Quantum Mechanics


The Double Slit experiment

Quantum Mechanics, Electrodynamic Mechanics, and the Zero Point Energy

What is the Zeeman Effect?

A letter from a friend in The Netherlands -- some comments regarding the book ‘Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality’, by Manjit Kumar

Sub-Atomic Particles


The Double Slit experiment

Question: I have been wondering about the perspective of Quantum Mechanics and the Interpretation of the Double-Slit Experiment, from a young creationist perspective. (As we only have these made in the context of the Big Bang/billions of years theory).

Please may you try your best to answer my below queries:

1.  There are many well-known interpretations of Quantum Mechanics, based on the Double-Slit Experiment. 

Please may you tell me, which particular interpretation do you favour. (I.e. Many Worlds, Transactional, Hidden Variables or the standard Copenhagen Interpretation?).

2.  Does the context of the universe only existing for 6-10,000 years, influence the particular opinion you hold with regards to the above?

3.  Is your opinion in-line with most creationist physicists? (As far as you know).

Setterfield: As far as the double-slit experiment is concerned, I do NOT favor the Copenhagen interpretation. I favor a causal mechanism for all quantum behavior. For this reason, on the whole matter of quantum physics, I find myself very much favoring the SED (Stochastic Electrodynamics) approach rather than the quantum electrodynamic (QED) approach. SED physics explains all quantum phenomena in terms of the action of the Zero Point Energy which pervades the whole universe. It is the impacting waves of the ZPE on charged point particles which gives rise to quantum uncertainty, and imparts kinetic energy which appears as mass. It also explains gravity as outlined in some of my papers. In other words, there is a physical cause for quantum phenomena, not some strange property of matter.

For the double slit experiment, let me first state that de Broglie waves need to be defined in terms of SED concepts. When an electron is at rest, this charged point particle is being "jiggled" by the impacting electromagnetic waves of the ZPE. This means that the electron has an intrinsic frequency of oscillation caused by the ZPE waves. This oscillation frequency is the Compton frequency which is about 10^21 oscillations per second. This means that the electron is being hit by 10^21 ZPE waves per second. Haisch and Rueda note that this is the frequency when viewed in the electron's own rest frame of reference. They then point out that "When you view the electron from a moving frame, there is a beat frequency superimposed on this oscillation due to the Doppler shift. It turns out that this beat frequency proves to be exactly the de Broglie wavelength of a moving electron. The ZPF drives the electron to undergo the oscillation at the Compton frequency and this is where and how the de Broglie wavelength originates due to Doppler shifts." [B. Haisch & A. Rueda, Pgysics Letters A 268 (2000), p.224.]

Given that picture of the origin of the de Broglie wave of an electron, we now move on to the double slit experiment. Since the particle has waves associated with it, it might be considered rather like a motorboat on a lake. Picture the electron as the motorboat, and the waves it makes as the waves associated with the electron. Now the electron only goes through one slit, but the wave goes through both slits and then forms an interference pattern. These interference patterns caused by the waves also influence the paths of the particles. Some details about this can be found in "The Quantum Theory of Motion: An account of the de Broglie-Bohm Causal Interpretation of Quantum Mechanics" by Peter R. Holland, Cambridge University Press, Cambridge, England, 1993. On page 184 there is a plot of the trajectories that a particle would follow depending on exactly where it passes through the slit. This is in Figure 5.7, and the same diagram appears in a paper by C. Phillippidis et all, Nuovo Cimento 71B, pp. 75-87, 1982.

I trust that this gives you a feel for what is actually happening with the root cause being the ZPE and the electron itself, and its beat frequency wave.

As far as your second question is concerned, the context of the age of the universe has no bearing on this discussion. My only objective is to hold to an approach to quantum physics that has an actual physical cause for the phenomena we see. QED physics does not do this, but SED physics does.

As far as the third question is concerned, I do not know if Creationists have a "standard approach" to quantum physics. I have had discussions with a couple of creationist physicists, and I have met with diverse reactions as they seemed to hold to differing views.

