# Psychology Dictionary of Arguments

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Time reversal: Time reversal is a theoretical concept that states that the laws of physics could remain unchanged if the direction of time is reversed. See also symmetries, laws, laws of nature, asymmetry, time.
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Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments.

Author Concept Summary/Quotes Sources

Hennig Genz on Time Reversal - Dictionary of Arguments

II 254
Time reversal symmetric/Genz: for example, "angle of incidence" = "angle of reflection" is time reversal symmetric, i.e. it would not be possible to determine whether a film with billiard balls runs backwards.
II 255
Reflection/time reversal/Genz: the same applies to all reflection processes, forward as well as backward deterministic n.
>Symmetries
.
II 256
If there was a law: "angle of reflection = half angle of incidence", we would have no time reversal symmetry and we could see a film running backwards.
II 256
Time inversion invariant/Genz: e.g. Newton's laws of planetary motion: the directions in which the planets move could be reversed. Therefore, a film running backwards would not be recognizable.
>Laws/Newton.
Quantum mechanics/not time inversion invariant/Genz: the laws for elementary particles are excellent in one direction.
>Quantum mechanics.
II 259
In the last 200 years, the Earth was 4 hours slow, if one wanted to calculate a solar eclipse. Eventually the moon will stand still for the earth in the sky.
N.B.: in a backward running film, the tides would have the opposite effect that the earth rotates faster instead of slower! Thus the time directions have become distinguishable. By comparing the two processes.
N.B.: but we cannot tell from them which one is the real one and which one is the manipulated one.
Tides: the laws of the tides cannot be fundamental like those of the K mesons. They do not include the origin of deformations. They are not time-reversal symmetric.
Time-reversal symmetric: are fundamental laws about the collisions of molecules.
Time reversal symmetry/problem: how can symmetric laws of nature lead to processes that are not symmetric themselves?
Asymmetry/Genz: it is not the laws that are responsible for them, but the initial conditions or circumstances.
Order/Law/Genz: the superordinate law in such cases is that order cannot increase.
>Order.
II 258
Asymmetry/time reversal/Genz: asymmetry is much more pronounced in macroscopic (tides) than in microscopic (K mesons).
Tides: the law that the rotation of the earth slows down is forward
deterministic, but not backward deterministic! For example, because it is not possible to tell from a standstill how long ago the rotation came to rest.
>Tidal force.
There are many ways in which it has come to a standstill, but only one more to rest. The direction of time cannot be inferred from the observation of the standstill.
II 260
This does not mean absolute rotation, which is marked by centrifugal forces, but relative to the moon.
Friction/Genz: friction leads to time reversal asymmetry. (If you brake until standstill). Then we see in the backward running film a course of events prohibited by the laws of nature.
II 261
Statistical fluctuation/Genz: statistical fluctuation does not indicate a time direction.

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Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments
The note [Concept/Author], [Author1]Vs[Author2] or [Author]Vs[term] resp. "problem:"/"solution:", "old:"/"new:" and "thesis:" is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.

Gz I
H. Genz
Gedankenexperimente Weinheim 1999

Gz II
Henning Genz
Wie die Naturgesetze Wirklichkeit schaffen. Über Physik und Realität München 2002

> Counter arguments against Genz
> Counter arguments in relation to Time Reversal