A Quantum of Mystery
•Download as PPTX, PDF•
0 likes•439 views
We review the double slit experiment, the "central mystery" of quantum mechanics as Feynman put it. We included a number of animations, including some from Larry Latham specially done for this presentation! Unfortunately the animations don't seem to post correctly to slideshare, alas.
Recommended
More Related Content
More from John Ashmead
More from John Ashmead (20)
Recently uploaded
Recently uploaded (20)
A Quantum of Mystery
- 1. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 A Quantum of Mystery John Ashmead
- 2. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Sheldon explains it all
- 3. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 ``We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics.”
- 4. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 John, For my advanced 3D students, I have a practicum class. I find a client, set up a modeling/animation project or projects, and put the two together .… And one of the things I'd wanted to ask you about at Necronomicon was about the double slit experiment. Best, Larry
- 5. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Math Break
- 6. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Bleep this!
- 7. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Opening Shots
- 8. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Waves or Particles?
- 9. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Classic slit
- 10. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014
- 11. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 The Central Mystery
- 12. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Zeilinger
- 13. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Core of the Expt
- 14. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Actual Experiment II
- 15. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Try This at Home
- 16. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Bullet Point
- 17. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Waves
- 18. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Wave Function
- 19. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Wavicles
- 20. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Heisenberg Uncertainty Principle
- 21. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Feynman’s Paths
- 22. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Quantum eraser I
- 23. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Quantum Eraser II
- 24. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Whirling Waves
- 25. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Pilot Waves
- 26. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Branching universes
- 27. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Point of animation • Clarity • Exploration • Correctness • Imagination • ?
- 28. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 ``In reality, it contains the only mystery. We cannot make the mystery go away by 'explaining' how it works. We will just tell you how it works. In telling you how it works we will have told you about the basic peculiarities of all quantum mechanics.''
- 29. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Parting Shots
- 30. http://timeandquantummechanics.comA Quantum of Mystery - Balticon, May 24th, 2014 Roll Credits • Larry Latham: Lovecraft is Missing • Richard Feynman: On the Character of Physical Law • Brian Greene: several books, lots of stuff on youtube, great speaker
Editor's Notes
- Inspired by question from Larry Latham. He & his animation class did some of the clips you see here. Unfortunately he passed away before he could finish. See his remarkable blog, Lovecraft is Missing, for one of the best webcomics around. And this talk is dedicated to the memory of Larry: we never met in person, but we nevertheless had a meeting of the minds. You are missed!
- ``In this chapter we shall tackle immediately the basic element of the mysterious behavior in its most strange form. We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery. We cannot make the mystery go away by 'explaining' how it works. We will just tell you how it works. In telling you how it works we will have told you about the basic peculiarities of all quantum mechanics.''
- Not mathematical or too cute, but give a sense of the experiment itself There will be a quiz at the end, but fear not, is open mind
- Vary by wavelength, size of gates, & so on
- Have this on order, lots of bits on youtube Shows up a lot. Good graphics of the double slit experiment Will have stuff to say about the content Post clip (check for length), note that draws inferences about consciousness & the quantum which are unwarranted: much impact from the observer, but the observer can be a chunk of silicon
- from Larry Latham & his team
- Larry’s web comic, and not a bad description of how people like Einstein felt about Quantum Mechanics! Animate the double slit experiment! (see lecture description) There will be a quiz at the end, but, no worries, it will be open mind
- “When I hear you give your reasons,” I remarked, “the thing always appears to me to be so ridiculously simple that I could easily do it myself, though at each successive instance of your reasoning, I am baffled until you explain your process. And yet I believe that my eyes are as good as yours.” “Quite so,” he answered, lighting a cigarette, and throwing himself down into an armchair. “You see, but you do not observe. The distinction is clear. For example, you have frequently seen the steps which lead up from the hall to this room.” “Frequently.” “How often?” “Well, some hundreds of times.” “Then how many are there?” “How many? I don't know.” “Quite so! You have not observed. And yet you have seen. That is just my point. Now, I know that there are seventeen steps, because I have both seen and observed.” — started clip at start
- Try this at home; but do not look down the laser with your remaining good eye
- Edge diffraction!
- From Nova & Brian Greene, very good representation of the wave function.
- Note slant
- Character of physical law has been talking about the double slit on the left, the bullet diagrams: two humps added together, on the right, the interference pattern One of the great teachers Cut a bit from the end Meaning of the heisenberg uncertainty principle: tunneling & radioactivity transitors at every level: which path, energy versus time, momentum versus position without quantum mechanics we all vanish in a puff of logic existence of you & me: uncertainty in position increases uncertainty in momentum, minimum energy point is an order of magnitude description of atomic energy levels
- Note that the wavicle & the path picture are complementary, can see a wavicle as a whole bunch of paths that are traveling together for a bit, can see a path as the track of a small bit of a wavicle (a small bit that sometimes spends time out in the great black or in nearby other wavicles) Paths & branching universes
- Path integrals very appropriate 50/50 or 0/100 with beam splitter (function of the exact optical path length)
- two slits at start they go thru a prism that emits two photons each with 1/2 the energy, so you can look at one & make inferences about the other top on goes to D0, you can see the interference pattern (or not) bottom one can have come from top or bottom. gets diverged by a prism (PS) if from top, goes on red path. thru BSb D4? then we know it came thru top & so did other but if not, reflected off Mb & thru (sort of Bsc) hold that thought Bottom one same idea hits BSa if goes right, hits D3, ok the photon went thru bottom slit if not, hits Ma, BSc (which is getting a bit of a work out here) OK if a photon is detected at D2 or D1, it comes from both!, you can’t tell now use coincidence to spot if D3 or D4, no interference if D2 or D1 no path, but interference but the merging & splitting happened after the first one hit! add all the patterns together, just a giant lump, no help there can’t send signal back in time with this see in terms of path integrals, mostly easily
- And they are still more complex: loop back & thru again! True of a single slit as well, actually
- animation of hang-glider Pilot wave: particle at the center, sending out waves. Hang-glider exploiting thermals. Bohmian has the best pictures. Breaks down at high energies/multiple particles. Just gets more & more complex.
- Sliding doors Choices; what if Reminiscent of the paths above
- The ? mark is your open mind quiz: take all the time you need, the rest of your life if you wish!
- ``In this chapter we shall tackle immediately the basic element of the mysterious behavior in its most strange form. We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery. We cannot make the mystery go away by 'explaining' how it works. We will just tell you how it works. In telling you how it works we will have told you about the basic peculiarities of all quantum mechanics.''