[McQueen (OP)]

Wrong post.

[Kryptid]

But c = 1 is supposedly used as a dimensionless constant, if this is the case it should always be possible to substitute the real value of c which is  m/sec into the equation and still get the same result. It turns out that this cannot be done. It cannot be done because the equation yields the square root of a negative number, this means that it is impossible to substitute the real value of the speed of light into the equation and it will always remain as c =1. This means in effect that the whole equation is a charade and has absolutely no meaning.

Let's find out if this claim is true.

We'll see what happens when we consider an object moving at 73% the speed of light. In the case where c = 1, that would make v = 0.73. The component of the equation we are interested in is v²/c², so we substitute the values to get (0.73)²/(1)². According to the order of operations, exponents are calculated before division, so (0.73)² = 0.5329 and (1)² = 1. So we end up with 0.5329/1, which is simply 0.5329.

Now we will find out what happens when we use c = 299,792,458 m/s. 73% the speed of light in this case would therefore be 218,848,494.34 m/s. Continuing the calculation, (218,848,494.34)² = 47,894,663,474,885,012.0356 and (299,792,458)² = 89,875,517,873,681,764. Now we divide 47,894,663,474,885,012.0356 by 89,875,517,873,681,764 and we get 0.5329.

It's exactly the same number.