Schrödinger's Cat: Research on the Radical Subjective Solution of the Measurement Problem.

Dick Bierman & Stephen Whitmarsh,

University of Amsterdam

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

Projection Postulate

Quantum Physics Potentialities

Classical Physics Reality

Projection Postulate

Quantum Physics Potentialities

Classical Physics Reality

Collapse of wave function by what is commonly called a

“measurement”.

Measurement problem

If the measurement is affecting the ‘measured’

it is extremely important to precisely define what

constitutes a measurement

Measurement problem

Definition 1:

A measurement is something that you do with a measurement device….

Usable in the daily practice of physics,

but incorrect: a problem!

(von Neumann)

Possible solutions

Many World solution (Everett)

Deterministic solution (Bohm)

Objective Reduction (Penrose)

Radical subjective solution (Wigner, Stapp)

Radical 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…..

Hall, J., Kim, C., McElroy, and Shimony, A. (1977). Wave-packet reduction as a medium of communication.

Foundations of Physics 7 (1977), 759-767.

Experimental Setup Hall, 1977

Experimental Setup Hall, 1977

Decay

Experimental Setup Hall, 1977

50% of cases

pre-observation

Experimental Setup Hall, 1977

1 µs delay

Experimental Setup Hall, 1977

(final)

observation

Assumptions1. Consciousness of first observer collapses the

state before second observation.

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

3. Final Observer can report this verbally (consciously)

Weaknesses in Hall, 1977

Assumption 1 is violated: Delay between first and second observation too short (e.g. Libet, 1979).

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

Libet et al. (1979): Subjective Referral of the Timing for a Conscious Sensory Experience. Brain 102, 193-224.

Improvements in replication

Hall et al. 1977

Delay 1 µs

Dependent variable: verbal report

Amsterdam 2003

Delay 1000 ms

Dependent variable: brain signals

First Amsterdam setup

PRE-OBSERVER OBSERVER

First Amsterdam setup

GeigerCounter

50%

Delay1000ms

Deadtime 2000ms

OBSERVER

EEG measurement

PRE-OBSERVER

Radioactive source

Analysis procedure

Preobserved beeps

NOT preobserved beeps OBSERVER

EEG trace

EEG trace

Analysis procedure

Average EEG from onset-time of event (beep)

ERP

Results first Amsterdam Setup

df = 29Peak Difference

(microvolts)t p Non-parm p

N=30N20 1.002 2.12 0.043 19-11: 0.20P40 0.903 2.64 0.013 22-8: 0.016N100 0.350 0.66 0.52 15-15P200 -0.09 -0.18 0.86 15-15N300 -0.04 -0.08 0.93 15-15P350 -0.54 -1.17 0.25 12-18: 0.36

FC-leads

N400 0.098 0.25 0.80 16-14: 0.86P100 -0.16 -0.67 0.50 12-18: 0.36N160 -0.152 -0.84 0.41 13-17: 0.58P-leadsN200 -0.956 -3.93 0.0005 7-23: 0.005

Bierman, D.J. (2003). Does Consciousness Collapse the Wave-Packet?

Mind and Matter 1(1), pp. 45-57

Conclusions study 1

Radical Subjective Reduction supported A quantum-measurement is only complete when ‘acted’ upon by

consciousness.

Copenhagen interpretation supported The collapse of the wave packet occurs with measurement,

creating reality from potentiality.

But wait! Strong claims need strong evidence, so a second study was

performed

Alternative explanations

Sensory Cueing (ultra sounds) EM radiation Chance

Improvements in replication

Amsterdam 2003

Audio Speakers 16 EEG electrodes Quantum source of

measurement

Amsterdam 2004

Air-pressure headphones 32 EEG electrodes Quantum & Classical

source of measurement

Analysis procedure

So now we’ve got 4 different conditions:

No pre-observer Pre-observer

Quantum ERP ERP

Classic ERP ERP

Hypothesis

Effects of pre-observation in pre-conscious time-interval (0 - ±350 ms) – replication of 2003 experiment

No effects of pre-observation when source is Classic – the state-vector should already be collapsed

Second Amsterdam setup

GeigerCounter

50%

Delay1000ms

Timed Delay

Deadtime 2000ms

OBSERVER

EEG measurement

PRE-OBSERVER

Second Amsterdam setup

GeigerCounter

50%

Delay1000ms

Timed Delay

Deadtime 2000ms

OBSERVER

EEG measurement

PRE-OBSERVER

Results

Bierman, D. J., Whitmarsh, S. (2006), Consciousness and Quantum Physics: Empirical Research on the Subjective Reduction of the State Vector. (Book Chapter) The Emerging Physics of Consciousness, The Frontiers Collection. Tuszynski, J. A. (Ed.).

Results

Results

1. No effects of pre-observation when source is Classic

2. No effects found of pre-observation (thus no direct replication of 2003 study)

No pre-observer Pre-observer

Quantum ERP ERP

Classic ERP ERP

Discussion (no effects of pre-observation)

Uncertainty about the stimulus-origin was introduced by the addition of a classical source: Conscious observation of the stimuli did not yield a

definite measurement because it remained unknown what was actually measured (a quantum or a classic event)

So Subjective Collapse by the pre-observer was actually prevented!

Discussion (effect of quantum/singular source)

A different state of event stimuli was still

introduced (quantum/classical) Since the pre-observer could not collapse the

quantum state, the effect should still be seen on the final-observer’s EEG…

That’s what we found!

Exploration Quantum/Classic

Exploration Quantum/Classic

Results

1. No effects of pre-observation when source was Classic

2. No effects found of pre-observation (thus no direct replication of 2003 study)

3. Effect of event-origin (quantum/classic) in final-observer’s brain signals!

No pre-observer Pre-observer

Quantum ERP ERP

Classic ERP ERP

Alternative explanations

Sensory Cueing (ultra sounds) EM radiation Chance Differences in ISI / decay-time distribution

Shorter intervals with quantum vs. classical events post-hoc.

Conclusion

Although no direct replication of the 2003 findings,

The second Amsterdam setup is still consistent with the subjective reduction solution of the measurement problem

But wait… lets try to reconcile the two… (effect of pre-observer & classic source)

Reconciliation in third A’dam setup

PRE-OBSERVER

!CQ

PRE-OBSERVER

?Q C

Sensitivities Care was taken to maintain exactly the same time-distributions

of the quantum and classical events.

Preliminary Results

Analysis done over only a fraction of intended number of subjects (20 out of 64).

Conclusion

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

Initial results due to differences in decay-time distribution?

However, it could be that the assumptions underlying this approach are invalid Consciousness may be not just observing, but measuring

We will find out!

Thank you for your attention.

Shape of difference waves