Herbert Dingle (Wiki).
Poul Anderson and James Blish address technology and its effects on society. We have seen that their technological speculations encompass various alternative FTL drives and that both referred to Mach for this purpose. Blish had mentioned Mach, Einstein, Milne and his own fictional Haertel. In his second Jack Loftus novel, he adds Dingle!
In Milne's relativity, the light speed limitation is a mere mathematical convenience;
Dingle found two Einsteinian errors;
in 2011, Haertel showed that Einstein's relativity was a special case of Milne's relativity which was a special case of Haertel's own relativity;
in 2030, an FTL drive is one practical outcome of Haertel's theory;
in the 2050s, Jack Loftus and colleagues visit the Coal Sack nebula and the Heart Stars.
A project would be to write detailed accounts of every FTL drive in Blish's and Anderson's works.