They say that in the future all things will be possible. But I’m afraid to say that time travel will never occur. Sorry Spielberg.
Imagine one day, if you will please, an ordinary day. On this day a man, we’ll call him Jeff, goes into a coffee shop and orders a drink. The assistant reaches for one of two cups, and this is here what Sir Terry Pratchett called The Trousers of Time occur. In one universe, in theory (in theory, remember this, it’s important!) reachable by time travel, Jeff is given the red cup, in the other he’s given the blue cup. Unbeknownst to Jeff, the red cup hasn’t been washed properly and contains a seed, the assistant doesn’t notice and pours the coffee in. Jeff drinks the coffee and chokes on the seed. In the blue cup universe, there’s no seed, but Jeff walks out the shop, drinking his coffee, doesn’t look where he is going and gets hit by a passing car. In either universe, Jeff dies but sometimes trousers have more than two legs. Normally in the case of bad seamstressing.
In the red universe, someone helps Jeff by performing the Heimlich manoeuvre. Sadly, this person breaks one of Jeff’s ribs, and because this Jeff is a massive arsehole he sues the person for saving his life. People stop doing the Heimlich and thousands of people are killed every day by small seeds, grapes, pen lids, coins and all the other nonsense people try to swallow on a daily basis. Jeff becomes an internationally reviled arsehole and commits suicide to avoid the press. But already there’s too many variables. In red universe 1, the assistant spots the seed and washes it out, so Jeff doesn’t choke. In red 2 Jeff see’s the seed, complains and doesn’t choke. In red 3 Jeff does choke on the seed, but outside, this means the only people who can help are gawping muppets who film a man dying on their phones, thus creating a universe where mobile phones become banned, some of the people who saw Jeff die have trouble and either seek therapy, commit suicide, develop a sexual fetish for auto-erotic asphyxiation, (some die, some don’t), one goes on to develop a messiah complex because he was thinking about killing someone when Jeff died in front of him, and goes on a killing spree. In red 4 that same man is actually a woman, but because the mental profiling system doesn’t like female serial killers, she goes uncaught for months before finally being shot by police in the case of “The Black Widow Choker” after strangling 45 people in a 6 month period. The people in red 4female who witness the shooting are affected as well, one is a war veteran who has seen enough of that and commits suicide, because in red 4female, just like every other universe, very little is done for the mental health of its populace.
That’s just a few options in the Red Cup world. These trousers are become more like octopus pyjamas. Or maybe Cthulhu’s!
In the Blue cup universe, the man who hits Jeff was playing with his stereo and didn’t see him, in another it was a woman speeding away from her abusive partner and in yet another it was some old man whose reactions weren’t as quick as he wanted them to be. In all three of those, Jeff dies again, but the people around are affected in different ways. In Blue 1 the car stereo companies got together and created a new stereo controlled by thought, thus moving technology forward in a massive leap that is very quickly used for pornography, murder and fraud. In Blue 2 the woman was escaping from her abusive partner, after years of abuse, but she was so happy to be free, she didn’t see Jeff and killed him instantly. In another Blue 2 universe, the one escaping was a man, after years of daring not to say anything, but because he hit Jeff his story hit the news and people finally took the news of men being abused seriously and did something to help men from abusive marriages. In Blue 3, the old man was a retired doctor. He tried to save Jeff, but couldn’t. He never forgave himself and took an overdose at home. All the people who saw Jeff get hit were affected, one never drove again, losing his job as a paramedic and not being there to save a child who fell out a tree. The doctor’s wife had to find him and she was so heartbroken she died, thus her family was affected too. In Blue3.2 the doctor triggers an argument to ban old people from driving, he loses his only sense of freedom and independence and falls into a pit of depression, resulting a drug/gambling/other addiction and eventually kills a man with a tennis racket. In Blue3.3 he loses his license, can’t go to his granddaughter’s birthday party and she chokes to death on a birthday cake, because someone there heard a rumour about people suing if you did the Heimlich.
In all these universes there’s a certain amount of free-will, cause and effect and a series of unfortunate events. In yet another universe Jeff is sick and doesn’t go out at all, in another he has a bottled drink instead. In the red and blue universes there’s a chance that the assistant will burn himself with the coffee and sue the coffee company, which closes down and is replaced with a main brand coffee chain who ups the prices and fills the town with hipsters and skinny white girls in battered Ugg’s who swarm over the town like cockroaches. The influx of money causes an economic leap in the town which saves its ailing tourist industry, sadly bringing more hipsters who eventually move away from the main stream and cause a massive drop in the town’s finances, rendering it obsolete until it’s bought by a chain company who turns the whole town into an industrial complex. The desert effect in a city.
If you wanted to travel back, just to warn Jeff not to go and drink coffee it could be that nothing happens, but even if it does it could be an entirely different route to any of the Red/Blue universe theories and cause a different chain of events. In which case, whichever history you go back to, there’s no guarantee that the future you came from will exist when you live through to it again.
Oh, yes, because you travelled down a different trouser leg, the future you came from no longer exists, thus you can’t get back to it, and you’d have no choice but live through everything again. But who do you know you’re not now the universe’s Jeff? You could be the one to buy coffee, choke, get run over or be an enormous douche.
I think it’s safe to say that you should leave time travel to Christopher Lloyd, Michael J. Fox, Ebenezer Scrooge and all those other randoms.
I might see if I can get some more sleep now.