|Principles, philosophy of science: physical principles are not the same as laws of nature. Rather, laws can be gained from principles or traced back to principles. Examples are the principle of the shortest time, the principle of the smallest effect, the uncertainty principle. See also theories, laws of nature, laws, natural constants._____________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. |
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Irrevocability/principle/Genz: evolution explains why some principles seem irrevocable to us without being so.
Understanding/principle/principles/Genz: a deeper understanding is achieved if one can show that a theory can be derived from principles.
Theory of relativity/Einstein/Genz: has done this for the three theories of relativity.
Principles/Genz: Natural laws can be traced back to principles.
Principle/Principles/Explanation/Genz: final objective: explanation by principles.
God is not a mathematician - but a rider of principles.
Principle/Genz: For example, it could be that a successful physical theory defines a measured value which is clearly defined by the theory, but from its definition it follows that it cannot be calculated.
Principle/laws/science/physics/mathematics/relativity theory/Genz: the relativity theories can be founded retrospectively by principles. Einstein himself found it. The most important principle of the general theory of relativity:
Definition Equivalence principle/Genz: indistinguishability of gravity and acceleration.
1. Principle for the derivation of the Special Theory of Relativity: Light is - unlike sound - no vibration of a medium, resulting in the principle of the independence of the speed of light from the movement of the source. (Based on the physics of electricity and magnetism).
2. principle for the derivation of special relativity: the laws of nature shall apply to all observers who move in the same direction with constant and equal speed. (Can be traced back to Galileo).
Principles/Universe/Nature/Euan Squires/Genz: Thesis: in the universe, principles apply that can be seen and formulated without mathematics.
Mathematical laws of nature: are then nothing else but formalizations of these principles by more precise means.
Explanation: however, it is the principles themselves that enable explanation and understanding.
Description/Measure/Measurement/Relativity Theory/Squires/Genz: the General Relativity Theory declares it indispensable that we can describe the universe independently of the choice of variables for space and time. Here mathematics is even excluded!
Principles/Elementary Particle Theory/Particle Theory/Standard Model/Genz: the standard model follows from the principle that observers at different locations at different times can choose their conventions independently of each other without changing the laws: the same natural laws should apply everywhere.
Framework: in which this demand is formulated: is the relativistic quantum field theory. However, this is mathematical in itself.
Principles/Genz: thesis: the laws of nature follow from simple, non-mathematical principles. For example, the Dirac equation has been found mathematically, but it is a realization of laws whose form is determined by non-mathematical principles such as symmetry.
Mathematics/Genz: is like a servant here who separates equations that do not satisfy the principles.
Principle/Genz: what principles allow seems to be realized, no matter whether it is mathematically simple or not.
For example Hadrons: that they meet the requirements of group SU (3) seemed to follow first from a mathematical principle. Today it is known that hadrons are made up of quarks.
Principle/Genz: for the purpose of application, it may be necessary to formulate a principle mathematically. For understanding, however, we need the non-mathematical principles.
Progress/Genz: one can even say that in physics they are accompanied by the substitution of mathematical principles with non-mathematical principles.
For example Plato tried to explain the structure of the cosmos with five regular bodies. Kepler recorded this, and later they were replaced by the assumption of random initial conditions.
For example, spectrum of the hydrogen atom: was calculated exactly by a formula. Later this was understood by Bohr's atomic model.
Principle/Newton/force/Genz: For example, the force exerted by one body on another is proportional to the reciprocal of the square of the distance between the bodies.
That's mathematical. Newton himself could not base this assumption on principles. Only Einstein was able to do that.
Principles of quantum mechanics: see Quantum Mechanics/Genz._____________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.
Gedankenexperimente Weinheim 1999
Wie die Naturgesetze Wirklichkeit schaffen. Über Physik und Realität München 2002