Hey you guys, I am studying topology change in the superstring theory and since I do not have a good background on mathematics since I am in the tenth grade, I would like one of you people to show some mathematical examples on the operation of flop. Which I've read is a systematic procedure for changing the topology of geometrical space in a minimal manner. It involves singling out a sphere in space, continuously shrinking its volume down to zero and then blowing its volume back up in an orthogonal direction. The point at which it is zero is the singularity. The end result is a new geometrical space different from its original. And of vourse this can be applied to Klazua-Klein. Now my request is for someone here to show me some mathematical proof of this and if you know more in detail about this operation could you tell me please..

*If oyu don't feeling like typing my request up, giving me a link to a website that shows this would be fine.. thx

-STT