Wednesday, June 6, 2012

Paradoxes

"Dad, what is a paradox?" asked my son one day. This is a difficult question, so how to explain it to a kid on first grade at school? Here's how I answered:

A paradox is something that is is both true but still impossible at the same time. Here's an example: a man is named "unnamed". So he has a name, but at the same time he is unnamed. So that is a paradox.

Yes, I know, the above is not really a good example of a paradox, it is more like a game of words. Similarly, a boy's name could be "girl", or a dog's name could be "cat". Stupid, really. But I think I managed to explain what this paradox thing is all about, briefly and using an easy-to-understand example.


Actually, what first popped to my mind was the classic "I am lying" paradox. A person says "I am lying", but how can he lie if he just stated truthfully that he is lying? That is a classical example of logical paradox. But on the other hand, if you are a mathematician, the above forms an equation which is just plain false. Anyway, I found the liar paradox too hard to explain.

So are there real paradoxes, things that really are impossible but true at the same time? One that is not a word game? I think some could be found in quantum physics. For instance the tunneling phenomenon could be considered as one. No particle can exceed the speed of light, ever, except during tunneling it temporarily can. Although, if you consider particles as a field covering all space-time, which is actually is, it is no longer a paradox.

Still looking for a real paradox.