GROSSBELLIN

FEATURE OF HUMAN ACHIEVEMENT IN INTELIGENT AND SCIENCE

The conceptual evolution and the historical development of quantum theory, from its inception a the hypohtesis of the quantum of action and the contributions of Max Planck, Albert Einstein and Niels Bohr are discussed in this statement.
The inception of the theory is due to a breakthrough in the understanding of the interaction between radiation and matter.
The quantum of acton, proposed by planck, to account quantitatively fo the distribution of body radiation was taken up by Einsten. Einstein led the development of the quantum theory in its initialy stages by giving the quantum hypothesis a physical significance and by espanding its application to various electromagnetics phenomena. He boldly observed that a break with the classical understanding of the quatum phenomena is necessary een though leading physicists resisted such an observation. Bohn connected the structure of the atom with the quantum hypothesis. He intuitively pieced together different ideas prevalent at that time.
He was also able to ecplain the physical and chemical properties of elements withi the framework of his atomic theory. At this leve, the theory on quantum phenomena is known as quantum theory.

1. the discovery of the quantum of action
The historical roots and the conceptual foundaton of the quantum of acton can be traced down to the development o thermodynamics and its analysis of irreversible processes and the introduction of the concept of entropy. Thermodynamics is the quantitative statistical analysis of the effect of heat on the macroscopic processes of the microscopic entities. These thermodynamic processes are governed by the fundamental thermodynamic laws. Tthe stdy of the second law of thermodynamics paved the way fo the discovery of the quantum action.
The second law of thermodynamics states the heat will not pass spontatneously from a colder
to a a hotter body. Rudolf Clausius reformulated the second law to make it compatible with the first law. Heat can not of itselt pass from a colder to a warmer body, the rest of the universe remaingi unchanged, This means that without doing work, heat can not bi tranferred from a cold to a hot body, Max Planck interpreted the second low as the process of heat conduction that cannot bi completely reversed by any means. Planck espressed that in every natural process the
sum of entropies of all bodies involved itn the process increases. So asystem cannot bi completely brought back to tis itinital state without doing work on it.