How long could humanity survive if the sun is destroyed?

December 22, 2004 9:08 PM

Terrorists destroy the sun.... How long does humanity survive??? (the inside... there's more???)

If, hypothetically, the sun were to blink out of existence, how long would humanity be able to survive? I'm assuming our planet would stay intact and not slam into other planets, and just be spun out into space to freeze. With all of our technology, (assuming, say, a week's notice. Long enough to prepare what we have, not long enough to use anything we DON'T have,) how long until the bulk of humanity freezes? One day? Two? and what about those (think high level government) with access to resources to try to survive? Could they pull out a week, a month?

Thoughts?

posted by John Kenneth Fisher to science & nature (32 comments total)

20 minutes.
posted by mr_crash_davis at 9:33 PM on December 22, 2004

93,000,000miles/186,000mps = 8 min 20 seconds..gravity well and all...
posted by HyperBlue at 9:39 PM on December 22, 2004

Yeah, Hyperblue, I figured that as soon as the sun blinked out of existence, all of humanity would freak out and the nukes would launch. Give 5-10 minutes or so for them to hit their targets...20 minutes was a safe guess.
posted by mr_crash_davis at 9:41 PM on December 22, 2004

The bulk of humanity probably freezes pretty quickly -- only those with access to totally weatherproof dwellings and a good deal of energy survive the first few weeks. That's just from the cold.

Now, the earth isn't going to cool to absolute zero, given that there's quite a bit of heat from geothermal activity, but the question in my head is how long the atmosphere remains breathable even if very, very cold. There are two concerns I can think of. The most immediate is if the lowered temperature results in a viscosity problem (at what temperature would the gases in the atmosphere change state?). The second is the fact that all plant life is going to die and stop converting CO2 back into O2.

Assuming there's some way around that, small portion of humanity might survive as long as their food could hold off by taking advantage of a few geothermal hotspots. Of course, given that the ecosystem is totally wrecked, beats me how food gets found or produced. Maybe through a few non-wrecked ecosystems, like down by the thermal vents at the bottom of the now ice-covered ocean. Or maybe lots of grow lamps.

But I think the state of the atmosphere is probably the kicker. If it weren't for that I'd say some portion of humanity might find a way to live for a long time.
posted by weston at 9:45 PM on December 22, 2004

HyperBlue is referring to the time it would take us to notice given the speed of light limitations.

I'm not knowledgeable enough to answer this but I did find an answer from an astro grad student at the MadSci network:

You're right. If the sun went out, the Earth would freeze over very quickly. However, human technology (warm clothes, houses, and burning things for heat) would probably keep many of us alive long enough to starve to death.

The Sun warms the Earth's atmosphere by about 15 degrees C per day. That amount is offset by infrared radiation, which cools the planet by the same amount. If the sun were to turn off, the cooling would continue, and the atmosphere would drop to freezing in just a few days.

However, the warm water of the oceans represents a very large storage of heat. As the atmosphere cools, the oceans would give up this heat. My calculations suggest it would take about three months for the oceans to begin to freeze.

In the meantime, the air over the oceans would be much warmer than the air over the land (since the oceans are giving up heat, but the land isn't). This means it would be warmer if you lived on a coast, but the temperature difference will create violent superstorms there.

Humanity has a few months' worth of oil and gas in storage: assuming the horrible weather prevented oil transportation, we could probably keep warm for a few months before freezing to death. Our reserves of food vary wildly depending on the country, but we generally keep more food around than fuel (because you can only harvest grain for a short time every year). So we're more likely to freeze to death than starve. The United States, with its large reserves of oil and food, its effective transportation system, and its temperate climate (most houses have heating systems), would probably last longer than most. However, billions worldwide would probably die in the first couple of weeks.

Good thing this will never happen!
posted by vacapinta at 9:49 PM on December 22, 2004

Yeah, we're just 'falling' towards the sun. Take it away, our fall continues in a straight line... No big deal.

