Here's another theory of mine. Let's imagine a molecule, it's atoms are held together by the electrostatic force of attraction. Now if you were to strike a match, you remove a few atoms from the whole substance. This results in the liberation of the electrostatic force that bounded the two atoms, now this force acts on the neigbouring molecules and releases those atoms as well, this also affects the oxygen molecule (O2) in the atmosphere, which seperate to liberate more electrostatic force. This process continues, and this process is heat. Now, we observe that a hot body only can emit light. And i suggest that this heat liberated is the that we see from it. This i suppose would explain all the things that light is supposed to explain, photoelectric effect, the double slit experiment. If i have made some stupid mistake somewhere, please tell me. Or for any doubts or views you may hold in "light" of this. (forgive the pun). Let me know.