The sun will come out tomorrow...except, what if it doesn't?

[Grall]

I've been thinking... Yes, contrary to what some may believe, this does happen every once in a while!

Our sun has alledgedly been shining ~4bn years, and will continue to do so in a normal, ordinary fashion for about that much longer still apparantly. However, as an interesting thought experiment, what if it suddenly and abruptly winks out RIGHT NOW?

Of course, we wouldn't notice it for ~11 mins or whatever, so we'll just look at it from our own perspective... The sky goes black. Poof.

Panic ensues, of course. Then it starts getting cold. And then it gets REALLY cold.

How fast will it get so cold that everything freezes? Can we last more than a week, or will it only be days before too much heat radiates away that we can't survive?

How long until our atmosphere condenses? By then it'll really be over. Even bunkers with their own power supplies would not be able to sustain life, the atmosphere would leak out when there's no air pressure outside.

Cheery thoughts, isn't it!

 

[_xxx_]

Days, not even a week. You see in winter that a 10°C day will go down to -20°C in the night easily. So I guess 2-3 days max.

Obviously we would all die, the whole biosphere on Earth would be gone.

 

[John Reynolds]

My first thought was trying to imagine how utterly dark it would be to step outside.

 

[digitalwanderer]

I thought stars went out with a bit of a bang, not a whimper or just like a light shutting off.

I have a feeling it would get REALLY hot before it got cold....

 

[zed]

there was a twiligt zone episode (one of the better ones)
http://en.wikipedia.org/wiki/The_Midnight_Sun

How fast will it get so cold that everything freezes?

depends on what u mean everything, the core of the planet) Though for the surface Im sure it will be quicker than a week, turn off a heater in a room it goes cold quick, the atmosphere is very thin

btw IIRC light takes ~8mins to get here (but thats pedantic)

 

[Grall]

My first thought was trying to imagine how utterly dark it would be to step outside.

Imagine what it would be like to drive down a busy highway in broad daylight when this suddenly happens... The result would be pretty disastrous.

Even finding your way home if you're out walking would be difficult, if there aren't streetlights that turn on automatically when it gets dark.

Digi:
Not all stars go out with a bang... In fact, most don't. You need a pretty massive star for bangs to happen, much bigger than our sun.

REALLY massive stars start to produce iron in their core before they've exhausted all of their nuclear fuel. However, unlike all the other preceeding elements, iron cannot be fused into a heavier element in order to create energy; instead it TAKES energy to fuse any of the other heavier elements. You might consider iron (and anything heavier) as the "ash" created by the fusion process...

Anyway, when you get enough iron in a massive star's core the outwards pressure created by the fusion process won't be able to balance the enormous inwards pressure created by gravity... The result is the core collapses in on itself, sending a titanic shockwave through the outer layers of the star, thus triggering a supernova detonation.

Eta Carinae is such a star, it's a blue variable hypergiant binary, the main star massing around 80-100 solar masses, possibly more, and it's tremendously unstable. Scientists have measured considerable quantities of iron in its spectrum, meaning it could be getting ready to blow its top at any moment (on a cosmic scale anyway, meaning it'll probably happen some time within the next few tens of thousands of years, heh.)

When that happens, Eta Carinae will outshine the planet Venus in our sky, despite the star's roughly 6000 lightyears away!

 

[Tahir2]

Good thought experiment.

My initial thought was not the heat of the Sun disappearing but the gravitational effect on the rest of the solar system. At the moment we are in orbit around the Sun but if it disappears what happens to our orbit and would the effect be strong enough to 1. shake off the atmosphere 2. rip the planet apart or 3. none of the above?

The Sun disappearing is one way to get rid of that global warming problem anyway!

 

[Gubbi]

I've been thinking... Yes, contrary to what some may believe, this does happen every once in a while!

Our sun has alledgedly been shining ~4bn years, and will continue to do so in a normal, ordinary fashion for about that much longer still apparantly. However, as an interesting thought experiment, what if it suddenly and abruptly winks out RIGHT NOW?

I'd be worried about the advanced alien race that would be capable of cooling that amount of mass that fast.

Cooling 1.9891×10^30 kg with a temperature ranging from 5.500K to 15,000,000K to a temperature where we can't see it anymore (800-900 K) overnight would require one hell of a heat sink.

If nuclear fusion in the core stopped, considering the volume of the sun, 1.4×10^27 m3 and the current power output of ~4×10^26W, it would be millenia before we would notice.

