(May 21, 2015 at 4:38 am)Ben Davis Wrote: ... the Fermi paradox bubbles my brain too. I mean, the sheer overwhelming vastness of space with the innumerable galaxies, stars, planets... statistically, however complex, difficult or unlikely our arisal, it must have happened elsewhere in the universe. Right?
Maybe. But given the vastness of time as well as space, thousands of civilizations could have formed long ago, and have been dead for millions of years.
It may be that interstellar travel has always presented unsurmountable obstacles. Voyager 1, if it were heading for the nearest star system, would take 70,000 years to get there, according to Wikipedia. It took decades just to get to the outer part of our solar system. It may be impossible to build a spaceship that is going to be able to successfully take a human being (or its alien "equivalent") from one star system to another, excepting when two star systems collide.
Even if someone could travel near the speed of light, just imagine what would happen to the spaceship when it runs into something. Even a tiny speck of dust would be catastrophic. You can ask our rocket scientist, Alex K, about this. He could probably do the math for the kinds of forces involved.
And, of course, weightlessness itself is harmful to humans, especially for an extended period of time, so that is another problem that would have to be solved.
And right now, the earth's magnetic field and atmosphere protects us from harmful radiation. A substitute for that would also be necessary.
I think that the idea of interstellar travel and colonization of remote solar systems is fantasy. I will only change my mind on this if and when the above problems are solved. You can ask Alex K what he thinks about this, but I suspect he will give you an optimistic guess. (He still might agree with me.)
"A wise man ... proportions his belief to the evidence."
— David Hume, An Enquiry Concerning Human Understanding, Section X, Part I.
