The last person you want to talk to about space travel is a physicist, or astrophysicist, or anyone that studies space. Because when you ask them that, their minds go to the vast distances between stars. They start thinking in mass and energy. Equations come into their minds. Now some will grant a sci-fi technology like hyper drive, warp drive, wormholes, etc., but most say that without shortening the time it takes to travel between the stars it would be near impossible for a being to make that journey. The physicists are making an assumption about the nature of life for a space faring civilization. You can’t blame them, they are only human. They are assuming that they die, or that they die on time scales similar to ours.
On a recent cover of National Geographic was a picture of a baby and caption asking if that child would live to 120. But this is now. It is in the realm of possibility now. What about tomorrow? What about when we completely understand the entire genetic code and can turn on and off genes at will? When we understand biology completely, perfectly, will we not make disease a rare event? Will we learn to keep our cells healthy and dividing normally forever? This won’t happen in our lifetimes. Everyone reading this blog today will die. But it might happen for our grandchildren, or their grandchildren. Will they eliminate death and be immortal? Ask a biologist about space travel and they think differently. They are not thinking of mass and propulsion systems, they think of life.
Think of being immortal. If you lived one million years you could live in every country, every tribe, for a thousand years each and have a whole lot of time left. You could spend a century a piece learning every language on the planet. Every American could take a turn at being president. You could meet everyone alive. Read every book, see every movie. Fish in every lake on Earth. Climb every mountain. Walk every road on the planet. Piss in every pool. A century or five terra-forming Mars and Venus would be nothing. Eventually you would look to the stars and think, “A thousand years, no problem.” Our population growth would demand we expand or die. A round trip of say 3,600 years would mean little to us. Interactions on an interstellar scale would take millennia, but they would happen. For an astrophysicist, it’s still science fiction, but for a biologist it’s the future. If a sentient being lived life on a timescale of millions of years, a rational person would presume that they had already taken to the stars. What else would there be left to do?