Weird Time: Star Trek

Plot: A Romulan hell-bent on revenge travels back in time to destroy Vulcan and generally play havoc with the time-space continuum. Oh, and Spock's come back, too.

What type of time travel is it? Ah, well you see it isn't really time travel. Well, it is time travel but with an added parallel universe twist for good measure.

OK. This could be a tricky one!

Let's start off by imagining that for every decision you make, another version of yourself in an alternate universe makes the opposite decision.

So there's an infinite number of universes where every possible event, natural and man-made, is played out.

Believe it or not this is somewhat backed up quantum mechanics, which can be summed up as the theory all possibilities that can happen do happen in a parallel universe.

Normally this has no consequence to any of us as we go about our daily lives.

But in Star Trek, Eric Bana and the gang travel through a black hole and into one of these alternative universes. For some reason they are also transported 150 years into the past as well.

What's the problem? Cleverly the writers have managed to avoid the nasty paradoxes. If I can go back in time to an alternative universe I can shoot my granny in the knowledge that I'd be safe.

I'd just be living in a universe where I killed my poor gran and so therefore my mum and all that side of the family, including my alternative self didn't exist.

So all bets are off as the future in the universe I am in hasn't been written yet.

When the Romulan ship kills Jim Kirk's dad this changed how the new Star Trek universe would play out. A bit like a butterfly effect, this would change plenty of things in the alternative future.

This explains why there are two Spocks in the film. They are from different timelines and so can shake hands without much worry.

It is ingenious. BUT the idea you can travel to these universes through a black hole is extremely dodgy.

If you go into a black hole you're not going anywhere. Well, in fact, you're going to be torn apart, completely shredded into the smallest possible pieces, well before you reach the 'other side' even if there is one.

For more science jiggery-pokery, take a swift glance at the Mercury's Weird Science blog.