The classic story of birthday paradox

(Achilles Paradox of Zhi Nuo, an ancient Greek mathematician) Achilles couldn't catch up with the tortoise who started earlier than him in the race, because when he reached the point where the tortoise started, the tortoise crawled forward again. The distance between Achilles and the tortoise can be narrowed infinitely, but it will never catch up with the tortoise.

(The Dichotomy Paradox of Zhi Nuo, an ancient Greek mathematician) When an object travels a certain distance to reach D, it must first reach half of the distance D, then a quarter, an eighth and a sixteenth, so that it can be divided indefinitely. Therefore, this object will never reach 0.

"There are as many points on the line segment of 1 cm as in the Pacific Ocean"

Cantor (1845- 19 18) successfully proved that points on a straight line can correspond to points on a plane one by one or to points in space one by one. Because of infinity, there are as many points on the line segment of 1 cm as there are points in the Pacific Ocean and the whole earth.