2. QM-RAY
•“Behold the weird”
•The collapse of the collapse of the wave
function
•Existential quantum mechanics
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
3. “Behold the weird”
•Double slit experiment
•Uncertainty principle
•Checkpoint Copenhagen
•Schrödinger’s Cat
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
4. Double slit
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
5. Uncertainty
principle
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
6. Copenhagen
interpretation
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
7. Schrödinger's Cat
One can even set up quite ridiculous cases. A cat is penned up in a steel
chamber, along with the following diabolical device (which must be secured
against direct interference by the cat)…
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
8. The collapse of the collapse
of the wave function
•Collapse real
•Hidden variables
•Multiverse
•Shut-up-and-calculate
•“That which does not destroy you…”
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
9. Objective collapse
•Wigner’s Calibrated Panel of Infants
•The all collapse all the time channel
•Penrose finds decoherence in a grain of
sand
•The case of the highly charged cat
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
10. Wigner’s
Panel of infants
1. Perception
counts as
consciousness.
2. Consciousness
induces
deviations from
laws of physics.
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
11. Unified dynamics for microscopic &
macroscopic systems (1986)
- Ghirardi, Rimini, Weber
•Eliminate special role of observer
•Posit an interaction which is non-linear,
stochastic, & depends on surround
•Get a GRW collapse perhaps every 100
million years
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
12. The road to reality
• Tiny mirror in two
states at once
• With gravity involved,
this costs energy
• Forcing it to pick one of
the two states.
• And causing the beam
to lose coherence
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
13. Highly charged cat
Charge up your Let its wave function diffuse
cat
Observe your cat Accelerated charges
radiate
Tune
your
radio
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
14. Hidden variables
•Statistic
interpretation
•Einstein-
Podolsky-
Rosen: elements
of reality
•Bell’s theorem
•Bohmian
mechanics
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
15. Einstein podolsky rosen
You can’t know both x-spin & z-spin at the
same time, & yet you can.
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
16. Bell’s Theorem
Measure along x, or
along z, or along
their bisector, but
only one
measurement (of
each spin) per
round
One poke per
measurement
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
17. Information Distance
Information distance Information distance
from A to B is the obeys the triangle
uncertainty left in B inequality
when A is known. d ( A,C ) ≤ d ( A, B ) + d ( B,C )
B
d ( A, B ) d ( B,C )
A C
d ( A,C )
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
18. Information ZigZag
1.0
θ left θ right
0.8
0°
0.6
0.4 .020
.0
0.2 10°
50 100 150 .020 .064
( ) ( )
d (θ ) = − lg cos 2 (θ 2 ) cos 2 (θ 2 ) − lg sin 2 (θ 2 ) sin 2 (θ 2 )
p ≡ cos 2 (θ 2 ) 20°
θ = 10° → p (θ ) ≈ 99%, d ≈ .020
θ = 20° → p (θ ) ≈ 96%, d ≈ .064
.064 > .020 + .020 Violates triangle inequality!!!
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
19. The right way to get
it wrong
Nick
Herbert’s
Faster-Than-
Light
Telegraph
June 2012,
Scientific
American
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
20. Bohmian Mechanics
• Well-defined
particles
• Guided by a pilot
wave that obeys
Schrödinger
equation
• Problems with
many particles,
high energies
• Popular, if weird
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
21. Multiverse
•Many worlds, many minds, many
words
•Quantum suicide/a plethora of
observers
•Splitting headaches
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
22. Universes Fork
Observers fork too
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
23. Experimental tests
• Quantum suicide
• Count of observers (many minds) has implications
• Leakage between universes
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
24. Splitting headaches
• Why this set of alternatives &
not that?
• When does split happen?
• How does split happen?
• That’s rather a lot of
"I am glad of all details," universes, isn’t it?
remarked my friend,
"whether they seem to • What counts as an observer?
you to be relevant or
not." • Can different universes chat?
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
25. Shut-up-&-calculate
•Arguably most popular
•Let the pencil do the
thinking. Or
Mathematica.
•Pencils a bit short on
imagination sometimes.
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
26. “What we call
`reality’ consists of
an elaborate
papier-maché
construction of
imagination and
theory fitted in
between a few iron
posts of
observation.”
- John A. Wheeler
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
27. Many Interpretations
• Deterministic
• Wave function real
• Hidden variables
• Collapse real
• Observer part of
interpretation
• Local/non-local
• Time symmetric
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
28. “That which does not destroy you
makes you strong”
• 27+ rival
interpretations
•Critics such as
Wigner, Bell,
Einstein, …
•300+ foundational
experiments
(Auletta)
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
29. Existential Quantum
mechanics
•The wave function needs no interpretation
•Decoherence
•Radical conservatism
•At the edge of the known
•A game of chess
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
30. Pusey, Barrett, &
Rudolph •The quantum state of
a system can be
inferred uniquely
from the physical
state
•Provided the
predictions of
quantum mechanics
are correct. (They
are.)
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
31. Decoherence
How does
classical
definiteness
emerge
from the
quantum
sea?
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
32. Decoherence still
cohering
•Toy cases
•Bound states
•Quantum Zeno effect
•Stochastic resonance
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
33. Radical
conservatism
Be conservative by
sticking to well-
•Cat states
established physical •Long range entanglement
principles, but probe
them by exposing •Phonons
their most radical
conclusions. •Bose-Einstein condensates
- J. A. Wheeler
•Majorana fermions
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
34. At the edge of the
known
•Entropic gravity
•Origin of the
universe
•Dark flow
•Whispering
gallery of the
multiverse
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
35. A game of chess
•Multiple
levels of
analysis
•Appropriate
mathematics
http://research.cs.queensu.ca/Parallel/
QuantumChess/QuantumChess.html
•Your move!
