What is the density of light? I'm relatively new to Physics and very new to the forum, so please forgive any (potentially) hilarious mistakes or stupidity in my question, knowledge, and use of the thread. But really, what is the density of light? Light is a particle like anything else, and all particles have a density, so what is it? How does it impact light's interactions with matter/energy/fields? Are any of light's properties dependent on its density? Do different light particles have different densities? Any answers/insight would be greatly appreciated. Thanks for any/all replies!