One of the iconic equations in science, E=mc², but it seems a tad convenient to me.
Essentially, as c is a constant, it is just E=qm where q is a constant. I.e. Energy and mass have an conversion factor that is simply a constant number.
But if we did not measure any of the units of energy, mass, distance or time in the exact units we do (and most of those are totally arbitrary units) it would be a different constant, and not exactly c²
So why is the equation so conveniently E=mc² and not E=qmc² or E=qm ?
And yes, I got an A in physics O'level, but it was a long time ago...