Part of the show Peruvian Mummies, Ancient Environments and the Sahara
James via email asked:
Could you please explain to me the very basics of string theory? I failed lego at school and I'm not very technical.
String theory is a way of looking at the world to try and work out what we're made of. You may have heard that we're all made of atoms, and atoms in turn are all made of other little bits such as electrons, neutrons and protons. If you break it down even further, things like neutrons and protons and stuff are made up of even tinier particles called quarks and leptons. All these different particles are what makes up stuff. There are different forces that can act on stuff to make things move and stick together. These are gravity, electromagnetic force and the weak and strong nuclear forces. Sounds a bit Jedi to me! These help to stick stuff together. We have a standard model for how you explain stuff, which is that quarks and things stick together and protons and neutrons stick together etc. But you can't really explain how gravity actually works using this kind of model. So some very clever maths bods have been trying to work out a way of explaining how gravity works using the bits that we have. They've come up with string theory, which says that all these tiny bits of stuff are actually like bits of string that wobble around in lots of different ways. It depends how you're seeing that particular waving string as to what you see. So if you see it waving in one sort of way you see a lepton, and if you see it in another way you see an electron. So everything is basically little bits of waving string and this can apparently explain gravity. You can find out more at www.superstringtheory.com. However, no-one has found any evidence that this is the case. All the things it predicts happen at such high energies that no-one has been able to look at them yet.