stimulus101 said:
Why is it that the constant c (speed of light in a vacuum) is measured in ARBITRARY units that the human race practically MADE UP and why is this arbitray number (300,000) used universally as a proportion by which to multiply in many equations such as e=mc^2? If an alien race created their own units they could theoretically come up with the number 2 which would really screw things up. Am I the only person on Earth who thinks this is odd?
You may be the only person on Earth who doesn't understand what it means! (No, I take that back!

)
You dont' have to conjure up an alien race to argue that way. People use both km and miles on earth. (Not to mention "yards", "meters", "furlongs", and "Li".)
How fast something is going does not depend upon what units you use to measure it. A car is going the same speed whether I say it is going at 80 km per hour or 48 miles per hour. Light has the same speed whether it is 300000 km per second or 185000 km per hour.
What "the speed of light is constant" means is completely different from that.
If two people, on the bed of a flat bed truck going past me at 50 km per hour (30 miles per hour) throw a ball back and forth, and can throw that ball at 60 km per hour (36 miles per hour) then the person catching the ball, forward of the person throwing it, will say it is moving (relative to him) at 60 km per hour while I would say it moving (relative to me) at either 110 km per hour.
Light doesn't do that. If a person passing me at 1/2 the speed of light, c/2, were to turn on a flashlight as he passed, we would
both say that the speed of light is c.