For a more detailed response, please see Quantum Effects and the Zero Point Energy

Quantum Mechanics, Electrodynamic Mechanics, and the Zero Point Energy -- Six Questions

Question 1: Is it not true that Quantum Electro-Dynamics (QED physics) first predicted the Zero Point Energy? If so, why do you say that the QED version of the ZPE is only virtual, while the SED version is a real physical entity?

Barry: The ZPE was not first predicted by Quantum Electro-Dynamics (QED physics). QED physics only developed in the late mid 1920’s. The ZPE was first predicted by Planck’s second paper which was published in 1911. Planck’s first paper in 1901 had introduced what is now Planck’s constant, h, as an arbitrary mathematical device to get an answer to the black body radiation problem. Although mathematically acceptable, Planck was concerned that there was no physical basis for his constant, h. This worried him and he sought a solution to this problem for almost a decade. Then his second paper was published in which the radiation problem was again completely resolved, but there was a real physical reason for the quantity h. It represented the strength of an electromagnetic background field (the ZPF) which was present even at absolute zero of temperature. This was discussed in detail by Einstein and Stern in 1913, Nernst (1916) and others. In 1925, Robert Mulliken found the proof for the existence of this ZPF in the color spectrum of boron monoxide.

Then in the mid-1920’s there were 4 papers which followed the lead from Planck’s 1901 mathematical excursions instead of his 1911 paper, whose predicted ZPF had just been proven to exist. These papers led to quantum electrodynamics (QED) and most of the subsequent discussion focused on and built on these 4 papers. It was some time after this development that the QED concept of the ZPE evolved. But that was after a number of quantum effects had already been explained on the basis of those 4 papers as simply an intrinsic property of matter and/or the action of the Heisenberg uncertainty principle (HUP). In contrast, the SED position, which re-emerged in the late 1960’s, turns this all around to another viewpoint. It states that, on the basis of the real ZPF predicted by Planck’s second paper, and whose actual existence was proven by Mulliken, the quantum effects discussed by those 4 papers (and others) can all be explained and derived classically when the action of this ZPF or ZPE is taken into account.

Putting it another way, in QED physics, the action of the Heisenberg uncertainty principle (HUP) allows the momentary formation of virtual particle pairs in a vacuum. Because each particle can be described as having a wave (de Broglie waves) associated with them, these virtual particles must all have electromagnetic waves associated with them. These waves are the waves of the ZPE on the QED formalism. They result entirely from the action of this Principle (an abstract concept) and are therefore virtual, not real.

Thus QED has everything back to front; the HUP permits virtual particles which have associated waves which are the ZPE waves. In contrast, SED physics says the existence of a real ZPE causes the uncertainty in position and momentum etc in subatomic particles because they are battered by these waves and they execute a violent “jitter motion” as a result. Thus the HUP and its uncertainty is secondary to the ZPE. Furthermore, the concentration of energy when the ZPE waves meet allows the momentary formation of virtual particle pairs since energy and mass are inter-convertible. Their formation has nothing to do with the HUP. Everything is therefore the direct result of a real ZPE on SED physics whereas on QED physics, everything stems from the action of the HUP so that the ZPE itself is a secondary or tertiary outcome.

In other words, in SED physics, the ZPE is the driving force, the actual reason why there are quantum effects, and there is no need to invoke a Principle (Heisenberg’s) or some strange behavior or property of matter to account for these effects. Thus in SED, the ZPE is primary, while in QED it is only a secondary mechanism. So QED did not predict the ZPE first…Planck’s second paper did. And the SED position flows directly from that.

Question 2: What is unphysical about the ZPE in QED physics and why should it be replaced with a different ZPE from SED physics?

