Sean1218 said:
I was actually sort of wondering the same thing. How does math tell you, for example, that everything is actually made of little strings? I don't really get how you get to that conclusion.
It doesn't. At least not directly.
In most aspects, physics is a hard science. This means that claims are supported by "observation". I put "observation" in quotes, because what it actually means is "prediction". It's gotten to the point where all observations are performed so indirectly that it's almost hard to call them observations anymore (Ex: No one has
seen an electron). We accept a claim in physics only if it accurately predicts the results of experiments.
Historically, we have seen that despite all its complexity, the physical world is predictable enough to be modeled by mathematics. Now, a mathematical model is useful in physics so far as it remains true. For most purposes Newtonian models are perfectly sufficient, but they fail at high speeds, and at small scales. A lot of the work in physics, then, is testing the limits of a theory: is it still true in this case, or in that one?
The thing is there are an
infinite number of potential ways to model the world. One potential way to explain the world is to say that some omnipotent being dictates every occurrence. However, physicists typically stick to the rule that "simpler is better". That is, if we can find a few equations from which we can predict ANY known phenomena, then that's a better explanation than a whole bunch of equations. If we can find only a few fundamental forces, then that's better than a whole bunch. If we can find only a few basic particles, then that's better than a whole bunch (although that's getting into chemistry).
[Aside: it may seem arbitrary or even unscientific to rely on the idea of "simpler is better", especially since our human preference for simplicity biases us so much towards accepting simpler explanations more readily. However, the majority of the body of work in physics has not to do with developing theories, but with testing "laws". A theory is an explanation, but a law is merely a description of the outcome of experimentation. For example, look at "F=ma". While it could be thought of as a theory, it actually represents a series of experiments which physicists have conducted over centuries. Perhaps there aren't naturally such quantities as "mass", "acceleration" and "force", but even still the measured outcomes experimentally fit exactly with the equation, and so we call it a law. In this sense, whether or not we represent our experimental data as a giant chart with the results and conditions of all experiments or just as a simple equation, the basis of physics is entirely scientific. In other words, physics is always asking "How?", but it rests on the scientific foundation of "What Happens?"]
So, physicists are trying to find a single, simple model that explains all known phenomena. String theory is that attempt. Different physicists/mathematicians have been trying to find mathematical models which accurately predict all known phenomenon. The idea is that once a model checks out mathematically (by which I mean that all known laws can be derived from it), then we will try to go about testing it by trying to reproduce a phenomenon yet to be observed which the model predicts ought to be possible.
If a new model accurately predicts all known phenomena and more, then it is accepted as being the best explanation as to how things work. However, physics never actually scientifically proves that there ARE tiny little strings. It can't even prove that there are such things as atoms! It can't even prove there is such thing as "matter" in our usual conception! All it proves (or is trying to prove) is that if we imagine that there are little strings that behave a certain way, then we can predict phenomena.
