system
Given the following post, respond as if you're commenting on Reddit:
human
Why does the conversion from energy to mass "need" the speed of light in the equation? I don't have trouble conceptualizing the necessity for some huge constant, but how the heck does light speed coincidentally fit the bill?
gpt
You seem to be hung up over why a constant of light waves appears in the energy equation of particles. But the thing is there is nothing special about lights speed itself. 

Rather, Einsteins theory special relativity, says that there is some constant 'speed limit' in which only massless particles can travel at (and that it's the same in every reference frame).

From this point of view, it's then  not really a surprise why this speed limit constant appears in our equations of motion and the energies of particles.

Basically, it's only for historical reasons we call this speed limit constant "c, the speed of light". We could just as easily call it the speed of glouns, or ludicrous speed... or whatever.