jado said:
what is matter made of?
...
if you are serious about asking then you should follow the QG scene because several possibilities are being studied.
the most recent conference was July 2008
http://echo.maths.nottingham.ac.uk/qg/wiki/index.php/QGsquared-slides
go down to where you see YIDUN WAN
on Monday, parallel session in C19.
Yidun Wan has found that the networks describing the quantum state of geometry
can have some tangles in them which behave as if they are fundamental particles
in other words, matter is complications in the universe's geometry-----local snarls tangles braids knots crisscrossings whatever.
And Yidun Wan has found analogs of the P, C, AND T transformations----parity, charge, and time reversal. so these topological quirks in the geometry are behaving under P, C, and T reversals the way that they should be. Also two quirks can get together and form a third quirk---they can interact====as you would expect twists, braids, knots whatever to interact.
OK so that is one idea of how microscopic geometry could give rise to matter. Matter could just be manifestations of geometry at micro level.
And that might easily be WRONG. But if you are interested you should follow what the various QG (quantum gravity) approaches are coming up with these days. It is a lively area of research.
Yidun Wan has some 3 or more papers out about it, besides the recent conference talk.
And there are other people offering other ideas.