Hi guys!

 

From what I understand about the string theory:

It is a theory that is trying to unifry the four fundamental forces of nature (electromagnetism, gravity, the weak force, and the strong force).

 

The string theory tries to create a set of master equations that will unifry all those four forces.

 

My question is, what will the equations actually tell us? What will they calculate?

Ahhh... just the type of question I wanted (I just did a presentation on this today, so its fresh in my mind )

 

Alright, back on topic.

 

Basically, at the time of Einsteins death, there were two theories that described our universe, General Relativity, which dealt with super-massive things, and Quantum Theory, which dealt with things on the sub-atomic level. Problem was, they conflicted with each other. Since they were both supposed to explain the SAME universe (ours), they should not have conflicted. Thats where string theory comes in. It attempts to reconcile the two, and provide a set of eqauations that provide the reasons for anything and everything happening in the universe at any given time... and hopefully that will allow us to predict what happens when the two theories (gen. rel. and Quantum) need to be used simulataneously, such as at the center of a black hole, or at the beginning of our universe, split-seconds before and after the big bang. It could tell us how we came to be here, and how and why our universe developed how it did.

Basically' date=' at the time of Einsteins death, there were two theories that described our universe, General Relativity, which dealt with super-massive things, and Quantum Theory, which dealt with things on the sub-atomic level. Problem was, they conflicted with each other. Since they were both supposed to explain the SAME universe (ours), they should not have conflicted. Thats where string theory comes in. It attempts to reconcile the two, and provide a set of eqauations that provide the reasons for anything and everything happening in the universe at any given time... and hopefully that will allow us to predict what happens when the two theories (gen. rel. and Quantum) need to be used simulataneously, such as at the center of a black hole, or at the beginning of our universe, split-seconds before and after the big bang. It could tell us how we came to be here, and how and why our universe developed how it did.[/quote']

 

A great descriptio there LazerFazer! I'd just like to add this: search these forums and you'll find loads of threads about String Theory and maybe these links will interest you.

 

http://en.wikipedia.org/wiki/String_Theory

http://www.pbs.org/wgbh/nova/elegant/

 

Cheers,

 

Ryan Jones

Thanks alot for that guys!

 

By the way, you know the PBS.org website you gave me? We watched the whole set of Elegant Universe videos at school, which was pretty cool!

Have you actually read The Elegant Universe? It provides some interesting insight into string theory, why it came about, how it came about, and what evidence we have to 'proove' it.

 

It's usefull if you want a more indepth understanding of string theory, as the PBS/Nova series leaves out a significant amount of material to make it more understandable for the masses.

 

cheers,

LazerFazer

Thanks for the clearance! I was wondering what "strong force" and "weak force" are though?

The strong nuclear force holds quarks together, the weak nuclear force holds nucleons (protons and neutrons) together. The weak force is actually just a less direct effect of the strong force, though.

Thanks for the clearance! I was wondering what "strong force" and "weak force" are though?

They are two of the four fundamental forces in physics (I think I´d prefer the term "intercations"). As usual for such a rather broad question, wikipedia is a good start: http://en.wikipedia.org/wiki/Fundamental_force.

The weak force is actually just a less direct effect of the strong force, though.

Can you explain what you mean by that? It doesn´t sound as if it´s correct.

The strong nuclear force holds quarks together, the weak nuclear force holds nucleons (protons and neutrons) together. The weak force is actually just a less direct effect of the strong force, though.

 

The weak force changes quark identities by exchanging a W or Z. I don't think it has anything to do with nuclear attraction. The strong force doesn't act on leptons, so I don't see how the weak force can be characterized as a "less direct effect if the strong force." I echo Atheist's call for clarification.

Have you actually read The Elegant Universe? It provides some interesting insight into string theory' date=' why it came about, how it came about, and what evidence we have to 'proove' it.

 

It's usefull if you want a more indepth understanding of string theory, as the PBS/Nova series leaves out a significant amount of material to make it more understandable for the masses.

 

cheers,

LazerFazer[/quote']

 

Actaully, I haven't. I've only watched the series. But, if you think its a good read, then, I'll try and get hold of the book!

Can you explain what you mean by that? It doesn´t sound as if it´s correct.

The weak force changes quark identities by exchanging a W or Z. I don't think it has anything to do with nuclear attraction. The strong force doesn't act on leptons' date=' so I don't see how the weak force can be characterized as a "less direct effect if the strong force." I echo Atheist's call for clarification.[/quote']Ah, I'm wrong, then, sorry about that.

 

I thought the weak nuclear force just referred to the attraction between individual quarks in neighbouring nucleons.

I thought the weak nuclear force just referred to the attraction between individual quarks in neighbouring nucleons.

 

To be technical, the "strong force" is really the residual force left over between the colorless hadrons (analagous to the Van der Walls force between nuetral molecules, which is a residual of the electromagnetic force). The fundamental force between quarks and gluons is really the "color force" or more properly Quantum ChromoDynamics (QCD).

 

The weak force has nothing to do with the strong force.

Which book of the elegant universe do you recommend?

 

I did a search on Amazon, and two books came up:

*The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory

*The Elegant Universe

So what exactly is the conflict between relativity and quatum theories? Where do they disagree?

Hehe.. although not an answer to my question:

Relativity deals with massive objects, and its equations work fine with it

Quantum physics deals with extremely tiny particles, like atoms and subatomic particles.

 

They start to falll apart when dealing with objects like black holes. Which one should scientists use? Relativity because a black hole is extremely massive, or quantum physics, because the black hole is extremely small? Whichever one is used, the values that come out is non-sensical, and that is where they collapse.

@aommaster

 

Not sure what the full title is... but its by Brian Greene.

 

As for the falling apart of QM and GR, I was under the impression that it's when you use BOTH together that you get nonsense values. Such as infinite probabilities, and things like that. And yes, combining the two would be required in the case of a black hole, which is both massive (gravitationally) and miniscule (spatially).

 

LF

About the books....that is the problem. BOTH of the books are by Brian Greene! And both seem related to what I want. Which one is it?