Birth of the Quantum Mechanics


0

Birth of the Quantum Mechanics

Birth of the Quantum Mechanics

The history of quantum mechanics is a fundamental part of the history of modern physics. Quantum mechanics’ history, as it interlaces with the history of quantum chemistry, began essentially with a number of different scientific discoveries: the 1838 discovery of cathode rays by Michael Faraday; the 1859–60 winter statement of the black-body radiation problem by Gustav Kirchhoff; the 1877 suggestion by Ludwig Boltzmann that the energy states of a physical system could be discrete; the discovery of the photoelectric effect by Heinrich Hertz in 1887; and the 1900 quantum hypothesis by Max Planck that any energy-radiating atomic system can theoretically be divided into a number of discrete « energy elements » ε (Greek letter epsilon) such that each of these energy elements is proportional to the frequency ν with which each of them individually radiate energy, as defined by the following formula:

E= hν  ( where h is a numerical value called Planck’s constant ).

Then, Albert Einstein in 1905, in order to explain the photoelectric effect previously reported by Heinrich Hertz in 1887, postulated consistently with Max Planck’s quantum hypothesis that light itself is made of individual quantum particles, which in 1926 came to be called photons by Gilbert N. Lewis. The photoelectric effect was observed upon shining light of particular wavelengths on certain materials, such as metals, which caused electrons to be ejected from those materials only if the light quantum energy was greater than the work function of the metal’s surface.

In the late nineteenth century it seemed that physics was largely complete. But a nagging problem arose when the idea that temperature represents the average kinetic energy of atomic-scale particles was applied to electromagnetic radiation.


Like it? Share with your friends!

0
WEB EDUCATION