longer to drop, but he didn’t have any data.
And, of course, life based on geothermal and chemical energy (the ecosystems around the hydrothermal vents, and the “ocean-floor lakebeds” ecosystems) would continue, so it wouldn’t be a total loss.
What if we move from the Earth model we all know and love to a Earth with more gravitionally driven geothermal activity? Say Io, perhaps, but without the whole covering the whole planet with lava, or perhaps Europa or Ganymede. How much would a core with those gravitational effects offset the loss of solar heat?
Was I the only one who read refusal’s post with a bad B&W 50s sci-fi B-movie playing in my head, especially when he says, “My calculations suggest…”
There’s refusal in the lab at the blackboard wearing his long white coat while a cast of assorted dimwits look on. The dimwits of course include any or all of the following: A crusty old military officer, a comic-effect Joe-grunt military underling, a representative from the press (maybe our dashing hero or just some schlub or a wisecracking newshound), a gorgeous vixen who they’ve managed to shoehorn into the plot in some extremely improbable way, and maybe some other older authority figure like the senior scientist who hired refusal or the town mayor.
