You may or may not know that if you heat up a lighter flint till it is red hot, then throw it against a wall, it goes up in a flash of sparks.

I've been thinking about this and wondering why. Any bright ideas?

If flint could burn I would say that it broke and the surface area increased a shit-ton, but it doesn't as far as I know...

how do u heat it up that much

1)blowtorch
2)lighter "flints" are actually mischmetal: http://en.wikipedia.org/wiki/Mischmetal it burns readily
3)the reason it makes a lot of sparks is because you are smashing off lots of little pieces of mischmetal and they are burning because they are hot enough to do so.
4)some guys in BB have made flash powder out of mischmetal before. It's highly dangerous, of course, because it's so damn easy to ignite