Post-Modern Physics without Relativistic Mass

The change from classical physics to modern physics has long been viewed to be marked by Einstein's Theory of Special Relativity SR published in 1905 coming with a fundamental revision of Newtonian mechanics introducing the new concept of relativistic mass increasing with velocity, as opposed to Newtonian invariance of mass under motion, and the mass-energy equivalence of the most famous equation in physics $E=mc^2$. 

When I discuss these topics with chatGPT I am informed that the idea of relativistic mass has been put aside as no longer relevant, in a return to the idea of classical physics that mass is invariant and so does not change under motion. That is certainly as step forward to more clarity since the concept of relativistic mass under motion coming with a concept of rest mass of bodies at rest, was $a source of endless confusion. 

What then about mass-energy equivalence $E=mc^2$? Has it also been abandoned? Here chatGPT is ambiguous:

• All forms of energy $E$ as potential, kinetic, electric, chemical and nuclear energy in principle can be traded with $m=\frac{E}{c^2}$  for some mass $m$. 
• As concerns potential, kinetic, electrical and chemical energy $E$ the corresponding mass $m$ is so small because $c^2$ is so large, that the trading does not make sense because sufficiently small coins are not available. 
• But for nuclear energy the trading is viewed to make sense because $E$ is so large that $m=\frac{E}{c^2}$ is not zero. 
• Accordingly, the nuclear fusion reaction in the Sun is viewed to result in a loss of mass about 4 million tons per second. The loss is estimated to be less than 0.1 percent after 10 billion years of burning mass. 

It appears the chatGPT still clings to $E=mc^2$ although the conviction is shaking: Mass-energy trading does in particular not make sense for chemical reactions, only possibly for nuclear reaction where an idea of loss of mass or mass defect still hangs on. 

We then ask chatGPT if there is a fundamental difference between chemical reactions supported by spatial re-configuration of electrons, and nuclear reactions supported by spatial re-configuration of nucleons? 

The answer is that the only fundamental difference is the nature of the forces involved, Coulomb force or strong force, and not $E=mc^2$. 

Quantum models of chemical reactions do not involve $E=mc^2$, because it has no role to play. Likewise, quantum models of nuclear reactions do not involve $E=mc^2$, since it has no role to play. 

So what remains is to give $E=mc^2$ a role by insisting that any $E$ computed by a quantum model without $E=mc^2$, in principle can formally be traded with some mass $m=\frac{E}{c^2}$ of unspecified nature. But this trade has no physical meaning and so is only a formality which can be viewed as the only remaining homage to Einstein, when now his relativistic mass has been put into the dust bin of meaningless physical concepts including phlogistons. 

It may be time to now let it be joined by $E=mc^2$. This would open to a clarification of the concept of energy as basically connected to work as force times displacement, then appearing in the form of kinetic energy, mechanical energy, friction energy, potential energy, electrical energy and chemical/nuclear energy connecting to inertial force, friction force, elastic force, gravitational force and Coulomb force.

This would essentially mean to give up SR and returns to rational physics. If you still want to speculate about space ships traveling at half the speed of light, you could then instead turn to Many-Minds Relativity connecting the views of observers traveling at very high speeds with inspiration from Ebenezer Cunningham seeking to make sense of SR in the 1910s.