Mach's Principle Dissected
In the development of General Relativity, Einstein’s vision of the cosmos, he considered what is known as Mach’s Principle. Einstein preferred to consider only the relative motions between material bodies without any consideration of an absolute background reference frame. I have named this the space denial philosophy, and it works very well for translational or linear motion. However, there is a single preferred rest reference frame for rotational or circular motion, that stubbornly stood between Einstein and his goal of the banishment of space altogether.