attention smart people: string theory

[uethanian]

i was just reading up on an article about string theory and it got me thinking...

they say that some of these strings (if they do in fact exist) vibrate as open strings and others as closed loops. now its easy enough to demonstrate how an open string vibrates. stretch it across two points and pluck it, or even better, excite it with an electromagnet. but is there any way to vibrate a closed loop?

obviously it would have to be suspended in air or a vacuum, by electromagnets i suppose. from the article it looks like closed loops can vibrate in multiple dimensions (harmonics?) just like open strings. can anyone offer some insight on this?

[Parabolic Box]

I'm confused. Are we talking about superstring theory, or just vibrating musical strings?

[Kael]

Been a while since I've looked at super string theory, but I am enough of a nerd that it was a topic I actively researched for a time. If I remember correctly there are 11 dimensions needed to make the math jive with super string theory. Think of the vibrating loops as closed coils that oscillate at a particular frequency. Not just in the 3 dimensions that we are easily aware of, but in all 11. The difference between a closed string and an open string vibrating should be to difficult to concieve. After all, it isn't like the open strings are stretched between two fixed points and vibrating. They are floating around vibrating just like the loops.

Check out the book "The Elegant Universe" for a pretty layman friendly take on the theory. It is a few years old now, so there are probably updates to the theory that aren't included in it, but it is a good primer for the average joe.

[fdeck]

AFAIK the one thing that string theories have not yet produced is an experimental prediction.

[Kael]

Originally Posted by fdeck

AFAIK the one thing that string theories have not yet produced is an experimental prediction.

+1, although in it's defense, the things that are predicted by string theory are very, very difficult to find as they are really ehf'in small. There are a LOT of people currently looking for real world evidence to support string theory because it makes so many problems in physics work out.

Till it is verified all it is is a pretty theory though.