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Show Physics lecture focuses on phonons entitui 'Durth lecture in the "Frontiers of Science" series Monri hononsThe Fingerprints of a Crystal" was presented 0 Physic? n6 u" Mark H' Greene Ha" by tne Department of and Bilz' a Un'versity visiting professor of physics UniversitleiFber f the faculty of Jhann Wolfgang Goethe Dr R.T ' f.ranltfurt. Germany, was the guest speaker. PropertiP t discussed the features of solids and used the 1,5 crvsta,s an example. He explained how light labeled it ??ergy to electrons in the form of kinetic energy and Dr Bi, .e. '"fraction of light with electrons. z then went on to discuss lattic vibrations--the motion of phonons in a crystal. In phono-phonon interactions, solids break down into liquids as a result of heat generated by the movement of the phonons. After looking at phonons and electrons as particles of a crystal Dr. Bilz talked about the interaction of the two. When the two particles collide, the kinetic energy of the electron is converted into heat. Dr Bilz concluded his lecture by saying that phonons are the equivalent of fingerprints for solid matter. Although they don t directly identify a substance, they give definite indirect impressions of the solid. |