[astorgard]

But destruction of Earth is inevitable!

Even if we manage not to destroy ourselves in the next hundred thousand years, we still have to deal with some "soft" and "hard limits".

First we have comets/asteroids impacts. I guess we might have the technology to deflect them in the next 5000 years or so, so this shouldn't be a problem.

Gamma ray burst, close super nova explosions and glacial periods would severely damage half of Earth, but, again, as long as this doesn't happen in the next 5000 years or so, I think we will develop the technology to recover from that also.

Let's fast forward to 600 million years where things start to get interesting: the level of carbon dioxide will fall below the level needed to sustain photosynthesis... So no more plants. But if we are still around here by then, I guess this should also not be a problem as we will be able to synthesize whatever chemical we need.

In 1000 million years the solar luminosity will be 10% higher than at present. This will cause the atmosphere to become a "moist greenhouse", resulting in a runaway evaporation of the oceans. Hmmm... 1000 million years is enough for us to come with a solution for this, but who knows?

In 2500 million years Earth will lose its magnetosphere.

In 4000 million years the surface of Earth will melt from heat.

In 7500 million years the Sun will absorb Earth.

So... if we want to preserve man kind I would say that, in order to "play it safe" before things get more complicated, we have around 500 million years to escape Earth and ten times that to escape the solar system.

I'm quite convinced that we will manage to do both. I'm also pretty sure we will be there to witness it: we just have to hang on for ~50 years or so until we get functional cryogenic chambers; from there it is just a matter to tell the operators to wake us up in 5000 years once immortality is achieved.

Who is with me? :)

[modeless]

See How To Destroy The Earth by QNTM: https://qntm.org/destroy

[lazyweb]

Was about to post the link as well. Very funny / interesting read, sucked me right in!

[marcinzm]

> cryogenic chambers

This is an interesting discussion point. There are things worse than death and if you're frozen then you won't have a chance to escape them. Basically if you think I Have No Mouth and I Must Scream is possible then you need to consider cryogenic freezing somewhat more carefully.

[adrianN]

You're very optimistic. I think it's more likely that we lose technological society in the next hundred years or so due to environmental destruction and the resulting wars and collapse. Recovering might be possible, but it will take a pretty long time.

[dhosek]

Olaf Stapledon’s Last and First Men http://www.amazon.com/exec/obidos/ASIN/0486219623/donhosek presents one possible future history on this kind of time scale. It is very much a product of the 1930s though, with rather disturbing racism, sexism and the kind of casual anti-Semitism that the rise of Hitler made impossible. Once he gets away from contemporary times, though, that tends to fade away and it’s very much a memorable book.