We will examine several well known phenomena, some of which are considered unsolved mysteries in physics.
Did you ever uncover the solution to an unsolved problem in physics by yourself? If you have a good understanding of physical issues, then after putting together the facts known by almost every physicist, you have a good chance to find the solution to one such problem by yourself. Just concentrate while you read few pages that contain somewhat technical description.
Ready? Let’s start.
The van der Waals force and the Strong Nuclear Force
The force holding molecules together inside a liquid droplet is called the van der Waals force, named after the Dutch physicist.
The Strong Nuclear Force (sometimes called just Nuclear Force), is the force holding nucleons (protons and neutrons) in the atomic nucleus.
Van der Waals force and the Strong Nuclear force share some interesting features.
Residual forces that vanish in distance
Two of the fundamental forces in Physics, the electromagnetic and gravitational forces, act between bodies, and their intensities decrease progressively and continuously as the bodies move away from each other. Unlike these forces, the van der Waals force, acting between non-ionized molecules, has a particular feature: when molecules are far apart from each other – it cancels out and doesn’t act at all. It only goes into action when the molecules come close to each other. This is a totally different behavior than the common interaction pattern of the fundamental forces mentioned above.
How does this happen? Non-ionized atoms and molecules seem neutral when measured at a distance: here, the fields of the positively charged nucleus and those of the negatively charged electrons cancel each other – a phenomenon called “screening”. See the “naïve illustration” below: the term naïve means that quantum mechanics assigns wave function to every particle, and here we look on the electrons as if they were localized like in the Bohr atomic model.
But when the molecules are close to each other, the electrons in the external shells react to the neighboring molecule and the charge distribution varies. In the new setup, the electron’s energy is lower, and a net attractive force appears. Quantum mechanics provides an accurate description of these forces. Thus, the van der Waals force is strong enough to maintain the molecules in a non-gaseous state at appropriately low temperatures.
Similarly, the force holding the nucleons together, the Strong Nuclear Force, is indeed very strong, but it is quite weak in comparison to the Strong Interaction force holding the quarks together inside the nucleon. Another interesting feature of this force is that as the two nucleons move away from one another, this force ceases to apply. Here too, this phenomenon contradicts the attraction laws of electromagnetic or gravitational fields, in which the force decreases progressively when distance grows. In the case of two nucleons – the attraction between them cancels totally when they move away from each other.
Both forces are now called in the literature “residual forces”, because they are significantly weaker than the basic forces from which they derive.
The characteristic of the nuclear force to stop operating at a certain distance, is called “cutoff” and has no theoretical explanation admitted by the physicists’ community.
Another characteristic of molecules in liquids is the familiar phenomenon of being incompressible, which means that a liquid’s volume hardly decreases when pressure is applied to it. In fact, the liquid’s specific volume is almost constant, because when two molecules move one toward the other, they first feel attraction, but at a certain distance, strong repulsive forces appear. Quantum Mechanics provides an explanation for this attraction and repulsion. These repulsion forces are very intense, easily resisting pressure, and the system thus reaches an equilibrium, in which the liquid maintains a quasi-constant density even when pressure goes up. Moreover, the molecular density of a given liquid is independent of the number of molecules.
A similar phenomenon is the density of nucleons inside the atomic nucleus. One could assume that neighboring nucleons attracting each other could get closer to each other as the number of nucleons increases. But this does not occur – the nucleon density in a large nucleus is almost identical to that in a small nucleus (with the exception of very small nuclei).
This phenomenon doesn’t have an explanation either.
The volume of external electrons
The volume of the outer electrons of a molecule inside a droplet is bigger than their volume in a free molecule.
This is a quantum mechanical effect explained again by the interaction between nuclei of one molecule and electrons of another molecule. The molecules are thus partially overlapping each other when they are in a liquid droplet.
A similar phenomenon was found in nucleons. In 1983, experiments discovered that the volume of the nucleons’ quarks is bigger inside a heavier atomic nucleus. This effect is called “The first EMC effect”; and it has been bewildering physicists until today, since there is no explanation that is admitted by the entire physicists’ community.
