150 likes | 265 Views
Phys 3250: Topics in Relativity. Instructor: Dr. Spencer Buckner Office: SSC B-326 Office Hours: MWThF 10:15 – 11:15am and 1 :30 – 2:30pm or by appointment Website: buckners@apsu.edu Class Meeting Time: Wednesday 12:20 – 1:15pm Class Meeting Place: SSC B-107. Textbooks.
E N D
Phys 3250: Topics in Relativity Instructor: Dr. Spencer Buckner Office: SSC B-326 Office Hours: MWThF 10:15 – 11:15am and 1:30 – 2:30pm or by appointment Website: buckners@apsu.edu Class Meeting Time: Wednesday 12:20 – 1:15pm Class Meeting Place: SSC B-107
Textbooks Schaum’s Outline for Modern Physics by Ronald Gaurteau & William Savin
Grading Exams………45% A…90 – 100% Homework…35% B…80 – 89% Project………15% C…70 – 79% Participation…5% D…60 – 69% F…<60%
Exams There will be three exams during the semester: one about every fifth class meeting. The exams will consist of a number of numerical problems similar to the homework and at least one essay question. The exam dates are: Wednesday September 24 Wednesday October 29 Wednesday December 3
Homework Homework will be assigned each week and will be due the following week. Most problems will be out of the Schaum’s Outline for Modern Physics but additional supplemental problems from other sources may be assigned. Solutions to the homework will be posted in the class D2L shell and on www.apsu.edu/buckners within a day or two of the due date. First Homework Set: Schaum’s Outline Chapter 1 Supplemental Problems #1.11, 1.13, 1.17, 1.18, 1.19 & 1.20
Project There will be one project on a topic in relativity, either special or general, during the semester. The results of the project will be presented in a poster format to be displayed during the final exam period on Friday December 5 @ 1:30pm. You must be available next to your poster to defend it during the entire exam period.
The Need for Relativity First published in a four part paper by James Clerk Maxwell between 1861 and 1862. Maxwell showed that light was an electromagnetic wave whose propagation speed was equal to the inverse square root of the product of the two fundamental constants in his equations. Question: What is the medium through which light travels?
The Need for Relativity II Given that light was an electromagnetic wave, a medium for the wave was postulated: the luminiferous aether. Performed in 1887 by Albert Michelson and Edward Morley at Case Western Reserve University to detect the motion of Earth through the luminiferous aether Watch YouTube video on Michelson-Morley experiment
The Need for Relativity III To account for the null results of Michelson and Morley, one proposal was that light speed velocities should use a Lorentz transformation rather than a Galilean transformation. Problem is, while Maxwell’s equations are invariant under a Lorentz transformation, Newton’s equations aren’t. Plus, Maxwell’s equations gave a speed of propagation of the electromagnetic force: the speed of light. There was no propagation speed inherent in Newton’s equations.
Galilean Transformations are simple addition and subtraction This doesn’t work for the electromagnetic force and Maxwell’s Equations. It works fine for Newtonian mechanics and the gravitational force
The Need for Relativity IV The orbit of Mercury wasn’t what it was supposed to be. The perihelion of Mercury's orbit precesses by just over 574 arcseconds per century. Perturbations due to the other planets and the oblateness of the Sun could account 531 arcsecond per century. The other 43 arcseconds per century could not be explained using Newtonian gravity.
Colored Card Question The null results of Michelson and Morley proved there was no luminiferous aether. proved that the Earth dragged the luminiferous aether with it as it moved through space. proved that, when dealing with light, velocities required a Lorentz transformation rather than a Galilean transformation. didn’t prove anything.
Another Colored Card Question The precession of the perihelion of Mercury was evidence that the planet was dragging the luminiferous aether with it and thus slowing its motion. the force of the Sun’s gravity on Mercury was stronger than it should be due to its proximity to the Sun. Newton’s law of gravity was wrong and no longer useful anywhere. due to its high orbital speed, a Lorentz transformation for velocity was required to get the correct orbit.
5-Minute Essay My name is _______. I am a (sophomore, junior, senior). My major is ___________. I am taking Topics in Relativity because I want to learn _______________. When I graduate I want to __________.