Schrödinger's Cat: Research on the Radical Research on the Radical

Subjective Solution of the Measurement Problem. Subjective Solution of the Measurement Problem.

..

Dick Bierman & Stephen Whitmarsh, University of Amsterdam

Presented at QuantumMind, Salzburg, july 15-21, 2007

If the measurement is If the measurement is affecting the ‘measured’ affecting the ‘measured’ it is extremely important it is extremely important to precisely define what to precisely define what

constitutes a constitutes a measurementmeasurement

MeasurementMeasurement

Def1: A measurement is something what Def1: A measurement is something what you do with a measurement device….you do with a measurement device….

Usable in the daily practice of physics Usable in the daily practice of physics

But incorrect: a problem!But incorrect: a problem!(von Neumann)(von Neumann)

The Measurement ProblemThe Measurement Problem‘solutions’‘solutions’

Many World solution (Everett)Many World solution (Everett) Deterministic solution (Bohm)Deterministic solution (Bohm) Non linear Schrodinger equation (GRW)Non linear Schrodinger equation (GRW) Objective Reduction (Penrose)Objective Reduction (Penrose)

Radical subjective solution (Wigner, Stapp)Radical subjective solution (Wigner, Stapp)

Radical SolutionRadical Solution

…. The reduction of the state vector is a physical event which occurs only when there is an interaction between the physical measuring apparatus and the psyche of some observer…..

from Hall, J., Kim, C., McElroy, and Shimony, A. (1977). Wave-packet reduction as a medium of communication. Foundations of Physics 7 (1977), 759-767.

Note that the radical solution is associated with Schrödinger’s Cat.

Hall et al experiment Hall et al experiment

AssumptionsAssumptions

1.Consciousness of first observer collapses the state before second observation.

2. Final Observer (brain) is sensitive for difference collapsed and non collapsed state

3. Final Observer can report this

Weaknesses in HallWeaknesses in Hall

Assumption 1 is violated: Delay between Assumption 1 is violated: Delay between first and second observation too shortfirst and second observation too short

Assumption 3 is inconsistent: The Assumption 3 is inconsistent: The dependent variable is a conscious verbal dependent variable is a conscious verbal report, too late!report, too late!

Improvements in replications Improvements in replications

HALL et al 1977HALL et al 1977

Delay few Delay few microsecondsmicroseconds

Dependent variable: Dependent variable: conscious verbal conscious verbal reportreport

Amsterdam 2002-2007Amsterdam 2002-2007

Delay 1000 msecsDelay 1000 msecs

Dependent variable: brain Dependent variable: brain signals before final signals before final observer is conscious pobserver is conscious p

Amsterdam original set-upAmsterdam original set-up

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Amsterdam original set-upAmsterdam original set-up

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Pseudorandom switch between conditions Pre-observed - not pre-observed

Dependent variable: brainwaves of final

observer

Analysis procedureAnalysis procedure

Predetermined: we only analyze peak Predetermined: we only analyze peak amplitudes. amplitudes.

We also apply non-parametric statistics We also apply non-parametric statistics (because of non normality of the (because of non normality of the distribution of data)distribution of data)

Results pooled over conditionResults pooled over condition

5

0

-5

[µV]

-200 -100 0 100 200 300 400 500 600 700[ms]

N20

P40

N100

P200

N300

P350

N400

allfc

5

0

-5

[µV]

-200 -100 0 100 200 300 400 500 600 700[ms]

allp

P100

N160 N200

Results split for conditionResults split for condition(preobserved and not-preobserved)(preobserved and not-preobserved)

5

0

-5

[µV]

-200 -100 0 100 200 300 400 500 600 700[ms]

allfcParentOther

5

0

-5

[µV]

-200 -100 0 100 200 300 400 500 600 700[ms]

allpParentOther

Study 1-RESULTS peak analysisStudy 1-RESULTS peak analysisWhatWhat

PeakPeak

Preobs-Preobs-Obs(MuV)Obs(MuV)

