h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Although I may not agree with everything you say exactly (for instance the only reason 1+1 = 2 is that is a basic assumption of maths and although maths might be something very different if that wasn't one of our basic assumptions it is not based on experimental evidence. Anyone interested in further proof of this look in a 1st year maths degree book and be prepared to be confused)

That aside your piece does deal quite well with a very interesting subject. That of cause and effect. How do we know what causes what? Do we even know what order events occur? in fact according to Einstein the only time you can be certain of the order events occur is when they are at exactly the same point in space. This is not due to a lack of information as quite obviously you are able to see for example which of 2 lights flashes first but more a question of perspective and observation.

Taking a simplified example,Imagine two bells situated say 200m apart. These bells are set to ring at the same time. You now stand such that you are looking along the bells in a straight line with them. when the bells ring the sound takes a few moments to travel the distance to your ears. The sound from the further bell takes more than half a second longer to reach your ears, so to your mind you beleive the closer bell rang first. Of course someone stood somewhere else could beleive something totally different and from their point of view they are correct.

Now we are working up to the real point, although in the previous example there was a correct answer i.e. that we know that both bells ring at the same time even if we stood anywhere a good scientist could easily work this out. So now you will have to accept a few basic facts that I will just throw at you without any proof to truely illustrate my point. When objects travel at high speeds they reduce in length along the direction of travel. This only becomes obvious as near light speed but with a simple thought experiment this makes a very interesting point.

Imagine a train, maybe an old steam train, travelling at half the speed of light. Along it's track it passes through a tunnel that when the train is stationary is the same length as the train. of course when the train then travels through it at very high speed it is significantly shorter than the tunnel i.e. both ends of the train can be inside the tunnel simultaniously. Nothing exciting there just a little bit weird. But now imgaine you are on that train, relative to you the tunnel is travelling towards you at this enormous speed and the train is stationary(ok a very smooth train!). this of course means that the tunnel must now be shorter than the train, i.e. both ends of the train can be outside the tunnel at the same time.

So what conclusion can we draw? What actually happens? the answer is that both these things actually "happen" it just depends where you observe them from. This really confuses people the first time they hear it but it is a genuine effect used here to illustrate that maybe there isn't an answer to everything of what exactly happened first or even what it was you saw, it all depends on who asks the question.

Weird huh?