Saving the Earth from the Sun when it becomes a red giant.

[ElasticCollision]

I recently read about the fate of the Sun, and therefore the Earth, in 5billion years and began to wonder if humanity would survive.

Of course in the meantime there are other things which could spell our extinction, such as the Moon leaving the influence of Earth's gravity, the Milky Way/Andromeda collision and much sooner; global warming.

However, I imagined what exactly humans could do to survive the Sun's red giant phase, imagining we had survived these other problems.

I was surprised and fascinated to come across a paper that actually looks into ideas about this very thing. I was mostly surprised because I wouldn't have expected science to begin thinking about such a far off problem.

 

The paper: http://arxiv.org/pdf/0811.4052.pdf

 

As a short summary of the paper, for those who don't wish to read it all:

There are two plans,

1) "we propose to construct some kind of parasol to shadow Earth" however this will only shield the Earth for an extra 5billion years.

2) In order to survive further than 5billion years: "shift Earth into the Kuiper Belt (50 AU) by means of the swing-by technique whereby the overwhelming part of the gravitational energy needed will be transferred from the orbit of Jupiter and Saturn."

 

I just wanted to know what people's thoughts on these plans are. Of course the swing-by technique holds many problems and dangers, but with better technology, could this be plausible?

And has anyone else got their own theories for things that could be done to survive the red giant phase?

[EquisDeXD]

The sun expanding would essentially just increase the amount of solar radiation Earth received, but the sun might get big enough that Earth would get trapped in it's corona, so Earth would have to move away somewhat which it's already doing on it's own right now, but then if you set up a shield, that would definitely decrease the amount of solar radiation. But after that, when the sun actually begins shedding its outer layers, that won't be enough, the plasma will be too strong, and you'd need enough energy to actually move Earth all the way to the Kuiper belt, and I don't know where you could harness that kind of energy.

But, there's a good chance we'll figure out how to live on other planets before this, it's still a ways away.