Where do cavemen fit in the theory of Creationism?

[Didasko]

I already answered the bit about darkness, but reading this, another subject occurs to me: how could God create matter and light at separate time periods even though they are both different forms of the same thing (E=mcc)? I certainly don't know.

Quite simply. There is a lot of matter that does not give off light. Special circumstances must be present to change it to light.