Special Relativity Without the 2nd Postulate
http://tosca.phys.oxy.edu/~alec/Courses/P366/Notes/LTs.pdfIt is impossible to formulate an alternative to Special Relativity while obeying the observed symmetries of spacetime and agreeing with the experimental evidence.
Submitted in section: Physics: Relativity: Special Relativity: Special Relativity Without the 2nd Postulate