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AMAZON multi-meters discounts AMAZON oscilloscope discounts . One example of this phenomenon, which greatly perplexed yesterday’s scientists, is that of a ferromagnetic object being physically acted upon by magnetic force. Forces other than the magnetic kind also act upon objects or entities separated by a distance. Here, I can think of electrostatic, gravitational, molecular, and nuclear forces. Electromagnetic waves, such as radiant light, might well be included, and there are undoubtedly others. For example, those versed in parapsychology often allege that physical objects can, under some circumstances, be acted upon by force fields emanating from the mind. Although the manifestations mentioned are apparently di verse, they incorporate a common feature—action at a distance without need for an intervening medium. It was this latter aspect that inspired the postulate of the “ether.” Supposedly, the ether was everywhere but it was elusive because of its tenuous nature—it had a viscosity of zero! Although endowed with the properties of “nothingness,” it served as the medium of transmission for light and other electro magnetic radiation; that is, it supported wave motion. The static forces exerted by magnets, by charged bodies, and by gravitation were not so glibly explained. Then, and now, such forces were simply ascribed to “fields” and the role of the ether was somewhat more nebulous. The mathematicians next extended the concept of the field and endowed it with properties of self-propagation, which eliminated the need for the ether. This new concept came at a favorable time, because experiments carried out to detect the presence of the ether were not successful. Besides, whether one comprehended the mathematics or not, the notion of radiant energy traversing the vacuum of space did not stretch the imagination any farther than the elder hypothesis. Fortunately, the mathematical descriptions provided by Maxwell’s equations and by other theories dealing with fields, harmonized with experimental investigations and facilitated the development of practical devices. Nonetheless, the imaginative mind remains undecided over the part played by the intervening space when any type of force exerts influence over a distance. If the influence manifests itself over a gap of true “nothingness,” does this imply the propagation of particles of some sort between the source of the action and that which is acted upon? This, too, was given much thought by many brilliant minds. And, like the ether, we find that the emitted particles are still with us, but dressed in a new style. For example, the prevailing concept of the photon, the elemental carrier of radiant energy, postulates a rest mass of zero. Thus, the ghost of the extinct ether returns to haunt us! There is considerable scientific speculation that gravity, magnetism, and the electric field are somewhat different manifestations of a universal law of nature. The coupling between magnetism and moving electric charges is evidenced by electric motors and generators and by the myriad devices that exploit the phenomenon of electromagnetic induction. It is easy to assume a matter-of-fact attitude regarding the relationships between electricity and magnetism. However, it is instructive to reflect that these “simple” facts of technological life eluded the scientists of the nineteenth century until they were experimentally observed and interpreted. In one case, Hans Christian Oerstead recognized the significance of the deflection of a compass needle by a current-carrying wire. In the other case, Michael Faraday was seeking a relationship between steady magnetic fields and electric currents in stationary conductors. Although he found none, he recognized the significance of currents induced in certain situations where relative motion existed between the magnetic field and the conductor. In our era, the assumed relationship of gravity to electricity and magnetism has thus far been quite elusive. Despite the powerful concepts of relativity and quantum physics, the relationship between gravity and other forces does not appear to be strong. But perhaps history will repeat itself—a surprise observation might one day be made of an unsuspected cause-and-effect relationship that will shed a new light on the nature of gravitational force. Actual experiments are already being carried out to detect and explain “gravity waves.” It is known that gravitational force does not communicate its influence instantaneously. Like the forces of magnetic and electric fields, gravitational influence cannot propagate through space faster than the speed of light. And the force associated with the gravitational field, like that of the magnetic and electric fields, diminishes inversely in proportion to the square of the distance between two bodies, poles, or charges. Unlike the force fields of magnetism and electricity, gravitational force produces only attraction, never repulsion between bodies! Although this subject has been a favorite for science-fiction writers, the quest for a method of reversing, or neutralizing, gravity is by no means the exclusive indulgence of those who deal in fantasy. Just as practical motors and generators have been profoundly influenced by re search in cryogenics and superconductivity, solid-state theory, plasma physics, and materials technology, subsequent progress in the development of a unified field theory can be expected to manifest itself in improved hardware and new control techniques. Surely, the harnessing of basic forces is what motors and generators are all about! |
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