SCIENCE fiction is filled with visions of galactic empires. How people would spread from star system to star system, and communicate with each other in ways that could hold such empires together once they had done so, is, though, very much where the “fiction” bit comes in. The universal maximum speed of travel represented by the velocity of light is usually circumvented by technological magic in such works. The truth is that, unless there has been some huge misunderstanding of the laws of physics, human colonisation of the galaxy will be hard.
A number of scientists reckon a more modest approach towards spreading life to other star systems might be possible. In the chill of deep space, bacteria somehow shielded from cosmic radiation might survive dormant for millions of years. Perhaps alien worlds could be seeded deliberately with terrestrial micro-organisms that might take hold there, jump-starting evolution on those planets.
There are many obstacles to directed panspermia, as this...Continue reading
Source: Science and technology https://ift.tt/2vehW30
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