Presentation on theme: "1 Time & quantum mechanics Chestnut Hill Book Festival, 2010 1 John Ashmead."— Presentation transcript:
1 Time & quantum mechanics Chestnut Hill Book Festival, 2010 1 John Ashmead
2 Lord Kelvin’s two small problems
3 Time stretches, Breaks, And turns back on itself.
5 Michelson-morley Apparatus Up & down stream versus side by side LF contraction
Relativity speed of light constant laws of physics the same for all observers* *but definition of simultaneity may differ!
7 Twin paradox
8 Graph of the twins, but with the photos from each going to the oher Massive acceleration not distinguisha ble from massive gravity
9 http://www.youtube.com/watch?v=f0VOn9r4dq8 Time seriously twisted
10 Black hole at the center of the galaxy 10
11 Black Holes Should Generate Ring of Light http://www.technologyreview.com/blog/arxiv/25182/
12 Falling into a black hole The scout, trapped by black hole, sends signals out. Same as with twins, slowing photos. What happens when they stop? We don’t actually know! Comes out on the other side?
13 How to build a time machine
14 Can get one so that it is past of the other! Some technical details have been elided Visser's recipe for a time machine: Acquire a traversable wormhole Induce a "time- shift" between the two mouths of the wormhole Bring the wormhole mouths together
15 Closed time-like curves
16 Why pick on grandfather? It seems that the only way to prove that time travel is impossible is to cite a case of killing one's own grandfather. This incessant murdering of harmless ancestors must stop. Let's see some wide-awake fan make up some other method of disproving the theory.” – letter to Astounding Stories
18 Quantum mechanics Black body radiation Atoms The double slit experiment
19 Black body radiation
20 No ticket! Planck desperate No excitation of the higher energy modes So, no infinity
21 Atoms exist! Like a bullet bouncing off a sheet of kleenex, a bit of a surprise. Coulomb showed atoms made of electrons & protons.
22 But shouldn’t! Protons & electrons rush to meet In 10^-8 seconds, destroy, giving off lots of energy
23 Uncertainty principle Think about a musical note Short, high frequency, well defined position Pure tone has less well defined position Well-defined time Well-defined frequency Time & frequency CANNOT both be well-defined [that’s math!]
24 Electron tries to get close, can’t If far from atom pulled in As it gets close is squeezed up But then momentum builds up And it races out Atom is a balance of these two pressures. No uncertainty, no us! That’s certain!
25 Double-slit experiment How can you be in two places at once when you aren't anywhere at all? - Firesign Theater
26 Double slit experiment
27 Bullets & waves
28 Double slit, in motion
29 Single slit, in motion
30 If you look, you destroy the interference
31 Relativity vs The quantum Niels BohrGuess who Smooth Localized Predictable But time is dynamic Quantized Fuzzy Uncertain But time is boring
32 Relativity Quantum mechanics Time a bit fuzzy Time an average over quantum fluctuations None of the others Blend of relativity & quantum mechanics
36 New Theories of Everything, Barrows From eternity to here, Sean Carroll How to build a time machine, Davies Physics of the Impossible, Kaku Time Machines, Nahin Timeless Reality, Stenger Endless Universe, Steinhardt & Turok Black Holes & Time Warps, Thorne The New Time Travelers, Toomey
37 www.timeandquantummechanics.com The future is here. It's just not widely distributed yet. William Gibson 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 What does that mean? Huh? "Time & quantum mechanics." I don't even know what the hell that means. – Old Jack Burton, on a dark & stormy night I have no doubt that in reality the future will be vastly more surprising than anything I can imagine. Now my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose. – J. B. S. Haldane