Isaac Newton

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Isaac Newton (1642-1727) is an English scientist known for his contributions to physics and mathematics. He is generally regarded as the greatest genius in the history of science -- this despite the fact that his understanding of physics had systematic flaws that could only come to light when measurements of the ultra fast, the ultra small, and the extremely far away could be obtained.

He was one of the creators of calculus, the other being Leibniz. Their creations of this extremely productive field of mathematics came at almost exactly the same time, and questions of priority or possible borrowing have never been entirely put to rest. Most people give Newton credit for being first, however. Newton is most famous for his theory of gravity according to which the force that holds the planets in their orbits around the sun is the same force as causes objects to fall to earth. His three laws of motion were extremely powerful in promoting progress in science and technology.

The physics of Isaac Newton, i.e. that prior to the discoveries of Einstein and later investigators, is known as "Classical Physics". In most ways the physics of Newton stands even today as the theory that gives correct answers about how things will work in the real world. It is the basis for beginning work in high school and university physics.

A discussion of the "fall" of classical physics, and its replacement by the relativity theories of Einstein, the quantum mechanics of Bohr, Heisenberg, and the other masters of early 20th century physics, is also a good example of what science is and of what it does not promise to be or to do. Science never says that a theory is true. All that science can legitimately do is to establish that a given theory has given reliable results in the past, has been tested over and over again and never yet been found to give the wrong answer. But it must always be ready to make some finding that shows that the theory is wrong. That is what happened to Newton's physics when studies were carried to physical interactions on the scale of individual atoms and their components, to speeds that are a large percentage of the speed of light, and to interstellar distances. Take, for instance, the laws that apply to the movements of electrons around the nucleus of an atom. At the lowest orbits of these electrons they obey rules that are so different from the way that planets move around the sun or a fishing sinker swings in a circle at the end of a piece of string that it took researchers a great deal of time and ingenuity to figure them out. Yet the higher the orbits of electrons are raised away from the atomic nucleus, the more their orbits approach following the rules for the objects we are familiar with from our everyday life. So the old classical rules of Newtonian mechanics turn out to be "correct" as special cases of quantum mechanics. And both are regarded as models, not as accounts of reality. If the models are "right" (i.e., adequate models), then we will be able to make good predictions, predictions that will get our spacecraft to the moon, etc.

Newton's contributions to science had a great influence on philosophy and religion as well. The notion of Deism, in which God creates the world and then leaves it running without interference, is a theological view that was highly influential among the drafters of the United States Constitution. It has its roots in the discovery by Newton of the profound degree to which the world is governed by universal physical laws. The decidedly empirical origins of his discoveries, divorced as they were from a scriptural basis, also contributed to a new attitude of inquiry evidenced in the Enlightenment which had great political as well as religious implications.

Unlike Creationist believers, scientists do not say, "You must believe Newton." They do not even say, "Believe Newton because what he says is so plausible." What they says is, "As long as you don't have to deal with things like global positioning satellites and other such things whirling around at incredible speeds, you can safely be guided by Newtonian physics. It's all grounded in objective evidence. Humans started with the evidence and ended up with classical physics (at least for a while). They didn't start with Newton's Laws and then go out and cull a world of facts looking for those that would support those laws. The remarkable thing was that Newton was able to look at so much evidence that did not seem to have anything to make it hang together and yet come out with a systematic account of physics that only needed, later on, to be corrected for the kinds of events that occur at the limits of our experience.

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