________________
A Critique
m =
Mo
1 -
22
173
It can be readily seen that if v is small, the difference between mo and m is practically zero. But when v approaches the value of c, then the increase of mass becomes very great, reaching infinity, when the velocity of the moving body reaches the velocity of light.
By further deduction of this principle of relativity of mass, Einstein concluded that energy has mass and disclosed a fundamental truth about physical reality viz., matter and energy are not different elements as pictured by prerelativity scientists - the former inert, tangible and characterised by a property called mass and the latter active, invisible and without mass. He established that mass is simply concentrated energy. In other words, matter is energy and energy is matter. He expresses the interchangeability of matter and energy by the most famous equation in history: E=mc2. The mass/energy dualism of our ordinary conceptualizaion does not exist in the formalism of relativity or quantum theory. Einstein's equation E=mc2 means that mass is energy and energy is mass. Therefore, strictly speaking, mass is not a particular form of energy. Every form of energy is mass. Mass does not change into energy or vice versa. Wherever energy, E is present, mass m is present also and the amount of mass m is given by E=mc2. The total amount of energy, E, is conserved and hence, the total amount of mass, m, is also conserved. This mass, m, is defined by the fact that it is a source of the gravitational field. It explains how radioactive substances are able to eject particles at enormous velocities for millions of years. It reveals the magnitude of energy that slumbers in the nuclei of atoms. Translated in concrete values, it shows that one kg. of coal, if converted entirely into energy, would yield 25 billion kilowatt-hours of electrical energy. Inter-changeability of matter and energy explains the dual role of the electron as a unit of matter and a unit of electricity and the baffling interplay of matter and radiation, waves and particles becomes more understandable.