T (df=29)T (df=29) Prob.Prob. binomialbinomial

N20N20 1.0021.002 2.122.12 0.0430.043 0.200.20

P40P40 0.9030.903 2.642.64 0.0130.013 0.0160.016

N100N100 0.3500.350 0.660.66 0.520.52 11

P200P200 -0.09-0.09 -0.18-0.18 0.860.86 11

N300N300 -0.04-0.04 -0.08-0.08 0.930.93 11

P350P350 -0.54-0.54 -1.17-1.17 0.250.25 0.360.36

N400N400 0.0980.098 0.250.25 0.800.80 0.860.86

P100P100 -0.16-0.16 -0.67-0.67 0.500.50 0.360.36

N160N160 -0.152-0.152 -0.84-0.84 0.410.41 0.580.58

N200N200 -0.956-0.956 -3.93-3.93 0.00050.0005 0.0050.005

Control analysisControl analysis

Split data randomly rather than according Split data randomly rather than according to Exp. Condition and repeat analysis.to Exp. Condition and repeat analysis. Effectsizes are on the average an order of Effectsizes are on the average an order of

magnitude smaller and statistically non magnitude smaller and statistically non significantsignificant

Conclusions study 1Conclusions study 1

Copenhagen interpretation supportedCopenhagen interpretation supported God plays diceGod plays dice

And …Consciousness stands outside of And …Consciousness stands outside of quantum physics (dualism) or must be quantum physics (dualism) or must be considered a ‘hidden variable’ with non local considered a ‘hidden variable’ with non local aspectsaspects

But wait a minute: Strong claims need strong But wait a minute: Strong claims need strong evidence….. So study 2!evidence….. So study 2!

Bohr

Replication set upReplication set up

GM detectorAlpha source

Pre Observer

Final Observer Computer

delay

EEG amplifiersTrigger-in

Audio-beep

Visual pre-observation for

~ 50% of the events

Count down clock

Results averaged over 4 conditions (classical-Results averaged over 4 conditions (classical-quantum, preobserved- not preobserved)quantum, preobserved- not preobserved)

4 clusters of electrodes

TABLE 3. Peak latencies (in milliseconds), amplitudes (in V) of all conditions per pooling. t- and (2 tailed) p-values of the difference between pre-observed and not pre-observed condition Classic C-Diff Quantum Q-Diff

Peaks Lat I II

t (df=49)

p III IV

t (df=49)

p

Na 23 -0.181 -0.169 -0.060 0.952 -0.175 -0.395 0.736 0.465 Pa 39 0.536 0.757 -0.892 0.377 0.426 0.545 -0.435 0.665 Nb 51 -0.502 -0.321 -0.674 0.503 -0.681 -0.44 -0.961 0.341 P100 94 4.901 5.281 -1.284 0.205 5.800 5.65 0.386 0.701 N200 184 -7.266 -7.335 0.145 0.885 -7.137 -6.748 -1.364 0.179

Frontal

P300 301 -1.131 -1.036 -0.255 0.800 -0.679 -0.933 0.778 0.440 Na 23 -0.134 -0.021 -0.816 0.418 -0.088 0.031 -0.589 0.559 Pa 35 0.522 0.402 -0.798 0.429 0.149 0.183 -0.218 0.828 Nb 47 -0.300 -0.198 -0.482 0.632 -0.450 -0.175 -1.264 0.212 P100 90 1.064 1.195 -0.531 0.598 1.565 1.445 0.417 0.678 N200 180 -3.819 -3.646 -0.742 0.462 -3.841 -3.542 -1.519 0.135

FrontoCentral

P300 332 0.000 -0.056 0.198 0.844 -0.294 -0.119 -0.799 0.428 Na 27 -0.396 -0.434 0.101 0.920 -0.475 -0.515 0.296 0.768 Pa 39 0.005 0.137 -0.485 0.630 -0.013 0.056 -0.178 0.859 Nb 55 -0.802 -0.601 -0.862 0.393 -0.747 -0.549 -0.636 0.528 P100 90 5.208 5.415 -0.886 0.380 5.584 5.632 -0.212 0.833 N200 184 -5.957 -6.019 0.246 0.807 -5.468 -5.528 -1.451 0.153

