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The photoelectric effect is the emission of electrons from a material caused by electromagnetic radiation such as ultraviolet light. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, solid state, and quantum chemistry to draw inferences about the properties of atoms, molecules and ...
In 1887, he made observations of the photoelectric effect and of the production and reception of electromagnetic (EM) waves, published in the journal Annalen der Physik. His receiver consisted of a coil with a spark gap, whereby a spark would be seen upon detection of EM waves. He placed the apparatus in a darkened box to see the spark better.
He spent the next three years in a physics fellowship at Yale University, where he performed research on the photoelectric effect with Ernest Lawrence. [4] Beams was appointed a professor of physics at the University of Virginia in 1929 and was chair of the department from 1948 to 1962. [ 5 ]
Robert Andrews Millikan (March 22, 1868 – December 19, 1953) was an American physicist who received the Nobel Prize in Physics in 1923 for the measurement of the elementary charge and for his work on the photoelectric effect. Millikan graduated from Oberlin College in 1891 and obtained his doctorate at Columbia University in 1895.
However, the later discovery of the photoelectric effect demonstrated that under different circumstances, light can behave as if it is composed of discrete particles. These seemingly contradictory discoveries made it necessary to go beyond classical physics and take into account the quantum nature of light.
They describe experiments that, except for some specific and necessary idealizations, could conceivably be performed in the real world. [2] As opposed to physical experiments, thought experiments do not report new empirical data. They can only provide conclusions based on deductive or inductive reasoning from their starting assumptions.
A fraction of the photons produced a measurable electric current due to the photoelectric effect. [2] [3] The count detections were recorded photographically using silver bromide film, [1] by the means of a string electrometers. The efficiency of the coincidence counting was of the order of 1 for 10 events. [2]
1905 – Einstein explains the photoelectric effect by extending Planck's idea of light quanta, or photons, to the absorption and emission of photoelectrons. Einstein would later receive the Nobel Prize in Physics for this discovery, which launched the quantum revolution in physics.