Wot? Be more specific, please.
Darkness is simply the absence of light. Light is the propagation of "wavicles" called photons (the quantum particle comprising light) through space, which travel at the speed of light, or c, at certain wavelengths, which are visible to the human eye. The higher the concentration of photons, the brighter the light. This is part of Einsteinian physics.
Why is this question on here if it has NOTHING to do with Trek?