Einstein and 20 th Century Physics

1. Einstein and 20th Century Physics • Einstein’s early years • The Miracle year: 2005 • The Quantum Nature of Light • Brownian motion and atomic theory • Special Relativity • Newton and absolute space and time • Thought experiments • E = mc2 • General Relativity • Quantum Weirdness • Einstein’s later years

2. I. Albert Einstein (1879- 1955) The Early Years Pauline and Hermann Einstein Eduard and Hans Patent clerk (1902 – 1909) 1903 - 1919 MilevaMaric (1875 – 1948)

3. II. The Miracle Year: 1905 A. The Quantum Nature of Light • the wave nature of light Maxwell’s Accomplishments • Speed of light = 300, 000 Km/sec • (186, 000 mi/sec) • Light is electromagnetic energy • Maxwell’s equations • the aether returns! 4 equations describing EM • electromagnetism The first color photograph 3 key inventions James Clerk Maxwell (1831 – 1879) 1. Electric motor Michael Faraday (1791 – 1867) 2. Electric generator 3. Transformer

4. II. The Miracle Year: 1905 A. The Quantum Nature of Light Quantum of light = photon Quantum mechanics

5. II. The Miracle Year: 1905 B. Brownian Motion and Atomic Theory Proof of the existence of atoms

6. II. The Miracle Year: 1905 • Special Relativity • Galileo’s principle of relativity • Newton’s space, time, and gravity • Experiments to detect the aether • Thought experiments • Twin paradox • Riding next to a beam of light The Cosmic Speed Limit (300, 000 km/sec) Inertial reference frame = constant speed and not changing direction = no acceleration No absolute simultaneity Why special?

7. 4. E = mc2 Energy = mass x the speed of light squared (explained by Einstein) Implications for travelling at the speed of light Hadron Super Collider Nuclear Power Plant

8. Summary of Special Relativity • the speed of light is a constant – it is invariant • nothing in the Universe can travel faster than the speed of light • space and time are not absolute – they vary according to speed • there is no absolute simultaneity • E = mc2 has many implications and applications • Special relativity is contrary to Newtonian physics

9. III. General Relativity 1915 2 problems with Special Relativity Gravity not dealt with Deals with constant velocities – what about acceleration? “My happiest thought” Equivalence principle – riding in elevators Confirmation

10. Mass warps space (That’s Gravity!!) Newton and Gravity Black Holes

11. Big Bang singularity General Relativity Prediction Cosmological constant – “My biggest mistake” 14 billion years ago Edwin Hubble: 1929 Georges Lemaître : 1931 Confirmation

12. IV. Quantum Weirdness Quantum mechanics Uncertainty Principle Applications of QM Electron weird behavior Electron behavior unpredictable “God does not play dice” Werner Heisenberg (1901 – 1976) “Einstein! Stop telling God what to do!”

13. V. Einstein’s Later Years Einstein the rock star Nobel Prize 1921 Unified Field Theory Four fundamental forces Elsa Einstein (1876 – 1936) The strong interaction The electromagnetic force The weak force The gravitational force Einstein’s office in Princeton University

14. Einstein’s letter to FDR

15. Einstein’s God A knowledge of the existence of something we cannot penetrate, of the manifestations of the profoundest reason and the most radiant beauty - it is this knowledge and this emotion that constitute the truly religious attitude; in this sense, and in this alone, I am a deeply religious man. I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it. I believe in Spinoza's God who reveals himself in the orderly harmony of what exists, not in a God who concerns himself with the fates and actions of human beings. More on Einstein’s God

16. Einstein and Politics Einstein the Zionist

17. Einstein’s legacy

18. Special and General Relativity Explained