Einstein 1905

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 Plancks 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 Perrins 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
• Plancks Radiation Law (1900)
• Radiation emitted/absorbed in chunks
  (quanta)
• Mathematical artefact
• Applies only to oscillators

13
Einstein and Light

• Einstein inconsistency in Plancks Law
• Einstein new statistical approach (1905)
• Light itself behaving like particles
  (quanta)
• Explained Plancks 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 3x108
  m/s)
• light em wave of speed 3x108 m/s
• Speed relative to ether ?
• Absolute frame of reference for light ?
• Experiments

16
Einsteins 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 mc2

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
• Einsteins 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)

• Heros 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