Many people understand that the third pedal on a piano allows the notes to be held out for longer by not allowing the strings to be muffled inside, but the first and second pedals are a mystery. The first pedal is also a mystery to me so I won't discuss that one, but the second pedal makes the notes played softer. There is a fair amount of physics that goes into making this happen in a piano. To reduce the sound, the strings are lightly touched so that they cannot vibrate as vigorously, but not too much so that they are cut out. But why does reducing the amount a string vibrates reduce its volume? It is not because the speed at which the string rotates is reduced, but rather because its amplitude is reduced. The amplitude of a strings vibration is directly proportional to its volume. So as the amplitude is decreased by the mechanisms in the piano, the volume that the piano plays at is decreased. If anyone does know what the first pedal does, I am interested so leave a comment.