Book Title: Microcosmology Atom in Jain Philosophy and Modern Science
Author(s): Jethalal S Zaveri, Mahendramuni
Publisher: Jain Vishva Bharati
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Atom in Modern Science
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theory of electrodynamics. The fundamental difference between the Newtonian laws and Electrodynamics is the concept of "field of force", i.e. an electric charge produces a 'condition' in space around it so that another charge feels a force. This was a much subtler concept than that of Newtonian 'force' and eliminated the existence of ether. It produced a most profound change in the basic concept of physical reality. It was Einstein who clearly recognised this fact 50 years later, when he declared that no ether existed and the electromagnetic fields were physical entities which could travel through empty space and could not be explained mechanically. Ultimately, it resulted in the realization of the electromagnetic nature of light.
ELECTROMAGNETIC RADIATION-LIGHT
Much earlier, there were two theories about light: One which Newton favoured was that it was composed of particles, called corpuscles; the other was that it was made of waves. A proper theory of the propagation of light did not come until 1865, when Maxwell succeeded in unifying the forces of electricity and magnetism. Maxwell's equations predicted that electromagnetic waves travel at a fixed speed. Thus, light is a rapidly alternating electromagnetic field travelling through space in the form of waves at a fixed speed.
In due course, it was established that radio-waves, light, and X- rays are all waves forming the electromagnetic spectrum, a tiny fraction of which the visible spectrum -- is visible in the form of light. This remained the accepted and proven theory of light upto 1905.
Einstein's theory of light was that it is composed of tiny particles called photons. A beam of light is analogous to a stream of bullets. To prove his theory, Einstein referred to a phenomenon called the photo-electric effect, in which when light impinges on a metal surface, it sends electrons flying off. If a photon hits an electron, it knocks it away just as one billiard ball hitting another one knocks it away.
It was also found that the velocity of the rebounding electrons did not depend upon the intensity of the impinging light,
