The Math of GR
Part 2
In 1905, Albert Einstein published his Special Theory of Relativity (SR). In 1907, Minkowski published his geometric interpretation of SR.
https://arxiv.org/ftp/physics/papers/0703/0703002.pdf
The Red Pill on Minkowski's theory is this:
The observers in Minkowski Space, if they existed there, would not be in motion relative to each other. All observers actually all exist at the same point in Minkowski Space and never move relative to each other. If you do not believe me, just look at the Minkowski space diagram.
But is this really what's going on? SR is applied to observers in relative MOTION, and they are only in the same place at time T = 0.
To interpret it, you need to know how an "Observer" is described in Physics.
Next
Proving the Relativistic Energy-Momentum relation, the hard way and the easier way.
This adds the proof for the relativistic mass effects from motion, proving that gravity causes it.