Well, that was the joke, it was a play on while(True). It's an infinite loop, because you can never detect truth. And neither Hertz nor Mach said anything about

Well, that was the joke, it was a play on while(True). It's an infinite loop, because you can never detect truth. And neither Hertz nor Mach said anything about usefulness. Also, I wonder why I can only think of physicists when thinking about definitions of science. The work of a lot of scientists today can be described by while not tenured: publish bully others into citing you if you have time: do a bit of empirical work