In the particular case of momentum equals mass times velocity, it is an implication of Hamiltonian mechanics. But I don't think that's the motivation that led Hamilton to invent Hamiltonian Mechanics. Irrational numbers are very, very important in physics and math. If you have some span of real numbers between 1 and 2, almost all of them are irrational.
Welcome to the October 2022 Ask Me Anything episode of Mindscape! These monthly excursions are funded by Patreon supporters (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number — based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good — and sometimes group them together if they are about a similar topic. Enjoy!
Support Mindscape on Patreon.
See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.