Strong and weak nuclear forces

 (work against the mainstream) This is an IMAGINE

Author : Luis Biarge Baldellou – Email:


The strong nuclear force and weak nuclear forces are considered two of the four fundamental interactions of nature (  and ( )

Strong interaction is in 2 areas : “is the force that binds protons and neutrons together to form the nucleus of an atom” and also “that holds quarks together to form protons, neutrons and other hadron particles.”


Weak nuclear force: “It is responsible for the radioactive decay of subatomic particles and initiates the process known as hydrogen fusion in stars.” –


Force weak or unstable: “Outside the nucleus, free neutrons are unstable” –

Force strong or stable: “However, inside a nucleus, protons can also transform into a neutron via inverse beta decay.” – – also “The transformation of a proton to a neutron inside of a nucleus is also possible through electron capture:” and “The same reasoning explains why protons, which are stable in empty space, may transform into neutrons when bound inside of a nucleus.”

Non stable ““free neutrons decay by emission of an electron and an electron antineutrino to become a proton, a process known as beta decay” –

We can make a translation, so “strong” for stable and “weak” for unstable.


So really only is the difference of stable or unstable in the same force.

Look that in this definition all are same both: strong is “also “that holds quarks together to form protons, neutrons and other hadron particles”,  and also weak is “Outside the nucleus, free neutrons are unstable” the same neutrons is stable according to quarks and unstable according to decay”

Nucleus stable and unstable : “When certain combinations of protons and neutrons form an atomic nucleus, there is the possibility that the nucleus may be unstable. There may be too few or too many protons for the number of neutrons present, or there may be too few or too many neutrons for the number of protons present. In any case, if the nucleus is unstable, that nucleus is said to be radioactive. There is another case in which a nucleus can be unstable, and that is that it is simply too large to be able to stay together” and “Recall that atoms of the same element that have differing numbers of neutrons in them are isotopes of that element.” –


From here I can say that an stable nucleus is strong nuclear and a unstable nucleus is weak nuclear or radioactive and this is normally by difference in number between protons and neutrons.

Another form is that nucleus too large is always unstable and against it the short are stable.

So weak and strong force only can to be the same.


What is stable (strong) and unstable (weak)?: I go to make example with magnet and magnetism but the example is not complete because all magnet we know have both poles.

The magnet has both poles (+ and -) and by that can to join to other poles of other magnets or only to charges + and also charges -. A stable nucleus has protons and neutrons and this means that have magnets with both poles (+ and -) and charges only +.

Imagine then that you have magnets bipolar and charges +, according to this the magnets can to be null charge total and join with charges +, in a stable relation.

When the nucleus has many neutrons bipolar or many protons + or many in total become unstable but not excessively and by that say that the force is weak (slowly) by decay or radioactivity.

Against the weak (slowly) by a few difference in charges, the so called strong is strong because a stable relation the magnetic is quick. So stable is quick or strong like the union of 2 magnets by the contrary poles and unstable lose the stability and by that has a few fail in the form (we cannot make with magnets where were a excess of one of the 2 charges in form that many + charges reject theirs without compensation of – charges). Look that we not have in our common life charges of only one sign, all are bipolar.

There are many examples of stable and unstable: for example more with magnets, if you take a magnet any time with the correct polarity, later in any connections you put other perpendicular go losing stability. Another example making a wall, if you put the correct brick all go well, but if sometimes you introduce an irregular brick the wall go taking unstable, and many other examples.

Remember that a + nucleus is stable because the atom is neutral with the electrons around the nucleus.


All this you can also by study at lower level, protons and neutrons are combination of quarks and this also say “strong force” but really this are the combination final in the nucleus to make strong union or weak decay.

Also, really neutron has charge in bipolar form “Even though the neutron is a neutral particle, the magnetic moment of a neutron is not zero because it is a composite particle containing three charged quarks” –


More: free neutrons are not stable, against the example of magnet, in the magnet the combination is bipolar but in charges are from one only pole  and by that neutrons out of the nucleus is unstable and the 2 charges end separates.

Non stable ““free neutrons decay by emission of an electron and an electron antineutrino to become a proton, a process known as beta decay” – this is a decay to separate the charges.


Now it’s moment to understand that the neutron is the particle that permit the universe like we know, without neutrons the protons could not join and by that only would exist the hydrogen (1 proton and 1 electron). And also for the antineutron.

This is well asked in the history of the page of strong interaction ( “It was known that the nucleus was composed of protons and neutrons and that protons possessed positive electric charge while neutrons were electrically neutral. However, these facts seemed to contradict one another. By physical understanding at that time, positive charges would repel one another and the nucleus should therefore fly apart.” – the proton with their double charge is what admit this combination.


Author: Luis Biarge Baldellou


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