time & quantum mechanicstimeandquantummechanics.com/papers/taqm-chbf.pdf · chestnut hill book...

Time & quantum mechanics

Chestnut Hill Book Festival, 20101

John Ashmead

Saturday, July 10, 2010

Lord Kelvin’s two small problems

2

Black body radiation Properties of

light


• Time stretches,

• Breaks,

• And turns back on itself.

3


4


Michelson-morley

5


Relativity

• speed of light constant

• laws of physics the same for all observers*

*but definition of simultaneity may differ!


Twin paradox

7


8


9http://www.youtube.com/watch?v=f0VOn9r4dq8

Time seriously twisted


http://www.youtube.com/watch?v=f0VOn9r4dq8

http://www.youtube.com/watch?v=f0VOn9r4dq8

Black hole at the center of the galaxy

10


Black Holes Should Generate Ring of Light

11http://www.technologyreview.com/blog/arxiv/25182/Saturday, July 10, 2010

http://www.technologyreview.com/blog/arxiv/25182/

http://www.technologyreview.com/blog/arxiv/25182/

Falling into a black hole

12


How to build a time

machine

13


14

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


Closed time-like

curves

15


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


Quantum mechanics

18

• Black body radiation

• Atoms

• The double slit experiment


Black body radiation

19


No ticket!

20


Atoms exist!

• Like a bullet bouncing off a sheet of kleenex, a bit of a surprise.

• Coulomb showed atoms made of electrons & protons.

21


But shouldn’t!

22


Uncertainty principle

• Think about a musical note

• Short, high frequency, well defined position

• Pure tone has less well defined position

23

!5 5

!1.0

!0.5

0.5

1.0

Well-definedtime

Well-definedfrequency

Time & frequencyCANNOT

both be well-defined[that’s math!]


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!24


Double-slit experiment

25

How can you be in two places at once when you aren't anywhere at all? - Firesign Theater


Double slit experiment

26


27

Bullets & waves


28

Double slit, in motion


Single slit, in motion

29


If you look, you destroy the interference

30


Relativity vs The quantum

31

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 re

lativi

ty

& qua

ntum

mecha

nics


Gravitational radiation

33


Loop quantum gravity

34


Lindner’s double slit in time


• 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

36


37www.timeandquantummechanics.com

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


http://www.timeandquantummechanics.com



time & quantum mechanicstimeandquantummechanics.com/papers/taqm-chbf.pdf · chestnut hill book...

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