* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download From Heaven to Hell
Fictitious force wikipedia , lookup
Equations of motion wikipedia , lookup
N-body problem wikipedia , lookup
Centripetal force wikipedia , lookup
Centrifugal force wikipedia , lookup
Classical mechanics wikipedia , lookup
Work (physics) wikipedia , lookup
Modified Newtonian dynamics wikipedia , lookup
Fundamental interaction wikipedia , lookup
Classical central-force problem wikipedia , lookup
From Heaven to Hell Name: Luis Fernando Melgar Arias College: Michael Polanyi Date: December 12, 2013 Subject: Mechanics Sonnet LX Like as the waves make towards the pebbled shore, So do our minutes hasten to their end; Each changing place with that which goes before, In sequent toil all forwards do contend. Nativity, once in the main of light, Crawls to maturity, wherewith being crown'd, Crooked eclipses 'gainst his glory fight, And Time that gave doth now his gift confound. Time doth transfix the flourish set on youth And delves the parallels in beauty's brow, Feeds on the rarities of nature's truth, And nothing stands but for his scythe to mow: And yet to times in hope my verse shall stand, Praising thy worth despite his cruel hand. - William Shakespeare First and foremost I find it my duty to say that no mere essay can ever come close to the unique and wondrous experience that comes off Reading Newton’s own Principia, no matter how thorough and well thought the essay may be. What will be discussed are Newton’s main points and arguments, some characteristics of his process, and of course his overall conclusion. Newton revolutionized not only how we used things, but he also changed the way we think. His Law of Universal Gravitation was not only applied to celestial bodies and balls of catch, many believed it could tell us how we thought and acted, such an assumption led to dreaded confusions and dire repercussions. Law 1: Every body continues in its state of resting or of moving uniformly in a straight line, except insofar as it is driven by impressed forces to alter its state. Newton’s foundation is geometrical, meaning mathematical, but Newton birthed a thought never entirely grasped before, that of calculus. It is calculus that allowed him to measure the movements of the planets, or “wonderers”, it is what ultimately brought the laws of the universe all together and what paved way to the predominance of physics within the natural sciences; it is geometry and mechanics, math and physics. Let us assume that Newton is right, that two bodies are always attracted to one another by their gravitational force, specifically proportional to the product of their masses and inversely proportional to the square of their distance. Basically, as the product increases the gravitational force increases, and as the distance increases the gravitational force decreases. For this to be true though, we must assume that bodies have mass, that bodies have force, and that there is such a thing as a “gravitational force”. The greatest, most important assumption we must accept is that all objects, ALL objects, have a force. Law 2: The change of motion is proportional to the motive force impressed, and takes place following the straight line in which that force is impressed. The three laws of motion are essential for the rest of Newton’s theory to stand. Danna Densmore, author of Newton’s Principia The Central Argument, notes the laws as being “sort of postulates” that must be accepted and that no one would argue, things that are held true by common experience. These Laws are a blend between postulates and common notions or, better-said, just very strong postulates. Newton does not start straight off with the Laws, he first gives some definitions about quantity of matter, force, and velocity, definitions for centripetal force, all which are things we need to prove what follows. Newton’s first proposition, of his first book, describes, geometrically, the movements of the moons and planets (he never mentions moons and planets until book III), inherent forces suffering impressed forces at all times, which in turn is caused by a centripetal force (gravity). This is proved by the lemmas, the lemmas by the laws, and the laws by definitions. This is Newton’s evidence; he worked geometrically and applied it to actual movements seen both on earth and the heavens. This was his great intellectual displacement. His great impression was done once he proved a rock behaved the same as the moon. Law 3: To an action there is always a contrary and equal reaction; or, the mutual actions of two bodies upon each other are always equal and directed to contrary parts. Now that we know what is to be assumed, the forces and their behaviors, and what evidence there is, geometric constructions and observations, we should order them logically, as Newton did, to follow up his argument and overall proof. Remember we want to understand his Universal Law of Gravitation, which says we are at a constant tug of war with whomever is next to you, as the moon is with the earth, the sun and the planets respectively. Moreover we want to know that this force of attraction is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. First we must know that every planet gravitates towards all parts of every other planet, that is proposition 7 of book III, then we must follow the rules of philosophizing, 2 and 3, along with the proof of propositions 1,2,5, and 6 of the same book III. We conclude after such strenuous process that as the product of the mass shifts so does their gravitational force, for every action has an equal an opposite reaction, and so would be as the distance between their centers increases or decreases the gravitational force will be affected. Book III, Proposition 4: That the moon gravitates towards the earth, and is always drawn back from rectilinear motion, and held back in its orbit, by the force of gravity. The pinnacle of Newton’s work, as many scholars consider it including Dana Densmore, comes when Newton calculates the accelerative force of the moon and compares it to the moon in our atmosphere, and finally with a rock we find on earth, concluding (and this is the amazement) that they are all the same! For so long was it believed that the laws that ruled the heavenly bodies were different, perfect, far beyond the ones that ruled us here. Newton set things straight and confirmed that the same laws that ruled outside in our universe, rules us here. One this pinnacle of Newton’s is accepts, the rest comes easier to understand, because once the phenomena outside our atmosphere, in our atmosphere, and within our atmosphere is recognized as the same, then it seems no trouble to reason that there one universal force pulling things together (or apart?). Proposition 8: If the matter of two globes mutually gravitating towards each other be everywhere homogenous in regions that are equidistant from the centers, the weigh of each globe towards the other will be inversely as the square of the distance between the centers. One cannot pretend to deal with Newton’s whole process in one essay, it is hard enough to set out the main themes, but one can appreciate a birds eye view along with some details (the modern equation of universal gravitation for instance is F=G(M1*M2/r^2)). What we can say generally is that from the nature of geometrical curves, shapes, and figures, we come to explain the nature of planetary orbits, all abiding by the same law of gravitation. Due to Newton’s speech; “all phenomena”, “same kind, same causes”, “universal qualities”, “only admit what is true and sufficient”, one is tempted to apply these rules (Newton’s Rules of philosophizing) to our way of thinking and acting, our way of doing, our way of moving, loving, caring, and living in general. Claude Bernard, French physicist, certainly thought so; these Newtonian Rules cluttered his speech when in defense of vivisections. But more horribly is the twisted application of such to social order is seen when considering the Nazi regime, Soviet Russia, or the Marxist view in general. Those who believe one can plan the economy, control discovery, and limit art, those who believe human beings are the same subject matter as moons and rocks. For I am led by many reasons … Newton must be recognized for what he did, and praised for it too. He shed a light unto a much-fogged universe, he gave life to the heliocentric model, and made a major leap for scientific worth. Though there is still a long way to go, and the Law of Universal Gravitation does a great job explaining celestial movement, but tells us nothing about the highly complex order within our minds, our society, our language, our art, and even our culture here at the Michael Polanyi College. Newton said he was “led by many reasons” to do what he did, but such a FORCE is as unknown as is our very human nature to question, answer, choose, love, and believe.