Debates on Quantum Physics

Quantum mechanics is a difficult and involved topic, and this page has been added to discuss alternative views, published and/or communicated directly with me.

Dr David Harriman’s “Philosophical Corruption of Physics”

At the Lyceum Summer ’97 Objectivist Conference, David Harriman presented a course on “The Philosophic Corruption of Physics”, a version of which is available from Ayn Rand Bookstore. One thing he showed was the strong influence, on the development of quantum mechanics, of the philosophy championed by Ernst Mach. This held that all physics could and should do is describe the relationships between appearances, which are all reality is. The final effect of this was the belief that “matter is just an image in our mind”: a belief which pre-dated quantum mechanics. Rather than being a logical consequence of quantum mechanics, as claimed by its proponents, this was actually the assumption behind their subjectivist interpretations.

In discussions after this course, the interpretation of quantum mechanics I have described above — that quanta are waves while travelling, yet are absorbed as discrete packets — was criticized on the basis that it violated “locality”. That is, information about that absorption (or whatever other “quantum” interaction we are concerned with) must somehow be “made known” to the rest of the wave at faster than the speed of light. However, that violation of locality, first proposed in Bell’s Theorem and subsequently apparently confirmed in lab experiments, appears to be an experimental fact, even over distances greater than 10 km (see Science 277:481 (1997)). Dr Harriman’s interpretation of Bell’s Theorem was that it could be explained by the instruments influencing the results. However, my understanding of the recent results indicate that faster-than-light transmission of information on the quantum states would still be required even then. (Note that this violation of locality still does not allow communication at speeds faster than light, as you have no control over the quantum correlations involved; also note that Little’s Theory of Elemental Waves purports to provide an explanation for the results without violating locality). (Note added November 2001: Subsequent to the above events, Dr Harriman has criticised Dr Lewis Little’s Theory of Elemental Waves (see below) on the grounds that locality is indeed violated).

Therefore, I stand by the interpretation of quantum mechanics proposed above. Whether and when the structures of quantum waves “break down”, so that, for example, the two “far ends” of the wave are no longer part of the same wave, and their quantum interactions are no longer correlated, is another matter, and something that can be answered only by future scientific inquiry. But for the present, I see no contradiction between the science of quantum mechanics and the absolutism of reality.

Quantum Entanglement Despite Photon Absorption?

The thoughtful gentleman Daan Strebe has discussed a number of issues regarding my interpretation of quantum mechanics. The most pertinent is an experimental result in which light traverses a silvered mirror (so its wave goes half one way, half another). At both destinations beyond the mirror is a substance which converts a single photon into two photons each of half the original energy. If these are reflected back, the waves can interfere constructively or destructively depending on the relative path lengths. This occurs even if only a single photon is involved. Yet if my interpretation is correct, the photon is absorbed at only one place, so the re-emitted wave comes from only that point, so there should be no interference pattern.

If these results are as claimed, at first appearance they would disprove my interpretation, as the “wave functions” appear to remain “entangled” even after photon absorption. However, from the description of the experiment (particularly, precise conversion of one photon to two of half the energy, and simultaneous emission from both paths), it sounds like the wavelength doubling found with “nonlinear crystals”. What I propose is happening is that there is no photon absorption involved: the wavelength doubling is a wave phenomenon, not a particle one. In that case, there is no “collapse” of the wave function: it remains a wave throughout, hence the continued wave interaction is to be expected. If this explanation is correct, then the phenomenon described cannot be used to locate the “position” of a photon. For example, one could not make a photon-path-detector out of it which would destroy the diffraction pattern in the famous single-photon, double-slit diffraction experiment.

If that prediction is wrong, then absorption is involved.But that is not the end of the matter. Then I would say that a photomultiplier (as used to detect the wave interference) is different: there are some wave -> quantum -> wave phenomena in which the interaction collapses the wave function, and others in which it doesn’t. While I can’t understand why this would be so, I admit the possibility for the sake of argument. This hypothesis is easily tested. Set up one of the above mentioned single-photon, double-slit diffraction experiments in which leaving out the measuring device gives you a classic diffraction pattern but including it destroys it. Allow no living thing to actually see the results of the photon detector. If the diffraction pattern is still destroyed, then the collapse of the wave function is due to simple quantum absorption by a physical system, and since this doesn’t always happen, collapse of wave functions is caused only by certain types of quantum interaction. Of course, it would be fascinating to find out what and why.

In the amazing case if the diffraction pattern is not destroyed, only then we have proved that a conscious observer is necessary for collapse of the wave function: and life gets really interesting! This becomes a whole new ball game, if we could show that consciousness has that power. However, even that bizarre result – which I don’t believe is possible – wouldn’t actually give any comfort to subjectivism. The people who report such experiments with the most glee are the first to point out (with yet more glee!) how unexpected and counter-intuitive they are. Which proves the observer isn’t causing the result. Even if consciousness somehow caused the final collapse of QM waves, they are collapsing according to their own nature, irrespective of the preconceptions or wishes of that consciousness.

Now, this of course would be rather earth-shattering in its implications. Indeed, it would open up a whole new area of physics (including the answer to the question, “Is a cat conscious enough?” [referring to whether Schroedinger’s cat is a suitable observer of its own demise]). But all (!) we have done is add “conscioustrons” to our panoply of interacting things. We still have no input into how they behave. Unless we can do another experiment in which the physicist makes a diffraction pattern appear and disappear according to his expectations or whim rather than reproducibly according to nothing but the experimental setup. But one thing the history of QM shows, is that quantum systems act reliably according to their own nature, whatever the experimenters’ hopes or fears.

Dr Lewis Little’s “Theory of Elemental Waves”

For an interesting alternative reality-based interpretation of quantum mechanics, the “Theory of Elementary Waves” (TEW) proposed by Lewis Little is worth investigation. Basically, this postulates that elementary particles are in fact particles, and their apparent wave-like properties and all the resulting “quantum weirdness” is due to the interaction of those particles with separate entities, “elementary waves”, which fill space, are purely waves and which carry information about the quantum states of all matter in the reverse direction to the particles. It is claimed that this theory, which does away with wave-particle duality entirely, is not only consistent with all the experimental results so far, but makes certain precise predictions that differ from the wave-particle model and which therefore provide a means for experimental testing. Further details can be found on the TEW website.

TEW is a very interesting theory, and I look forward to experimental testing. However, I consider it premature to present it as “the answer” to quantum “weirdness”. It may very well be the answer, but I think it unwise to link philosophy to science in such a way that the validity of a particular scientific theory reflects on the validity of a philosophy of reality and reason.

TEW appears to say that light, for instance, is a particle (photon) and its “wave” properties are a result of the actions of the elementary waves. But from my understanding of the science, there is no doubt that light is an electromagnetic wave. I would be interested if anyone has any intelligent comment on this aspect.

For my original discussions of quantum mechanics, see Holes in the Heart of Reason and Subjectivism, Reality & Quantum Physics. Also see On the Nature of Quanta, for an hypothesis on the true wave nature of quanta and the origin of particles.