Quantum leap

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In the everyday language of the 21st century, a quantum leap is a step forward that brings a development forward within a very short time. This contradicts the original physical meaning . Therefore, quantum leap is considered a so-called Janus word (autoantonym).

Etymology and development of the technical meaning of the word

The term “quantum leap” was coined in the 1910s. The word component quantum is derived from the energy quantum introduced by Max Planck and goes back to the word quantum , which means in Latin: how much , how big . The “qu” at the beginning of the word describes question forms in Latin.

The background to the formation of the term was the Bohr model of the atom , in which atoms only change their energy in discrete steps. This property was contrary to the assumption that in nature all processes are continuous . The states and thus the possible energy values ​​in Bohr's atomic model are numbered with quantum numbers . The transition from one state to another was assumed to be volatile. This gave rise to the name quantum leap . This sudden transition between otherwise stationary states was a central component of Bohr's model of the atom.

In some early physical publications this term was explicitly written with quotation marks, and some physicists such as Erwin Schrödinger rejected this visual term as inapplicable. At the end of an intensive discussion at a conference in Copenhagen in September 1926, however, according to Werner Heisenberg, it was clear to all participants, including Schrödinger, “that an interpretation of wave mechanics without quantum leaps is impossible”. Schrödinger is quoted as saying: "If we want to stick with this damned quantum jump, then I regret that I even dealt with this subject." Just a few years after it was first mentioned, the more abstract term "transition" was introduced Replaced "quantum leap" in technical terminology.

The "quantum leap" followed in the English physics literature the analogous concepts quantum jump (in 1924) and quantum leap , but as in the German literature, these terms were gradually (in 1932) by the word transition corresponding transition replaced.

After it became possible in the late 1980s to prepare individual quantum systems in a targeted manner and to observe their dynamics, quantum leaps could also be proven experimentally, and the term continues to be used in current research literature. However, the understanding of the process has changed: while the Bohr model assumes an abrupt, discrete transition and the model does not contain any intermediate states, today we assume a continuous development from the initial state (e.g. an atom in the excited state in the vacuum of the electromagnetic field ) into a superimposed state (in the example: the original, excited state with the ground state and an emitted photon , with the weight (the probability amplitude ) of the second part increasing over time). At most, the quantum mechanical measuring process , in which a photon (or none) is detected and the superposition is destroyed , is regarded as “erratic” (depending on the interpretation of quantum mechanics ) .

Use in everyday language

Compared to processes in everyday life, a physical quantum leap is extremely difficult to observe because of its very minor effects. In contrast to this, the (advertising) linguistic usage in business and politics understands a quantum leap to mean an (supposedly) unusually large advance in a certain area.

A quantum leap is usually supposed to be a qualitative major advance in which something new or different arises or is created. For example, the progress in medicine from stethoscopes to ultrasound . If something just gets bigger or bigger, one does not speak of a quantum leap - unless it is a previously unthinkable or impossible increase that also leads to qualitative changes in other areas. For example, the growth of American and Russian nuclear weapons fundamentally changed the structure of political power in the world.

According to the Oxford English Dictionary , the use of quantum leap to mean "extraordinarily large / significant" first appeared in 1956. In a discussion on the balance of power between the US and the Soviet Union in a post-war nuclear world, one journalist wrote:

"The enormous multiplication of power, the 'quantum leap' to a new order of magnitude of destruction."

"The enormous multiplication of power, the quantum leap into a new dimension of destruction."

In marketing , a quantum leap refers to a transition from one model of a product to another, in which a particularly large improvement is said to have been achieved.

