MonoRealism Philosophy Site

On the Nature of Quanta

Introduction

Previously I have proposed that there is no fundamental mystery to the "contradictory" behaviour of quanta. Quanta propagate as waves and are absorbed as particles; that is their nature; and that is how they always behave. This still leaves unanswered how to unite these qualities into a single consistent concept of their nature.

I wish now to propose a more fundamental way of conceptualising the nature of quanta.

Dr Lewis Little has approached the wave/particle duality of light and fundamental particles by proposing that they are particles, whose wave-like properties arise from the influence upon their motions by waves travelling in the opposite direction.

I propose an opposite interpretation. Quanta are not particles whose wave-like properties can be explained by some kind of pilot wave, but they are in fact waves whose "particle-like" aspects have another explanation.

I believe this gives an interesting conceptual basis for further investigation. On the face of it, it explains:

  • Diffraction and other wave phenomena of quanta;
  • Why the particle nature of light, electrons etc is a misinterpretation;
  • What an actual particle is and how it comes to be - and how it can still behave as a wave sometimes

In the following I will mainly deal with light (by which I mean electromagnetic radiation of any wavelength) that is emitted or absorbed by atom-bound electrons, as I find it the most simple to visualise.

Primary Considerations

When considering the production of radio waves, which are a simple result of oscillating electrons emitting electromagnetic radiation, I find it hard to escape the conclusion that this is what such radiation is: waves.

But what evidence is there for particles? As far as I am aware, it is simply that light is emitted and absorbed in discrete quantities of energy at discrete positions in space. But that conclusion does not follow from the observations. Energy exchanges in discrete quantities do not imply particles: all it implies is that there is some mechanism by which light is absorbed in discrete amounts at discrete locations. If a wave theory can incorporate this phenomenon, the mysterious duality disappears.

Development of the Model

Assume that de Broglie's model of electron orbits is an accurate description of reality. That is, electrons exist in atoms as standing waves around the nucleus. The reason discrete amounts of energy are required to lift them to a higher state is that because of the nature of standing waves, only discrete states exist. Similarly for the emission of discrete amounts of energy. The reason that light is absorbed in a discrete place is the same as the reason it is emitted in a discrete place: every photon is emitted or absorbed by a single electron, and those reside around particular atoms.

My fundamental conceptual proposal is this:

  1. The absorption of light to lift electrons to a higher orbital and the emission of light on falling to a lower orbital are not due to a "particle" of light "hitting" an electron, but to a wave-wave interaction between the electron wave and the electromagnetic wave.
  2. This interaction is frequency-dependent, such that the frequency of light required is proportional to the energy difference between the electron's relevant orbital levels.
  3. The actual energy is spread over the light's wavefront: the higher the amplitude, the higher the energy density.
  4. Consequently, an electron is shifted to a higher orbital when:
    • Light of the required wavelength interacts with the electron, and
    • The required energy is available from the total accessible wavefront
    • That energy is localised as it is effectively "sucked up" into the electron from the required area of wavefront
  5. Similarly, when an electron drops from a higher orbital to a lower one, it produces light of the appropriate wavelength (appropriate to the energy difference), with a total energy equal to the orbital energy difference, spread out over a spherical or directional wavefront depending on the details of the emission.

In summary: the absorption of "photons" is localised to one place because such absorption always involves interaction with a single electron wave, usually one bound to an atom; the proportionality of "energy" to frequency is an effect of a requirement for a specific frequency in whatever wave-wave interaction is involved (say, some kind of resonance); and the actual energy required is pulled out of the required area of wavefront.

An Explanatory Thought Experiment

Say that when an electron in an atom of element X drops from energy level A to energy level B, it emits a "photon" of wavelength 300 nm with energy E.

Let us design a simple experiment to show the quantum nature of photon absorption. Our single-photon emitter consists of an atom of element X with an electron in energy level A, which we induce to drop to level B, emitting a 300 nm photon. Our detector consists of X in the lower state, and it detects or "observes" our photons by absorption, bumping up an electron from level B to level A. We can readily demonstrate the usual quantum mechanical results with this arrangement: e.g. a photoelectric-type effect (only photons of 300 nm will do the job, and a single photon will bump up 1 electron, 2 photos will bump up 2 electrons, etc); and with a double-slit arrangment, we can show diffraction of our single-photon waves.

But why is it imagined that this has anything to do with light being a "particle"?

Clearly, if every time an electron of X drops from A to B it emits the identical amount of energy E via light of wavelength 300 nm, then there is something about the physical nature of that orbital shift which requires the production of 300 nm light. Given that, it is to be expected that the reverse process, the bumping up of an electron from B to A, requires absorption of the identical amount of energy of the identical wavelength!

Implications

The propagation and absorption of light is perhaps most easily visualised as a soap bubble being inflated until it hits a pin. The expanding soap bubble represents the light wavefront of a single photon emission, and its thickness is like the amplitude/intensity/energy density of that wavefront; the pricking of the bubble on the pin is like the "point-like" absorption of the photon by an electron. Of course, the pin doesn't absorb the bubble, but the analogy is still useful. As with light, the propagation of the "destruction" through the "wavefront" is much faster than the outward progress of that wavefront.

