1. The 4 Fundamental Forces of Nature The Sources of these forces: In order of decreasing strength
Strong Nuclear Force:
Binds nuclei together. Still being researched.
Electromagnetic Force:
E&M phenomena. Chemical forces. Most everyday forces. Maxwell, Coulomb, Ampere, Faraday, ...
Weak Nuclear Force:
Nuclear decay. Fermi, Bethe & others. Still being researched.
Gravitational Force:
Newton (“classical” mechanics)
Einstein (general relativity)

2. The 4 Fundamental Forces of Nature The Sources of these forces: In order of decreasing strength

3. The 4 Fundamental Forces of Nature
“Electro-Weak” Force:
Since ~ the late 1960’s, in some sense have reduced the 4 fundamental forces to 3!
The Electromagnetic Force & the Weak Nuclear Force were combined into one theory.
S. Weinberg & A. Salaam:
The 1972 Nobel Prize in Physics!