# Einstein's theory of relativity

#### greygrid19

Hello, I have a question about a possible revision of Einstein's theory of relativity. The fact is that its root error is indicated by the fact that at the initial moment of time, that is, when all three coordinates of the two systems coincide, we mistakenly decided at some point in time to take the speed as constant c instead of the variable dc, we got that at an infinitely small point in time, a constant final velocity was recorded — obviously, this does not happen. Therefore, when I typed the following expression in wolfram mathematica: {d (x ^ 2) + d (y ^ 2) + d (z ^ 2) == (dk) ^ 2 * (dt) ^ 2, d (w ^ 2 ) + d (y ^ 2) + d (z ^ 2) == (dk) ^ 2 * (df) ^ 2}, he in one of the solutions gave an answer that is quite suitable for the context of the problem in understanding the absolute time (with the Reduce command ) Please explain if it is possible in simple terms, do I have the right to such an interpretation as one of the interpretations, and maybe, if my reasoning is correct, I will incorrectly interpret the theory of relativity itself — but if it’s incorrect, how should I interpret it? Thank you very much!

#### studiot

we mistakenly decided at some point in time to take the speed as constant c instead of the variable dc, we got that at an infinitely small point in time, a constant final velocity was recorded
Perhaps if you were to rephrase this we might be able understand what you mean.

c is the speed of light at all times and all places (coordinates) in Special Relativity.

• topsquark

#### greygrid19

but the speed of light does not instantly apply — it also takes some time to travel a constant path c, but we must take into account that both systems move relative to each other with a velocity v less than c (modulo), and Einstein’s theory of relativity assumes instantaneous perception of the final signal c when all coordinates coincide, that is, for an infinitely small period of time.

#### topsquark

Forum Staff
but the speed of light does not instantly apply — it also takes some time to travel a constant path c, but we must take into account that both systems move relative to each other with a velocity v less than c (modulo), and Einstein’s theory of relativity assumes instantaneous perception of the final signal c when all coordinates coincide, that is, for an infinitely small period of time.
We usually choose the coordinate systems to coincide at t = 0, so you don't need to think about the time that way, much less anything instantaneous. That c is a constant has been measured and is one of the initial assumptions to derive the Lorentz transformation so it doesn't matter where or when or how you measure c.

-Dan

#### studiot

I'm sorry that is even less clear than before.

In the first post you said c is a speed.
Now you say it is a path.

• topsquark

#### Woody

• 