Parallel Worlds

Imagine. Somewhere in a galaxy far, far away (as they say in the movies) there’s another you. This "other" you shares everything that you have. She has your past, your history, your family, your name, your body, your sense of identity, your dress-sense, your possessions, your sense of humour. She is identical to you in every way. She likes what you like. She not only thinks she is you, in a very real sense she is you.

She is sitting in exactly the same place as you are now, reading this blog, just as you are. She is wearing the same clothes. What’s the weather like outside? Well in her world the weather is exactly the same. If it’s sunny in your world, it’s sunny in hers. If it’s raining in your world, then it is raining in hers.

But at this point, maybe, things begin to change. You carry on reading this blog, intrigued, whereas the other you interrupts her reading after the first sentence and decides to go for a walk instead. Outside she meets someone she hasn’t seen in ages, who asks her out for a drink. A romance ensues. Later they marry and have children. The two worlds are beginning to diverge.

Small changes lead to greater and greater effects. So in your world you marry a completely different person, and have different children and sometime in the future, one of your children is responsible for a great breakthrough in medicine which saves large numbers of people from a major epidemic.

A war for resources that might have happened did not happen. People live who might not have lived. Some of these people are responsible for huge changes in how we go about our daily lives. And on and on like this, until the two worlds are utterly different from each other.

It is the "parallel worlds" scenario beloved of science fiction writers. You imagine a world quite like our own, but weirdly different in significant ways. So, for instance, in one episode of Doctor Who the protagonists believe themselves to be in London, only when they look up there are Zeppelins in the sky and the world is being ruled by a malevolent dictatorship. They realise they are in a parallel universe.

You think this is all just the stuff of fantasy? You are wrong. It is legitimate scientific theory. It is not only likely to be true, in all probability it is true.

The theory goes something like this: if space is infinite and matter is distributed evenly throughout then every possible scenario must be taking place in one part of the universe or another. So there’s not just one "you", there’s an infinite number of you, all diverging from the pattern at varying points along the way.

It’s like that trick you do with mirrors, reflecting a mirror in a mirror, till you get an infinite regression of mirrors disappearing off into the distance. An infinite number of Earths, going around infinite suns in solar systems exactly like ours. Infinite versions of the internet, with an infinite number of blogs by CJ Stone, all varying in an infinite number of ways.

Well I know it sounds far-fetched, but, according to the physicist Max Tegmark, in his theory of Parallel Universes it is the simplest possible explanation for how the universe actually works. Unless we imagine that the universe stops at some point and turns into something else - a kind of cosmic terminus-building with a big sign saying "Please Mind The Gap When Disembarking From The Universe"- then the best assumption is that it goes on forever; and if it goes on forever, then every possible story-line you can imagine is happening in some part of the universe or another.

As for that other you: she might have gone out for a drink tonight, but she missed reading a very interesting article instead.

And who knows how this might change the world?