Time travel paradoxes in the Terminator films explained

I have always been fascinated by books and films featuring time travel, not least the plausibility of explanations for certain paradoxes.

In the Terminator series of films, there is the John Connor and Kyle Reese loop. A future John Connor sends Kyle Reese back in time to save Sarah Connor, his mother. Interestingly, Kyle Reese ends up becoming John Connor's own father. Thus the paradox of a closed loop. Without complicating the matter with Skynet and the machines, the actions of John Connor and Kyle Reese then creates an endless time loop.

Sean Shaffer explains the paradoxes, including about the development of Skynet (which came first, the chicken or the egg) very well in Den Of Geek

The paradox that's created in the Terminator series is that Skynet is built because an already built Skynet sends back a machine that will ultimately be destroyed and become the basis for Skynet. The question here is which came first, the machine or Skynet? The same goes for John Connor's life. John Connor is only conceived because he sent his dad back to impregnate his mother. It basically goes back to the original question of what came first, the chicken or the egg?

It's also in these events that we not only see how taking out one part of the equation would equate to a whole another timeline, but it also shows us how closely connected John Connor and Skynet really are. To put it simply, Connor and Skynet can't survive without each other, almost like Harry Potter to Voldemort. Their legacies are so intertwined that taking one out would possibly ruin or enhance the other, but ultimately create a timeline that cannot be predicted.

It's worth reading the entire article.

Similarly, but even more complicated is the relationship between The Doctor and the Daleks. The Doctor has his own timeline as a time traveller, which doesn't follow the linear timeline of the Daleks history.

time travel - go fast and go forward but go nowhere

Professor Stephen Hawking recently wrote an article in the Daily Mail suggesting that time travel may be possible.

A well known paradox that suggested time travel to be impossible, called the grandfather paradox, where a traveller goes back in time to prevent him or herself from being born, Hawking overcame by proposing that time travel to the past is impossible.

Any kind of time travel to the past through wormholes or any other method is probably impossible, otherwise paradoxes would occur. So sadly, it looks like time travel to the past is never going to happen. A disappointment for dinosaur hunters and a relief for historians.

But the story's not over yet. This doesn't make all time travel impossible. I do believe in time travel. Time travel to the future. Time flows like a river and it seems as if each of us is carried relentlessly along by time's current. But time is like a river in another way. It flows at diff erent speeds in diff erent places and that is the key to travelling into the future. This idea was first proposed by Albert Einstein over 100 years ago. He realised that there should be places where time slows down, and others where time speeds up. He was absolutely right. And the proof is right above our heads. Up in space.

Hawking suggests that a means of travelling to the future would be by super speeds in a vehicle where the time elapsed during travel is less compared to that on earth. This would mean that when the travellers returned to earth, it would be in further in the future. For example, travelling for a day and returning to earth one year later.

Given that going back in time is impossible and the cost involved would be enormous, there really would be no point.

We are all time travellers, moving forward towards the future, albeit at at one second per second. There is no advantage to travelling through time faster than this rate and leaving our lives behind to go to a future that is uncertain. We may as well be cryogenically frozen, to wake years later.

As for travelling to the far reaches of space for research and then returning to earth, the travellers would return to a different world with possibly no memory of the mission itself.

building a time machine

Dr Ronald L Mallett, a physics professor at the University of Connecticut thinks he can build a time travel machine.

He's written a book -

The Time Traveller: One Man's Mission To Make Time Travel A Reality, by Ronald L. Mallett with Bruce Henderson, published by Doubleday (£14.99 - UK) and Avalon Publishing Group ($24.95 - USA)

From the UK Daily Mail

"Mallett isn't mad," the New Scientist article said. "None of the known laws of physics forbids time-travel.

"In theory, shunting matter back and forth through time shouldn't be that difficult."

So, how do you build a machine which will take you back into the past - or forward to the future?

In fact, there have been several plans for a time machine devised by physicists since Einstein's mind-blowing discovery that reverse timetravel should be possible.

and

But consider, too, all the weird paradoxes that the time machine would create. You could come face-to-face with your past self, causing untold confusion. What, for example, would happen if you killed your past self? Would both versions of 'you' die at the same time?

Mallet believes these paradoxes would not in themselves prevent the construction of such a machine. But there are plenty of sceptics.

Some physicists think that the laser upon which his machine depends would need to be impossibly large or powerful. Others point to Stephen Hawking's 'chronology protection conjecture', which says that quantum effects may conspire to prevent the possibility of a time machine.

But, while some physicists have questioned Mallett's approach, no one has yet proved with absolute certainty that the machine would not work.

Temporal instability in the space-time continuum?

***********************
Argh, back to work today. I could do with a week off work!

the story of Håkan Nordkvist, time traveller

A person in Sweden claims to have time travelled to the future. From his blog:

It all happened on the afternoon the 30th of August. It was a beautiful day and I was on my way home from a job in Färjestaden. When I got home, I found water on the kitchen floor. Somehow there was a leak. I got my tools and opened up the doors to the sink. And started to work.

When I reached in to examine the pipes, they seemed to be further in than I remembered. I had to crawl inside the cabinet, and as I did so, I discovered that it just continued. So I kept on crawling further and further into the cabinet. In the end of the tunnel I saw a light, and when I got there, I realized I was in the future. I meet myself as 72 years old, the year was 2042. I did a lot of tests on him to see if he was really me. And the strange thing is that he knew everything about me. Where I hid my secret stuff when I was in first grade, and what the score was in the soccer match against Växjö Norra in the summer of -88. He knew it all.

We even had the same tattoo, although he's was a little faded. He told me some of the stuff that will happen, but not so much. And I promised not to tell anyone. I made a film with my mobile phone. Unfortunately the quality is not the best. But it´s what I have got. Actually I don't´care if people thinks I am a liar. I know I'm not. I met myself in the future, and I was fine. That's all I know.

But if it happened to me it probably must have happened to someone else.

/Håkan Nordkvist

Here is a film clip based on the film from his mobile phone

Now, if you travelled to the future and wanted proof, wouldn't you bring back a newspaper of that future day?

There was also a time traveller from the future called John Titor whom some people believe.

My comment is that we need more convincing proof.

***********************

That German Shepherd Kane is staying over until Monday. I asked his people a few days ago if they had planned to go away for Easter, but they hadn't. Thankfully, they've agreed to let me borrow Kane. I enjoy going on walks with him, as he does too.

Ted dropped Kane over around 3pm and around 4.40pm I took him on a long walk around the suburb, dropping into Margaret's house for a quick visit and a beer, then past the oval at the local primary school. Jake the black labrador-kelpie was having a play with his people, so I let Kane off the leash. It was a lot of fun.