Quantum object

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Quantum object (or micro-object ) is a term used in quantum theory to relate the experimental results described by observables to an object in the sense of classical physics (such as “particle” and “wave”). This applies in particular to elementary particles and other objects of comparable mass, i.e. objects in atomic and nuclear physics , but also larger particles such as molecules if they have low kinetic energy and thus a large De Broglie wavelength .

Conceptual problem

Quantum objects show results in experiments which, according to the ideas of classical physics, suggest that these quantum objects must be particles and waves at the same time .

With quantum objects, phenomena occur that contradict our experience, which was shaped by macroscopic objects. Such phenomena are, for example, that an object in the double slit experiment seems to go through two slits at the same time and thereby "interferes with itself" ( Dirac ), the collapse of the wave function during observation, quantum entanglement and related quantum teleportation , the quantum eraser or Bose-Einstein -Condensation .

This epistemological problem is based within the quantum theoretical formalism on the fact that not all possible measured values, e.g. B. Place and impulse , can be ascribed at the same time, which was natural for an object of classical physics, i.e. everyday experience. It is said that certain observables cannot be objectified at the same time in quantum physics .

Interpretations

Since the 1920s it has been customary to circumvent this problem in the sense of the Copenhagen interpretation by dispensing with an objectification in quantum physics , i.e. the conception of objects in the "microscopic quantum world", and describing them with an instrumentalist language, as it appears to us when examining with classic measuring instruments.

The communist ideology , which could not do without the objectivity of measurement results, rejected the Copenhagen interpretation as agnostic and understood the different manifestations of quantum objects shown in the experiment as a physical confirmation of dialectical materialism . Accordingly, the real existing matter contains a contradicting character, which in the case of the quantum objects was called “wave-particle dualism”.

Not least the understanding of superconductivity and superfluidity with the help of quantum theory led to the fact that - in contrast to the Copenhagen interpretation - the devices required for quantum mechanical measurements were now also described with the help of quantum theory. A theory of the quantum mechanical measurement process was developed, but it continued to describe only the behavior of the observables.

In the second half of the 20th century, a rational interpretation of quantum mechanics was developed, whereby the classical object concept developed by Immanuel Kant was modified in such a way that, using quantum logic within the framework of a specially developed formal language, the quantum objects were understood without contradiction as components of a real outside world can be. Within the framework of this method, quantum objects are constituted on the basis of a “ quantum ontology” in such a way that the apparently contradicting experimental results no longer require “interpretation”, but are directly understandable consequences of this ontology.

literature

  • Brigitte Falkenburg : Language and Reality. In: Foundation of Physics 40 (2010), pp. 1171–1188, here in particular pp. 1181–1184: The Constitution of Quantum Objects.
  • Peter Mittelstaedt : Language and Reality in Modern Physics. Mannheim 1986. ISBN 3-411-00650-1 .
  • Peter Mittelstaedt: The object concept in Kant and in contemporary physics. In: DH Heinemann, K. Engelhard: Why Kant today? Systematic meaning and reception of his philosophy in the present. Berlin 2004. ISBN 3-11-017477-4 .
  • Peter Mittelstaedt: Rational Reconstructions of Modern Physics. 2nd edition Doordrecht 2013. ISBN 978-94-007-5592-5 .

Web link

Individual evidence

  1. ^ Mittelstaedt: Rational Reconstructions of Modern Physics. Pp. 118-119.
  2. ^ Philosophical dictionary. 10th edition, Berlin 1976, ISBN 3-920303-35-0 , pp. 358-361.
  3. ^ Mittelstaedt: Rational Reconstructions of Modern Physics. S. 120.
    Mittelstaedt: The Interpretation of Quantum Mechanics and the Measurement Process.
  4. ^ Mittelstaedt: Rational Reconstructions of Modern Physics. Pp. 121-122.
    Mittelstaedt: Language and Reality in Modern Physics. Esp. Pp. 70-117.
    Falkenburg: Language and Reality. Pp. 1181-1184.
    Mittelstaedt: The object concept in Kant and in contemporary physics. An easy to understand summary.