Who invented the theremin?
The theremin was invented in 1920 by Russian physicist Léon Theremin while he was researching sensors that detect motion.
Reference: Encyclopaedia Britannica
The theremin was invented in 1920 by Russian physicist Léon Theremin while he was researching sensors that detect motion.
A hurdy-gurdy makes sound when the player turns a crank that spins a rosined wheel against the strings, working like a violin bow.
Sodium is soft enough to cut with a knife.