Abstract

Despite changeability of the world, the human mind also ponders on those quantities that remain constant over time. This was the case in ancient times, in the middle ages, and the same applies in modern physics. This paper discusses i.a. Zenon paradoxes, the principle of inertia, and the Emma Noether theorem, ending with the modern, so-called Zeno’s quantum effect. The foot-notes concern the ancient “Achilles” paradox, spot speed, as well as some of the facts taken out of the life-history of Emma Noether, as well as the example of applying her theorem.