Strong and Weak Force

2026-04-29T02:40:33Z

JamesSoule:

Claimed by '''JAMES SOULE (Spring 2026)'''

Strong and Weak forces are nuclear forces that govern subatomic behavior in our universe.

Strong and Weak forces are two of the four fundamental forces, with the other two being gravity and the Electromagnetic Force. This article will serve as an overview of the concepts, applications, and history of Strong and Weak forces.

==Strong Force==
The Strong Force binds the nucleus together, and is the strongest force in the universe. It is <math> 10^{38} </math> times stronger than the force of gravity, operates at a scale of <math>10^{-15} m </math>, and is 137 times stronger than the electromagnetic force. While this force holds together protons and neutrons to create a nucleus, it also is responsible for holding together the quarks that make up those subatomic particles in the nucleus. We specify that this force is keeping together quarks in the nucleus, since electrons that are outside the nucleus are not made of quarks, and therefore not held together by the Strong Force.

However, the strong force requires a medium particle (also called an exchange particle), known as gluons.

==Weak Force==
The weak nuclear force, despite its name, is <math> 10^{31} </math> times stronger than the force of gravity, but operates at a short range. Controlling interactions on a scale of <math> 10^{-17} m </math>, it is 100x shorter than the range of the Strong Force. The Weak Force's main interaction with the nucleus is "flipping" a proton into a neutron, and vice versa. When a neutron "flips" into a proton, the element changes, but the mass of atom stays the same. In this flipping process, an electron will be emitted to counteract the proton's charge.

==History==

'''Finding the Strong Force:'''
* '''1935''': Hideki Yukawa proposed the existence of "mesons"—intermediate-mass particles—that acted as the exchange medium for a new force that held nucleons together. This idea was used to develop later theories about the forces binding the atom.

* '''1970s:''' Eventually an understanding of Quantum Chromodynamics allowed us to analyze fundamental forces in the atom by analyzing the color charge of quarks by their gluons, which emit an analyzable color.

'''Understanding Beta Decay'''

* '''1935:''' Enrico Fermi proposed his theory of Beta Decay to explain how atoms changed identity. It proposed how a force can cause a neutron to flip, and produce an electron. However, he had no way to physically prove this.

* '''1956:''' It was not until the Cowan–Reines Neutrino Experiment that there was physical proof of Fermi's theories. This was the discovery of Neutrinos, and proves the "invisible" part of Fermi's theories to be real.

Strong and Weak Force

2026-04-28T20:40:56Z

JamesSoule:

Claimed by JAMES SOULE (Spring 2026)

The strong and weak forces are the forces that govern the subatomic behavior of atoms.

This is a short introduction to the nuclear strong and weak forces, the other two of the four fundamental forces. These two forces will not be covered in depth by this class, and as such this is just a general overview.

==Main Idea==
The strong nuclear force governs interactions on a scale of <math> 1 fm = 10^{-15} m </math>. The strong force is <math> 10^{38} </math> times stronger than the force of gravity, and 137 times stronger than the electromagnetic force. It is the strongest of the four fundamental forces (gravity, electromagnetic force, strong nuclear force, and weak nuclear force). The strong force is what binds neutrons and protons together to create nuclei. Because it is stronger than the electromagnetic force, it allows particles with the same charge sign to be compressed together despite their revulsion due to the electromagnetic force. On an even smaller scale, the strong nuclear force is what holds quarks together. When quarks are held together, they create particles such as protons and neutrons. Quarks are a class of subatomic molecules that, when combined, create hadrons, the most stable of which are protons and neutrons. Electrons are NOT hadrons.

The weak nuclear force, on the other hand, governs interactions on a scale of <math> 10^{-17} m </math>. The weak force in atoms causes radioactive decay in the atom, and is the force that allows neutrons to decay into protons, etc.

==History==
Prior to the 1970s, it was unclear how the nucleus managed to hold itself together. Classical electromagnetism implies that nuclei shouldn't stay bound together. A strong attractive force, greater in magnitude than the repulsion due to electromagnetic force was needed to explain what held the extremely positively charged nucleus together. It was in the 1970s that the nuclear strong force was first proposed.

With regards to the weak force, Enrico Fermi was fundamental in proposing the idea for it. In 1933, he suggested a mechanism to explain beta decay (which occurs when a neutron decays into a proton, an electron, and an antineutrino). The mechanisms behind this force were not directly confirmed until 50 years later.

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Strong and Weak Force

Strong and Weak Force