It's amusing how quickly images of future technology date. One of the crew interacts with a computer via a 1980s keyboard and a CRT monitor, for instance - not even a touch screen, far less by speaking, and in text, no GUI. In many other ways it's far-sighted, however.
Interstellar space is such a potential playground for science fiction. It's quite irresistible to authors and film-makers but the enormous distances have always been a huge problem: how could you make these journeys in a human lifetime, far less a time short enough for the action of space battles and political intrigues? Einstein's Theory of Special Relativity shows that the speed of light is a sort of ultimate speed limit of the physical world. As accelerated objects move at speeds closer and closer to the speed of light, they get more and more massive, so it gets harder to accelerate them further. Worse, some invented method for faster-than-light communication would open up the most horrible paradoxes: you could receive the answers to questions before you decided to ask them, for instance. Most people prefer to believe it's just not possible, rather than allowing that the normal sequence of cause and effect might sometimes break down. So we're stuck with travel no faster than the speed of light which means four years at least to the nearest star, even supposing we can make our spaceships move close to the speed of light, and many thousands of years to most others.
The normal solution of science fiction is to assume some advance in physics that will enable a way round this problem. For example, you can learn probably more than you ever wanted to know about Star Trek's "warp drive" in Memory Alpha, the Star Trek wiki. I still remember the gasps in the cinema when the Millenium Falcon entered hyperspace for the first time. There are probably very few Britons who don't know about Doctor Who's TARDIS, especially with the hugely successful reboot of recent years (but I need to get something off my chest here: I HATE it that they now show the TARDIS flying about like some sort of helicopter. It's WRONG. WRONG.). From thousands of science fiction novels that casually invoke such unknown physics, let me mention one personal favourite: M John Harrison's brilliant Light, in which the inventor of faster-than-light travel is also a serial killer.
Let's face it. There is every chance that the physical world just doesn't work this way. No faster-than-light travel is possible and all our Star Treks and Star Wars and Doctors are just fantasies, not even "science fiction". Don't cry.
I like it that Alien takes the less preferred but more likely solution. The human crew are placed in suspended animation for most of their enormously long journeys and only revived after the many years of travel - unless, of course, they intercept signals of intelligent life that turn out to be warning them to keep away from beasties that will use them as incubators for a few hours before bursting fatally out of their stomachs. Anyway this device allows recognisable humans to make interstellar journeys although it does raise interesting questions beyond the scope of the movie, about the maintenance of a culture when communication involves such long intervals of time.
We're not really adapted for interstellar travel. Our individual lifespans are so short. But interstellar travel might eventually make sense if we evolve or, more likely, engineer ourselves into beings that live for, say 1,000 years. Then a 10 or 20 year journey to a nearby star would be a fine way of spending a little bit of your life. This might become possible with our existing bodies through bio-engineering, as imagined so excitingly by Freeman Dyson, or we might even find some way of divorcing consciousness from the body and supporting it in machines: "uploading" a person into a computer. Then the "person" would keep working as long as the machine did.
Of course science fiction has tackled these ideas as well. A student on one of my courses handed me a copy of Diaspora by Greg Egan. The protagonists in this book are our cultural and, umm, mechanical descendants but they have long since moved beyond organic bodies. As minds existing within machines they can contemplate journeys of thousands of years; they are effectively immortal. Most of the interest and possibly the deterrent value of this book lies in the nature of its protagonists, their motivations and relationships. In a time after biology these transhumans are not exactly people we can imagine having a beer and a chat with.
I haven't even mentioned Alcubierre and so on, attempts at identifying a road to faster-than-light travel based on known physics (which, so far, involve using a sort of matter not known to exist as well as demanding the generation of infeasible amounts of energy). Even if these technologies ultimately prove to be possible I believe they belong to an extremely distant future. I think changes to the physical nature of humanity will make thousand-year journeys feasible and attractive first.
So, Alien notwithstanding, I think the future of interstellar travel is summed up in a couple of phrases often heard in Scotland: "ye canna change the laws o' physics, Captain"; and "it's not for the likes of us".