Barry: Look at how it developed historically in my answer above. When the quantum condition from Planck’s first paper and the Heisenberg uncertainty principle (HUP) are applied to atomic particles at absolute zero, theoretically each particle should have some residual motion and hence energy. After a detailed treatment of this Eisberg and Resnick wrote: “We conclude that there must be a zero-point energy because there is a zero-point motion…the particle cannot have zero total energy.” This follows directly from the HUP. Thus the ZPE became part of the QED approach, but only indirectly through the HUP. There was no physical mechanism involved. The following comment epitomizes this: “[This] shows that even the lowest state has some energy, the zero-point energy. Its presence is a purely quantum mechanical effect, and can be interpreted in terms of the uncertainty principle.” [Gasiorowicz, Quantum Physics, p.105]. Essentially this says that the ZPE exists because the HUP requires it as an artifact of atomic particle existence.

In contrast, Einstein and Stern in 1913 concluded that if dipole oscillators (charged point particles like electrons etc) were immersed in a sea of irreducible energy, whose strength was proportional to h, at zero degrees of temperature, “then the Planck radiation formula would result without the need to invoke quantization at all.” In 1916, Nernst concluded that this required a cosmological origin for the ZPE. These are real, basic physical effects from a ZPE on the SED approach: it is not coming from the application of some mathematical Principle.

Another example: the uncertainty in position and momentum of the electron. QED attributes it again to the results of applying a basic mathematical Principle (HUP). This is putting the cart before the horse. SED physics states that the uncertainty results from the incessant battering of the electron by the impacting waves of the ZPE. It has a real physical cause which does not require the application of any Principle. The only thing needed is a real ZPE. 

Question 3: If QED physics is on the wrong track, how did that happen and what has SED physics done that is different?

There were 4 papers, all based on Planck’s 1901 approach, from the mid-1920’s that steered the argument in the QED direction. They were the proposal by Born et al. that Planck’s arbitrary constant be used as a description for atomic behavior, the introduction of the Schroedinger equation, the suggestion of the Heisenberg uncertainty Principle, and the indication that sub-atomic particles had accompanying de Broglie waves.

These four had their counterparts in SED physics. Max Planck himself in 1911 had demonstrated that Planck’s constant was a measure of the strength of the ZPE and, as such, the ZPE was linked with atomic phenomena and explained the problematic black-body radiation curves. De Broglie in 1962 indicated that this approach should be re-examined as physics appeared to have taken a wrong turn in the mid-1920’s. In 1966, Edward Nelson produced an entirely classical derivation and interpretation of the Schroedinger equation. In 1975, Timothy Boyer used classical physics plus a ZPE to demonstrate that the action of the fluctuations of the Zero Point Fields on subatomic particles produced the same outcome as the HUP. Then B. Haisch and A. Rueda went on to show that the de Broglie wavelength of a particle comes from the interaction between the particle’s motion and its Zero Point oscillation. The de Broglie wave of the particle then appears as a “beat” phenomenon.  So by the late 1990’s, the four major bases of QED were shown to be explicable in terms of classical physics when a ZPE was added. SED research has moved on from there, even though QED physics has a head start of over 60 years.

Question 4: Is it not true that, unless SED physics can replicate all the features of QED physics, then it has no status as a serious alternative? Is it not true that it cannot and has not added any new physics? If not, is not the QED position superior to SED?

Barry: I have already suggested that you examine the literature and see what SED physics has already achieved in that field. Many of the features of QED physics have already been replicated. Be aware, though, that QED physics has a head-start of over 60 years and that requires some considerable number of man-hours to catch up on all the results. The requirement of an instantaneous equivalence on all issues by SED physics is clearly unreasonable.

However, we can go further, since some very important independent results have emerged from SED studies. These SED physicists have shown that atomic orbits are actually maintained by the ZPE. They have shown that the stability of matter right throughout the cosmos is dependent entirely on the action of the ZPE in a way which was not possible under QED formalism. This in itself is new physics and a major development which commends the SED position for serious consideration.

