Simplify the following text for a Grade 12 native English-speaking person.
Original: In 1638 , Galileo published his analysis of several situationsâ '' including the celebrated `` interrupted pendulum '' â '' which can be described ( in modern language ) as conservatively converting potential energy to kinetic energy and back again .
Simplified: This included the famous `` interrupted pendulum '' . This can be described ( in modernized language ) as conservatively converting potential energy to kinetic energy and back again .