Distance dependence of the potential
The solid line in the following graph represents the distance dependence of the force potential between two neutral molecules .
The following graph looks almost identical. It describes the distance dependence of the Strong Nuclear Force potential :
As far as we know, this similarity between the graphs was never adequately discussed in the literature of physics.
|Electric field within a liquid droplet||Strong interaction inside atomic nuclei|
|Holds electrons inside the molecule by means of a relatively strong force||Holds quarks inside the nucleon by means of a relatively strong force|
|Holds molecules within a liquid droplet by means of a much weaker force (the van der Waals Force)||Holds nucleons inside the nucleus by means of a much weaker force (the Strong Nuclear Force)|
|Not felt by molecules when they are far apart from each other||Not felt by nucleons when they are relatively far apart from each other|
|Liquid molecules have a quasi-constant density||The nucleons within the atomic nucleus have a quasi-constant density|
|The volume of electrons of a molecule inside a liquid droplet is bigger than that of a free molecule||The self volume of nucleonic quarks inside a heavy atomic nucleus is bigger than that of the deuteron (The first EMC Effect)|
|The graph describing distance dependence of the force potential looks like a Ski Jump||The graph describing distance dependence of the force potential looks like a Ski Jump|
It turns out that the characteristics of the atomic nuclei are amazingly similar to those of liquids, if we substitute a droplet by an atomic nucleus, molecules by nucleons and electrons by quarks.
Before you go and invent a model that explains these results, let me point out two well known facts. First, most of the mass of the molecule resides in the atomic nucleus. The second fact, discovered in the 1970s, is that more than one half of the nucleons’ mass is not carried by the quarks of the external shell of the nucleons.
Until here, anyone who successfully completed a physics undergraduate degree would probably agree.
And here is now your chance to solve these mysteries. Take a short break, and find by yourself what the structure of the nucleon is and what kind of forces hold the quarks together.
If you got this far, then it may well be trivial to you. All is needed is to assume that every nucleon has a core that strongly attracts the quarks, and that quarks repel each other. This completes the analogy between the Strong Interaction and the Electric Force and their corresponding residual forces (the Nuclear Force and the van der Waals force). This model of the nucleon is supported by the experimental evidence revealing that less than half of the nucleon’s linear momentum is carried by quarks, implying that the nucleon contains another kind of physical object.
Can it be so simple? The nuclear liquid drop model has been known for over 70 years now, just like the analogy mentioned above between the van der Waals force and the Strong Nuclear Force. But, for some reason, physicists did not go one tiny step further, which would be to assume that the nucleon too has a core (nucleus), allowing for an equivalent construction of the Strong Nuclear Force, in analogy to the van der Waals force, and the analogy between the laws of the Strong Interaction and those of Electrodynamics.
In fact, until today, the question how the strong interaction explains the strong nuclear force is listed as one of the important unsolved problems in physics.
The historical events that brought this blackout
The 20th century witnessed the development of a branch of Physics called Quantum Mechanics, resulting in major technological breakthroughs. In the 1950s and 1960s, physicists were aware of two particles the existence of which was considered impossible according to Quantum Mechanics. These particles were Omega– and Delta++.
It was already known back then that protons and many other particles are composed of smaller entities, the quarks. Omega– and Delta++ were known to be composed of quarks as well, but the quark combinations and their properties did not seem coherent. At that time, it was not known that the quarks carry less than half of the proton mass and the first EMC effect was not known either. Physicists were sure that the quarks are the only massive objects inside the proton.
The existence of Omega- and Delta++ seriously challenged the knowledge acquired till then, seriously enough to motivate scientists to concentrate their efforts on the development of a new physical theory, based on a series of fantastic assumptions, describing forces and particles unlike anything known up to that point. The theory, called QCD (Quantum Chromodynamics), a central pillar of the Standard Model, won an unshakable status already back in the 1970s, in spite of a long series of incompatibilities with experimental findings (described in this website).