However, let us consider something else by way of a major illustration. For the latter half of his life, Einstein sought to find a unified field theory. Since then, many physicists have spent a significant portion of their lives attempting to link Relativity theory and quantum mechanics. Despite many attempts, both QED theory and Relativity have failed to be linked in these attempts over the last 75 years or so. However, with ease, it can be shown that SED physics not only links Relativity and quantum phenomena in one overarching theory based on physical reality (see "Zero Point Energy and Relativity," with others like it referenced in the Cosmology and the Zero Point Energy) but also, as other SED physicists have pointed out, it presents an “already unified” approach to physics. To my mind, these are significant developments that need to be taken notice of. They unequivocally show that SED is a far more viable and flexible tool than QED has ever proven to be. Furthermore it has predictive value that may yet attract some attention.

This interdisciplinary nature of the emerging SED approach should capture the imagination of physicists and cosmologists. However, it is important to put the new SED ‘wine’ into ‘new wineskins’, not complain that it does not sit well in the old formalism. Until that is done, there is no use stating that Relativity as it currently stands or QED as it is today does not allow these results to be obtained, and so conclude that this approach to a young universe cannot bear fruit.

Let me put it this way: according to the QED approach, the ZPE only exists because of virtual particles which come into existence by the HUP. Imagine for a moment that for some reason there were no virtual particles and hence no ZPE. On this QED approach there is nothing which will change any of the constants of physics in this situation, so that is unthinkable by QED formalism. However, on the SED approach, if there were only a very small ZPE, not only would there be very few virtual particles, but Planck’s constant and other atomic constants, including light-speed, would vary because the properties of the vacuum would be different. A real ZPE has real physical effects which are not taken account of by QED formalism and Relativity as they now stand. Thus QED physics is deficient in this area when compared with SED physics.

Question 5: In your papers you seem to give a somewhat different emphasis to events and interpretations which QED physicists consider basic to their position. Why is that?

Barry: First, the history of what Planck did as seen from the point of view of some QED physicists also disagrees with the approach in 1978 by T. Kuhn in his book Black Body Theory and the Quantum Discontinuity 1894-1912. In order to recover from the wreckage which that book made of some prominent interpretations of events and the way QED theory developed, a symposium on the topic was presented by the Max Planck Institute in 2000. (note: the symposium paper is quite long and takes some time to download). However, even at the beginning of the symposium, it had to be admitted that at least 5 interpretations have existed on the way the topic developed and its interpretation.

However, in 1962, de Broglie also presented his views and those of others on the development of QED. He noted that the Zero Point Energy (ZPE) in the 1920’s was called “the undulating field” in which all particles were immersed. This book ultimately led to the SED position today. So, in all honesty, it must be admitted that the position adopted today by some QED physicists and the historical development they present is, at best, only one of several possibilities.

However, a glance at Planck’s equations in his paper of 1911 tells the story completely in itself. In that paper, the black body radiation equation is in two segments. The first segment gives the temperature-dependent terms that give the basis for the black body spectrum. The second segment gives the temperature independent terms involving Planck’s constant, h. This second segment remains when the temperature drops to absolute zero and there is no heat radiation at all. Since the entire equation is dealing with heat and electromagnetic radiation, the second segment must also be referring to electromagnetic radiation. Furthermore, since the terms in this second segment indicate that this radiation exists everywhere at absolute zero, it must be an intrinsic part of the vacuum. Thus this equation in Planck’s second paper implied the existence of an electromagnetic ZPE back in 1911. That is basic, even if it is not the QED position.

Question 6: Does not the so-called “double-slit experiment” prove the truth of the QED position?

Barry: According to QED physicists the double slit experiment does support their position. A word of explanation is in order here. If you allow water waves to go through two slits close together, the waves emerging on the opposite side produce an interference pattern of maximum and minimum intensities. The diagram below illustrates the situation.


