Apparently, a well-respected astronomer recently stated that we would never meet intelligent aliens. Not because intelligent life doesn't exist elsewhere, mind you; I don't think that
anyone really accepts that one any more. No, because going from one star to another is impossible, you see.
Am I the only one shocked by the sheer arrogance of this assertion? We can't do it right now, so it must not be possible. The thing is that while we can't do it
right now, it's not at all unbelievable that we may be about to do it in a century or two. Right now, we really have all that we need to go to another star, except for three rather important things.
The first is a source of cheap, high density energy. We have fission, of course, but fission really isn't good enough to cross to the next star in a reasonable length of time. All going well, we will, relatively soon, have fusion, but the same objection applies; you'd have to carry a lot of fuel to get up to decent speeds and slow down again, and the more fuel you have, the more fuel you need, because you have to
accelerate all that fuel.
Bussard ramjets, devices which capture and fuse interstellar hydrogen using enormously powerful magnetic fields, powering the fields and accelerating with that fusion, once looked like a decent proposition, but it now appears that there isn't actually
enough interstellar hydrogen to make them practical. There is one other obvious option; antimatter. We can, right now, produce tiny quantities, enormously expensively, in particle accelerators. If we could somehow produce it in a reasonably energy-efficient manner, and contain it, well, the sky would no longer be the limit. Journeys would still take many years, but it's only quite recently that we can cross from continent to continent in days; people have made long journeys in the past. People have lived in space for over a year and a half before now. It's not totally mad.
Then there's radiation shielding. It's a big problem if you're going at a respectable fraction of the speed of light; aforementioned interstellar hydrogen will be coming at you so quickly that it will act much like gamma rays. Huge quantities of lead might work, but would add weight. There has apparently recently been some progress by NASA and similar in producing fields to deflect the stuff, amazingly enough, but it's a long way from usable.
Third, and in ways most important, we don't really have the will. Even if we had the other two, it would be an enormously expensive
endeavour; why bother?
The thing is, though, we've been in space for slightly over 50 years. In a few centuries, we may have the technology to do this, and we'll have far cheaper production of everything. Cheap energy makes a lot of things possible. If there is other intelligent life out there, it may have been in space for 500 years, or 5000, or 50000. It may be longer-lived than us and think little of spending 50 years in space to get to the next star. It may be more tolerant of radiation than us.
I don't think that anyone reading this will see
starships, but equally I think it absurd to assume that humanity will
never go to the stars.
By the way, if you're reading this half way to Alpha
Centauri, I do apologise; the
starship thing obviously takes longer than I expected if you have already worked through the
good bits of 21st century Internet, and are reduced to reading this drivel!
