Lorentz explained the physics

A reader refers to Einstein historians Isaacson and Holton, and writes:

Lorentz, for example, simply used the equations found in Special Relativity purely as a mathematical formulation with no actual physical reference.

Just read Lorentz's 1895 paper where he explicitly uses those equations to explain the Michelson-Morley experiment (MMX) and other experiments.

The consensus of physics textbooks is that the MMX was the crucial experiment for special relativity. Those Einstein historians say that Einstein was not influenced by the MMX and may not have even known about it.

When Lorentz, Poincare, and Minkowski argued for the correctness of the Lorentz transformations, they all cited the MMX. When Einstein wrote his first paper on the subject in 1905, he did not specifically mention the MMX. Einstein did write a 1909 survey paper where he credited Lorentz with using the Lorentz transformations to explain MMX.

Thus Lorentz's special relativity was certainly not a purely mathematical formulation with no actual physical reference. He explained the physics much better than Einstein, and did it 10 years earlier. Among those who credit Einstein, it is largely for giving an alternative mathematical derivation of the Lorentz transformation, and avoiding the physics.

Those who credit Einstein must somehow explain the undisputed fact that Lorentz and Poincare had published all the equations for special relativity before Einstein. So they make silly arguments about how Lorentz and Poincare did not understand what they were doing, or that "Lorentz and Einstein were great friends", or that anyone who does not recognize that "Einstein is the greatest mind of the 20th century" must be "some kind of neo-nazi or anti-semite".

The reader asks:

Can you even explain how GR predicts blackholes, and why? Do you even understand the theory?

Einstein is the one who did not. The Wikipedia article on black hole explains:

Considering the exotic nature of black holes, it may be natural to question if such bizarre objects could exist in nature or to suggest that they are merely pathological solutions to Einstein's equations. Einstein himself wrongly thought that black holes would not form, because he held that the angular momentum of collapsing particles would stabilize their motion at some radius.[70] This led the general relativity community to dismiss all results to the contrary for many years. However, a minority of relativists continued to contend that black holes were physical objects,[71] and by the end of the 1960s, they had persuaded the majority of researchers in the field that there is no obstacle to forming an event horizon.

Einstein was famously wrong about the big bang and gravity waves, the other big consequences of general relativity.

The reader also writes:

Planck wrote (and there are many sources for this info) that he did NOT believe that light was truly a particle! I give up.

That is correct. I said:

Planck's view is closer to the modern view that light is quantized when absorbed or emitted (ie, observed), but has wave properties otherwise.

It was proved in 1801 that light was not truly a particle, and that has been the dominant view ever since. If it were truly a particle then it would have localized position and momentum, and quantum mechanics teaches that is impossible.

I realize that A. Douglas Stone is an expert on lasers and surely understands this, but he is not correct in the way that he promotes Einstein.