QED Full Form | Full Form of QED
QED Full Form - Quod Erat Demonstrandum
Quod Erat Demonstrandum
- Q.E.D. is an abbreviation of the Latin phrases "Quod Erat Demonstrandum" (literally, "which was to be demonstrated"). In simple terms, the use of this Latin phrase is to point that something has been definitively proven.
- Q.E.D. could also be written at the top of mathematical proofs to point out that the result required for the proof to be complete has been obtained.
- Its use originates from the standard kind of a proof: Start out with basic axioms, then use deductive logic to successively derive new results, until the statement to be proven has been derived.
- It is also used in physics to point that the concept required to succeed in the answer has previously been demonstrated.
- The term is additionally used both formally and informally during a wide variety of disciplines, also as in everyday conversation in many parts of the English-speaking world.
QED Full Form - Quantum Electro Dynamics
- Quantum electrodynamics may be a field of physics that studies the interaction of electromagnetic wave with electrically charged matter within the framework of relativity and quantum physics.
- More plainly put, it's a relativistic quantum theory of electromagnetism. It basically describes how light and matters interact. More specifically it deals with the interactions between electrons, positrons and photons.
- It is the elemental theory underlying all disciplines of science concerned with electromagnetism, like atomic physics, chemistry, biology, the idea of bulk matter, and electromagnetic radiation.
- It has been called "the jewel of physics" for its extremely accurate predictions of quantities just like the anomalous moment of a magnet of the electron, and therefore the Lamb shift of the energy levels of hydrogen.
- It is the primary physical theory ever developed that has no obvious intrinsic limitation and describes physical quantities from first principles.
- Nature accommodates forces other than the electromagnetic force, like those liable for radioactive disintegration of heavy nuclei (called the weak force) and therefore the force that binds the nucleus together (called the strong force).
- A theory called the quality model, has been developed which unifies the three forces and accounts for all experimental data from very low to extremely high energies. This doesn't mean, however, that QED fails at high energies. It simply means the important world has forces aside from electromagnetism.
History of QED
- The word 'quantum' is Latin, meaning "how much".
- The word 'electrodynamics' was coined by André-Marie Ampère in 1822. The word 'quantum', as utilized in physics, i.e. with regard to the notion of count, was first employed by Max Planck, in 1900 and reinforced by Einstein in 1905 together with his use of the term light quanta.
- Quantum theory began in 1900, when Max Planck assumed that energy is quantized so as to derive a formula predicting the observed frequency dependence of the energy emitted by a black body.
- This dependence is totally at variance with classical physics. In 1905, Einstein explained the photoelectric effect by postulating that light energy comes in quanta later called photons.
- In 1913, Bohr invoked quantization in his proposed explanation of the spectral lines of the atom. In 1924, Louis Broglie proposed a scientific theory of the wave-like nature of subatomic particles.
- The phrase "quantum physics" was first used in Johnston's Planck's Universe in Light of recent Physics.
- These theories, while they fit the experimental facts to some extent, were strictly phenomenological: they provided no rigorous justification for the quantization they employed.
- Modern quantum physics was born in 1925 with Werner Heisenberg's matrix mechanics and Erwin Schrödinger's quantum mechanics and therefore the Schrödinger equation, which was a non-relativistic generalization of de Broglie’s (1925) relativistic approach.
- Schrödinger subsequently showed that these two approaches were equivalent. In 1927,Heisenberg formulated his uncertainty principle, and therefore the Copenhagen interpretation of quantum physics began to require shape.
- Around this point, Paul Dirac, in work culminating in his 1930 monograph finally joined quantum physics and special theory of relativity, pioneered the utilization of operator theory, and devised the bra-ket notation widely used.
- In 1932, John von Neumann formulated the rigorous mathematical basis for quantum physics because the theory of linear operators on Hilbert spaces. This and other work from the founding period remains valid and widely used.
- Quantum chemistry began with Walter Heitler and Fritz London's 1927 quantum account of the covalent bond of the hydrogen molecule. linus pauling et al. contributed to the next development of quantum chemistry.