“Quantum leap” is not the only term from physics that has found an alienated media use. The term “ Big Bang ” was also adopted in a similar way.

literature

  • Erwin Schrödinger: Are there quantum jumps? Part I . In: The British Journal for the Philosophy of Science . tape III , no. 10 , August 1, 1952, p. 109–123 , doi : 10.1093 / bjps / III.10.109 ( informationphilosopher.com [PDF; accessed on January 21, 2018]).
  • Erwin Schrödinger: Are There Quantum Jumps? Part II . In: The British Journal for the Philosophy of Science . tape III , no. November 11 , 1952, p. 233–242 , JSTOR : 685266 (chargeable).
  • HD toe: There are no quantum jumps, nor are there particles! In: Physics Letters . A172, 189, 1993 ( uni-heidelberg.de [PDF; 67 kB ]).
  • MB Plenio, PL Knight: The Quantum Jump Approach to Dissipative Dynamics in Quantum Optics . In: Rev. Mod. Phys. tape 70 , 1998, pp. 101–144 , arxiv : quant-ph / 9702007 (description of the dynamics of open systems using quantum leaps).

Web links

Wiktionary: Quantum Leap  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ^ A b Paul S. Epstein : On the theory of the strong effect . In: Annals of Physics . tape  355 , 1916, pp. 515, 517 ( limited preview in Google Book search).
  2. ^ Christian Speicher: A quantum leap in physics. In: nzz.ch. June 27, 2013, accessed January 21, 2018 .
  3. ↑ a b Klaus Hentschel : Quantum Jumps . In: Daniel Greenberger , Klaus Hentschel , Friedel Weinert (Eds.): Compendium of Quantum Physics: Concepts, Experiments, History and Philosophy . Springer-Verlag, Berlin / Heidelberg 2009, ISBN 978-3-662-51795-6 , pp. 599 , doi : 10.1007 / 978-3-540-70626-7 .
  4. ^ Adolf Smekal : Bohr's frequency condition and X-ray spectra . In: Negotiations of the German Physical Society . 1919, p.  149 f . ( google.es - see pp. 150, 154).
  5. ↑ Hellmuth Vensky: The cat pissacker named Schrödinger. In: The time. August 13, 2012. Retrieved December 19, 2017 .
  6. ↑ Werner Heisenberg : The non-illustrative quantum leap . In: Physikal. Leaves . tape  2 , no. 1 , p. 1946 , doi : 10.1002 / phbl.19460020102 ( wiley.com [PDF; accessed January 20, 2018]).
  7. ^ Paul S. Epstein: About the interference ability of spectral lines from the standpoint of quantum theory . In: Session reports of the mathematical and natural science class of the Bavarian Academy of Sciences in Munich . 1919, p. 79 ( limited preview in Google Book search).
  8. ↑ a b Merril Perlman: The history of using 'quantum' to mean 'really big'. In: Columbia Journalism Review. August 4, 2014, accessed December 12, 2017 .
  9. Jump up ↑ JC Bergquist, Randall G. Hulet, Wayne M. Itano, David J. Wineland : Observation of Quantum Jumps in a Single Atom . In: Phys. Rev. Lett. tape 57 , October 6, 1986, pp. 1699 , doi : 10.1103 / PhysRevLett.57.1699 (English).
  10. ↑ Search result "quantum jump" 1995-2019. In: arxiv.org. Retrieved November 19, 2019 .
  11. ↑ James Gleick : Physicists finally get to see quantum jump with own eyes. In: nytimes.com. October 21, 1986. Retrieved January 21, 2018 .
  12. ↑ Howard Carmichael : Quantum jump experiments . In: Daniel Greenberger , Klaus Hentschel , Friedel Weinert (Eds.): Compendium of Quantum Physics: Concepts, Experiments, History and Philosophy . Springer-Verlag, Berlin / Heidelberg 2009, ISBN 978-3-662-51795-6 , pp. 595 , doi : 10.1007 / 978-3-540-70626-7 .
  13. ^ Ernst Peter Fischer: Max Planck: History of Science . Complete Media, 2011, ISBN 978-3-8312-5683-9 , p. 6f ( google.com ).
  14. ↑ Glossary : Krachaktuell , Die Zeit, February 4, 1999; Retrieved December 19, 2017.