Sir Isaac Newton
Newton (4 January 1643 - 31 March 1727) was born in Lincolnshire England to Isaac Newton Sr. and Hannah Ayscough. However his father had died three months before his birth during the English Civil War. His mother remarried and left young Isaac in the care of his grandmother, Margery Ayscough. He was educated in the local villages and then sent off to The King's School, Grantham, and then later attended Cambridge University at the age of nineteen to where he originally studied to become a preacher.
In June of 1661 he attended Trinity College, Cambridge where he would study the teachings based upon Aristotle’s work, how ever is was noted that he preferred to study the more modern philosophers such as Descartes and astronomers such as Galileo, Copernicus and Kepler. Soon after obtaining his degree Cambridge had to close its doors due to the Great Plague. In this time Isaac studied at home, in this time spent he developed new means for optics, developed a new method of calculus and began his works on the laws of motion and gravity.
As Newton went through life he came to develop new methods of optics used in astronomy, and is also by many considered to be the father of calculus. Most famed however is his works on the laws of motion, which then led to his theory of gravity. In this he was able to calculate the orbit of the moon and other celestial bodies, but he had not ever made it to the conclusion that mass is the cause of gravity. The source reason why there was gravity remained a mystery to him. Although today we do know that mass is the cause behind gravity we still do not understand the exact nature of how gravity works.
Newton founded Classical Mechanics which views space as some thing distinct from body and time as something that passes uniformly without regard to whatever happens in the surrounding environment. In this view Newton spoke of absolute space and absolute time. Up until this time space and time were argued to not be real entities, but instead abstracts of the plenum world. Empty space was viewed as impossibility, that space was used to compare different arrangements of bodies. In relation to time, that no time could possibly elapse with out some change occurring in which time was needed to be used as a measurement. In conjunction of space and time Newton questioned the nature of true motion. This is to say that a body moved through absolute space which the velocity was measure in absolute time. However it should be said that Newton did not regard space and time as genuine substances, but rather as real entities with their own manner of existence as necessitated by God's existence. In this sense that God had an omnipresent view of the universe which Newton was trying to describe.
The goal that Newton had in mind is that the universe is absolute in that if you knew where every object was in the universe then you could then calculate from the trajectories where every thing would end up at any specific time. In this model of the universe both time and space had to be absolute. This is to say that there is a sense of now. Every passing moment in the universe had a moment of right now that was constant through out the universe. In addition to this there had to be a sense of distance. This is to say for example, if you had a rod of metal that was one meter in length then it will always be one meter in length. If it is in rest, if it is in motion, if it is in zero gravity, or if it is on a planet the rod will always be one meter in length.
In this theory he needed to state that there is absolute time and absolute space and in this gravity also became an absolute force that was instantaneous in effect. That is to say for instance, if some force were to suddenly make the sun disappear and no longer exist, then all the planets would feel the effect instantly and at the same time, stopping their orbit and shoot off into space. In regards to time he modeled the universe as having an absolute now. Any given moment in time was the same exact time throughout the universe, which by accepted modern physics is incorrect.
The thing of importance in regards to time however is that what we think of in every day life as time, that which we measure the hours of the day is called Newtonian Time. When we think of an hour of time passing, then we are talking of Newtonian Time. In modern science we regard Newtonian Time as a perfect ideal that is not real. This is to say that what we experience as time, how we describe time in day to day life is best described in using the Newtonian model of time, but in more advanced physics this model of time is insufficient to be able to describe the events that are recorded. However since we normally think about time in our day to day lived in the Newtonian model, we then use the model of Newtonian Time to compare all other models of time against this perfect ideal of what we think time is.