On 11 mai, 13:30, "Jacques" wrote:
Dear David,

"N:dlzc D:aol T:com (dlzc)" schrieb im ...

Then let c = 1. There are units systems where that is true.

I have no problems to understand that. The consequence of it is E=m, meaning
that double mass contains double energy and half of the mass contains half
of the energy. What puzzles me is that you can multiply the mass in kg by
the square of the speed of light in m/s and you obtain exacltly the energy
in joule. How is this possible? If it is not a mere coincidence, which it is
not likely to be, how is it possible? What is the explanation of this
extraordinary fact?

I hope you understand my question.

Thanks
Jacques

The answer to this is simple.

kg simply is a complex combination of other dimensions

kg = (J s^2) / m^2

since the dimensions of the speed of light are m / s
then the dimensions of c^2 are m^2 / s^2

Now let's look at the dimensions of the equation

E = m c^2

J = ( (J s^2) / m^2 ) * m^2 / s^2

If you simplify

J = J

André Michaud