1. Einstein 1905 and the birth of modern physics

2. Einstein Year Einstein 1905  Nature of Light  Atomic Theory  Special Theory of Relativity

3. Early Years  Born in Ulm (D) 1879  Primary and secondary school (MUC)  Family move to Milan 1894  Aarau Gymnasium (SCH) 1895  ETH (ZUR) 1896

4. Student Years  Not a model student  Lack of interest  Diploma in maths and physics 1900  Unable to find University assistantship  Temporary schoolteaching

5. Bern 1901- 1905  Tech expert in Swiss Patent Office (Bern)  Swiss citizenship in 1901  Daughter with Mileva Maric in 1902  Adoption  Married in 1903  Son in 1904

6. Bern 1901-1905  Engineering problems (day)  Fundamental physics problems (night)  Olympia Academy of Philosophy  Arrival of Micheal Besso  Five scientific papers on thermodynamics

7. Contemporary Physics  Mechanics F = ma Law of Gravity  Electromagnetism Elec +Mag =EM Light = electromagnetic wave  Radiation Planck’s Law  Radioactivity Energy mystery

8. Einstein 1905  The Nature of Light (cornerstone of quantum theory)  Atomic Theory (reality of atoms)  Special Theory of Relativity (physics of relative motion)

9. I Atomic Theory  Greeks – matter composed of atoms  Dalton – atoms of the chemical elements differ  Avogadro –atoms and molecules  Mendeleev – Periodic Table  Maxwell – Kinetic theory of gases No direct evidence

10. Einstein and Atomic Theory  Molecular dimensions in liquids  Well received  Statistics of molecular motion in liquids  Fluctuations  Effect on immersed particle - Brownian motion  Mean free path calculation

11. Einstein and Atomic Theory  1906-08 Perrin’s Brownian Motion experiments  1908 : Confirmation of Einstein predictions Atomic theory = reality  Role of probability and statistics in nature  Einstein established  Nobel Prize for Perrin

12. II Problems with Light  Radiation studies  Ultraviolet Catastrophe  Planck’s Radiation Law (1900) “Radiation emitted/absorbed in chunks (quanta)”  Mathematical artefact  Applies only to oscillators

13. Einstein and Light  Einstein : inconsistency in Planck’s Law  Einstein : new statistical approach (1905) “Light itself behaving like particles (quanta)”  Explained Planck’s law, Photoelectric Effect  Conflict with wave theory of light  Rejected for 17 years

14. III Relativity  Galileo: Principle of Relativity  Laws of mechanics independent of uniform motion  Impossible to detect motion internally  No absolute frame of reference for motion  Newton : absolute space

15. Relativity and Electromagnetism  Maxwell : electromagnetic theory  Radiation = electromagnetic waves (speed 3x10 8 m/s) light = em wave of speed 3x10 8 m/s  Speed relative to ether ?  Absolute frame of reference for light ?  Experiments

16. Einstein’s Relativity 1905  Relativity applies to all laws of physics (includes electromagnetism)  Speed of light = universal constant (general principle) Implication: time and distance not absolute

17. Implications of Special Relativity  Length of a body  Time interval  Mass of a body

18. Implications of SR  Time is relative  Time + space = spacetime  Mass is a form of energy E = mc 2

19. Response to relativity  Controversy (1905-08)  Kaufmann experiments (1908)  Bucherer experiments (1909) By 1911 Special Relativity accepted

20. Career Progress  1905 PhD (ETH)  1908 Privatdozent (Univ Bern)  1909 Assoc Prof (Univ Zurich)  1911 Prof (Univ Prague)  1912 Prof (ETH Zurich)  1914 Prof (Univ Berlin), Director (FW Institute)  1913 Separation

21. Middle Years (1908-1916)  Relativity and accelerated bodies (1908-15)  Principle of Equivalence  General Relativity (1915) “Gravity = curvature of space-time”  Bending of light by gravity  Slowing of time by gravity  Cosmological implications

22. After the War  1916 Photoelectric effect (Millikan)  1919 Evidence for GR (Eddington) 1921 Nobel Prize (Photoelectric effect)  1923 Compton Effect (light quanta)  1925 Electron waves (quantum duality)

23. Between Wars  1919 Remarried  1920s Anti-semitism in Germany Einstein’s work attacked  1930-33 Rise of Nazi Party  1930-33 Visiting Prof at Caltech (US)  1933 Hitler assumes power  1933 Flight to Princeton (US)

24. Princeton Years (1933-55)  Hero’s Welcome  American Icon  Letter to Roosevelt (1939)  Manhattan Project  Regret at Hiroshima (1944)  Nuclear disarmament (1940s)  McCarthyism (1950s)

25. Princeton Years (1933-55)  Interpretation of quantum theory  Relativity and electromagnetism Unified Field Theory  Evidence for relativity (1950s)  New York Times Iconic figure

26. Einstein Today Atomic Theory Reality of atoms Stat. applications Quantum Theory Wave/particle duality Applications Special Relativity Particle physics Nuclear fission and fusion

27. Einstein Today General Relativity Underlies cosmology Evolution of Universe Unified Field Theory Still not solved Holy grail of physics