 If you have only one slit, there is only one peak in the wave intensity opposite the slit. The contrast is shown in the image below.

slit patterns


When something similar is done with a beam of electrons, a single slit again produces a single intensity peak in electron distribution on a screen immediately opposite the slit. A beam of electrons fired at a double slit produces an interference pattern on the screen behind, just as exists for waves. This shows that there is a wave associated with the electrons. The situation is illustrated below.

electron waves1 electron waves2

These waves have different origins on QED and SED physics. Wave-particle duality is deeply embedded in QED theory. In the approach adopted in that theory, all the information about a particle is encoded in its “wave function,” a complex mathematical expression, which describes its behavior in the form of a wave. On the basis of the Heisenberg uncertainty principle (HUP), QED physics then states that if the position of the particle is determined by an observation or measurement, the wave-like nature of the particle will disappear, or colloquially, the “wave function will collapse.” As a result, the interference pattern will not be seen on the screen behind the double slit.

In contrast, the SED position is that a moving electron is being continually “jiggled” by the Zero Point Energy. This linear movement (or in the case of electrons bound to atoms, their movement around the nucleus) means that the oscillation of the “jiggle” becomes a traveling wave instead of a jitter motion about a fixed point. So an electron can again be considered as both a particle and a wave on the SED model. However, the act of observation will not interfere with the production of the traveling wave, so, unlike the QED situation, the interference pattern should remain. Which situation is closer to actual reality?

In 1987, Mittelstaedt et al went some way to disprove the QED position experimentally using photons. However, because their procedure was not precise enough, some doubts were raised about the outcome. However, in 2012, Menzel et al. were able to identify the path that each particle had taken in their experiment. Yet at the same time they demonstrated that this procedure had no effect on the interference pattern [Proceedings of the National Academy of Sciences USA, 109:24]. In other words, the QED position is called into question and the SED position supported. Furthermore, since the very basis of the QED position was the HUP, this principle may also be considered suspect. As a result, the SED explanation of uncertainty, due to the action of the ZPE, is favored.

Barry Setterfield, 25th November, 2014.

Question: What is the Zeeman Effect and How is it Understood?

Barry: There are several aspects to the Zeeman Effect that you were asking about. Historically, the Zeeman Effect was discovered first, where atomic spectral lines were split into several components. Then the Anomalous Zeeman effect appeared where there was additional splitting which was not immediately explicable. It was this “anomalous” Zeeman Effect that ultimately led to the discovery of electron spin. In current scientific terms both results are now simply combined to be called the Zeeman Effect. Let me put the story together for you in the following way.

Historically, when these effects were first observed, the picture of what was happening with the atom and electrons in their orbits around the nucleus was also still developing. It was known empirically that electron “orbits” had discrete levels, and this was incorporated in the Bohr model of the atom in 1913. The explanation for this from an SED point of view indicated that these levels were the ones where the energy lost by the electron (by radiating energy according to classical rules as it circled the nucleus) was equal to the energy supplied by the Zero Point Energy (ZPE) as it impacted the electron. The energy supplied by the ZPE came into the orbits via the angular momentum, given by Planck’s constant, h, which was also a measure of ZPE strength. In 1913, it was already known that when an electron fell from an outer orbit to an inner orbit, it emitted light of a given wavelength. The wavelength and frequency of these ‘spectral lines’ could both be measured extremely accurately. It was because of this accuracy and increasingly precise instrumentation that the whole scenario developed.

Because of these accurate spectroscopic observations, Arnold Sommerfeld modified the Bohr model of the atom to have elliptical orbits instead of circular orbits for the electrons. Each elliptical orbit could have the same energy as the principal quantum orbit in the Bohr model, but the angular momentum (given by Planck’s constant, h) was different for each and was quantized. This meant there was a “shell” of finite thickness which contained all the elliptical orbits (orbitals) of the same energy. Because all the orbitals within a given shell had the same energy, the whole shell has the same (Bohr) quantum number, such as n = 1 or K; n = 2 or L; n = 3 or M;  n = 4 or N and n = 5 or O. Nevertheless, these orbitals effectively divided each shell into sub-shells for the electrons up to a maximum of 4 subshells, because their angular momentum was quantized. They were labeled as the s, p, d and f orbitals or subshells, as in the diagram for the n = 5 shell here in Figure 1.

electron orbits

Figure 1: Elliptical orbits of the same energy but with quantized angular momentum.

