How do we know numbers like Pi are infinite rather than just incredibly long?

Visualizing the Infinite Beauty Of Pi And Other Numbers

Why do prime numbers make these spirals? (2019)

Johan Commelin - Main interest lies in algebraic geometry and algebraic number theory.

Number theory learning seminar (2015)

Algebra Number Theory book

Does anyone “know” a proof of Fermat’s Last Theorem? (2019)

ANTIC - Algebraic Number Theory In C.