> What happens if the sun gets blocked out?

We all starve to death.

If can make enough electricity we could make our own light to grow plants.

Significant portion of population will starve though. But energy unused by them could help grow food for remaining fraction.

If significant portion of the population starts starving then there will be all out wars, social instability, chaos, anarchy and whatnot. This could send us back to the stone age.

Well, yes, but a few working power plants would make the situation a bit better for as long as we can still maintain them, wouldn't they?

What's your contingency plan, everyone commits suicide the day the volcano erupts?

I don't have one, and it's not my job to. All I know is that civil order is a very fragile thing. We saw how things evolved with covid. A virus with a 0.2% fatality rate was enough to bring the worst recession in recent history, millions of dead, and hospitals to the brink of collapse. What do you think would happen if suddenly half the world's population can't find food to survive? They'll sit back and wait while you develop your contingency plan, or they will fight for their survival with all means in their disposal? In case of nations this means an all out war.

I mostly agree, but:

> A virus with a 0.2% fatality rate was enough to bring the worst recession in recent history, millions of dead, and hospitals to the brink of collapse.

The worst recession in recent history? I regard 2008 as recent, and as a recession, this is definitely not worse than that was.

The writing is on the wall. We just have to wait a few months for the shockwave to reach us. A lot of small businesses that closed due to lockdowns won't open again, especially in the entertainment industry.

I guess if we have nuclear we will still be able to pass the time coding whilst we starve.

Or nuke everyone else to get their food supplies.

Things that would screw up if the sun got blocked: all photosynthesizing life, the hydrological cycle (it would freeze solid), the atmosphere (it would precipitate out).

Merely having a fallback power solution would be the least of our problems.

Except we could produce food using artificial light, melt water, and evaporate the frozen atmosphere.

Yeah, in vast airtight geothermally heated caverns that don't yet exist, using a closed cycle ark-ship ecology that has neither been perfected nor really even seriously tried, and with an "outside" that would be as ferociously hostile to human life as the surface of Pluto.

Good anime setting, not really a plausible human future.

That list - especially the last item - would take orders of magnitude more power than has ever been available from any human-engineered source.

I meant locally for local use, not globally. We’d basically be living on a sunless Mars except with a lot more resources.

I'm not sure how you'd bootstrap any of the measures you describe in an environment of extreme environmental hostility and complete societal breakdown. Reads like futurism blind to practical reality.

We should start now.

We can burn coal for thousands of years. Thankfully nobody will care about emissions anymore.

I'm not sure nuclear power plants would be able to handle that kind of assault...

Also, you kind need complex societies to function to not have them melt down. After a super volcano or asteroid collision, that one could be dicey.

I actually can't tell if this is satire. Well done!

I think temperature on earth would eventually drop to a few kelvin. The earth’s heat and heat generated by the moon’s gravity stretching the planet would increase that, initially, but I doubt it would be over 100 kelvin. That’s not cold or even cold cold, but cold³. If there still would be oceans, they would be a mix of nitrogen and oxygen.

I’m not sure living on it would be much easier than living in space. You would have better radiation protection and more raw materials, but staying warm might be harder.

I think air pressure (the weight of air above us at sea-level) compresses the air sufficiently for it to reach a temperature much greater than you would expect, e.g around negative 20 degrees Celsius.

(This figure needs verification, I'm going from memory).

But earth would still be radiating out heat, would it? If so, where would the energy come from to maintain that temperature?

I'm a fan of nuclear power, but if the sun gets blocked out, nuclear isn't going to help you. Sure you'll keep your lights on, for a short time, and you get to watch total environmental and civilization collapse.

The atmosphere would turn into liquid.