1. Overview of the Structure of Physics

2. Overview of the Structure of Physics Where does this course fit in?
Along the way, some comments on Physics History & trivia.

3. Overview of the Structure of Physics Where does this course fit in?
Along the way, some comments on Physics History & trivia.
Niels Bohr
1922 Nobel Prize in Physics for
“His services in the investigation of the structure of atoms and of the radiation emanating from them.”

4. *Harald Bohr later became a world famous mathematician!
Interesting Trivia (to me)! Neils Bohr is the Only Nobel Prize winner to have also been an Olympic Medalist!
In the 1908 Olympics,
he & his brother Harald* were on the Danish soccer team, which won a sliver medal!
*Harald Bohr later became a world famous mathematician!
Interesting Trivia (to me)!

5. The Structure of Physics
Classical Physics is The Foundation
of pure & applied (macroscopic) physics & engineering!
Newton’s Laws + Electromagnetism
+ Statistical Mechanics + Thermodynamics.
These give a good description of most of the macroscopic world.
Classical Mechanics
(Newton, Lagrange, Hamilton,..)
The Physics of the 17th & 18th Centuries.
Still useful in the 21st Century!!
Physics I!

6. Physics Structure Classical Electromagnetism & Optics
This course!
Classical Electromagnetism & Optics
(Newton, Coulomb, Gauss, Faraday, Maxwell,..)
The Physics of the 18th & 19th centuries.
Still useful in the 21st Century!
High Speeds (v ≤ ~ c)  Special Relativity (Einstein, ..) 20th Century Physics!
Small Size (atomic & smaller):
Quantum Mechanics
(Bohr, Schrödinger, Heisenberg….)
20th century physics!

7. “Mechanics” The 4 Fundamental
HOW objects move (behave) under given forces.
(Usually) Does not deal with the sources of forces.
Answers the question:
Given the forces, how do objects move?
Forces in the universe are classified into 4 types:
The 4 Fundamental
Forces Of Nature!
Some version of Mechanics
applies to all four!

8. The 4 Fundamental Forces of Nature The sources of the forces, in order of decreasing strength
The Strong Nuclear Force:
Binds nuclei together. Explained by the “Standard Model” & Quantum Chromodynamics.
Still being researched.
The Electromagnetic Force:
E&M phenomena. Chemical forces. Most everyday forces. Maxwell, Coulomb, Ampere, Faraday, ...
The Weak Nuclear Force:
Nuclear decay. Fermi, Bethe, others. Electroweak Theory.
The Gravitational Force:
Newton (classical mechanics), Einstein (general relativity), Hawking….
This course!

9. The 4 Fundamental Forces of Nature The sources of the forces, in order of decreasing strength

10. The Four Fundamental Forces
The “Electro-Weak” Force
Since ~ the late 1960’s, in some sense, the
4 fundamental forces
have been reduced to three!
That is, the Electromagnetic Force & the Weak Nuclear Force
were combined into one theory. This was first done by S. Weinberg & A. Salaam. For this work, they received the
1972 Nobel Prize in Physics!

11. The Standard Model of Particle Physics
“Periodic Table for Elementary Particles”!
Quantum Chromodynamics (QCD)
+ the Electroweak Theory
Protons & Neutrons consist of 3 Quarks each.

12. The Standard Model

14. Statistical Mechanics
The Rest of Physics!
What we’ve mentioned so far is  all of physics except:
Statistical Mechanics: The mechanics of systems of huge numbers (>> ~ 1023) of particles.
Statistical Mechanics
1. Uses Probability & Statistics to calculate macroscopic properties from microscopic force laws.
2. Is the major link between microscopic & macroscopic physics!
3. Contains Thermodynamics as a sub-theory!