What is your absolute pettiest gripe about a scientific mistake in some printSF?

My pettiest gripe is about Alastair Reynolds Diamond Dogs - at least in my edition of it - an early math puzzle misidentifies the first four primes as 1 3 5 7 (instead of 2 3 5 7). [Which to be clear has been debated on this sub, here, so we do not need to rehash the discussion about the primality of 1.]

But what are yours? The pettier the better!!