Quantum-Relativity, (qr).

              The poor young lad did his best.

Had Einstein not been hypnotized into neo-Pythagorean-claptrap, promulgated by "pure", so-called "mathematicians" who are far better described as "the flat-earth-arithmetic" "rotationally-challenged"; then he would have found Quantum Relativity (GUT) about 100-years ago already.

In other words; our "no-GUT puzzle" was not my dear posthumous colleague’s fault; what caused this lack of closure was the neo-Pythagorean claptrap so-called "mathematics" that Einstein actually said that he found unhelpful. Had Einstein paid any real attention to Maxwell, then he might have stood a chance, but even Maxwell just blithely repeated Euler's fundamental misunderstanding.