QM, Reality, & You - John Ashmead - May 27th, 2012 - Balticon http://timeandquantummechanics.com/?p=959
Hinweis der Redaktion
Request by Miriam: what is your next talk?\nA problem?\nNext day shipped off a wonderful title (you can see it here)\nNew problem. OK, we have the title, now what?\nAnswer here.\n\nStart with phenomenology\n
Collapse into the selected one\n\n\n
Cordelia Chase put it, behold the weird\n
And entanglement\n\nDefine wave function. For now, a mathematical object that tells us how a particle moves. Later, much discussion.\n
And quanta\n\nClassical physics has limits as well, but in quantum mechanics, like a glob of mercury\n\nEssential for atoms, no uncertainty no atoms\n\n10-8 seconds classically to get down to center\n
Copenhagen interpretation clearest in the Stern-Gerlach experiment: the poster child for the Copenhagen interpretation\n\nhttp://www.pci.uzh.ch/static/documents/Stern-Gerlach-Experiment.jpg\n
This is crazy\n\nKübler-Ross five stages of grieving:\nDenial\nAnger - objections in our case\nBargaining\nResignation - shut up & calculate\nAcceptance\n
\n
\n
“there are only two avenues through which experimentation can proceed to obtain information about [1]: observation of infants where we may be able to sense the progress of the awakening of consciousness, and by discovering phenomena postulated by [2], in which the consciousness modifies the usual laws of physics.\n\nVery scientific. Hard to get naive babies however\n\nhttp://jwsokol.com/scc/wp-content/uploads/2011/07/holden-andrew-portrait-of-a-surprised-baby.jpg\n\n\n\n
Good example of scientific method\n\nEliminates special role since it uses a potential that does all the dirty work\n\nNon-linear, stochastic, & depends on surround actually sounds a lot like decoherence, below.\n\nA bit of a long shot.\n\nMore interesting for the principle. Did kick off a lot of variations! Dickson wrote a book on the whole class of such theories.\n\nNever seen\n\n\n
Tiny mirror should lose coherence from gravity, if weight of grain of dust.\n\nFirst - hard part - calibrate your system. Normal Mach-Zehnder interferometer would see effects of phase. Instead, set up two cavities so that the photon oscillates for a long period of time, perhaps a second, between the two sides, thus never getting to the detector.\n\nIf the mirror is decohered by gravity, then the photon will be detected.\n\nShows up in Verlinde’s entropic gravity\n
Get cat, turn into picture\n\nhttp://scrappinoutloud.blogspot.com/2009/08/black-cat-svg-just-in-time-for.html\n\nhttp://www.halloweenclipart.com/halloween_clipart_images/angry_scared_black_cat_hissing_with_its_back_arched_0071-0810-2316-0831.html\n\nhttp://2e6vizille.wikispaces.com/file/view/1197122845337673748paulshannon_Old_Timey_Radio.svg.med.png/112448403/1197122845337673748paulshannon_Old_Timey_Radio.svg.med.png\n
Picture appropriate to hidden variables, tunneling under the castle\n\nQuantum mechanical statistics a problem for hidden variables\n\n
Bohr’s response; you are only allowed to speak of what you can measure. Feynman: you are only required to speak of what you can measure.\n\n
\n
If you know that when sock A is red, sock B is green 99% of the time, and when sock B is green sock C is blue 99% of the time, then when sock A is red, sock C has to be blue 98% of the time.\n\nInformation distance is a more format, precise way to characterize this.\n
\n
\n
Nice pictures\n\nSee also consistent histories\n
\n
Benefits:\nNo collapse\nObserver included\n
Experimental tests:\n\nQuantum suicide: control the gun via a radioactive decay. But keep the decay from happening using the quantum zeno effect. Now the decay doesn’t happen so the gun doesn’t go off.\n\nAlternative, have a plethora of observers, in MWI in some versions, \n
Quantum suicide\n\nRivers, neurons, branches of timelines\n\nIf the statistics depend on the \n
Pencils & thinking, einstein; sometimes the pencil thinks for me!\n\nModel testing\n\nDefeatist/resignation\n\nAnd keeps you from pushing the boundaries\n
Hidden variables\n\nQuantum mechanics wave functions complete, or so it seems. Statistics alone would indicate this. \n\nhttp://www.forizslaszlo.com/tudomany/wheeler_law_without_law.html \n
\n
Conan quoting Nietzsche, in an unexpected burst of erudition. And time travel. Also, basis of a currently popular song, Stronger.\n\n\n
\n
Last week in nature physics\n\nPrepare two quantum states so cleverly that they will cancel when they intersect. Canceling not something that comes naturally to hidden variable theories. The precise nature of the cancellations lets us infer the original quantum states. Therefore they are real.\n
Venus & the half shell\n\nBack to the crime scene\n\nHow to get some numbers out\n\nhttp://www.armee.gc.ca/35rgc/images/sape.jpg\n\n
A set of harmonic oscillators in a heat bath\n\n
\n
Entropic Gravity - & the collapse?\nOrigin of the universe\nWhispering gallery of the multiverse\n
Quantum mechanics interesting & important, rich source of metaphors. Our successes in understanding it very encouraging, ability to transcend own limitations, even if sometimes we have to let the pencil do the thinking!\n\nBut the stuff we care about exists at a level of abstraction well above that of the quantum. Problems of free will & determinism not a function of classical/quantum: both are deterministic in their own way, but both are incalculable.\n\n\n