Newton’s Universal Time

Sir Isaac Newton discovered the laws of gravity, which is the basis of modern physics today. The laws of gravity were one of the steps Newton took in trying to explain the universe. Newton’s idea of the universe was that it worked like clockwork and could be explained and predicted easily. Newton believed that in this clockwork universe time remained constant in all frames of reference. Following this idea he believed that it was the same time on the moon as it was on earth. Newton expanded his idea into moving frames of reference. He believed that time would remain constant in moving and stationary frames of reference.

Figure 1 explains this idea clearly. Imagine we have two observers. One is stationary (red) and one is moving along the x-axis (blue). Newton believed that the time the two observers measured would be the same. His idea of having time as a constant was flawed as Newton did not know about time dilation, which causes time measurement to be different in moving frames of reference. Einstein later fixed these problems with his theory. Newton’s idea of a clockwork universe was nonetheless an important step forward.