Steven Hawking, the brilliant scientist, occasionally ventured into dubious socio-political pronouncements. One of his most foolish was the declaration that humanity had 100 years – later amended to 600 years – before it destroyed itself and the planet, and that humans needed to abandon Earth for theoretically habitable exoplanets.
The feasibility of human interstellar travel is beyond both current technology and current understandings of physics.
One can always posit that a revolution in physics will allow us to travel faster than the speed of light, and some interstellar dreamers do. (But one can also posit a much more likely revolution in public policy that leaves the Earth habitable and humanity sustainable.) In any case, Hawking himself did not believe such a revolution in physics was likely. In fact, he was pretty sure we already had it all figured out. How he squared the two ideas, I’m not sure.
To me, the notion that we could make a vessel with the power to undertake and withstand a journey of a few thousand years in space, and sustain generations of crews and passengers for the duration, shows a remarkable naïveté about both physics and human history. The radiation and lack of gravity from a couple of months on the International Space Station does a real number on your health and DNA. Human history goes back about the same length of time that a journey to the stars would take.
And who would these hardy passengers and their generations of inbred offspring be but some elite children of privilege, a tiny fraction of the doomed billions left behind?
This world view marries an exaggerated pessimism about humanity with a foolish scientific optimism.
Hawking did have some possibly feasible ideas about sending interstellar probes, within workable time frames in the hundreds of years. These flyby probes could neither carry crew nor could they stop. But they could send back data. The object of these probes, in Hawking’s mind, would be to find habitable planets.
But were we to find a habitable planet orbiting another star, it seems likely some kind of life would already exist there. It’s an ugly neo-colonial impulse to contaminate such a world with ourselves, an invasive species, like a gift of smallpox blankets.
And if we were to only find semi-habitable planets, the interstellar dreamers believe we could simply terraform said exoplanet. (Why we can’t terraform our own Earth instead – which is a much simpler operation – is never addressed.)
Other believers in the interstellar delusion imagine sending a small capsule with a few petri dishes of freeze-dried human DNA (presumably with robots instructed on how to reinvigorate them), like so many spores to the stars. It brings to mind the compulsive sperm donor or the fertility doctor using a little of his own superior jizz to impregnate his patients.
This interstellar venture is neither likely nor a good idea. We – the Earth, life, humans – are phenomena of our particular sun and solar system. We are sun creatures, and this is our neighborhood. We are the sun.
And though it’s likely there is life in the solar systems of other stars, it is thankfully too far away to mess with us or us with it.
The finite life of our planet and our sun – coming to an end in the next few billion years – does give me a tinge of sadness, but I keep in mind the creative impetus that made and makes the universe is everywhere and probably eternal. We are not only the sun, but we are the universe.