torsdag 20 februari 2014

Physics Illusion 4: Elementary Particles, Quanta and Wave-Particle Duality

  • Sound is a wave phenomenon as local variation of a pressure field in air. Sound is not a corpuscular flow of sound particles named phonons flying from source to ear.
  • Light is a wave phenomenon as local variation of an electromagnetic field in a vacuum. Light is not a corpuscular flow of light particles named  photons flying from source to eye.

Modern physics dominated by elementary particle physics based on the Standard Model is based the idea of particles as pointlike (or stringlike) carriers of charge and mass (fermions) and forces (bosons).
The Standard Model today consists of a wild  zoo of 61 particles and physicists have since 50 years desperately been seeking alternative models with particles replaced by one-dimensional strings or two-dimensional branes, however without much success.

A pointlike elementary particle is supposed to have a dual wave character as a distributed field in what is referred to as wave-particle duality with the idea that both characters can show up in different situations, like Dr Jekyll-Mr Hyde or schizofrenia syndrom.

The carrier of the electromagnetic force is an elementary particle named photon, by which the propagation of light is described as a stream of photon particles, much like the corpuscular theory of light proposed by Thomas Hobbes in 1643 and adopted by Newton. The corpuscular theory of light was replaced by Huygen's wave theory of light once Newton had faded away and reached a completion with Maxwell's equations (1862) describing virtually all of electromagnetics including light by set of wave equations for electric and magnetics fields, an unprecedented triumph of mathematical physics.

With the formidable success of Maxwell's equations describing light as wave, one would imagine that any corpuscular theory of light could safely be put into the dustbin of scientific garbage, but then Einstein entered the game in 1905, stimulated by the energy quanta suggested by Planck in 1900 to avoid the ultraviolet catastrophe of blackbody radiation, with an idea of light quanta as a corpuscular particle theory of light picked up from the dustbin in an attempt to "heuristically" explain the photoelectric effect.

Einstein's particle idea then combined with the new atom physics in the form of quantum mechanics based on Schrödinger's wave equation, connected by a trick of wave-particle duality invented by Bohr.

Since schizofrenia is a serious syndrome, one may ask what makes modern physicists cling to a  primitive particle theory of light as a stream of photons, when there is an educated wave theory in the form of Maxwell's equations?

Why not get rid of the primitivism of a corpuscular theory of light once and for all? Or is a corpuscular theory of light only a harmless heuristic way of thinking, which we can use if we want to explain things to kids?

No, it is not harmless and in fact the opposite because it creates artificial mysteries draining human and material resources with questions without answers like:
  • What is a photon particle?
  • How do photon particles travel? 
  • What is the speed of a photon particle?
  • How do photon particles interact with matter?
To understand how silly these questions occupying physicists minds, let us compare light with sound:
  • We know that sound is a wave phenomenon of pressure variations supported by vibrating air molecules. 
  • We know that sound is not a stream of sound particles as phonons from source to ear. 
  • We know that transfer of sound from source to eardrum is a resonance phenomenon between two resonators (vibrating membrane of loud speaker and eardrum) connected by a medium (air) supporting pressure variations transferring forces from membrane to eardrum.
The analog for light is developed as Computational Blackbody Radiation explaining that blackbody radiation is a resonance phenomenon of electromagnetic waves with a high-frequency cut-off avoiding the ultra-violet catastrophe by finite precision computation. 

In short, there is as little reason to speak about photons as light particles as there is to speak about phonons as sound particles. 

It is true that a simple mathematical model of sound propagation can be formulated as a particle model with sound particles moving along straight lines combined with simple reflection laws:

But this is only a simple mathematics model and does not describe the real physics of propagation of sound as a wave phenomenon. Neither does a particle model for light have anything to do with the real physics of light as wave.

The term elementary particle is thus misleading and should better be replaced by something like elementary wave. Hopefully the zoo of elementary particles can then be reduced to a smaller number of elementary waves. This the basic idea of string theory, which however is set to the excessively small size of Planck's quanta $\sim 10^{-34}$ beyond any physics rationale.

Quantum mechanics is a wave theory for atomic dimensions in which particles serve no purpose.

2 kommentarer:

  1. In short, there is as little reason to speak about photons as light particles as there is to speak about phonons as sound particles.

    This is a straw man argument.

    You are building your argument on sound in a fluid, where phonons are excitations in a solid. And still further, some phonons are connected with sound in a solid, but not all! This is a very important point. Phonons are used to explain and model a lot of different thermodynamic and transport properties in solids and are quantum mechanical in nature. It is by all means a quasiparticle! There are still som classical phenomenons that can be modelled with phonons, like sound propagation for instance, it is after all a long wave phenomena.

    Still further, waves in a fluid propagate through a medium, while light in a vacuum doesn't propagate in anything that is known so how can one make a comparison?

    Making a comparison like that is very poor physics!

  2. Both are wave phenomena described by similar wave equations and so a comparison is natural.