If Time Travel is Possible, Where are All the Time Travelers?
It is an indisputable fact that sometime in the future mankind will stumble upon the secret of time travel. We can be certain of this because time travelers from the future have been captured on film as a quick perusal of the Internet will show:
Sceptics will of course point out that there is little or no scientific evidence to show that time travel by humans is even possible let alone an actuality, but such people are – ironically – living in the past. Experience has shown time and again that science is fallible. The Internet, however, isn’t.
But seriously folks…
As much as I love Dr. Who and H.G. Wells’s The Time Machine, I am forced to conclude that time travel does not and will not happen. I’m not saying that it’s a scientific impossibility but possible does not equal inevitable or actual.
Every now and then, some publicity hungry scientist will trot out some far-fetched scheme for traveling through time by taking advantage of the quirks inherent in Einstein’s Theory of Relativity or the weirder extremities of quantum mechanics. This leads to somewhat lurid articles in the popular press about how one day our grand kids will be spending their vacations hunting dinosaurs or attempting to assassinate Hitler before he comes to power. There is, however, always a huge gap between what the physicists say and what the newspapers would have us think the physicists say.
What the physicists really do say invariably comes down to not an awful lot. It’s usually some head-up-their-arse guff along the lines of using vastly more energy than we could ever get our hands on to warp space-time and zap the odd atomic particle a few milliseconds into the past. Great big fat hairy deal. The basis for a temporal tourist industry it isn’t nor ever will be.
But let’s suppose for the sake of open-mindedness that a time machine isn’t beyond the wit of man. Our understanding of the workings of the universe is far from complete so maybe, just maybe…
Well, if we go down that route, we ought to ask ourselves one question: where are the time travelers?
The future is a long, long time. Whether time machines come into existence ten yours from now or ten thousand, makes very little difference. There are potentially millions of years of human history ahead of us. If only a few people from every one of those years decided (or will decide depending on your point of view) to pop back to see what homo sap got up to in this day and age, that would amount to an awful lot of people. In fact, its not entirely silly to posit that if time travel lies in our future, then most people on Earth today don’t belong here and haven’t actually been born yet.
Which brings me back to my question. If time travel is possible, where are the time travelers?
If there’s one of the buggers, there must be millions. And if there are millions, I for one would have spotted them. And I haven’t. Ergo, they ain’t here.
So let me, in the spirit of philosophical inquiry, put forward a hypothesis that explains this apparent paradox. Let us suppose that the laws of physics and human ingenuity could – and will – one day combine to build a time machine.
As we all know, if you travel into the past, you change the future. So Mr. Proto-Time-Traveler, by messing with causality, creates a future in which he is never born and therefore does not build a time machine.
No matter. We now have a new time stream in which someone else builds a time machine. Back they come to our time and yet again the future ain’t what it used to be.
And so on.
So we have ourselves a seemingly infinite set of futures, each one superseding the other and wiping out all previous futures.
With infinite futures, we end up with infinite possibilities, so somewhere down the line there has to be a future where time travel is never invented. Once that future comes into existence, it stays in existence because no time traveler ever pops back into the past to destroy it.
In other words, if time travel is possible, it will inevitably lead to time travel never happening (or have happened).
Think about it.