A space flight approaching tau zero was vividly described by Poul Anderson in 1970. I fondly remember how the crew accelerated the ship to a speed when a billion years in the rest of the universe passed for them in seconds — and where a “thump” meant they had just passed through another galaxy. Spoiler: the book has a happy end, when the starship is finally able to decelerate, witness the big crunch and find a planet on which they could live.

I myself am very sceptical with regard to space travel. Homo Sapiens evolved to live comfortably on about 10% of planet Earth, and even colonizing the closest planets is awesomely difficult. Interstellar travel will certainly never involve transporting our current biological forms across the unimaginably vast distances of space. Even in our solar system we will send robots. Or they will send themselves. Or they will not. I will explain in an upcoming article on Fermi’s paradox.