Modern Physics, History of Modern Physics
A new era in physics, usually referred to as modern physics began towards the end of the 19th century mainly to address many physical phenomena that could not be explained by the laws of classical physics. The most significant contributions were Einsteins theory of relativity and Max Plancks quantum theory. The theory of relativity leads us to the deduction that matter and energy are interconvertible. It has brought about a radical change in the concepts of space, time, mass and energy and established that the velocity of light in free space is a constant and that no object can travel with a speed greater than the velocity of light.
History of Modern Physics
Einstein put forth the equation E = mc2, which quantitatively states the equivalence between mass and energy. The theory of relativity describes the motion of bodies of extremely mass small moving with velocities comparable to that of light. Quantum theory considers that light and other forms of electromagnetic radiation behave both as waves and particles, small particles of matter also exhibit this dual nature. In modern physics mass and energy are not considered individually, but in combination. Modem physics deals with sub microscopic and high speed phenomena whereas classical physics deals with relatively large scale and low speed phenomena.
Concept of Modern Physics
Modern physics is conveniently divided into several fields that include. Atomic physics (study of atoms and atomic particles). Nuclear physics (study of the structure of the nucleus), Quantum mechanics (study of laws governing the motion of sub-atomic particles), High energy particle physics (study of the production of sub atomic particles), Solid state physics, (study of the behavior of solids), Cryogenics (study of matter and energy at very low temperature), Super conductivity (study of the conductivity of matter under special conditions), Plasma physics (study of highly ionized matter), etc.