San José State University
Thayer Watkins
Silicon Valley
& Tornado Alley

The Conventional Concept
of a Nuclear Strong Force
is a Colossal Blunder

In the early years of the 20th century it was observed that nuclei contained protons which are repelled from each other through the electrostatic force. Since most nuclei do hold together it seemed reasonable to hypothesize another force acting between proton that was stronger than the electrostatic force, at least at small distances. Without much justification it was further hypothesized that this strong force acted between neutrons and between neutrons and protons. Basically the nuclear strong force was just giving a name to what holds nuclei together. As it turns out it was wrong.

The emergence of a so-called nuclear strong force as the explanation of why nuclei hold together is a prime example of a false syllogism. This all-too-prevalent false syllogism in science is:

Proposition A implies Proposition B
Proposition B is true
Therefore Proposition A is true

To draw that conclusion it would have to be established that Proposition B is true only if Proposition A is true, which is a much stronger proposition than what is used in the false syllogism. The usual procedure is that the truth of a Proposition B is noted then a search is carried out to find a Proposition A. At that point the seach stops and the truth of Proposition A is declared and cited in science books including text books for students. All that is legitimately justified is a statement that Proposition A would account for the truth of Propositon B.

There is an alternate explanation for the structure of nuclei and it is based upon extensive empirical evidence. In contrast the conventional theory is based upon nothing more than the existence of stablel nuclei. The empirical evidence from which the alternate explanation arises is the binding energies of 2931 nuclides. The mass of a nucleus is generally less than the mass of the neutrons and protons (nucleons) that make it up. The difference is called its mass deficit. The mass deficit expressed in energy units is called binding energy. The binding energy behaves like the loss of potential energy which occurs when the nucleons come together to form a nucleus and it is the energy that must be supplied to break a nucleus up into its constituent nucleons.

The incremental binding energy of a neutron for a particular nuclide is its binding energy less the binding energy of a nuclide having one less neutron. The incremental binding energy of a proton is defined similarly. These incremental binding energies reveal important aspects of nuclear structure.

Here is an example of the relationship between incremental binding energy of neutrons (IBEn) and the number of neutrons in the nuclide.

The odd-even fluctuation is evidence of the formation of neutron spin pairs. It is also evidence of the exclusivity of neutron spin formation. A neutron can form a spin pair with one and only one other neutron More details are given in What holds a nucleus together?

The sharp drop in IBEn after 50 occurs because a neutron shell is filled at 50 neutrons and additional neutrons have to go into a higher shell. The filled-shell numbers are known as nuclear magic numbers.

The same effects occur for proton-proton spin pair formation on binding energy

The effect of neutron-proton spin pairs is revealed by a sharp drop in incremental binding energy after the point where the numbers of neutrons and protons are equal.

Here is the graph for the case of the isotopes of Krypton (proton number 36).

As shown above, there is a sharp drop in incremental binding energy when the number of neutrons exceeds the proton number of 36. This illustrates that when a neutron is added there is a neutron-proton spin pair formed as long as there is an unpaired proton available and none after that. Furthermore this illustrates the exclusivity of neutron-proton spin pair formation. It also shows that a neutron-proton spin pair is formed at the same time that a neutron-neutron spin pair is formed.

There is however another force that is not exclusive and is distance dependent. It corresponds to what is called the nuclear strong force but would be more appropriately called the nucleonic force, the force between nucleons.

The Interactions of Nucleons
through the Nucleonic Force

The thought occurs as to whether the force involved in spin pairing might be what conventional theory refers to as the nuclear strong force. The problem with that is that spin pairing is in a special way. One neutron can pair with one proton and with one other neutron. All other forces, such as the electrostatic, magnet and gravitational forces, are not excparticlelusive; i.e., they interact with all other particles having the same type of charge. This is inherent in the concept of a force; that a field is produced which they other particles interact with.

But suppose the spin pairing is called the nuclear strong interaction as an alternative to th e nuclear strong force. Then there is the problem that another force is involved in the physics of nuclei. That force cannot be the weak force is 10−13 times less powerful than the electrostatic force. This other force is about one fifth the magnitude of the spin pairing force and comparable in magnitude at nuclear distances to the electrostate force between charged particles.

There is an elaborate structure of analysis built upon the conventional concept of the strong force being an attraction between all nucleons. It is quite plausible that that analysis would hold equally well for an exclusive force between nucleons since it is unlikely that the analysis considered interactions between more than two nucleons.

There is much more to the analysis but what is given here illustrates that much more is involved in nuclear structure than simply giving a name to what holds a nucleus together as the nuclear strong force, particularly since that speculative hypothesis may well be flat wrong. As stated previously, more details are given in What holds a nucleus together?

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