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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 Collapse of wave function by what is commonly called a “measurement”. Classical Physics Reality 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 Assumptions 1. Consciousness of first observer collapses the state before second observation. 2. Final Observer (brain) is sensitive for the difference between collapsed and noncollapsed 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 Amsterdam 2003 Delay 1 µs Delay 1000 ms Dependent variable: verbal report Dependent variable: brain signals First Amsterdam setup PRE-OBSERVER OBSERVER First Amsterdam setup EEG measurement Deadtime 2000ms Delay 1000ms Geiger Counter 50% Radioactive source PRE-OBSERVER OBSERVER Analysis procedure EEG trace Preobserved beeps NOT preobserved beeps OBSERVER Analysis procedure EEG trace ERP allfc ParentOther [ µV] -5 0 5 -200 -100 0 100 200 300 400 500 600 700[ ms] 0 100 200 300 400 500 600 700[ ms] allp ParentOther [ µV] -5 0 5 -200 Average EEG from onset-time of event (beep) -100 Results first Amsterdam Setup Peak FC-leads P-leads N20 P40 N100 P200 N300 P350 N400 P100 N160 N200 Difference (microvo lts) 1.002 0.903 0.350 -0.09 -0.04 -0.54 0.098 -0.16 -0.152 -0.956 df = 29 t 2.12 2.64 0.66 -0.18 -0.08 -1.17 0.25 -0.67 -0.84 -3.93 p 0.043 0.013 0.52 0.86 0.93 0.25 0.80 0.50 0.41 0.0005 Non-parm p N=30 19-11: 0.20 22-8: 0.016 15-15 15-15 15-15 12-18: 0.36 16-14: 0.86 12-18: 0.36 13-17: 0.58 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 Copenhagen interpretation supported A quantum-measurement is only complete when ‘acted’ upon by consciousness. 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 timeinterval (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 EEG measurement Deadtime 2000ms Geiger Counter Delay 1000ms 50% Timed Delay OBSERVER PRE-OBSERVER Second Amsterdam setup EEG measurement Deadtime 2000ms Geiger Counter Delay 1000ms 50% Timed Delay OBSERVER 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. 2. No effects of pre-observation when source is Classic 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. 2. 3. No effects of pre-observation when source was Classic No effects found of pre-observation (thus no direct replication of 2003 study) Effect of event-origin (quantum/classic) in finalobserver’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 Q ? C ! C Q PRE-OBSERVER PRE-OBSERVER Sensitivities Care was taken to maintain exactly the same time-distributions of the quantum and classical events. 200 180 160 140 120 frequency 100 Quantum Delay Classic Delay 80 60 40 20 0 7000 -20 8000 9000 10000 11000 12000 13000 time in tenths of milliseconds 14000 15000 16000 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