Thus, this model requires that the "sucking up" of the requisite energy, which must be propagated through the wave front, is much faster than the speed of light itself. This is the same principle behind the "non-locality" of quantum events which has been experimentally confirmed: this non-locality is again just intra-wave collapse at super-luminal speeds.

Further, the model proposes a small but non-zero amount of time between the beginning of coupling of the light and electron waves, and the successful bumping up of the electron's energy level. It is during this time that the "sucking up" of the required area of wavefront, containing the required total energy, occurs. If insufficient energy can be found within that time - for example, the wavefront is too disperse, or another electron "beats it to it", the coupling and consequent orbital-jump will fail. What happens if the wavefront of a single photon has expanded so far that there is no longer time for its dispersed energy to be absorbed by this means? Perhaps it can no longer be absorbed (unless the wave locally overlaps another one, so the sum is enough), or perhaps at a big enough size the wavefront fragments into "pieces", each small enough to maintain communication from one end to another at the intra-wave speed of collapse.

Other Quanta

While this is easiest to see when dealing with light, owing to the way it is produced and absorbed, since all subatomic particles show the "wave-particle duality", they are actually waves too.

I propose that this is in fact the explanation of all quantum "weirdness". "Correlations" exist purely because we are dealing with a single wave; super-luminal "communication" occurs because "collapsing a wave function" is literally collapsing the wave, which occurs at superluminal speeds within the wavefront. But such "collapsing" can only occur at discrete points where the wave is absorbed (etc), giving the illusion of being a particle.

The Origin of Particles

According to this model, light is never a particle. Its apparent particle-like nature is simply due to the fact that light can only be absorbed in a single place (e.g. where an electron is), and that takes both a specific frequency of light and a discrete amount of energy (the amount the electron needs to jump to a higher orbital). Similarly, I think electrons are never particles, but always waves. I suspect the same of quarks.

An atom, however, is a "particle" because it is effectively a little "ball" consisting of a nucleus surrounded by standing waves of electrons. The electron "envelopes" of atoms (ignoring those which react chemically) cannot interpenetrate except perhaps at extreme speeds, due to electrostatic repulsion. Thus such atoms are particles - discrete objects which will bounce off each other like balls due to presenting an impenetrable "wall" of mutually repelling electron wave to each other. Similarly, nucleons - which provisionally I propose to be standing quark waves "orbiting" each other - are particles.

Yet even whole atoms attain wave-like qualities under certain circumstances. However, I believe this is because these particles are made up of waves - their nucleons and electrons - and under the appropriate circumstances behave like the composite waves they are. I think that their wave-like behaviour must be much more restricted than that of light or electrons, those waves being generally tied up in mutual orbits.

Further Questions

While conceptually this makes sense to me, I don't have sufficient of the maths and physics to work out a rigorous formulation, or to know if there are fatal flaws. Assuming it passes that test, these interesting questions are raised:

  1. What is the nature of the frequency-dependent interaction between electrons and light which requires or produces a specific frequency for a specific change in energy level?
  2. What is the speed of wavefront collapse (this will also be the speed of nonlocal "entanglement communication")? Philosophically, this cannot be infinite.
  3. What happens when a wavefront approaches or exceeds the area where it can no longer collapse in time to enable its absorption? Does it fragment, or just become immune to absorption without "help" from other overlapping wavefronts?
  4. Can the model really explain the wave-like nature of composite particles such as atoms and molecules? (This is probably not an issue: if the Schroedinger Wave Equations explain it, then so does this model)
  5. What is vibrating? Electromagnetic waves are presumably vibrations in electric and magnetic potentials, but what is vibrating to make an electon or quark?
  6. How do "matter waves" such as electrons transfer charge and mass when they move from place to place, and why is that charge and mass also quantized?

The greatest conceptual difficulty I have with the model is the nature of matter, as per questions 4-6. However I think it so neatly explains the nature of light that it is worth further exploration.

Testing the Hypothesis

One area in which I think the predictions of this idea differ from standard ones is indicated by the experiment proposed by Roger Penrose for testing the rate of "decay" of quantum superpositions in larger objects. In this experiment, a single-photon wave is sent along "two" paths and bounces off two identical macromolecular particles whose positions are then entangled, on the theory that both are simultaneously hit and not hit by the photon.

I believe that the force on the particle in this case is actually applied by the reflection of the wave as a wave: in which case, both macromolecules will be pushed back to the same degree, that being "half a photon's worth". It is possible that this prediction is inaccurate, as I'm not conversant with the relevant maths (perhaps the effect on the particle is in fact due to photon absorption). However the results of such an experiment will be extremely interesting.


For my original discussions of quantum mechanics, see Holes in the Heart of Reason and Subjectivism, Reality & Quantum Physics.

© March 2002; Expanded in September 2006 Robin Craig