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),

Experimental Setup Hall, 1977

Decay

Experimental Setup Hall, % of cases pre-observation

Experimental Setup Hall, µs delay

Experimental Setup Hall, 1977 (final) observation

Assumptions 1.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,

Improvements in replication Hall et al  Delay 1 µs  Dependent variable: verbal report Amsterdam 2003  Delay 1000 ms  Dependent variable: brain signals

First Amsterdam setup PRE-OBSERVEROBSERVER

First Amsterdam setup Geiger Counter 50% Delay 1000ms Deadtime 2000ms OBSERVER EEG measurement PRE-OBSERVER Radioactive source

Analysis procedure Preobserved beeps NOT preobserved beeps OBSERVER EEG trace

Analysis procedure Average EEG from onset-time of event (beep) ERP

Results first Amsterdam Setup Bierman, D.J. (2003). Does Consciousness Collapse the Wave-Packet? Mind and Matter 1(1), pp

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-observerPre-observer QuantumERP ClassicERP

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 Geiger Counter 50% Delay 1000ms Timed Delay Deadtime 2000ms OBSERVER EEG measurement PRE-OBSERVER

Second Amsterdam setup Geiger Counter 50% Delay 1000ms 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

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-observerPre-observer QuantumERP ClassicERP

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

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-observerPre-observer QuantumERP ClassicERP

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 ! C Q ? QCQC

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