Slide 1 ___________________________________
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Slide 1 ___________________________________ 1642 ___________________________________ Newton Young 1801 Maxwell 1865 Balmer 1885 J.J. Thompson 1889 Planck 1901 Einstein 1905 Rutherford 1911 Bohr 1913 1915 ___________________________________ ___________________________________ Einstein Proof of SR 1917 1923 De Broglie Schroedinger Heisenberg 1926 ___________________________________ 1927 Nuclear Physics ___________________________________ ___________________________________ Slide 2 ___________________________________ What Newton Gave Us…………………….. Space “ Absolute space, in its own nature, without relation to anything external, remains always similar and immovable.” Time “Absolute, true, and mathematical time, of itself, and from its own nature, flows equably without relation to anything external, and by another name is called duration.” Causality Newton’s third law – For every action there is an equal and opposite reaction. Particles Light is a particle No insight into atomic structure ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 3 ___________________________________ What Newton Didn’t Give Us…………………… How do objects which interact with each other exchange information? ___________________________________ ___________________________________ What is the “medium of exchange? Action at a distance? ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 4 ___________________________________ ___________________________________ Forbidden Speed of Light (c) Quantum & Special Relativity Speed .1 c Quantum Size or Distance ___________________________________ Special Relativity General Relativity ___________________________________ Newtonian 10-5 m ___________________________________ 1022 m ___________________________________ ___________________________________ Slide 5 ___________________________________ Modern Physics - Relativity - Quantum Mechanics - Nuclear Physics - Structure of the Atom ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 6 ___________________________________ J. Balmer - Solar Spectra J.J. Thompson - Discovers electron A.A. Michelson - Speed of Light / Ether M. Planck - Blackbody Radiation / Quanta A. Einstein - Photoelectric Effect / Relativity / Brownian Motion ___________________________________ ___________________________________ ___________________________________ E. Rutherford - Structure of Atom N. Bohr - Bohr Model of the Atom ___________________________________ L. De Broglie - Wave Nature of Matter ___________________________________ ___________________________________ Slide 7 ___________________________________ Michelson’s intent was to: 1.) Measure the speed of light. 2.) Detect the presence of the ether by detecting differences in the speed of light. ___________________________________ ___________________________________ ___________________________________ He referred to his results as the most famous non-result in history. ___________________________________ ___________________________________ ___________________________________ Slide 8 ___________________________________ His idea was to detect the change in the speed of light by comparing two beams of light which passed through the ether at right angles to each other. Lorentz concluded that the ether actually had a contracting effect on the apparatus and calculated the effect as, L = Lo (1- v2/c2)1/2 , the Lorentz contraction. ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 9 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 10 ___________________________________ Planck’s solution was the development of quantized (restricted) values of energy in a mechanical oscillation scheme (E = hν), 1901. Further developed by Einstein in the photo-electric Effect, 1905. Rutherford, 1911 atomic model (Gieger and Marsden) Bohr model of the atom, 1913. ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 11 ___________________________________ Structure of Atom - 99.99% space - very dense nucleus - electrons orbit outside the nucleus Problems ___________________________________ ___________________________________ Electric attraction between proton and electron = 4.6 X 10-18 Newtons ! So the acceleration of the electron toward the proton is 25 X 1012 m/s2 Time of flight = 10-12 seconds ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 12 ___________________________________ Bohr Model of Atom - Stable Orbits for Electrons - Transitions between Orbits Allowed - Requires a change in energy - Orbital sizes based on angular momentum 2πr = nh/mv or mvr = nh/2π Explains - stability of matter - line spectra - emission - absorption - hydrogen atom (ionization energy, ground state radius, Rydberg constant) ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 13 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 14 ___________________________________ Quantum phenomena can be linked to technologies amounting to 25% of the US Gross National Product (GNP) -2006 US GNP = 11 X 1012 $ -.25 X US GNP = 2.75 X 1012 $ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 15 ___________________________________ Quantum theory describes the nature and behavior of matter and radiation at the microscopic level. It is the most tested scientific theory in history and one of the most successful. However, after almost100 years of use it is still not entirely clear what the theory means. ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 16 ___________________________________ Quantum theory challenges the Newtonian world view in the following ways: -the universe is not causal ___________________________________ ___________________________________ -changes in nature occur discontinuously -reality does not appear to be independent of the observer -there are intimate connections between things in the universe ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 17 ___________________________________ Anyone who is not shocked by quantum physics has not understood it Niels Bohr ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 18 ___________________________________ The Double Slit Experiment The Uncertainty Principle Matter Waves Non-locality Entanglement ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 19 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Particle Screen Expected What Top Bottom pattern you see slit slit both both only only slits slits ___________________________________ ___________________________________ Slide 20 ___________________________________ “The double slit experiment is a phenomenon which is impossible to explain in any classical (Newtonian) way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery. We cannot make the mystery go away by explaining how it works.” Richard Feynman ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 21 ___________________________________ A philosopher once said, “It is necessary for the very existence of science that the same conditions always produce the same results.” Well they don’t! Richard Feynman ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 22 ___________________________________ In some strange way the universe is a participatory universe. John Wheeler ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 23 ___________________________________ ___________________________________ When it comes to atoms, language can be used only as in poetry. The poet too, is not nearly so concerned with describing facts as with creating images. ___________________________________ Bohr ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 24 ___________________________________ A Post Newtonian World View Newton Post Newton Atomism Objectivity Predictability Analysis ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 25 ___________________________________ No theory of physics that deals only with physics will ever explain physics. I believe that as we go on trying to understand the universe, we are at the same time trying to understand man. The physical world is in some deep sense tied to the human being. John Wheeler ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________
