This article by W. A. Scott Murray was originally published in the June 1982 issue (pg. 80) of Wireless World.
Link to plain html file: Theories-and-Miracles--Scott-Murray-June-1982.html. This is still the best way to read a text article (zooming in/out re-typesets the entire article). Download the file and open in any browser to read.
Summary
The phenomenon of the radiation of light and radio energy is a "miracle" — a well-established physical occurrence for which science can offer no physical explanation. Modern technology uses these radiations and others every day without understanding them. Progress toward understanding such things effectively came to a halt in about 1920, after which fundamental concepts in physics began to become confused and mutually contradictory. This lack of progress may have been due to one of two possible factors. Either Nature is too mysterious for us to understand, so that it is not worth the bother of trying, or our fundamental thinking may have taken a wrong turning 50 years ago. There are historical precedents both for such errors and for conservative pressures against correcting them. Nevertheless, enough material now exists to warrant a major re-think, based on a return to the earlier philosophy of realism in physical science which reflects the underlying simplicity of Nature.
Many thousands of professional radio engineers can design television transmitters, and almost anyone can build a radio receiver, but there is nobody who can explain in a plausible and watertight way how radio energy comes to be transferred from the Crystal Palace transmitting tower to the H-aerial on the roof of my house. This transfer of energy — the radiation process — is miraculous, if we define a "miracle" as a physical occurrence for which we can offer no physical explanation. (I'll just say that again: a miracle is a physical occurrence for which we can offer no physical explanation). It is just over 100 years since James Clerk Maxwell gave us a good working description of what happens — the equivalent of saying that if you lie in hot sunshine you will get sunburned — but he did not explain the radiation phenomenon; and nobody has explained it since.
Here, then, is a fine example of modern technology in action. We know how to build a radio transmitter and we can calculate very accurately what will happen when we switch it on. Something will travel from transmitter to receiver at the speed of light, and we shall be able to detect its arrival and make whatever use of it we please for our convenience and entertainment. But except that it may consist of physical energy, or at least that it may carry physical energy with it, we have no idea what it is that does the travelling.
Confronted with this true statement of our human ignorance, ninety-nine people out of every hundred will probably say they do not care. The radio is for listening to, not wondering about; wondering about such things is a job for scientists. But now we come to the crunch, for I have to make a similar report to you about the attitudes of the scientists themselves. Nine out of every ten physicists today would also say they didn't care — they are far too busy to be bothered with such abstract, impractical matters. On the other hand, the one physicist in ten who does care about such things is likely to be seriously worried.
If one were to identify and question this minority, their consensus view would almost certainly be that vast gaps exist in our knowledge of physical phenomena that take place not only in complex laboratories and remote galaxies, but also "right on our doorstep" — of which domestic radio radiation and sunlight are commonplace examples. From a purist point of view it is a pity that our progress in understanding such things should have come to a grinding halt in about 1920. (The fundamental basis for atomic energy was laid by Einstein in 1907, and that for the laser in 1917.) Of the new concepts which have arisen in physics since that time very few, if any, have dealt credibly with fundamental matters. I include in this category the major speculative adventure of the 1930s, which failed amid general confusion and is one of the main topics to be examined here.
There would seem to be little doubt that progress in fundamental physics, as opposed to technology, has not kept pace with contemporary progress in other branches of science during the past fifty years or so. It should have done, in view of the number of physicists at work all over the world, but it hasn't. Every now and then, it is true, some new hypothesis seems locally promising and is hailed as a triumph; but when one seeks to apply it elsewhere it does not fit, and it leads one sooner or later to a logical impasse. Nowadays, for reasons that we will explore in due course, we no longer reject a failed hypothesis as we should, but instead we tend to retain it on the pragmatic basis that it may prove more useful to have wrong concepts than no concepts at all. From that point it is very easy to forget that they are wrong concepts — scientifically disproved — and instead to go on building upon them as if they were true and valid: an elementary mistake, surely, but one which we go on making.
There are countless examples of this trouble in modern physics, so that it is the rule rather than the exception. The cumulative effect of such errors has been confusion on a majestic scale. We are left with a tangle of separate, uncoordinated, and very often mutually-exclusive concepts. "Sometimes light behaves as waves, sometimes as particles", it is said, yet the concepts of electromagnetic light-waves and particles (photons) are mutually exclusive. Our picture of the physical world has become less clear, rather than more clear, with the passing years. This, I submit, is evidence of a lack of progress. In the 1980s we have to admit that we have not yet found answers to some simple but important questions which were asked as long ago as 1920, and even earlier.
