Download Presentation
## Einstein 1905

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**Einstein 1905**and the birth of modern physics**Einstein Year**Einstein 1905 • Nature of Light • Atomic Theory • Special Theory of Relativity**Early Years**• Born in Ulm (D) 1879 • Primary and secondary school (MUC) • Family move to Milan 1894 • Aarau Gymnasium (SCH) 1895 • ETH (ZUR) 1896**Student Years**• Not a model student • Lack of interest • Diploma in maths and physics 1900 • Unable to find University assistantship • Temporary schoolteaching**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**Bern 1901-1905**• Engineering problems (day) • Fundamental physics problems (night) • Olympia Academy of Philosophy • Arrival of Micheal Besso • Five scientific papers on thermodynamics**Contemporary Physics**• Mechanics F = ma Law of Gravity • Electromagnetism Elec +Mag =EM Light = electromagnetic wave • Radiation Planck’s Law • Radioactivity Energy mystery**Einstein 1905**• The Nature of Light (cornerstone of quantum theory) • Atomic Theory (reality of atoms) • Special Theory of Relativity (physics of relative motion)**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**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**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**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**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**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**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**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**Implications of Special Relativity**• Length of a body • Time interval • Mass of a body**Implications of SR**• Time is relative • Time + space = spacetime • Mass is a form of energy E = mc2**Response to relativity**• Controversy (1905-08) • Kaufmann experiments (1908) • Bucherer experiments (1909) By 1911 Special Relativity accepted**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 (FWInstitute) • 1913 Separation**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**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)**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)**Princeton Years (1933-55)**• Hero’s Welcome • American Icon • Letter to Roosevelt (1939) • Manhattan Project • Regret at Hiroshima (1944) • Nuclear disarmament (1940s) • McCarthyism (1950s)**Princeton Years (1933-55)**• Interpretation of quantum theory • Relativity and electromagnetism Unified Field Theory • Evidence for relativity (1950s) • New York Times Iconic figure**Einstein Today**Atomic Theory Reality of atoms Stat. applications Quantum Theory Wave/particle duality Applications Special Relativity Particle physics Nuclear fission and fusion**Einstein Today**General Relativity Underlies cosmology Evolution of Universe Unified Field Theory Still not solved Holy grail of physics