330 likes | 547 Views
The Physicist’s Vacation. Day 128, Thursday, 20 March, 2014 De Broglie Waves & the Uncertainty Principle. Matter Waves (de Broglie Waves) Heisenberg’s Uncertainty Principle. The Physicist’s Vacation. Is light a wave or a particle?.
E N D
Day 128, Thursday, 20 March, 2014De Broglie Waves & the Uncertainty Principle • Matter Waves (de Broglie Waves) • Heisenberg’s Uncertainty Principle
Is light a wave or a particle? • Quantum Mechanics introduces the concept of a “wave-particle duality”
Dr. Quantum and the Double Slit Experiment • Dr. Quantum and the Double Slit Experiment
Matter Waves (de Broglie Waves) • E = nhf (Planck’s hypothesis for quanta of energy) • E = hf (Let quantum number n = 1) • f = E/h (solve for frequency f ) • What if matter was waves also? • F = E/h(de Broglie frequency) • nu = J/Js = 1/s • nu = v/ 1/s = (m/s)/m 1/s
De Broglie Wavelength • F = E/h(de Broglie frequency) • h/p = h/mv (de Broglie wavelength) • = h/E • m = Js/J
Dimensional Analysis check • nu = v/ = (m/s)/m = J/Js • J/Js = (1/2mv2)/[(1/2mv2)(s)] • (1/2)(2) (mv2)/[(mv2 )(s)] = 1/s
The De Broglie wavelength λ = h/p λ = h/(mv) λ = hc/E
The act of measurement disturbs the system • Try to measure the position of a ping pong ball with a broom handle.
Plancks Constant (h)and h bar h = 6.63 x 10-34 js h bar =1.05 x 10-34 js
Credits • Dr. Quantum Video • Youtube
Credits • Discharge tubes • library.thinkquest.org • Bohr’s postulates • www.ieap.uni-kiel.de/.../physik/HTML/f30_03.html • zopyros.ccqc.uga.edu
Credits II The Physicist’s Vacation http://www.iontrap.wabash.edu/teaching/pedagogy.html Noah measurement cartoon www.bizzarocomic.blogspot.com
Credits III Infra Red House ir-shield.com Infra Red Face www.lightandmatter.com/.../ch02/figs/irface.jpg Red Hot burner Images.jupiterimages.com Yellow Hot Burner feps.as.arizona.edu/outreach/images/other1.jpg
Credits IV Paragraphs on Plank’s hypothesis www.weber.edu Night vision Edmunds.com Orion Constellation Joemorris.mystarband.net Main Sequence www.smv.org
Credits V Cold stove burner www.happynews.com Wien’s Law Wikipedia Stephan-Boltzmann Law http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html
Credits VI • Cavity Radiation • http://megasociety.org/noesis/189_files/image008.gifDiagram • Invention Quote (Ellsworth) • http://www.patentstation.com/mdm/p142.htm#quotes
Credits VI • Photoelectric Effect Diagram • Wikipedia • Single and Double slit Diagrams • www.informationphilosopher.com • Work Function diagram • http://image.tutorvista.com/content/radiation-and-matter/stopping-potential-with-frequency.gif
Credits • de Broglie wavelength formulas • Wikipedia • Bohr model wavelength calculation • faculty.virginia.edu/.../answers/1/answer1.htm • Laws of Physics in Life Cartoon • typeset.vox.com/library/posts/tags/webstuff/