Here's an anecdotal reference to a study that says after 50 days, the global temperature would be 190K. That's cold, -80C, but only 20 degrees colder than the South Pole researchers put up with, properly prepared.

Without sunlight and photosynthesis, the oxygen cycle's going to stop. But folks with the resources to get near some kind of geo-thermal energy source would be in good shape. With a pre-historic heat source not dependent on the sun, and enough cans of alphagetti, they could probably survive 'til the oxygen gives out.
posted by deshead at 9:53 PM on December 22, 2004

I remember reading a short story where something like this happened - more specifically, a black hole came into our region of space and started pulling Earth away from good ol' Sol.

I think the main characters survived by more-or-less sealing off their house and melting the frozen O2 and Nitrogen that collected on the earth. Of course, the freezing happened at a much slower rate...

Damn, can't remember the author or title...or collection name...
posted by muddgirl at 10:24 PM on December 22, 2004

Come on... if they can destroy the Sun, they're way past "terrorist" and safely into "supervillain" territory.
posted by Caviar at 10:27 PM on December 22, 2004

muddgirl As I recall, the story was entitled, "A Bucket of Air." Can't find the author, I'm afraid.
posted by SPrintF at 10:33 PM on December 22, 2004

That would be "Pail of Air" by Fritz Leiber.

(I was curious about it...found the true title via Google Groups.)
posted by MikeKD at 10:59 PM on December 22, 2004

Also, (to help answer JKF's question) it looks like a search on "ABOA" turns up some Usenet discussions on this topic.
posted by MikeKD at 11:01 PM on December 22, 2004

Given the immense size of the sun compared to Earth (the charts never do it justice) and our relative close proximity, I imagine an exploding sun would probably take Earth out with it, so survival would be measured in the minutes, and it would not feel good.
posted by robbie01 at 11:47 PM on December 22, 2004

The Sun wouldn't go supernova, it would just go nova. Which means it would expand a good deal, but not quite enough to engulf the Earth. People on the dark side of the Earth would be relatively safe (at least until their side swings around).

This, actually, is the basis of the very interesting Larry Niven short story "Inconstant Moon" (in which the narrator gets his first hint that something is wrong because the moon is unnaturally bright)...
posted by neckro23 at 12:01 AM on December 23, 2004

It depends on what happens to the sun.

If the sun explodes (goes nova/supernova/loses magnetic containment) there is a very slight chance we'd notice it before we all died. Anyone on the side of the planet that is facing the sun would be boiled away in an instant by the x-ray and gamma radiation released in such an event. People who are in underground bunkers on the side of the planet facing away from the sun would experience some really weird phenomena, including electrical arcing from metallic objects and hair standing on end and water boiling in glasses on the table and other extreme examples of 'what radiation does to different things when things go pear shaped' before they died of radiation poisoning. It would be a battle to see whether they lived long enough for the shock wave of the explosion to reach the earth. The planet would either disintegrate or would have every last bit torn off down to the iron core, but that would be a moot point because what's left of the plasma that was in the sun would absorb and melt the planet within a few days.

If the sun suddenly winked out or collapsed into a brown dwarf, I don't know enough about orbital physics to know whether or not you would have any gravitational upsets. However, the above guesses from other users are probably pretty accurate ... the atmosphere starting to freeze within a few days, but before that, hurricanes of the fiercest nature you've ever seen would scour most of the planet. Only those that would be able to instantly set up an airtight habitats near a permanent thermal energy source or who would have access to something along the lines of a nuclear reactor with an unlimited supply of fissile matter would survive for very long... and even then, their survival would probably be measured in months, maybe years, as the planet would eventually cool. Mineral resources would become scarce, because it would become impossible to mine for minerals ... not only would it be far too energy-intensive, but it would be difficult to build tools that wouldn't break in the extreme temperatures. And that doesn't even bring into account what would be needed to build the environment suits that would be needed to go outdoors. Food would be able to be grown as long as grow-lights of the proper frequencies could be manufactured, but there would be problems with disease, monocultures, the lossy nature of the carbon and nitrogen cycles, and a lack of pollenating insects. There could also be problems with lack of solar radiation exposure in ways that we haven't discovered yet. Basically, you've got all of the same problems you'd have with an interstellar voyage lasting generations, without the forethought and support that would go into planning and supplying a trip like that.
posted by SpecialK at 12:14 AM on December 23, 2004