Note that, in this diagram, the orbital labeled “g” is the original circular Bohr orbit with the same energy as the other 4 elliptical orbits which make up the “shell” for n = 5. Note also, that not all shells have the full complement of 4 subshells. 

It is into this understanding of electron orbits in atoms that the Zeeman Effect makes its entrance. In the Zeeman Effect, a static magnetic field is applied to the atom. This applied magnetic field has the effect of splitting spectral lines into several components, so we are dealing with a splitting or change in the energy of the transition which made up the original line. For this to occur requires that an electro-magnetic interaction takes place with the electrons and/or their orbitals to change their energy. Why should any interaction occur at all?

First, remember that a charged particle in motion (like an orbiting electron) is actually an electric current, and all electric currents have a circling magnetic field. Thus each orbit or orbital is associated with both an intrinsic electric current and an intrinsic magnetic field. If we take the example of hydrogen, when there is no field applied, the emissions of light depend only on the principal quantum number n and the emissions occur at a single wavelength, as when an electron transitions down from the n = 3 level to the  n = 2 level as an example.
However, if an external magnetic field is applied, (or an external electric current as in the Stark Effect), the subshells or orbitals will be utilized and the single line will be split. For those elements with the n = 5 shell, there will be a large number of lines corresponding to the large number of orbitals available to the electrons to transition into. The Zeeman Effect for hydrogen is illustrated here in Figure 2:


Figure 2: The Zeeman Effect on the transition of electrons from the n = 3 or M shell to the n = 2 or L shell where each shell is split up into its separate orbitals of different angular momenta by the magnetic field

While the Zeeman effect in some atoms (e.g., hydrogen) showed the expected equally-spaced triplet, in other atoms the magnetic field split the lines into four, six, or even more lines and some triplets showed a wider spacing than expected. These deviations were labeled the "anomalous Zeeman effect" and were very puzzling to early researchers. It was at this point that Bohr gave up on his attempt to link physical reality with his equations. However, at that stage they were not aware that electrons and protons were balls of charge which were actually spinning. The structure of the electron had not even been considered. Today, science has generally come to accept electron and proton spins as a reality with experimental proof.

However, what has eluded many is the concept that there may be an uneven distribution of electric charge on the spherical surface, that is, there may be an eccentric focus to the electric charge that is not aligned with the spin axis. If that is the case, then the magnetic moment from the charged sphere becomes explicable. The charge, being essentially concentrated at one location on the surface, is effectively tracing out a circle as the proton or electron spins. This again is an electric current and has an accompanying dipolar magnetic field. This would then give rise to the magnetic moment of the charged particle. Instead of some abstract quantity as QED often portrays it, it is a simple physical reality.

There is a further point. It was found that two electrons can only be in the same orbital around the nucleus provided their spins are in opposite directions. Two protons can only exist in the same orbital within the nucleus again if their spins are in opposite directions. These spins are designated as + ½ or – ½. But notice something. Normally, like charges repel, but if their spins are opposite, the magnetic fields are attractive, and this is what keeps them in place. You do not need a “strong” or a “weak” force within the atom in this case; only the normal laws of electromagnetism.

The dipole magnetic moment from the spin of the electrons is also affected by any applied magnetic field. The added magnetic field causes the spinning electron to precess like a gyroscope. As it does so, the energy of the electron changes and this change in energy results in additional splitting or separation of spectral lines. The result is illustrated in Figure 3.

"Normal" Zeeman effect

This type of splitting is observed with hydrogen and the zinc singlet.


This type of splitting is observed for spin 0 states since the spin does not contribute to the angular momentum.



"Anomalous" Zeeman effect

When electron spin is included, there is a greater variety of splitting patterns.






Figure 3: Illustrations showing both the “normal” Zeeman Effect (left) and the “Anomalous” Zeeman Effect (right) with a more general illustration bdelow involving orbitals (left) and the effects on spin (right).


