The Science of Time: This is taken from appendix 5 of my new book, How to Time Travel, which will be available on Amazon in early September 2013.

From a practical standpoint, the science of time started with Isaac Newton in the seventeenth century, but underwent dramatic changes early in the twentieth century, when a little-known patent examiner published a paper in the Annalen der Physik in 1905. The paper contained no references, quoted no authority, and had relatively little in the way of mathematical formulation. The writing style was unconventional for a scientific paper, relying on thought experiments combined with verbal commentary. No one suspected that the world of science was about to be changed forever. The little-known patent examiner was twenty-six-year-old Albert Einstein. The paper was on the special theory of relativity, which quietly led to the scientific unification of space and time, and the scientific realization that mass is equivalent to energy. The ink of this one paper rewrote the science of time. However, we are getting a little bit ahead of ourselves. Let us go back and start with Isaac Newton.

The English physicist Isaac Newton (1642–1727) was the greatest and most famous scientist of his time, and with good reason. He is widely credited with playing a key role in the scientific revolution, hailed as the beginning of modern science. His most important work, the publication of Philosophiæ Naturalis Principia Mathematica, Latin for Mathematical Principles of Natural Philosophy, in 1687 set forth his famous three laws of motion (the foundation of Newtonian mechanics), along with his theory of gravity (Newton’s law of gravity). Newtonian mechanics and Newton’s law of gravity are still taught in high school and college science classes. Newton also contributed to optics and shared the invention (along with Gottfried Leibniz) of calculus, a critical branch of mathematics used in advanced science to this day.

Let us ask the key question: How did Newton scientifically view time? Newton thought of time as an absolute. He believed that time passed uniformly, even in the absence of change. Newton’s thoughts about the science of time would go something like this: The world is changing at varying rates, but time passes uniformly. The world stops changing completely, but time passes uniformly. Any event that occurs at a single point in time occurs simultaneously for all observers, regardless of their position or relative motion. Newton’s view of time as an absolute became a cornerstone of classical physics and prevailed until the early part of the twentieth century. In our everyday world, this view of time makes complete sense. Newton’s science of time only breaks down when observers are at vastly different distances from an event, or when the event or the observers are moving near the speed of light relative to one another. Obviously, this did not occur in the real-world situations of Newton’s era. In addition, the speed of light was not a consideration in Newtonian mechanics. Remarkably, Newtonian mechanics is still a highly successful theory for predicting and explaining typical real-world phenomena.

This next part of the story may surprise you. Newton is widely viewed as one of the most influential scientists of all time. His scientific accomplishments and writings make a strong case that his view of time as an absolute was his original work. However, this is probably not entirely true. The concept of time being an absolute actually started with Galileo.

Galileo was a brilliant Italian physicist, mathematician, astronomer, and philosopher. Galileo and Newton never met in person, since Galileo died the same year Newton was born, 1642. However, Galileo’s scientific writings not only played a role in the scientific revolution, but it is likely Galileo played a major role in shaping Newton’s thinking. In fact, the coordinate transformation methodology that treats time as an absolute is termed the Galilean transformation. Let us understand how this came about.

Time is an absolute (Galilean transformation)

There appears little doubt that Newton’s science of time was significantly influenced by Galileo’s 1638 Discorsi e Dimostrazioni Matematiche (Discussions on Uniform Motion), since Newton’s and Galileo’s views of time are essentially identical. For example, the transformation of the time coordinate from one frame of reference to another, regardless of the relative motion of either frame, left the time coordinate unchanged. As mentioned above, this type of coordinate transformation is termed the Galilean transformation, and it works as long as the frames of reference move at low velocities. This begs a question. What happens as the frames of reference move at velocities close to the speed of light? To address this question, we need to discuss the Lorenz transformation. Stay tuned for The Science of Time – Part 2/3.