Iron Sun has a variation on this.
posted by seanyboy at 12:41 AM on December 23, 2004

Heh. Seanyboy, where do you think I cribbed most of my "if the sun blows up" from? :D
posted by SpecialK at 1:30 AM on December 23, 2004

[this is good]
posted by Quartermass at 6:38 AM on December 23, 2004

"Yeah, we're just 'falling' towards the sun."

I was under the distinct impression that we were moving away from the sun...
posted by spaghetti at 7:17 AM on December 23, 2004

For the long term, consider that the only sources of energy that don't come from the sun are nuclear and geothermal.
posted by TheOnlyCoolTim at 7:27 AM on December 23, 2004

This is indeed good, thanks everyone. As a side note, I get that an explosion would annihilate us, hence my unrealistic 'terrorists blink it out of existence' setup, but it's pretty neat reading those responses too.

So the consensus so far seems to be a lot longer than I woulda thought. "die in the first couple of weeks" for instance, I would have guessed no one would be around a week later.
posted by John Kenneth Fisher at 7:28 AM on December 23, 2004

A lot of people would probably choose a quick, painless suicide rather than waiting around to either freeze or starve to death. And I respect their decision, even though it's not one I'd make myself, being more of a "Do not go gentle into that good night" kind of person.
posted by DevilsAdvocate at 7:38 AM on December 23, 2004

Oh, and thanks for reminding me of "A Pail of Air"--one of the first science fiction stories I ever read as a kid.
posted by DevilsAdvocate at 7:40 AM on December 23, 2004

Story: A Pail of Air
posted by John Kenneth Fisher at 8:04 AM on December 23, 2004 [1 favorite has favorites]

So, over family dinner conversation last night, the topic of obtaining hydrogen came up, and I remembered you can create Oxygen as a product of electrolysis.

I don't know if the energy requirements for a sufficient yield are prohibitive, but perhaps if they're not, you really could get the correct gases out of the water.
posted by weston at 8:46 AM on December 23, 2004

Here's a prediction for the human side of things, from Lord Byron, the British poet from the Romantic times. Let me just say his prognosis is not good.

I had a dream, which was not all a dream.
The bright sun was extinguish'd, and the stars
Did wander darkling in the eternal space,
Rayless, and pathless, and the icy earth
Swung blind and blackening in the moonless air;
Morn came, and went and came, and brought no day,
And men forgot their passions in the dread
Of this desolation; and all hearts
Were chill'd into a selfish prayer for light:
And they did live by watchfires - and the thrones,
The palaces of crowned kings, the huts,
The habitations of all things which dwell,
Were burnt for beacons; cities were consumed,
And men were gathered round their blazing homes
To look once more into each other's face;
Happy were those who dwelt within the eye
Of the volcanos, and their mountain-torch:
A fearful hope was all the world contain'd;
Forest were set on fire but hour by hour
They fell and faded and the crackling trunks
Extinguish'd with a crash and all was black.
The brows of men by the despairing light
Wore an unearthly aspect, as by fits
The flashes fell upon them; some lay down
And hid their eyes and wept; and some did rest
Their chins upon their clenched hands, and smiled;
And others hurried to and fro, and fed
Their funeral piles with fuel, and looked up
With mad disquietude on the dull sky,
The pall of a past world; and then again
With curses cast them down upon the dust,
And gnash'd their teeth and howl'd: the wild birds shriek'd,
And, terrified, did flutter on the ground,
And flap their useless wings; the wildest brutes
Came tame and tremolous; and vipers crawl'd
And twined themselves among the multitude,
Hissing, but stingless, they were slain for food:
And War, which for a moment was no more,
Did glut himself again; a meal was bought
With blood, and each sate sullenly apart
Gorging himself in gloom: no love was left;
All earth was but one thought and that was death,
Immediate and inglorious; and the pang
Of famine fed upon all entrails men
Died, and their bones were tombless as their flesh;
The meagre by the meagre were devoured,
Even dogs assail'd their masters, all save one,
And he was faithful to a corpse, and kept
The birds and beasts and famish'd men at bay,
Till hunger clung them, or the dropping dead
Lured their lank jaws; himself sought out no food,
But with a piteous and perpetual moan
And a quick desolate cry, licking the hand
Which answered not with a caress, he died.
The crowd was famish'd by degrees; but two
Of an enormous city did survive, And they were enemies;
They met beside
The dying embers of an altar-place
Where had been heap'd a mass of holy things
For an unholy usage; they raked up,
And shivering scraped with their cold skeleton hands
The feeble ashes, and their feeble breath


