Recent content by Corrado Campisano

sorry, I can't believe it's so hard to understand... take ANY mono-chromatic, spherical light source, on large scale (h=0) and no gravity (G=0): let's start with "empty" and flat spacetime when you turn the light on, it "implements" a reference frame, by defining the unit(s) of space...

of course, then G=1 too Well, I opened this thread to discuss a(t) and c(t), you mentioned the distinction between "coordinate speed" and "measured speed", about which we have quite different perspectives.To me, you're taking for granted you can build a reference frame out of thin air. I...

sorry Peter, I didn't explained my point clearly.Let's work in Planks units, so c=1, ok? That way no SI, no human related units, plain "ones", ok?Pls, take a better look at the definition of meter and second, so that you realize that: - 1 unit of time proportional to the period: "second is...

hi Peter, thanks for your reply, but I'm not satisfied with this explanation.First of all, "measuring the speed of light" is quite nonsense, or tautology, given our units of measure for space and time are defined upon light speed c, by using multiples of the T and the Lambda of a reference...

Hello, I was enjoying Zee's book on GR when I noticed the location of this "a(t)" thing in the metric sound quite disturbing to me. BTW: I experience the same annoyance and went down to the same conclusions, when I watched a related Theoretical Minimum lesson...Here's the setup, the flat...