EDIT: The specific heat capacity of the sun is 5.73 x 10^34 J/K, using a 100% hydrogen composition, and no ionization effects as a first order approximation. A energy loss of 4x10^26 J/s means that the sun would cool 1 kelvin every 1.43 x 10^8 seconds or every 4.5 years. The hottest part of the core is a much smaller volume than the outer layers, but the density is much higher (150 tons/m^3), so let's assume an average temperature of 1x10^7K. The energy in a Blackbody radiation spectrum varies with temperature to the 4th power (!!!). Let's say we can readily detect a 5% fall in radiation. That means the temperature of the Sun would have to fall 1.3% or 130,000 K, which would happen in "just" 600,000 years.


Just realised: with an power production density of 0.3W/m^3, the sun is a thoroughly unambitious nuclear fusion reactor design.

Cheers

 

[Grall]

Bah, you bring rationality to the table of a thought experiment! Fail!

Also, we should probably be very happy the sun is, as you say, unambitious; had it not been, its nuclear fuel would likely have been expended ages ago and we would never have existed...

Also, it would be fascinating to do some math on just how big a bang you could get out of a runaway nuclear fusion chain reaction using the mass equivalent to that of the sun, heh. Of course, in reality only a tiny percentage of the whole would fuse, but the thought is not limited to such insignificant details, heh.

I'm sure the end result would be a sufficiently large number that our human minds would have no way to properly put it into perspective...

 

[Mendel]

My first thought was trying to imagine how utterly dark it would be to step outside.

Just to note. I live in Finland and as everyone living way up north during the winter, I expect there to *very soon* be about a month of not seeing the sun...

 

[vazel]

It'll be fine once the Icarus II spaceship detonates an experimental nuclear bomb on the sun to reignite it.

 

[K.I.L.E.R]

It'll be fine once the Icarus II spaceship detonates an experimental nuclear bomb on the sun to reignite it.

Can that actually work?

 

[pjbliverpool]

Just realised: with an power production density of 0.3W/m^3, the sun is a thoroughly unambitious nuclear fusion reactor design.

Cheers

I haven't been through the full maths of your post but does that density take into account the entire suns mass? Because fusion only takes place in the core which will obviously only be a portion of that mass.

Also, we haven't actually created a sucessfull, sustainable fusion reactor yet

Grall, if I'm not mistaken, there is no way our sun can just blink out, It will first expand into a red giant so the worst we would see is the sun start to get slowly bigger, redder and hotter until it roasts us all alive.

Although I guess it could always fall into a massive dormant black hole that just happens to pass by but I'm sure we'd see the gravitational effects of that long before it swallows the sun.

 

[Grall]

I know it can't simply wink out from one instance to the next; as already pointed out just the residual thermal energy stored in the sun's mass would ensure it continues to shine for the foreseeable future with an almost inperceptible drop in power output even if the nuclear fusion process was to miraculously halt somehow...

I was merely thinking out loud, so to speak.

 

[AlNom]

It will if I succeed with my trilithium torpedo launch test tomorrow night.

 

[K.I.L.E.R]

Can we add feul to the sun in order to keep it going for longer and not turn into a red giant and kill us all?

 

[pcchen]

Can we add feul to the sun in order to keep it going for longer and not turn into a red giant and kill us all?

In theory, a smaller sun runs longer. So there are some ideas about manipulating the sun's mass to increase its lifespan. One idea is called "star lifting", which is by splitting the sun into dozens or hundreds smaller suns, basically into the minimal size which allows it to perform nuclear reaction on its own, to greatly increase its life time. Of course, the overall output will become much smaller so you'll need some better ways to collect these energy more efficiently.

 

[CNCAddict]

Better get used to living at the bottom of the sea..eating shrimp and worms. Bioshock comes to life

[YT]4LoiInUoRMQ[/YT]

I think this would be our only somewhat realistic ticket out. Any other ideas?

 

[Grall]

I thought of that, but 2 issues springs to mind:

1 - crushing pressure at ~5km ocean depth. How would we and our technology survive in such a hostile environment?

2 - Oceans and the earth's crust would freeze solid, thus depriving the hot springs of liquid water to circulate.

 

[pcchen]

I thought of that, but 2 issues springs to mind:

1 - crushing pressure at ~5km ocean depth. How would we and our technology survive in such a hostile environment?

2 - Oceans and the earth's crust would freeze solid, thus depriving the hot springs of liquid water to circulate.

Technically we don't need to be at the deep ocean. All we need is an active volcano. Or, Iceland. Of course, nuclear power is also useful (geothermal energy is, in a sense, nuclear powered).