Blew for a little life, and made a flame
Wich was a mockery; then they lifted up
Their eyes as it grew lighter, and
Each other's aspects. saw, and shriek'd, and died, beheld
Even of their mutual hideousness they died,
Unknowing who he was upon whose brow
Famine had written Fiend. The world was void,
The populous and the powerful was a lump,
Seasonless, herbless, treeless, manless, lifeless,
A lump of death, a chaos of hard clay.
The rivers, lakes, and ocean stood still,
And nothing stirred within their silent depths;
Ships sailorless lay rotting on the sea,
And their masts fell down piecemeal; as they dropp'd
They slept on the abyss without a surge
The waves were dead; the tides were in their grave,
The moon their mistress had expired before;
The winds were withered in the stagnant air,
And the clouds perish'd; Darkness had no need
Of aid from them. She was the universe.



Always a favorite.
posted by inksyndicate at 10:06 AM on December 23, 2004 [2 favorites has favorites]

It depends how far away you are from slashdot.
posted by zelphi at 11:07 AM on December 23, 2004

Thanks, inksyndicate. That was a great read.
posted by languagehat at 11:52 AM on December 23, 2004

JFK - any particular reason you're asking this question?

I have always wondered what would *really* happen (on Earth) if Jupiter went into fusion kind of ala Clarke's 2001, but rather if another gas giant collided into it (ala kooky "planet X" or whatnot) and gave it enough mass instead of the monolith tinkering with it.

neckro23 - I loved those story (I can't recall if it was that or the story about the iceberg trawler with the squid neuron computers hauling water to San Fran), I think I first read it in a Playboy =)

In the story, it was just a really bad flare that blasted Aisa, so the protagonists had a chance of surviving, not a nova.
posted by PurplePorpoise at 12:57 PM on December 23, 2004

Don't worry -- Hal Jordan will save us!
posted by Guy Smiley at 1:00 PM on December 23, 2004

JFK - any particular reason you're asking this question?

Since the dawn of time, man has yearned to destroy the sun.

-----
on preview: Tell that to Coast City, Guy.
posted by John Kenneth Fisher at 2:03 PM on December 23, 2004

I once had a very unfortunate psychosis, in which I fell asleep, then woke up a little after midnight. I somehow reasoned that this was in fact morning, and the sun should be up. But it was gone. Because of something *I* had done. And all life on earth was going to die, because of me. (I had displeased god or something).

I kind of freaked out, to say the least. The level of guilt was mind-crushing. I grabbed my cell phone and called 911, and checked into the psych hospital in the morning.

Talk about your dark night of the soul... hopefully I will never have another experience as bad as that.
posted by beth at 11:29 AM on December 24, 2004

Aliens notice the sun blink out, and eventually visit the planet, some hundreds of thousands of years later. Ice cores, and inference based on planet's proximity to the once burning star reveal the planet to have once been filthy with life. Many species, including humans are reborn by cloning them from DNA fragments recovered from the ice.

Humanity survives for billions of more years, though in a servile existance delivering pizzas and producing hollywood movies.
posted by jimfl at 12:33 PM on December 24, 2004