the.com/infinitesimal
a number so small it's basically zero, but mathematicians refused to just say zero.
means a quantity closer to zero than any positive number you can name, yet not actually zero itself.
from coined from modern latin infinitesimus, the ordinal for infinity, invented in the 1670s by mathematicians racing to build calculus.
newton vs leibnizboth used them, both accused of stealing the idea
kicked out19th century math purged infinitesimals for rigorous limits
comeback1960s logic proved infinitesimals can be made rigorous again
for instance
leibniz notation dx — the dx in dx/dy is a fossil of an actual infinitesimal
robinson's hyperreals — 1966 logic system where infinitesimals are legal numbers again
archimedes method — 250 bce, used infinitesimal slices to find areas before calculus existed