Quantum

In physics, a quantum (plural: quanta) is the minimum unit of any physical entity involved in an interaction. An example of an entity that is quantized is the energy transfer of elementary particles of matter (called fermions) and of photons and other bosons. The word comes from the Latin "quantus", for "how much." Behind this, one finds the fundamental notion that a physical property may be "quantized", referred to as "quantization". This means that the magnitude can take on only certain discrete numerical values, rather than any value, at least within a range. There is a related term of quantum number.

A photon, for example, is a single quantum of light, and may thus be referred to as a "light quantum". The energy of an electron bound to an atom (at rest) is said to be quantized, which results in the stability of atoms, and of matter in general.

As incorporated into the theory of quantum mechanics, this is regarded by physicists as part of the fundamental framework for understanding and describing nature at the infinitesimal level, for the very practical reason that it works. It is "in the nature of things", not a more or less arbitrary human preference.

Beyond electromagnetic radiation

While quantization was first discovered in electromagnetic radiation, it describes a fundamental aspect of energy not just restricted to photons.

The birth of quantum mechanics

From the experiments, Planck deduced the numerical values of h and k. Thus he could report, in the German Physical Society meeting on December 14, 1900, where quantization (of energy) was revealed for the first time, values of the Avogadro-Loschmidt number, the number of real molecules in a mole, and the unit of electrical charge, which were more accurate than those known until then. This event has been referred to as "the birth of quantum mechanics".

Translation

The word "Quantum" occurs as such in the following languages: English, French.

Translation(s) in other languages: Arabic: كم (فيزياء), Belarusian (Taraškievica): Квант, Bosnian: Kvant, Bulgarian: Квант, Catalan: Quàntum, German: Quant, Estonian: Kvant, Greek: Κβάντο, Spanish: Cuanto, Persian: کوانتم, Galician: Quanto, Korean: 양자 (에너지), Croatian: Kvant, Italian: Quanto, Latvian: Kvants, Lithuanian: Kvantas, Hungarian: Kvantum, Dutch: Kwantum, Japanese: 量子, Norwegian (Bokmål): Kvant, Polish: Kwant, Romanian: Cuantă, Russian: Квант, Albanian: Kuanti, Slovak: Kvant, Serbian: Квант, Finnish: Kvantti, Swedish: Kvantum, Ukrainian: Квант, Chinese: 量子, Turkish: Kuantum mekaniği.