Parietal

P300 289 0.309 0.189 0.385 0.702 0.596 0.737 -0.537 0.594 Na 31 -1.444 -1.534 0.261 0.795 -1.599 -1.384 -0.712 0.480 Pa 43 -0.829 -0.639 -0.616 0.541 -0.666 -0.467 -0.68 0.500 Nb 51 -1.146 -0.894 -0.890 0.378 -0.943 -0.795 -0.503 0.617 P100 90 7.543 7.990 -1.474 0.147 7.425 7.81 -1.021 0.312 N200 180 -5.707 -5.362 -1.052 0.298 -5.908 -5.373 -1.598 0.116

Occipital

P300 293 1.173 1.249 -0.417 0.678 1.322 1.833 -1.419 0.162

No pre-observation No pre-observation effecteffect

But…………But…………

TABLE 4. Differences of AEP peak amplitudes from the quantum and classic source.

Peaks Classic Quantum Classic –

Quantum t (df=49) p (2-tailed)

Na -0.287 -0.182 -0.105 -0.503 0.617 Pa 0.485 0.642 -0.157 -0.808 0.423 Nb -0.554 -0.416 -0.138 -0.683 0.498 P100 5.725 5.074 0.651 2.697 0.010 N200 -6.956 -7.279 0.323 1.200 0.236

Frontal

P300 -0.834 -1.090 0.256 1.096 0.278 Na -0.033 -0.066 0.033 0.230 0.819 Pa 0.165 0.322 -0.157 -1.052 0.298 Nb -0.307 -0.258 -0.049 -0.447 0.657 P100 1.503 1.126 0.377 2.457 0.018 N200 -3.700 -3.718 0.018 -0.068 0.946

FrontoCentral

P300 -0.237 -0.047 -0.190 -1.311 0.196 Na -0.508 -0.413 -0.095 -0.515 0.609 Pa 0.006 0.070 -0.064 -0.352 0.726 Nb -0.659 -0.695 0.036 0.178 0.859 P100 5.612 5.309 0.303 1.242 0.220 N200 -5.477 -5.979 0.502 2.301 0.026

Parietal

P300 0.633 0.238 0.395 1.984 0.053 Na -1.513 -1.488 -0.025 -0.143 0.887 Pa -0.587 -0.742 0.155 0.687 0.495 Nb -0.888 -1.028 0.140 0.640 0.525 P100 7.633 7.765 -0.132 -0.774 0.443 N200 -5.652 -5.538 -0.114 -0.454 0.652

Occipital

P300 1.536 1.204 0.332 1.508 0.138

An effect of source of events (Quantum vs Classic)

Was the (pre) Was the (pre) Observation Observation ‘Conscious’‘Conscious’

It was less specific than in It was less specific than in experiment 1experiment 1

Study 3Study 3

More information to pre-observerMore information to pre-observer

- I.e. was the source quantum or classic- I.e. was the source quantum or classic

Control of ‘decay-times’ distribution in all Control of ‘decay-times’ distribution in all conditions.conditions.

Preliminary Results Preliminary Results study 3study 3

ReviewReview

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Amsterdam 1Amsterdam 1

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Amsterdam 2Amsterdam 2

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Amsterdam 3Amsterdam 3

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ConclusionConclusion

The support for the idea that ‘consciousness The support for the idea that ‘consciousness collapses the statevector’ has evaporated.collapses the statevector’ has evaporated.

Initial results due to differences in decay time Initial results due to differences in decay time distribution?distribution?

However it could be that the assumptions However it could be that the assumptions underlying this approach are invalid. underlying this approach are invalid.

The measurement problem is more alive than The measurement problem is more alive than ever.ever.

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Thanks for your attentionThanks for your attention