Galileo's pendulum principle means that no matter whether the clock swings big or small, the time to complete a swing is the same.

Galileo discovered the isochronism of pendulum in 1583.

In Pisa, Italy, there was a 17-year-old college student Galileo who was studying medicine at that time. Inadvertently, he observed the chandelier hanging from the ceiling shaking slightly. Galileo found that in the process of hanging lamp swing gradually fading, the time spent on each swing did not change. This discovery caused Galileo to think. After returning to China, I continued to study and found and put forward the isochronism of simple pendulum.

Extended data:

The swinging pendulum swings through the mutual transformation of gravitational potential energy and kinetic energy. Simply put, if you pull the pendulum up, it will swing down due to the influence of gravity. After reaching the lowest position, it has a speed, so it is impossible to stop there directly (just like the brakes can't stop immediately).

Because of inertia, it will continue to cross the lowest position and swing back to the highest position because gravity slows it down to zero. At this time, the pendulum throws downward acceleration. Just go back and forth and keep swinging.

According to the above description, the pendulum can swing forever, but because of resistance, it will swing down gradually and finally stop. So use the spring to provide energy to make it swing.

Periodic formula

According to the formula, the pendulum length L is proportional to the square of the period T, so the longer the pendulum length, the longer the period (pendulum is a kind of simple pendulum). The simple pendulum period formula is only applicable to mechanical vibration with swing less than 5 degrees.

References:

Baidu encyclopedia-isochronism

References:

Baidu encyclopedia-pendulum