The application of an external magnetic field causes the spin axes of the proton and electron to precess as noted. The strength of the external field can be noted, and so can the rate of precession of these spinning charged spheres. This quantity is called the proton (or electron) gyro-magnetic ratio. This quantity is inversely proportional to the square-root of the ZPE strength or directly proportional to the square-root of the speed of light, as shown on pp.124 and 156 of the Monograph. Obviously, the stronger the applied field, the greater the effect; and this holds for the entire range of splitting of spectral lines by the Zeeman Effect. Thus the strength of magnetic fields can be measured in distant galaxies when we see Zeeman splitting occurring in the spectral lines. The stronger the magnetic field, the wider the splitting. One final note; where the net spin of all the electrons is zero, their individual effects cancel out, so there is no anomalous Zeeman effects under these circumstances. This is another factor that delayed the understanding of what was happening initially.

Barry Setterfield – 27th December 2014.



A letter from a Friend in The Netherlands:

After reading through the many pages of the very instructive book ‘Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality’, by Manjit Kumar, I am trying to formulate an assessment of what really has taken place in all those discussions. Firstly I had to sort out things a bit and reread some passages again, in the light of the last chapters. My observations are:

1.       Philosophically there is a tendency to lessen the emphasis on reality, which is in my opinion one of the sad consequences of the ideas of the Enlightenment, as expressed by Kant, when he said that ‘das Ding an sich’, the things around us, cannot be known directly and with certainty. For Kant himself this was still not a problem as he certainly accepted a cup of coffee out of the hand of his housekeeper as being an objective reality, but something shines through his statement, and this is, that objective reality disappears if you loose the fixed ground of Biblical teaching. In Genesis 1 it is clearly shown that creation and man are both created by God and therefore man can understand creation. Not exhaustively, but truly, as Francis Schaeffer used to say. Some time later, a student of the influential philosopher Hegel, told his master: "Sir, your system does not conform to reality", on which Hegel replied: "Too bad for reality, pal". Now the switch was pulled. This mentality has influenced intellectuals much more than I realized. We also encountered it in Germany, where Horst Beck pointed through the window and said: “There is an objective reality out there”, and Christian Knobel asked me: “What does he mean with: out there?” It seems almost impossible to call these people back to objective reality.

2.       Inevitably, out of it grew a tendency to switch the focus away from the object to the subject. This is clearly seen in history and theology, where the reader finally decides what the text means, while detailed text criticism is rather rare. Historical ‘facts’ are unimportant. So also here objective reality slides out of sight more and more, and is being replaced by the subjective insights of the observer. I did not realize myself that this mentality had also caught natural science in its claws, but Kumar’s book gives a clear testimony about this mentality.

3.       It is because of these aberrations that the brilliant scientists who built quantum theory, had not enough ‘drive’ to search further and refuse to accept that reality would fade out. They more and more relied on pure mathematics, Bohr saying that objective reality was unknowable and even that it probably did not exist. Complex mathematics was all that they – although very cleverly – could produce. Einstein has never accepted this, but he was also influenced by the philosophical ideas of Enlightenment and above that his creative powers had faded and came only in concentrated ‘bursts’, as he said.

4.       It is generally unknown but clearly described by Kumar that many of the people who built quantum theory continued being not happy with it. Not only De Broglie and Dirac, but also Schrödinger was very disappointed, as was Heisenberg. And Bohr died while he was working on a new reply on Einstein’s light box experiment! But they still believed that QED was the maximum they could achieve. The role of Planck is rather vague. He certainly did not realize the importance of his discoveries, as he still hated the idea of quanta. So his contribution to the discussions in the Solvay conferences was effectively zero.

5.       The last point: which of all the work on QED can be salvaged when we turn to SED? The very basis of QED is already different, the zero point field non-existing as a physical reality, many things supposed to be fixed turned out to be variable. A real revolution is going on! When I look at your discussions with Jarko, I see the same pattern as in the discussions between the main players in 1911-1927: a theory which is in the make and needs still a lot of iterative improvements. But of course, this is the way science works.