Paradigms
and Assumptions in Physics| Paradigms
and Assumptions in Physics |
In General
* Underlying assumptions:
The universe is governed by few, understandable laws; Physics takes place in
a smooth continuum spacetime; The assumptions change
as our knowledge increases, especially recently regarding the role of
determinism and predictability, locality, stability; And quantum gravity
challenges our view of spacetime.
* Practical idealizations:
Fields are defined by limits of vanishingly small charges; Cannot be done
operationally.
@ References: Margolis 93; Holton FP(96)
[role of themata].
Copernican
* Idea: There is nothing
special about our position in the Solar System (originally), or the Universe;
Has been formalized as the cosmological principle; > s.a. cosmology [including
anthropic principle].
Hierarchical
* Idea: Different levels
of description give different laws; The fundamental scale in questions asked
is related to physical length scales;
This theme is associated
with the concept of incomplete (as opposed to right or
wrong)
theory.
@ References: Cui ht/01 [levels
of description for particles]; Kulish 02 [electrodynamics].
Reductionism (of complicated things to simple ones) > s.a. complexity;
Emergence.
* Idea: Substance is
fundamental.
* Examples: Planetary motion reduced to simple orbits; Properties
of matter to atoms, particles.
* History: The idea can
be traced back to Leucippus' and Democritus' atomistic theory, and is related
to the concept of a model; Has been recently challenged
by
emergence ideas in quantum theory, complexity/chaos and computation (earlier
opposition by J W von Goethe [@ in Gleick 87] or D'Arcy Thompson [biology]);
1980's, A paradigm shift
is under way.
@ References: Rohrlich FP(89), FP(90); AS 78(90)14–15 & refs
there; Cohen & Stewart
94 [I]; Cornwell ed-95; Casti SA(96)oct [models];
Price qp/96-in
[independence of systems]; Harte PT(02)oct
[simplicity vs complexity]; Forster 03 [in mathematical logic]; Gunter CSF(05)
[history]; Morrison PhSc(07) [new ways of thinking, condensed matter and other
areas].
Symmetrical > s.a. symmetry.
* Remark: A very powerful theme, that reduces many problems of numerical
naturalness to questions of structure.
* Hidden symmetry:
The apparent symmetry of the world can vary with the length scale and the
state of the system; Systems with hidden (or spontaneously
broken) symmetries usually support wave motions.
Unification > s.a. physics [theories of everything]; unified
theories.
* Idea: Understanding seemingly different phenomena in a unified
way (e.g., unification of interactions), and relating different levels
of description
of reality (s.a. hierarchical above).
@ References: Cat HSPBS(98) [XX cy].
Causality > s.a. causality;
Predictability; Teleology.
* Idea: There is a hierarchy of properties a theory may have, that
goes causality → determinism → predictability.
Related Topics > s.a. field
theory, quantum field theory [linearity]; information; spacetime.
@ References: Israel FP(96)
[permanence of matter, continental drift and compact stars]; Svozil FP(02)
[conventionalism, in special relativity and quantum mechanics].
> Other: see locality; mach's
principle; realism.
> Working assumptions: see Large
Number Hypothesis.
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Send feedback and suggestions to bombelli at olemiss.edu – Modified
5 jul 2008