Thing here is, it's a fantasy book. The world doesn't work the same as here, Jeremy may be really scientific and analytical, but the Discworld is so intrinsically magical that he probably is drawing on the magical field of the disc.

"Sufficiently advanced technology is indistinguishable from magic." is a quote from Arthur C Clarke that Terry is fond of repeating (and reversing in the case of the wizards), I think Jeremy does enter that realm here.


In terms of the world of physics, do we know if there is a smallest amount of time? A universal tick? The answer is no. Scientists can postulate as to the nature of time, but the closest they can get (at the moment) is that it is a dimension like length, breadth and height - and what's the smallest amount of each of them?

The answer is - don't know. It's a common answer for a true scientist. We only know what it isn't.