Now when you have been searching diligently for something for fifty or sixty years and failed to find it, it may be sensible to pause and consider whether there might not be some reason for the failure. In our present case two possibilities are more likely than others: either the thing we are looking for doesn't exist, so that we are mistaken in looking for it, or we are looking for it with the wrong kind of spectacles. Let us examine these two possibilities in turn.
There is a doctrine of modern physics, whose origins we will identify later and criticise, which says that scientific theories are limited in their application to providing descriptions of physical events, and are intrinsically incapable (in an absolute sense) of explaining them. According to this doctrine, questions of the nature "what happens?" may give rise to descriptive answers — in numerical detail, of course — and are legitimate questions, whereas questions of the type "how?" or "why?" cannot be answered by science and are therefore improper questions which should not be asked.
To take an example, experiments show convincingly that all negative electrons are identical in their behaviour — "indistinguishable" in the approved jargon — and that short of its complete annihilation the physical properties of an electron never vary in any way; one never comes across bigger or smaller electrons, or parts of an electron. Now: to the question "Why is the structure of an electron so phenomenally stable?", current doctrine returns the answer that the mass of the electron is so small that its structure must be quantum-indeterminate, which means that the question of its mechanical stability does not arise. That question is a non-question, an irrelevance that does not require an answer.
For convenience of reference I propose to call this the Doctrine of Haziness: "Microphysical entities are hazy, and one should not ask old-fashioned questions about them". Personally I am very suspicious indeed of this doctrine. It seems to be just a little too flexible in its application to be intellectually honest. For instance, in another example,
Question: Why are the wavelengths of the spectrum lines from a gas in a discharge tube so precisely defined?
Answer: Because the permitted energies that electrons can assume within the atoms are precisely quantized.
Question: Oh — I thought it was the electron's angular momentum that was quantized?
Answer: That is also true. Both energy and angular momentum are precisely quantized.
Question: If that is so, then the position of an atomic electron must be precisely determined. How far is it from the nucleus?
Answer: We cannot tell you that, because of the Uncertainty Principle of Professor Heisenberg. We can only tell you where you are most likely to find it.
Question: So its energy and momentum are in fact not precisely determined?
Answer: That is so; they may take on any values within Heisenberg's limits.
Question: Then why are the spectral wavelengths, which you now say are dependent on indeterminate energy and momentum, themselves precisely defined?
Answer: Your questions presuppose that the atom has a mechanical structure. Our modern theory is a mathematical theory, not a mechanical theory. Hence the questions you ask are meaningless.
Question: But I thought you said the mathematical theory dealt with energy and angular momentum. Are these not ordinary mechanical quantities?
Answer: You are wasting my time. It is a matter of statistics. Look up the theory in any textbook.
You will have noticed the testiness of tone which arises characteristically at that point in the discussion. We shall look into that little "matter of statistics" and form conclusions about it which are not entirely conventional. As I said earlier, the doctrine of haziness seems a shade too convenient to be true. It enables its adherents to wriggle out of logical impasses by sheltering in mysticism, a particular mysticism which as we shall see is linked directly to an unexpected and, as I shall assert, erroneous and quite unjustified denial of the Law of Causation. These are deep waters which can bear being looked into. The doctrine of haziness also offers comfort to the lazy physicist (or shall we say, the too-busy physicist?). Current theories suggest that Nature may be stranger than our forbears thought, for human understanding. If so, we should not be surprised that we have made so little progress recently. (I need hardly emphasize that if this defeatist attitude should become held generally — and it seems to be gaining ground — it must spell the end of the philosophical road for physical science.)
The other possible explanation for our failure to achieve that steadily-improving understanding of the working of the physical world which human instinct (and previous experience in physics, and current experience in other disciplines) suggests we ought to be achieving, is that there is something there to see but that we have been looking for it with the wrong spectacles. We cannot see radio waves or electrons with the naked eye, of course, but we infer their existence from the readings of our instruments. Our "electron spectacles" are not the instruments we use, but the scientific theories with and against which we interpret our observations. A current theory is an expression of a contemporary attitude of mind.
