A pendulum clock is virtually a resonant device that oscillates at a fixed rate according to its length and opposes oscillation at another rate. But it is only suitable for working in a steady-state. In a moving and accelerating thing, it will not be able to tell the right time.

Christiania Huygens, (14 April 1629 - 8 July 1695) was a prominent Dutch mathematician and natural philosopher. He is particularly known as an astronomer, physicist, indecisive, and time scientist. He was born in The Hague on April 14, 1829. He got his initial education from your worthy father, then you got an education in Lyde. He was inspired Galileo.