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What made Earth a giant snowball 700M years ago? Scientists have an answer

sydney.edu.au

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Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#101

Post by huytersd »

duxup wrote: post #17

A recent PBS documentary did a great job talking about all the changes the earth has gone through: https://www.pbs.org/wgbh/nova/article/the-history-of-earth-i... They had a series on planets and some of their history too. Growing up I honestly thought that planets evolved into a sort of natural stable state that I guess I assumed would last until the sun or other external force decided otherwise. But it’s interestin…

I wonder if we’ll get to a computational space where we can completely simulate every atom in a small closed system. Are we there yet? Can you simulate at the atomic scale and get a perfect representation of reality or do we have to try and simulate something smaller?

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#102

Post by [deleted] »

foobarbecue wrote: post #53
Georgelemental wrote: post #18

Earlier quoted context omitted.

You have to make sure it doesn't drift away from the Langrange point, which is unstable…

What do you mean it's unstable? You orbit the Lagrange point, right? Sure you might have to spend some fuel maintaining the orbit, but we have a bunch of spacecraft at Earth sun L2 doing that just fine (e.g. the Webb). Is L1 less stable than L2 for some reason? edit: SOHO is at L1

[deleted]

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#103

Post by WarOnPrivacy »

Jenkins2000 wrote: post #38
WarOnPrivacy wrote: post #14

Earlier quoted context omitted.

> Have you done the calculation how much material is required for such an endeavor? It's a tiny fraction of what's required for a proper Dyson sphere. And we know civilizations can afford those because we can no longer see their stars. For anyone who's hung up on saving nickle, we could do a low budget Worldring² or even thriftier Shadow Squares®. ²Nivenlarry ®Larry Niven

I really liked Pandora's Star (The Commonwealth Saga) by Peter F. Hamilton.

> I really liked Pandora's Star (The Commonwealth Saga) by Peter F. Hamilton.

It looks promising; I'll check it out. Appreciate the recommendation.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#104

Post by simonh »

huytersd wrote: post #101
duxup wrote: post #17

A recent PBS documentary did a great job talking about all the changes the earth has gone through: https://www.pbs.org/wgbh/nova/article/the-history-of-earth-i... They had a series on planets and some of their history too. Growing up I honestly thought that planets evolved into a sort of natural stable state that I guess I assumed would last until the sun or other external force decided otherwise. But it’s interestin…

I wonder if we’ll get to a computational space where we can completely simulate every atom in a small closed system. Are we there yet? Can you simulate at the atomic scale and get a perfect representation of reality or do we have to try and simulate something smaller?

It's a bit of a stretch perfectly simulating one proton, I'm afraid.

https://www.quantamagazine.org/inside-the-proton-the-most-co...

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#105

Post by kej »

MR4D wrote: post #60
itronitron wrote: post #3

Seems like a low risk approach for taking over a planet would be to just park a large shade between the planet and it's star then let it enter a deep freeze. Then you could just remove the shade and let the planet warm back up before settling down.

I wonder how that would look from a feasibility perspective... Let's see - Earth's radius is 6,378 km. Area exposed to the sun therefore would be 6,378 * 6,378 * 3.14 = 127,731,695 [1] If you wanted to block just 1% of the light, that would take a shade of 1 million square kilometers, which would be equivalent to a shade that is 1,130 km on a side. Seems like it would be tough to do given all the dust and rocks float…

>Seems like it would be tough to do given all the dust and rocks

I wonder if there's a solution that uses the dust and rocks. Maybe you nudge some near-Earth asteroid near L1 and then blow it up or something.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#106

Post by downsplat »

I remember it was one of the remarkable take-away points of nonlinear system dynamics, aka chaos theory: the weather/climate system doesn't even have an "average regime" that it converges on. You can average over longer periods of time, and the resulting sequence doesn't necessarily converge to a single limit. Pretty mind boggling when you think about it. Long term enough, "this place's climate" doesn't even exist.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#107

Post by huytersd »

simonh wrote: post #104
huytersd wrote: post #101

Earlier quoted context omitted.

I wonder if we’ll get to a computational space where we can completely simulate every atom in a small closed system. Are we there yet? Can you simulate at the atomic scale and get a perfect representation of reality or do we have to try and simulate something smaller?

It's a bit of a stretch perfectly simulating one proton, I'm afraid. https://www.quantamagazine.org/inside-the-proton-the-most-co...

Oh wow. Maybe that can be a new scale measure of technological capability based on how much of reality we can perfectly simulate.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#108

Post by SketchySeaBeast »

WarOnPrivacy wrote: post #100
SketchySeaBeast wrote: post #34

Earlier quoted context omitted.

> And we know civilizations can afford those because we can no longer see their stars. That's a giant claim you just made like it's fact.

> That's a giant claim you just made like it's fact. You are correct. That is absolutely a thing I did.

But it doesn't make any sense, given we do not have good evidence of alien civilizations, not to mention Dyson spheres.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#109

Post by adastra22 »

huytersd wrote: post #101
duxup wrote: post #17

A recent PBS documentary did a great job talking about all the changes the earth has gone through: https://www.pbs.org/wgbh/nova/article/the-history-of-earth-i... They had a series on planets and some of their history too. Growing up I honestly thought that planets evolved into a sort of natural stable state that I guess I assumed would last until the sun or other external force decided otherwise. But it’s interestin…

I wonder if we’ll get to a computational space where we can completely simulate every atom in a small closed system. Are we there yet? Can you simulate at the atomic scale and get a perfect representation of reality or do we have to try and simulate something smaller?

We can get up to 100 or so lightweight atoms (the real limiter is the number of electrons, not the number of atoms. Larger atoms cost more). Maybe a thousand or so on supercomputers.

Quantum computing will change this though.

Re: What made Earth a giant snowball 700M years ago? Scientists have an answer

#110

Post by OnlyMortal »

itronitron wrote: post #3

Seems like a low risk approach for taking over a planet would be to just park a large shade between the planet and it's star then let it enter a deep freeze. Then you could just remove the shade and let the planet warm back up before settling down.

“space toupee”
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