Why so Difficult to Discuss Special Relativity with Physicists?

I fooled you. 

The attempted discussion with Swedish media physicist Ulf Danielson illustrates the difficulties met when trying to discuss aspects of the special theory of relativity SR with physicists, who must defend SR by all means to keep their academic jobs. The difficulties arise because, in a tradition mastered by Einstein, it is never clear what the premises are. In particular, there are several forms of SR:

• SR = consequences of the two postulates of SR. (1. Laws of physics must take the same form in all inertial systems. 2. Measurements of the speed of light must give the same result in all inertial systems).
• SR+ = SR + some physics.
• SR++ = SR+ + some more physics.

The postulates of SR have the form of stipulations without concrete physical content and the Lorentz transformation derived from the postulates is a coordinate transformation between inertial systems, which as such has no concrete physical content. Postulate 1 says that laws of physics must take the same form in all inertial systems, that is they must be Lorentz invariant. SR is thus empty of real physics as a specific coordinate transformation, which has no truth value as being the result of stipulations without concrete physics. Einstein's used the term Postulate to signify that SR is based on stipulations without truth value and not propositions about physics, which may be true or false. Since Postulates 1 and 2 are not contradictory, a physicist can argue that SR is not contradictory.

On the other hand, one can argue that Postulates 2  is a consequence of Postulate 1 and as such redundant, but not contradictory. 

SR+ = SR + Maxwell's equation for electromagnetic waves in a vacuum can be argued to be correct physics because Maxwell's equations for vacuum describe physics and are Lorentz invariant. But SR does not add anything to such a picture and can then as well be discarded.

SR+ with physics in the form of clocks and traveling symmetric twins with unsymmetric ageing leads to a paradox, which is "resolved" by adding some more physics like one twin staying at rest at home and the other traveling undergoing acceleration and retardation into a S++ with unsymmetric ageing seemingly without paradox. 

In this way SR+ can be just anything and as such can be twisted to fit with observations with the message that SR+ has experimental support including the postulates of SR, which in fact are stipulations beyond experimental verification. By adding some physics some experimental support can be constructed, but the role of SR itself is then unclear since the support concerns the added physics.

A physicist can thus ague that SR in basic form contains no contradiction, and in suitable SR+ form has experimental support. The message is that SR is a theory without contradiction, which has massive experimental support. It could not be better. With this message the physicist can keep his job.

But there is one form of SR+ which shows to be incompatible with experiments, and that is SR+ = SR+gravitation, which was the dream Einstein had to abandon as soon as SR was confronted with the reality of gravitational forces. A desperate Einstein tried to save his scientific life by cooking up a form of SR including gravitation, by effectively reducing to SR without gravitation by sweeping gravitational forces/acceleration away into geometry, named general relativity. Einstein thus gave up the basic stipulation of SR of Lorentz invariance to keep his job. The question is why today physicists have to in public confess to the sermon of Lorentz invariance to keep their jobs: When laws of gravitation are not Lorentz invariant. When Schrödinger's equation of quantum mechanics is not Lorentz invariant. When the equations describing the mechanics of solids and fluids are not Lorentz invariant. When Maxwell's equations with charges are not Lorentz invariant. Why cling to Lorentz invariance when doing so misses the whole cake? 

Summary: SR + Maxwell in vacuum is fine, but here SR has no role since Maxwell in vacuum carries itself. SR + gravitation does not work. The net result is that SR can be put into the wastebin of thought experiments without physics, and when that is done a step forward can be taken. Too long has physics been forced into a straitjacket of Lorentz invariance invented by the young ambitious Einstein from which the mature Einstein managed to escape but not his followers.