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Photoelectric Effect. Apply voltage to a metal to show that ejection of electrons does not depend on intensity of incoming light. Wow of Photoelectric Effect. First demonstration of particle nature of light. Predicted in 1905, demonstrated in 1915
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Photoelectric Effect Apply voltage to a metal to show that ejection of electrons does not depend on intensity of incoming light.
Wow of Photoelectric Effect • First demonstration of particle nature of light. • Predicted in 1905, demonstrated in 1915 • Therefore first step towards Quantum Mechanics.
Notes of Photoelectric Effect • Have same number of points below and above 0V, and make sure they are more than 8 for each. • Make sure that you have reached stopping voltage, actually passed it.
The Michelson Interferometer • Split the light, have two rays travel different length paths, look at interference pattern later.
Wow of The Michelson Interferometer • Most famous failed experiment ever. (1887) • Built to investigate aether. • Wave properties of light. • Used for understanding gravitational waves.
Millikan Oil Drop Experiment Charge very small oil vapor, move it under gravitational and electrical fields to get charge of the electron.
Wow of Millikan Oil Drop Exp. • First precise determination of charge of electron (1911) • Conclusive determination that electron is a fundamental particle.
How of Millikan Oil Drop Exp. • Squeeze the atomizer to supply particles into the chamber. • Radioactive source will add the charge. • A few of them will move into spacing between plates.
Notes of Millikan Oil Drop Exp. • You will need to keep more than 6 droplet in sight for at least 8 up/down pair. • This is a statistical experiment. Pay attention to error... • Timing is very important, so pay attention!!!
References • http://en.wikipedia.org/wiki/Michelson-Morley_experiment • http://en.wikipedia.org/wiki/Michelson_interferometer • http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/michel.html • http://en.wikipedia.org/wiki/Oil-drop_experiment • http://www.pha.jhu.edu/~c173_608/millikan/millikan.html • Phys 292/294/295/297 Manual