The missing link
Eliyahu Comay was studying during the 1960s at the Hebrew University in Jerusalem, where the eminent physicist Yoel Racah, who passed away in 1965, was a revered figure. The Physics study program at the Hebrew University was particularly focused on the theory Racah developed in parallel with Wigner. Comay recognized, already during his first PhD work in the early 1970s, that Omega– and Delta++ can be naturally explained by the theory developed by Wigner and Racah, in combination with Quantum Mechanics basic laws. Comay also realized that the masses of particles composed of quarks were consistent with Quantum Theory’s ordinary laws, established since before the invention of QCD.
But at this point he stumbled on an unexpected obstacle: scientific journals refused to publish his papers! He ended up renouncing and moving on to a different area, Nuclear Physics, studying the atomic nucleus. He completed his studies in this area and continued working in this field throughout his scientific career. It may have been his proficiency in the nuclear physics field that brought him to notice Standard Model’s Achilles Heel, and in particular its inadequacy to correctly describe the forces inside the atomic nucleus.
In 1983, Comay made an astonishing discovery, playing a critical role in describing the quarks’ physical properties. This discovery allowed him to develop an alternative model, explaining familiar phenomena in an amazingly simple way, including phenomena which contradict the Standard Model.
Nevertheless, and in spite of the fact that it has never been contradicted or refuted, Comay’s theory was never brought up for a serious discussion.
Since almost 40 years the Standard Model has been taught at universities as an unshakable truth. As a consequence, two whole generations of physicists grew to consider the Standard Model as fundamental truth requiring no proof, and ended up spending all their time and energy creating theories beyond it.
The scope of Comay model
The experimental findings below are explained in Comay model. These results do not have accepted explanation, and they seem contradicting the standard model (all the terms here will be explained later in this website):
– Increase in very high energy proton-proton elastic cross section
– Protons and Neutrons behave similarly when a hard photon hits them
– Protons and Neutrons interact strongly when a hard photon hits them
– First EMC effect
– Proton Spin Crisis
– Strong CP Problem
– Similarity of the potential vs distance graph of van-der-Waals and strong nuclear forces
– Nucleons within the atomic nucleus have a practically uniform density
– The nuclear tensor force and its sign
– Antiquarks have a larger volume inside nucleons
– The neutron’s negative electric charge tends to be found in external regions
– Pentaquarks were not found
– Strange Quark Matter was not found
– GlueBalls were not found
– Mesons are not confined inside the nucleon
Comay model explains more findings that do not contradict the standard model, although some of them do not have an explanation yet:
– Dirac monopoles were not discovered
– Linear momentum of quarks is 45% of the proton momentum
– Properties of the Omega– and the Delta++ baryons
– The three jets experiment
– Meson radius relations
– The relation between the proton volume and pion volume
– Problems with mass differences between mesons and baryons
– Strong force stops operating in a certain distance (cutoff)
– Baryon conservation law
Most of Comay work was conducted and published during the eighties and nineties. A concluding article that summarizes most of his findings regarding his model was published in 2004 .
Now, after you just solved several unexplained phenomena in physics, it’s time to study the basics. In this website we will cover in popular language many topics, some of them are highly advanced, in Quantum Mechanics, Quantum Field Theory, Wigner and Racah calculus and their tremendous impact on the strong force, and more. This will enable us to understand the solution of more than dozen unsolved problems listed above; some of them belong to the list of the most important unsolved problems in physics. Further, we will try to explain the historical events that brought the Particle Physics to this bizarre situation.
 J. Arrington et al., J. Phys. Conference Series 69, 012024 2007
 H. Haken and H. C. Wolf, Molecular Physics and Elements of Quantum Chemistry (Springer, Berlin, 1995). P. 15
 S. S. M. Wong, Introductory Nuclear Physics (Wiley, New York, 1998). P. 97
 A Regular Monopole Theory and Its Application to Strong Interactions, Published in “Has the Last Word been Said on Classical Electrodynamics?” Rinton Press, NJ, 2004 (http://www.tau.ac.il/~elicomay/LastWord.pdf)