Gravitation Quotes - page 2
There are already scientists-- respected scientists in this country who do experiments on things that most people consider supernatural, such as prayer. When Newton proposed the theory of gravitation it was dismissed as supernaturalism because it was action at a distance. What constitutes supernaturalism in today's science may very well not be supernatural in tomorrow's science.
Jonathan Wells
Superficially at least the forces of electricity and magnetism seem to present the same kind of problem as gravitation. Experiment shows that two electrically charged bodies attract one another (or repel if their charges are of the same kind) with a force which conforms to the same mathematical law as the force of gravitation - both forces fall off inversely as the inverse square of the distance. The same is true of the magnetic force also; two magnetic poles attract or repel one another with a force which again follows the law of the inverse square of the distance.
James Jeans
Minkowski... supposed that this fourth dimension of time was not detached from and independent of the three dimensions of space. He introduced a new four-dimensional space to which ordinary space contributed three dimensions, and time one; we may call it 'space-time'.... The succession of positions which a particle occupied in ordinary space at a succession of instants of time would be represented by a line in space-time; this he called the 'world-line' of the particle.... Newton's absolute space and absolute time fell out of science, and they carried much with them in their fall. First to go was the concept of simultaneity.... It now became necessary to find a way of treating gravitation which should not involve simultaneity. Einstein found through the medium of his 'Principle of Equivalence'.
James Jeans
A similar situation occurred in astronomy, where the Newtonian law of gravitation had been found to predict the orbits of the outer planets with great accuracy, but had failed with the orbits of Mercury and Venus. The relativity theory of gravitation had provided the necessary modification of Newton's law, and in working out the details of the new theory, Einstein had utilized the fact that Newtonian law gave the right result at great distances from the sun. Heisenberg, confronted with a similar problem, was able to avail himself of the fact that the classical mechanics gave the right result at great distances from the atomic nucleus. Here, and here alone Heisenberg's theory made contact with the world of the older physics.
James Jeans
Any region of space-time that has no gravitating mass in its vicinity is uncurved, so that the geodesics here are straight lines, which means that particles move in straight courses at uniform speeds (Newton's first law). But the world-lines of planets, comets and terrestrial projectiles are geodesics in a region of space-time which is curved by the proximity of the sun or earth... No force of gravitation is... needed to impress curvature on world-lines; the curvature is inherent in the space...
James Jeans
I expect that mathematicians have classified such fuzzy logics. Certainly they have been much used by physicists. But is there not something to be said for the approach of Euclid? Even now that we know that Euclidean geometry is (in some sense) not quite true? Is it not good to know what follows from what, even if it is not necessarily FAPP? Suppose for example that quantum mechanics were found to resist precise formulation. Suppose that when formulation beyond FAPP was attempted, we find an unmovable finger obstinately pointing outside the subject, to the mind of the observer, to the Hindu scriptures, to God, or even only Gravitation? Would that not be very, very interesting?
John Stewart Bell
Spinoza says that if a stone which has been projected through the air, had consciousness, it would believe that it was moving of its own free will. I add this only, that the stone would be right. The impulse given it is for the stone what the motive is for me, and what in the case of the stone appears as cohesion, gravitation, rigidity, is in its inner nature the same as that which I recognise in myself as will, and what the stone also, if knowledge were given to it, would recognise as will.
Arthur Schopenhauer
He took their facts for granted. He knew no more than a firefly about rays - or about race or sex - or ennui - or a bar of music - or a pang of love - or a grain of musk - or of phosphorus - or conscience - or duty - or the force of Euclidian geometry - or non-Euclidian - or heat - or light - or osmosis - or electrolysis - or the magnet - or ether - or vis inertiae - or gravitation - or cohesion - or elasticity - or surface tension - or capillary attraction - or Brownian motion - or of some scores, or thousands, or millions of chemical attractions, repulsions or indifferences which were busy within and without him; or, in brief, of Force itself, which, he was credibly informed, bore some dozen definitions in the textbooks, mostly contradictory, and all, as he was assured, beyond his intelligence.
Henry Adams
It is no coincidence, I am sure, that those who have the most to say about the Project are the ones who have had no direct contact with it. Which is similar to the attitude physicists have regarding gravitation or electrons - as opposed to that of the "well-informed" who read popular science. The "well-informed" think they know something about matters that the experts are reluctant to even to speak of. Information at second hand always gives an impression of tidiness, in contrast with the data at the scientist's disposal, full of gaps and uncertainties.
Stanisław Lem
Today we know that on the sub-atomic level the fate of an electron or a whole atom is not determined by its past. But this discovery has not led to any basically new departure in the philosophy of nature, only to a state of bewildered embarrassment, a further retreat of physics into a language of even more abstract symbolism. Yet if causality has broken down and events are not rigidly governed by the pushes and pressures of the past, may they not be influenced in some manner by the "pull" of the future-which is a manner of saying that "purpose" may be a concrete physical factor in the evolution of the universe, both on the organic and unorganic levels. In the relativistic cosmos, gravitation is a result of the curvature and creases in space which continually tend to straighten themselves out-which, as Whittaker remarked, "is a statement so completely teleological that it certainly would have delighted the hearts of the schoolmen."
Arthur Koestler
I do not see any reason to assume that the heuristic significance of the principle of general relativity is restricted to gravitation and that the rest of physics can be dealt with separately on the basis of special relativity, with the hope that later on the whole may be fitted consistently into a general relativistic scheme. I do not think that such an attitude, although historically understandable, can be objectively justified. The comparative smallness of what we know today as gravitational effects is not a conclusive reason for ignoring the principle of general relativity in theoretical investigations of a fundamental character. In other words, I do not believe that it is justifiable to ask: What would physics look like without gravitation?
Albert Einstein
The conclusion seems to be irresistible that such laws of nature as the principle of conservation of energy, the principle of conservation of momentum and the law of gravitation are necessary consequences of our modes of measurement. They are, in fact, elaborately disguised identities which could have been predicted a priori by a being of sufficiently powerful analytical insight who fully understood all that is implied in the way we measure space-time intervals.
Ernest Barnes
Gradually, during the eighteenth century, physicists and philosophers had become so accustomed to Newton's law of gravitation, and to the equality of gravitational and inertial mass, that the miraculousness of it was forgotten and only an acute mind like Bessel's perceived the necessity of repeating those experiments. By the experiments of Bessel about 1830 and of Eötvös in 1909 the equality of gravitational and inertial mass has become one of the best ascertained empirical facts in physics.
Willem de Sitter