We can be, and historically often have been badly misled by our theories. To take a classically familiar example, in times past the motion of the planets across the night sky could be described to any desired degree of accuracy on the basis of the Earth being the dynamic centre of the universe. It could be explained — that is, accounted for rationally with a minimum of underlying assumption — much more readily by means of a Sun-centred theory. From experience we have come to believe that the more closely a scientific theory reflects the mechanism of the physical world, the simpler will its concepts appear and the wider will be its field of application. In this example, planetary astronomy had been bogged down for a thousand years under the geocentric theory, and progress had virtually stopped. Further advance depended on the rejection or overthrow of the geocentric theory and its replacement by the alternative which is still in use today. And what an advance that proved to be! One of its earliest consequences was Newton's law of universal gravitation.
We may perhaps read that experience across into the area of fundamental physics where our recent progress seems to have been surprisingly, and disappointingly, slow. Slow progress does not prove that anything is wrong with our current theories and doctrines, but it raises that possibility. It is possible that some of our fundamental thinking may have been on the wrong lines (and by wrong lines I mean lines which do not accord with those of physical Nature). If so, then much of the elaborate, self-generating and untested structure of mathematico-physical theory that has been built up during the past fifty years may turn out in the end, to have been irrelevant, if not actually misleading. I am suggesting that the time is now ripe for a critical review of modern physical theory, much of which has not been of a type to inspire confidence.
There was for many years a powerful body of opinion which in the teeth of all the evidence for the heliocentric theory maintained that the Earth, as the abode of Man, must be the centre of the physical universe. To such opinion no factual proof was convincing: one can neither prove nor disprove an Article of Faith. Thus the ancient polarisation between churchman and scientist tended to continue. Yet it is a feature of modern physics, unexpected but explainable, that in its philosophy it is more akin to a religion than to a classical science. Mysticism has returned in a big way. It seems that in the fundamentals area we are dealing with matters of faith and doctrine, dogma and heresy, so that formal experimental proofs are no more to be expected in fundamental physics nowadays than in a theology. There may even be resentment against anyone who presumes to question the One True Faith; but this time the conservative Establishment is likely to be found within the ranks of science itself.
The significance of that remark will become clear when I declare my main thesis, which is that physical science made a sequence of errors during the 1930s from which it has never recovered. I am in good company in this, since that view was to a greater or lesser extent shared from the early days of Quantum Theory by Einstein, Planck, von Laue, and Schrodinger, all of whom were central in the original arguments. Theirs was a "realistic" view, which in the climate of the times did not prevail against the novel, mystical doctrines of Bohr, Heisenberg, Dirac, and others. The last-mentioned became established and remain formally accepted today. But attitudes may now be changing after fifty years: at any rate I hope so. I propose to identify some of the errors in the 1930's doctrines, show that they were indeed errors, and show how they came about. To my physicist colleagues I say, If your faith is not strong enough to withstand such criticism you should read no further, for I have no wish to cause you offence. To the layman I say, Here for your entertainment is a real-life, up-to-date version of Hans Andersen's famous story of the King's New Clothes.
To sum this up: every scientific theory is somebody's particular pet. Rather than attack the established theories of physics — which would force their doting owners to rush to their defence, and lead to quite unnecessary altercations — I propose to examine a selection of miracles. A miracle, you will remember, is a physical occurrence for which we can offer no physical explanation. There are plenty of miracles to choose from, so we can afford to be selective. We shall find that our miracles have a certain hallmark about them, from which we can deduce not understanding, perhaps, but clues towards understanding. The nature of current theories will become clearer, so that we shall discover when it is safe — philosophically safe to use these theories, and when dangerous. When fully developed this technique should enable us to judge the physical credibility of any new hypothesis, providing us with a critical faculty which in recent times has been woefully lacking.
The first miracle we shall examine will be the one I mentioned at the opening, namely the mechanism of the transmission of light energy through empty space. Our first philosophical milestone will be consequential and closely related to it: an understanding of the true function of "waves" in modern physics. We shall have to go back some 200 years in scientific history to find a suitable starting point. Our route will take us from Newton to Heisenberg: via electromagnetic theory and the acute distress it suffered when denied an aether; via practicable photons, quantization, non-existent matter-waves, and a restricted Principle of Indeterminacy; and ultimately to an affirmation that the Law of Causation is obeyed in physics not only statistically but in all circumstances. In each of these areas I will present ideas for your consideration which although far removed from conventional scientific doctrine are yet strictly in accord with the findings of experiment. These ideas will add up eventually to a self-consistent whole, but not yet, I regret, to a fully-developed Theory.
All that I have to say is very simple, and indeed I hope to show how simple Nature really is when the dust of man-made confusion has been swept away. William of Occam said that fundamental assumptions should not be multiplied unnecessarily, and I am a follower of William of Occam.
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