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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

#41

Post by Archelaos »

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.

"Just parking" between would not be possible without putting really a lot of energy into maintining the position of the shade. Due to orbital speed differences depending on the distance to the sun[1] and the pressure of the light[2] and solar wind[3] on the shade and Earth's gravitational interference. And the shade must be very much larger in diameter than the planet in order to cover it. How large depends on the distance from the planet.

[1] See https://en.wikipedia.org/wiki/Orbital_speed#Planets

[2] See https://en.wikipedia.org/wiki/Radiation_pressure

[3] See https://en.wikipedia.org/wiki/Solar_wind

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

#42

Post by saalweachter »

ljf wrote: post #29
nullhole wrote: post #19

Earlier quoted context omitted.

That'd make for a good story setup: aliens park a shadeship (c) at L1 and wait. They block out most but not all of the sun. After some time (months? years?), conditions on Earth become unbearable, so earthlings have to mount an attack. Kind of like the movie Sunshine, but with more believable physics. Edit: as a bonus, it could take place in ~50-100 years, when global warming has gotten worse. The aliens could disgui…

Love this idea for a story. As an alternative - it could be the oil producing countries, not aliens - seeking shade earth to disrupt solar and wind energy, and return to oil dominance.

Nah, you just need a simple Bond Villain Plot.

Step One: build a machine that can cool the Earth, solving global warming Once and For All.

Step Two: demand the governments of the Earth pay you $1 trillion to turn it off at the appropriate time.

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

#43

Post by dsign »

slashdev wrote: post #26
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.

Or you could just smack it with a really big rock. That nicely sterlizes the planet too, so you can reseed it with life from your planet after to make it more comfortable. Honestly it's all kind of silly because distances are so vast. It makes little sense to travel to a distant star - much better to build space habitats in your own star system. And even if you were going to do that for some crazy reason, there's no…

You are correct, but it's capitalism and the adrenaline kick. We are culturally conditioned folk, and all scripts about alien invasions that end up in movies follow a completely implausible scenario. Most don't even bother any longer to give a reason for invasion. I would blame the writers of those scripts, but movies without violence don't give the adrenaline kick and don't sell well.

Here is an idea for any writers reading this who want to break the violence cycle: whenever you feel you need to have a character kill another in a gratuitously violent way, twist the plot so that they instead end up having steamy sex. The readers will get an intense hormone rush that way too.

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

#44

Post by Loughla »

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.

Currently reading that. And I am trying like hell to figure out how all of the different stories will come back together.

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

#45

Post by slashdev »

dsign wrote: post #43
slashdev wrote: post #26

Earlier quoted context omitted.

Or you could just smack it with a really big rock. That nicely sterlizes the planet too, so you can reseed it with life from your planet after to make it more comfortable. Honestly it's all kind of silly because distances are so vast. It makes little sense to travel to a distant star - much better to build space habitats in your own star system. And even if you were going to do that for some crazy reason, there's no…

You are correct, but it's capitalism and the adrenaline kick. We are culturally conditioned folk, and all scripts about alien invasions that end up in movies follow a completely implausible scenario. Most don't even bother any longer to give a reason for invasion. I would blame the writers of those scripts, but movies without violence don't give the adrenaline kick and don't sell well. Here is an idea for any writers…

American viewers love gory violence, but get offended at steamy sex scenes. That makes no sense to me.

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

#46

Post by rainbowzootsuit »

ljf wrote: post #29
nullhole wrote: post #19

Earlier quoted context omitted.

That'd make for a good story setup: aliens park a shadeship (c) at L1 and wait. They block out most but not all of the sun. After some time (months? years?), conditions on Earth become unbearable, so earthlings have to mount an attack. Kind of like the movie Sunshine, but with more believable physics. Edit: as a bonus, it could take place in ~50-100 years, when global warming has gotten worse. The aliens could disgui…

Love this idea for a story. As an alternative - it could be the oil producing countries, not aliens - seeking shade earth to disrupt solar and wind energy, and return to oil dominance.

Slow down there, Mr. Burns.

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

#49

Post by ant6n »

saalweachter wrote: post #42
ljf wrote: post #29

Earlier quoted context omitted.

Love this idea for a story. As an alternative - it could be the oil producing countries, not aliens - seeking shade earth to disrupt solar and wind energy, and return to oil dominance.

Nah, you just need a simple Bond Villain Plot. Step One: build a machine that can cool the Earth, solving global warming Once and For All. Step Two: demand the governments of the Earth pay you $1 trillion to turn it off at the appropriate time.

Also sharks, with friggin lasers attached to their heads.

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

#50

Post by DelaneyM »

saalweachter wrote: post #42
ljf wrote: post #29

Earlier quoted context omitted.

Love this idea for a story. As an alternative - it could be the oil producing countries, not aliens - seeking shade earth to disrupt solar and wind energy, and return to oil dominance.

Nah, you just need a simple Bond Villain Plot. Step One: build a machine that can cool the Earth, solving global warming Once and For All. Step Two: demand the governments of the Earth pay you $1 trillion to turn it off at the appropriate time.

I mean, a trillion dollars to solve global warming sounds like a pretty good deal to me?
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