Ive been reading lately about the Planck constant and have been trying to learn more about it if possible. The way I understand it, the constant came about from experiments with black body radiation. Planck noticed that the experimental data fit the equation e=hf. My first question: how did he come up with the equation? My second question: why did this equation imply that light came in packets, or quanta? This is the one I have been wondering about the most. I know that einsteins work on the photoelectric effect pretty clearly shows that light is made up of "packets" or "chunks" called photons. However, is planck's work on black body radiation enough to make the conclusion that light is quantized on its own? As always, thanks so much for your explanations. PF has really taught me a ton about physics that I don't think i could have learned anywhere else.