The development of physics#

Reference: 20150319 物理大師楊振寧院士 科普講座 美與物理學

The above online video is given by Prof. Chen-Ning Yang. It is a worth watching video. Unfortunately, it is only offered in Mandarin. One of the interesting discussion is about the structure for physics development.

There are usually four steps

  1. Experiments

  2. Phenomenological theory

  3. Theoretical framework

  4. Mathematics

Each parts are iterated between each other several times and eventually they are established in a self-consistent way.

For example,

In classical mechanics, we study the dynamics of particles acted by forces.

  1. Experiment: Observation of the orbits from earth- Tycho Brahe

  2. Phenomenological theory: Kepler’s laws of planetary motion- Johannes Kepler

  3. Theoretical framework: Newton’s law of motion- Isaac Newton

  4. Mathematics: Calculus

In electromagnetic theory, we study the dynamics of fields that mediated the forces. The simplest gauge structure in nature.

  1. Experiment: Coulomb et. al.

  2. Phenomenological theory: Michael Faraday, Andre-Marie Ampere

  3. Theoretical framework: Maxwell’s equations

  4. Mathematics: Fibre bundle?

In quantum mechanics, we study objects that has the dynamics that has the particle and wave nature. A little bit of the mixture of the previous two…

  1. Experiments: Black-body radiation- Gustav Kirchhoff, Josef Stefan

  2. Phenomenological theory: Planck’s law- Max Planck

  3. Theoretical framework: Quantum Mechanics- Werner Heisenberg, Erwin Schödinger, Paul Dira, Max Born, etc.

  4. Mathematics: Hilbert space

In thermodynamics, we study a system with macroscopic number of degrees of freedom.

  1. Experiments: ??

  2. Phenomenological theory: Thermodynamics- Carnot,James Prescott Joule, Rudolf Clausius

  3. Theoretical framework: Statistical Mechanics -Ludwig Boltzmann, James Clerk Maxwell, Josiah Willard Gibbs

  4. Mathematics: ? or simply too many…