Help me understand String Theory

I'm not a theoretical mathematician or a physicist, so please don’t bash me for not knowing some fundamental concepts.
I watched a few hours of programs last night regarding string theory. I don’t need to understand the math behind it, but I do want to know more about the “extra dimensions”. From what I saw and from what I’ve read, the extra dimensions are simply included just to make the math work. Is that right?

This is from another site.

physics.about.com...
As with much of quantum physics, the mathematics that applies to string theory cannot be uniquely solved. Physicists must apply perturbation theory to obtain a series of approximated solutions. Such solutions, of course, include assumptions which may or may not be true.

Does that mean that a large amount of the theory is just made up to make the mechanics work?

Sounds like math by faith to me.

Back to the extra dimensions. Are we operating in the other dimensions or are we only operating in the 3 dimensions (4th being time, I suppose)?
I don’t get it.

Thanks.



Please include links to Externally Quoted material, when possible.

[edit on Sun Jan 25 2009 by Jbird]

Let’s begin. I will post a 3 part series by PBS which discusses the sciences that will be involved and it shows in a simple way how they answer your question.

To get the basics down and I know most won’t get a full understanding of what needs to be known by a post here at ATS and a few Youtube videos but we will try to answer some of the issues you and many others have posted. First we need to understand a couple of things, Quantum Mechanics and the String theory.



Quantum Mechanics

The other exemplar that led to quantum mechanics was the study of electromagnetic waves such as light. When it was found in 1900 by Max Planck that the energy of waves could be described as consisting of small packets or quanta, Albert Einstein exploited this idea to show that an electromagnetic wave such as light could be described by a particle called the photon with a discrete energy dependent on its frequency. This led to a theory of unity between subatomic particles and electromagnetic waves called wave–particle duality in which particles and waves were neither one nor the other, but had certain properties of both. While quantum mechanics describes the world of the very small, it also is needed to explain certain “macroscopic quantum systems” such as superconductors and superfluids.

String theory

String theory is of interest to many physicists because of the mathematical consistency involved and because of the large number of forms that the theories can take. String theory strongly suggests that spacetime has eleven dimensions,[1] as opposed to the usual three space and one time, but the theory can easily describe universes with four observable spacetime dimensions as well.

I know these are a little over the top, but enjoy.

Google Video Link

Google Video Link

Google Video Link

Definitive Back Engineered Alien Technology Research thread





[edit on 23-1-2009 by SLAYER69]

Well. I've seen the Elegant Universe program and I just watched two hours of an updated Stephen Hawking special...but they don't answer the question for me.

The question restated.

Are the extra dimensions used in String Theory just made up to make the math work?

It's very much to me like making a equation to explain God where God is a starting assumption. God is because God is.

Hmm, well I guess it's "made up" in a way. Since we acknowledge phenomena as real when observed and described through math, this theory however lacks the observed part I think. How can we observe something when we don't know where to look? Maybe we see it / are affected by it everyday but don't understand the dynamics. The math says it's just there, the dimensions. I guess we could call them bi-products of the math involved, since they are in a way "made up" to make things work. Maybe it's not been ruled out since it can't be disproven either? Haha, I have in no way studied this directly so this is just "layman" thoughts. I'll study this deeper later on, just have to complete a current project.

Originally posted by WickettheRabbit
Well. I've seen the Elegant Universe program and I just watched two hours of an updated Stephen Hawking special...but they don't answer the question for me.

Like has been stated in many papers and documentaries they have it as a theory and are at present unable to test the theory.

Staven Hawken as great as he is, is a relative newcomer to string theory.

That is the question isnt it.

watch the animation in this link, it might help you,

tenthdimension.com...

reply to post by SLAYER69


I would go that far to correct you in saying that the String Theory is a speculation. It will become a theory in the moment when we can find evidence for it .

I'd say that what happens in the other dimensions are math. Only a certain combination of those have effects that can be experienced in space time. Now even if those dimensions can't be experienced in space time does not mean they don't exist, but we just don't have any way to prove so outside solid concrete experience. I guess that makes string theory undeniable and unprovable, unless we can find a concrete use of the predictions made by this particular model which would make it more "real".

Originally posted by sty
reply to post by SLAYER69

 

I would go that far to correct you in saying that the String Theory is a speculation. It will become a theory in the moment when we can find evidence for it .

They go into great detail in that video over if it's a theory or philosphy
Great question

To me, if some equation is being solved, the string theory
solution is what in calculus is called a series solution.

They teach calculus in high school to advanced students but
I doubt the series approach is introduced although the look
at function series forms are given.

As near as I can figure it's something like this:

While you can't see the wind, you can see the effect it has upon the grass and trees. You can deduce things like density, velocity and direction from those effects.

String theory represents the closest approach yet to describing and accounting for the effects we see at the quantum level of the real world (if that isn't a contradiction of terms I don't know what is, lol). The extra dimensions are inferred in the same manner we infer the characteristics of the fluid motion we call wind. What is known for sure is that there is more to the universe than meets the eye, and string theory allows us to think about it in productive ways.

reply to post by WickettheRabbit

From what I saw and from what I’ve read, the extra dimensions are simply included just to make the math work. Is that right?

Are we operating in the other dimensions or are we only operating in the 3 dimensions (4th being time, I suppose)?

It seems nobody else is willing to give you a straight answer, so I shall.

Yes, the extra dimensions are simply included to make the maths work - specifically, to make the equations show values for certain physical quantities that we know they have through real-world observation.

We exist in all dimensions, but the remaining seven dimensions are so curled-up and miniscule we don't experience them (as far as we know).

Something else you should know is that 'string theory' is actually a family of theories, each of which describes a different universe put together in a different way. One of them may correspond to the reality we know. The rest correspond to realities we do not know. We have no reason whatsoever to believe such realities exist. They are by-products of the attempt by string theorists to make their theories fit the real world.

It has been theoretically computed that there are some 10^500 string theories (that's one followed by five hundred zeroes) so you can find one to describe pretty much any universe you can think of.

That is why a great many highly respectable physicists, Nobel prizewinners included, are highly sceptical of string theory. In the end, it describes nothing and proves nothing. Neither can it be tested by experiment.

Frankly, string theory is not something a non-physicist needs to be thinking about - unless he's a science-fiction writer looking for plot ideas. It's wild, wooly, probably a complete crock, and in the twenty-five years that it's been flavour of the month in theoretical physics, it has made exactly zero predictions about reality.

I pronounce you free of this burden: go, and worry no more.

reply to post by Astyanax


Thank you for your straight forward approach. I appreciate it very much. That's pretty much what I thought.

Faith in math. That's all.

www.tenthdimension.com...

Click on "see the videos" and play.
Best video ever!!!!
"It's starts with a dot..."

Originally posted by WickettheRabbit
Are the extra dimensions used in String Theory just made up to make the math work?

Yes and no.... they are a predicted outcome of the theory. Astyanax gave a very nice summary and a nice explanation of some of the problems that physicists have with the theory. To date, they haven't been able to make a single good prediction (this is a key component of any scientific theory... that in order to prove it you have to come up with experiments that say "if this is true then this outcome will occur.")

This is called the "null hypothesis" and so far nothing they have done has proven it's a workable theory.

But it's fun to play with and as an idea, it was a very compelling one to mathematicians and physicists. However (as we all know) just because something is fun and compelling doesn't actually mean it's true.

[edit on 26-1-2009 by Byrd]