The difference between “invention” and “discovery” is not as clear as one might think. A discovery can be as simple as observation of a previously unnoticed phenomenon, while an invention is a human-devised machine, tool, or apparatus that did not previously exist. For example, ancient people discovered that drops of water and certain gemstones distorted light in a predictable way. However, it was not until medieval times that others tried to reproduce this effect by applying new glass-shaping technology...

When the French physicist Pierre Curie (1859-1906) turned 35 years old, he was already a well-known scientist. He belonged to interesting discoveries in the field of physics of the crystalline state of matter and the piezoelectric effect, the magnetic properties of substances at high temperatures. A regular change in the properties of paramagnetic substances from temperature bears his name (Curie's law). However, at the turn of the XIX and XX centuries. his scientific interests changed: together...