Abstract: Some of the matter in the paper are excerpts from the author’s previous internationally published research paper [24]. Beginning with Newton’s classical theory of light and Continuity of action, The entire paper is developed into really a mega treatment. The researchers earlier to Max Planck and their failure to explain the nature of thermal radiation arriving at the well known ‘Ultraviolet Catastrophe’ has been extensively dealt with and finally arriving at the concept of ‘Quantum’ by Max Planck. After the discovery of the ‘Quantum’ by Max Planck in 1901, physicists began the research to such great extent that as on today nearly after 120 years, the word, ‘Quantum’ started appearing in almost all fields of research in Physics. Hence, the author has presented in this paper a large number of terms both frequently appearing such as ‘Quantum Electrodynamics (QED)’ and rarely appearing such as ‘Quantum Key Distribution (QKD)’ in the fields of Physics. The rarely appearing terms come only in specific cases and their descriptions are limited to just saying what it is. In spite of keeping the brevity of the paper, indeed it has become exhaustive and lengthy running into some 50 pages. The author has co-related the events of the Bhagavad Gita as a Quantum Universe wherein the author has compared Lord Krishna as an ever known Quantum Physicist thereby giving it a philosophical touch. There are in all over 40 figures. As a picture speaks thousand words, pictures of scientists are given at appropriate places. In addition to usual references, the author has mentioned few of his personal copies of books on the subject.

| DOI: 10.17148/IARJSET.2022.9204