Confused at a Higher Level

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About some problems in quantum mechanics& quantum electrodynamics; arguably one of the funniest talks ever given about QED.

Text of Confused at a Higher Level

  • 1. Confused at a Higher Level "Before I came here I was confused about this subject. Having listened to your lecture I am still confused. But on a higher level." - Enrico Fermi

2. Two clouds on horizonBlack body radiation Properties of light 3. Black body radiation 4. Atoms 5. Paradox #1: Double-slit paradox How can yoube in twoplaces at oncewhen youarentanywhere atall? - FiresignTheater 6. Double slit 7. Bullets and waves 8. Delayed choice 9. Quantum eraser 10. Delayed choice & quantumeraser 11. Six Blind Men & the Elephant 12. Shut up andcalculate 13. Collapse 14. Many worlds 15. Paradox #2: Innite means zeroQuantum electrodynamics continuously tosses up quantities which are:1) Innite2) Really small (but o*en measurable) 16. Lamb shi* 17. Renormalization 18. But tiny 19. Casimir eect, classical 20. Casimir eect, quantum 21. Innite and tiny ``It appears therefore that the theory as it stands now must be strangely near to the final solution, yet it cannot possibly be correct, as the mathematical procedure used to extract these results is plainly unacceptable. - Heitler 22. Paradox #3: how can time go both ways at one time? 23. Entropic timetime Time measured byincreasing entropy:emit The direction bombsexplode in, eggs Oppositecracks in, people age thermodynamics in, and the like. arrows of time Unfortunately, L. S. SchulmanSchulman has shownthat this can go bothways! 24. Acme Wormhole ConstructionCompany Vissers recipe for a timemachine: 1. Acquire a traversablewormhole 2. Induce a time-shi*between the two mouths ofthe wormhole 3. Bring the wormholemouths together 25. Daviess How to Build a TimeMachineHow do you go about constructing a traversable wormhole and turning it into a time machine? 26. Black Holes & Timewarps - Kip S. Thorne 27. Times Up for the TimeBandits Cover Story in New Scientist, 20th of September 2003 Forget about coming back to murder your great-grandfather. It never happened, and there are forces out there making sure it never will. 28. ConundrumFor better or for worse, most canonical quantum eld theories are found by starting with a classical eld theory and then quantizing it. To be sure, there is something intellectually unsatisfactory about this: given that quantum theory is the more fundamental theory, we would prefer to work in the other direction, that is, to recover classical eld theories from quantum starting points Wallace 29. This is often the way it is in physics our mistake is not that we take our theories too seriously, but that we do not take them seriously enough. It is always hard to realize that these numbers and equations we play with at our desks have something to do with the real world. Even worse, there often seems to be a general agreement that certain phenomena are just not fit subjects for respectable theoretical and experimental effort. Steven Weinberg 30. Through the looking glassI have no doubt that inreality the future will bevastly more surprisingthan anything I canimagine. Now my ownsuspicion is that theuniverse is not onlyqueerer than we suppose,but queerer than we cansuppose. J. B. S. Haldane