In this question, Orbicular made the following comment to Feb7 and my own answers;

Please keep in mind that - even though it is stated very often - noncommutative geometry does not give "real" insight to physics. The reason is that they only have toy models, all of which are unphysical (in the sense that they predict things which differ from real world measurements). Furthermore even the toy models are usually extremely complicated, killing most expectations to get a "real" model (which is not toyish).

First, I want to thank Orbicular for pointing this out, as it is something that I 'kinda' knew, but often forget. The purpose of *this* question, is to ask for a deeper explanation, either from Orbicular or someone else. In particular

to what degree does Quantum Algebra, Non-commutative Geometry, Representation Theory, and Algebraic Geometry influence/assist 'real' models and actual physics related to the physical world?

I don't wish for this question to turn into a debate about whether or not these maths will later be applied in some beautiful stringy-quantum-symmetry theory; I would much rather it be some explanation of the real use of these things. Specifically, I am interested in hearing about the use of Quantum Groups and their representations to Physicists along with some thoughts on the actual usefulness of the results in NC Algebraic Geometry of those articles I posted over here. Another particularly interesting subject I would like to hear about is the usefulness of commutative algebraic geometry in physics.

## Some things I have found

Just two references that I have found that at least address these things to some degree are Peter Woit's lecture notes on Representation Theory, and in Shawn Majid's book on Quantum Groups he discusses some definite physical motivation for studying quantum groups.

Thanks!

per seis ubiquitous in physics and chemistry. They usually abusively call it "group theory". See mathoverflow.net/questions/11784/… for starters. $\endgroup$ – Steve Huntsman Feb 8 '10 at 20:119more comments