Albert Einstein Theory of Relativity

Albert Einstein is the son of German-Jewish parents. He was born in 1879 in the town of Ulm, Würtemberg, Germany.

In 1905 Einstein suggested that the new source of energy was none other than matter itself. Einstein’s 1905 relativity paper, “On the Electrodynamics of Moving Bodies”, was one of three he published that year, at age 26, during his spare time; he was at the time working as a patent clerk in Zurich. Another was a paper explaining Brownian motion in terms of kinetic theory (at a time when some people still doubted the existence of atoms), and the third proposed the existence of photons, thus laying the foundations for quantum theory.

The theory of relativity is essentially about experiencing two objects that move relative to one another, hence the name: theory of relativity. The effects of relativity occur only at high speeds, at velocities comparable to the speed of light: time increases, scales shorten, and the mass of the moving object increases.

He reasoned that if the expenditure of energy needed to accelerate an object resulted in an increase in the mass of an object, then a decrease in velocity must produce a decrease in the mass of an object. The exact mathematical relationship between the mass of an object and the energy it contained flowed directly from the equations of the special theory, and was expressed in the famous formula: E=mc2 that is, that the energy of a body is proportional to the mass of the body multiplied by the square of the speed of light.

E = mc2, which means that energy is "equivalent" to the mass. Energy can be converted to mass, and vice versa. This is the so-called "mass defect".

In 1908 physics and chemistry joined hands when Max Planck took note of Einstein’s equation and suggested that the phenomenon of radioactivity could be explained as the direct transformation of matter into energy.
Albert Einstein Theory of Relativity

Quantum Mechanics in history

Quantum Mechanics is a fundamental branch of physics with wide applications. The foundations of quantum mechanics were established during the first half of the twentieth century by Werner Heisenberg, Max Planck, Louis de Broglie, Albert Einstein, Niels Bohr, Erwin Schrödinger, Max Born, John von Neumann, Paul Dirac, Wolfgang Pauli and others.

The history of quantum mechanics began essentially with the 1838 discovery of cathode rays by Michael Faraday, the 1859 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, and the 1900 quantum hypothesis by Max Planck that any energy is radiated and absorbed in quantities.

On 19 October 1900 the Berliner Max Planck at age 42 announced a formula that fit the experimental result perfectly, yet he had no explanation for the formula – it just happened to fit.

He worked to find an explanations through the late fall and finally was able to derive his formula by assuming that the atomic jigglers could not take in any possible energy, but only certain special ‘allowed’ values. He announced the result ion 14 December 1900 and this date is now considered the birthday of quantum mechanics.

According to the theorem proved by Gustav Kirchhoff in 1859 on the basis of the second principle of thermodynamics, the blackbody spectrum has a very remarkable property: It is a universal function of temperature only. In the 1877, Ludwig Boltzmann and Willy Wien restricted the form of this function by combining electromagnetism and thermodynamics.

In 1905, Einstein computed the entropy of dilute thermal radiation from the high frequency limit of Planck’s law.

In 1913, Niels Bohr emphasized that mathematical symbols from classical mechanics permitted visualization of the atom as a minuscule Copernican system. Although suitably quantized laws of classical mechanics are used to calculate the electron’s allowed orbits, or stationary states, classical mechanics can neither depict nor describe the electron in transit.

Arnold Sommerfeld and others extended the Bohr model with considerable but incomplete success. In1925, the first form of quantum mechanics, was invented by 23 year-old Heisenberg, which soon became known as ‘matrix mechanics’. Heisenberg focused attention on an ‘observable’ set of quantum amplitudes, each depending on not one but two stationary phase.

In 1932 von Neumann put quantum theory on a firm theoretical basis. Some of the earlier work had lacked mathematical rigour, but von Neumann put the whole theory into the setting of operator algebra.

In 1933 Fermi develops a successful quantum field theory of beta decay. It describes how neutrons spontaneously change into protons and emit electrons and neutrinos.
Quantum Mechanics in history

Brief biography of Albert Einstein (1879-1955)

Albert Einstein is one of the greatest scientists of all times. He questioned widely accepted scientific truths and fine-tuned the scientific theories of Sir Isaac Newton.

Albert Einstein was born on March 14, 1879 in Ulm, Wurttemberg, Germany. He studied math and physics in Switzerland and earned PhD at the University of Zurich in 1901. Einstein worked at the patent office in Bern, Switzerland from 1902 to 1909.

During this period he completed an astonishing range of theoretical physics publications, written in his spare time, without the benefit of close contact with scientific literature or colleagues.

In 1905 Einstein caused a stir by publishing five major research papers. These papers forever changed the way people thought about the universe.

One of these papers is the proposing "the special theory of relativity." He based his new theory on the principle that the laws of physics are in the same form in any frame of reference. As a second fundamental hypothesis, Einstein assumed that the speed of light remained constant in all frames of reference.

Later in 1905 Einstein showed how mass and energy were equivalent expressing it in the famous equation: E=mc2 (energy equals mass times the velocity of light squared). This equation became a cornerstone in the development of nuclear energy.

By 1916 Einstein had completed a general theory of relativity; his theories would profoundly alter the way in which scientists viewed the structure of the universe and made possible the development of the atom bomb.

Einstein received the Nobel Prize in 1921 but not for relativity, rather for his 1905 work on the photoelectric effect.

Einstein fled the Nazi regime in 1934 for the United States and worked at the Institute for Advanced Study Princeton University until his death.
Brief biography of Albert Einstein (1879-1955)