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Comment by temuze | Hacker News Reader

Interesting. I had to look up what the Fermi paradox is: http://en.wikipedia.org/wiki/Fermi_paradox

But this doesn't solve why the Earth wasn't already visited/colonized, correct?

The nearest life-bearing planet is most likely hundreds of light-years away. Faster-than-light communication doesn't mean faster-than-light travel, and nobody wants to sit in a spaceship for 200 years.

True, but the Fermi paradox is about the question of where's everybody, not where's the next galactic pub.

You take a right at Barnards star.

But suspended animation, often used in science fiction films with long spaceflights in them, would make a 200-year-long trip seem an awful lot shorter. I don't think it's too unreasonable to assume that a life-form that achieved near-light-speed travel will have also discovered a way to lie dormant during the trip if necessary.

Also, there's no telling how long an alien life-form might live, or how patient they might be. Basing things on human lifetimes and personalities seems a little anthropocentric given that we know practically nothing about alien life.

As long as we're doing away with assumptions, we should also throw out the one that aliens have a desire to propagate and colonize across the universe.

If you can get near light speed travel, then time dilation means that you won't experience a 200 year trip, only those you left behind. So any species venturing on a one-way trip wouldn't even blink at the prospect of light speed getting in their way.

I'm not a physicist, but as I understand it, it takes light 1 year to travel 1 light-year.

If the nearest life-bearing planet is hundreds of light-years away, even if you could travel at the speed of light, it would still take you hundreds of years to get there, from your frame of reference.

Time dilation just means it would appear to take even longer from the frame of reference of those you left behind (or those you were headed towards).

In the frame of reference of a photon, no time passes between emission and absorption, regardless of the distance it travels.

We haven't even ruled out life on the closest planet to us yet. (Or Mars.)

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