You can easily check whether an egg is raw or cooked by turning it on the table: the boiled egg turns faster. But how is that actually possible?
Spiral belts slow egg rotation
In a raw egg, the white and the yolk can move freely to a certain extent, which changes the center of gravity of the egg.
The yolk is attached to spiral bands, the hail cords, which are stretched when the egg turns. These movements slow the rotation of the egg.
In a hard-boiled egg, the white and the yolk are solid and the rotation is not slowed down.