welcome to modern physics!! modern physics phgn 300 fall
TRANSCRIPT
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Modern Physics PHGN 300 Fall 2009
Prof. Lawrence Wiencke
Welcome to Modern Physics!! PHGN 300 Fall 2012
Prof. Lawrence Wiencke TA Xiaoning Zang
Syllabus Organizational, Grading Short Survey Science and Engineering before Modern Physics http://inside.mines.edu/~lwiencke/PH300/F12 Or google mines ph300 2012
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PHGN 300 Topics • Review of Waves
• Special Relativity
• Light Quanta
• Atomic Models
• Intro to Quantum Mechanics
• Quantum Structure – Atoms, Solids
Solid State Devices
• Nuclei and Nuclear Physics
• Particle and Astrophysics
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1895
– First Electric Light Systems
– Moving Picture Projector
– First Automobile Race in US
– 1st female PhD in science earned
(Caroline Willard Baldwin) – Cornell
Most of the Physics Research –
Great Britain, Germany, France
Classical physics by the end of the 19th century
• Mechanics: – Galileo 1564-1642 ; Newton 1642-1727…
• Electromagnetism: – Coulomb 1736-1806 ; Ampere 1775-1836 – Faraday 1791-1867 ; Maxwell 1831-1879…
• Thermodynamics: – Carnot 1796-1832 ; Kelvin 1824-1907…
Kinetic Theory of Gases
• Thermodynamics and “atomic” theory of matter – Gay-Lussac 1778-1850: ideal gas: PV=nRT – Avogadro 1776-1856: the Avogadro number – 1895’s: Maxwell-Boltzmann velocity distribution
• It works… but, in 1895, nobody knows what an atom really is !
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1895
The atom considered fundamental unit of matter
• Inaccurate description
• Nucleus not yet discovered
no nuclear physics/engineering
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1895
No fundamental particles had been discovered
• No electron, muon, ..
• Also no proton or neutron
Higgs Boson (2012)
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1895 (II) • No Quantum Mechanics
– Deterministic philosophy
– Statistics and probability - motivated by???
– particle wave duality not understood
No Special Relativity
– But the speed of light had
been measured
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1895 (II)
• Astronomy – yes
– Spectroscopy of sun and stars
– Astrophysics – Newtonian
– Sun’s energy from gravity?
– Milky Way was the Universe
− no galaxies)
• Great debate about Nebula still 25 years away
– No Cosmology, No astro-particle physics
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Mechanical Engineering Steam power, industrial revolution
Strong material widely available – Steel
1890 – First US patent for ARC welding but no X-ray inspections
Electrical separation process for Aluminum invented in late 1880’s
Control systems existed limited to mechanical, hydraulic
No plastics, no lasers, no electronics No computer aided nothing
Engineering Hall 1894
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Materials Science
• Many metals known and studied
– Particulate and chemical/extraction metallurgical-and-materials processing
• No atomic physics
• No electron microscope
– (no electrons!)
• Band-Gaps? Photovoltaics
– Nano-Structures? Yeah, right.
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Electrical Engineering
• V and I really big
• Few buildings had electricity
AC (Westinghouse) vs DC (Edison)
• How is charge carried?
• Vacuum tubes just starting
• No transistors, circuit boards
• Maxwell’s equations known
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Math/Computer Science • Mathematics – well ahead of the physics
– Calculus (Newton)
– Number theory, Group theory, Set theory,
– Euclidean and non-Euclidian geometry
– Complex variables
– And even many of the equations known for hundreds of years
• – Legendre polynomials, Taylor series
– World wide Application?
− Celestial Mechanics (navigation)
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Math/Computer Science •
• Calculations done by hand
– with look-up tables.
• No computers
– Hollerith Tubulator machine
– Idea described (Babbage)
– Idea of mechanical computations not pursued
– No transistors, no atomic physics
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1895 Hints and Hot Topics Discovery of Helium
– Structure in spectra of heated gasses (and stars)
– Propagation of Radio Waves
• What exactly is waving?
– Relation between Temperature and Color
• Can’t be reproduced by classical theories
– Nature of light
– Kinetic Theory of Gasses