String Theory
 

What do you guys know about string theory?

Re: String Theory
 

Well, the details really don't matter if you don't have some background. String theory is an outgrowth of the long quest in physics to unify the forces of nature (and as you should know, there are four of them). Unifying forces means to write down a single model that describes two or more forces, thus showing that forces which we thought were different from one another are actually parts of a single, unified force. For example, the force of Electromagnetism and the Weak Force are unified in Electroweak Theory, which was written down in the 1960s (I think). So the deal is that we can unify three of the forces : E.M., Weak, and Strong Forces. But unifying Gravitaion in to this structure is difficult. String theory is an attempt to do that. So far, we don't have enough of the theory to make any experimental tests.

For more, I suggest "The Universe in a Nutshell" By Hawking and "The Elegant Universe" By B. Greene

My math prof. last semester specialized in Topology, so now he's a string theorist. He'd drop comments and such in class all the time, but I've not quite progressed to unified field theories yet...

Re: String Theory
 

I know that its about how tiny little string are what compose the world.
I also know that it tries to combine Modern Physics of big objects and physics on a molecular scale.
It also requires many many dimensions in order to work.
And if you actually look at it, it is really a bunch of garbage.

Re: String Theory
 

Try checking your library or movie store to see if they have PBS's The Elegant Universe. It's hosted by Brian Greene who wrote the book and it's really very interesting and has probably just the right amount of detail that one could still comprehend. I've watched it twice already, I highly recommend it.

Re: String Theory
 

Is that one of those Nova films?

Re: String Theory
 

The actual show is online here.
http://www.pbs.org/wgbh/nova/elegant/
Not necessarily. It might be true. It might not be true. That is the mystery of string theory. There is no way of testing it.

Re: String Theory
 

String theory is where the lines of physics become blurred. The real debate is whether it can actually be called a "Theory," because we have no way of testing whether it is true. When you can't construct an experiment that would falisify once and for all your theory, it isn't science, or so goes the thinking of Karl Popper. I really wouldn't worry about it, as it isn't likely to play into an engineer's life to often, but if theoretical physics is your game, this is where its at. My physics teacher maintains that "string theorists" are really nothing more than philosophers, which, if you want to be pedantic about it, is true.

Re: String Theory
 

You can actually watch all three hours of Nova's presentation of B. Green's "Elegant Universe" online at:
http://www.pbs.org/wgbh/nova/elegant/program_t.html
I added it to my bookmarks. :rolleyes: :p

Re: String Theory
 

I think this would have been an acceptable answer to your question.

http://www.google.com/search?q=string+theory

Re: String Theory
 

I saw that. I even had to write a paper about it. Because it was so out there and the nova show explained it so well, I used many of the analgies and paraphrased it. I told my teacher that I did (she had seen the episode eariler) and she said that was a good idea. She also lent me the book. But I didn't get far in the book.

The whole idea of string theory is very crazy and I don't follow much of what they are doing with it, even in the nova episode. But it makes some sence in a strange, head exploding way. But I only know much about it because it is so weird, I like it. Does it's findings, what it could mean change how I do anything, no, but it is fun to try and wrap your brain around n-dimentional branes.

Re: String Theory
 

Thus lies the problem, science is based upon and DEPENDENT on constant trials and tests to prove something is right. If you cannot test something, and just believe in it using reasoning skills, you now have philosophy not physics. Thus, it shouldn't be called a theory. Theory is a set of statements that are devised to explain a group of facts or phenomenons, and those that have been tested (from dictionary.com).

NOW, I DO believe in string theory, and I love it, but I think we need to take a step back and look at what really classifies as science (gravity & evolution) and a theory and what isn't. (i.e. creationism & intelligent design).

Re: String Theory
 

We just can't test it, yet. There was a time we thought it would be impossible to discover evidence of black holes and gravitational waves but technology is leading the way taking measurements and observations of these phenomena. Perhaps some day soon, Hawking radiation will also be discovered. Only time will tell (silly drumbeat - indicating a lame pun)

Re: String Theory
 

In my texbooks, science is defined as what is observable, measurable, recordable, and repeatable. Gravity falls uder this, but evolution, creationism, and intelligent design do not. For those last three, we only observe the effects of whichever one is true. (Have you observed any evolution recently? If so, tell the world. Of course, I haven't actually observed either of the others. Actually, microevolution-change within a species-has been proven. It's called selective breeding. And please don't flame me, but macroevolution-changing from one species to another-is unproven and unlikely.) So far as I know, string theory is not recorded, measured, or observed, so according to the definition of science I am using here, it is not science. It may be science according to another definition, but I don't know what that definition is.

Re: String Theory
 

The existence of additional tiny curled-up dimensions of space is predicted to have measureable effects at really really short distances. There have already been experimental observations which provide an upper bound on the "size" of those dimensions if they exist. So current string theory is testable, and definitely counts as science.

Re: String Theory
 

As discussed before, string theory is based on the unifying of the four fundamental forces of nature (this is through Theory of Relativity and Quantum Physics);gravity, electromagnetism, weak force, and strong force. Currently weak force and electromagnetism have been linked. Mathematicians and scientists are currently working to unify the Strong Force and Electroweak Force. My understanding is that they are very close to completing work proving the combonation of the two forces. The biggest challenge lies in the unification of gravity. Gravity has a very small effect on atoms and even smaller the corks that make up atoms. Currently (if what I've read is true), we do not have the technology to make measurements on gravity at such a small size; thus not allowing us to make any physical test for observation. Is this a theory? Yes because nothing is proven but the idea is out there kicking around and not completed. Is it a law of science yet? No, we don't have any proof saying that it's true and completed.

Hope this is helpful,

-Pat