String theory

[H2O]

What is String theory?

 

plz. reply:rolleyes:

[alan2here]

http://www.scienceforums.net/forum/showthread.php?t=23706

 

Go find the ones on quantum physics

Im afraid it won't explane string theroy but it will give you some

background info on such stuff.

 

I too would like an explonation of string theroy.

[Cyanide]

http://superstringtheory.com/basics/basic4a.html

There also have been numerous tv specials (on discovery I believe), so I'm sure you could visit their site and dig them up.

[ironizer]

I was thinking of the "string cheese theory"

 

it was mentioned in one of Brian Regan's comedy things... heck of funny, should watch it.

[alan2here]

There something that explains the concept without

ing

[Gypsy Cake]

What is String theory?

 

plz. reply:rolleyes:

 

Basically string theory is seen as an even more fundamental level to matter than the particles we know and love. Leptons, quarks. Even these smallest particles we know, and have with many of them been detected in some way, are (according to string theory) made up of loops that exist in multi-dimensions. The loops vibrate at different resonances which I think is supposed to determine the properties of the matter it exists in. I don't know but I think the loops might possibly be in non-matter as well ie. forces, dark matter, dark energy.

{I'm pretty sure most of what I've said up to this point is part of the theory}

 

Now then, string theory is being developed as a way of combining all the fundamental forces. It is still very in the early stages; but I think the scientific community is considering it. The problem is it's very hard to study. One, it's unbelievably small [understatement]. And two, we can only see in three dimensions when these loops are said to possibly reach 10 dimensions.

 

This knowledge will get you up to pretty much everything I know about it. If you want to know more there are a few books in the library about it.

 

Hope that was of some help.

[Severian]

It is still very in the early stages; but I think the scientific community is considering it. The problem is it's very hard to study.

 

Considering that it has been studied now for about 30 years, one would be forgiven for thinking that we should be beyond the early stages. The real problem with string theory is that it makes no predictions.

[Gypsy Cake]

Fair enough. Accepted, I didn't realise it'd been studied for so long, though I do believe they haven't got much closer to a proof in that time,

 

May I ask, naively, what sort of predictions string theory needs to make to progress?

[Severian]

The most obvious thing would be to predict the masses of the known particles. Of course, this would really be a 'postdiction' rather than a prediction, but it would be a start.

 

Usually String Theory also contains supersymmetry. So a prediction of the supersymmetry breaking scale would be nice. While we are at it, they could provide a mechanism for supersymmetry breaking which allows us to calculate their masses. This would then be a genuine prediction.

 

Or how about the Higgs boson mass...?

 

The real reason that they don't do this is because they can basically get any answer they please. More recently there has been a suggestion that there are 10¹⁵⁰⁰ different string theory vacua, each of which contains different low energy physics. Certain string theorists suggest that the only way of choosing one over the other is to apply the Anthropic Principle. If that is true, then it is not science.