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Schrödinger's Cat: 1/2 alive and 1/2 dead at the same time?
Does consciousness create reality? Seems like a big topic for a little blog post. But because I will be considering ONLY EXPERIMENTAL ATTEMPTS to answer this big question I can skip almost all the philosophical verbiage and cut to the chase.
When we wake up and open our eyes, there's the world. But was it there before we looked? The notion that consciousness creates reality (called
subjective idealism) has a long history but only recently with the advent of quantum physics has there been any opportunity to put this important question to experimental test. Unlike classical Newtonian physics which appears compatible with objectively existing substance, certain features of quantum mechanics (QM) do indeed suggest that consciousness might play an essential role in bringing the world into existence.
QM describes the world in two different ways, depending on whether the world's looked at or not. When it's not looked at, QM represents the world as mere POSSIBILITY WAVES. When it's looked at, some of these possibilities become ACTUAL EVENTS.
Unfortunately physicists do not agree about what it means "to look"--and we call this fraternal disagreement the
"quantum measurement problem." The physics majority believes that what is necessary for looking is "a machine that makes a record". But how does one go about building a solid record-making machine using only possibilities as parts?
Some physicists believe that "something extra", something outside of quantum mechanics is needed to resolve the measurement problem. Some have suggested that consciousness might be the magic trick that turns airy-fairy quantum possibilities into hard actuality. An impressive minority of physicists including
John von Neumann,
Eugene Wigner,
Pascual Jordan,
Henry Stapp,
Robert Mills,
E.H. Walker,
Euan Squires,
Fred Kuttner & Bruce Rosenblum have argued that consciousness plays a fundamental role in the quantum picture of things.
The mascot of the measurement problem is Schrödinger's Cat who is placed in a box with a quantum device that has 50% possibility for killing the cat and 50% possibility for feeding the cat. According to Schrödinger's own quantum equation, the cat is 1/2 dead and 1/2 alive until somebody looks in the box.
In the case of the cat, the measurement problem reduces to the question: "Does a conscious being need to look in the box, to make the cat alive or dead? Or is that question already decided inside the box itself by an irreversible process (record-making device) such as the breaking with a hammer of a jar of poison?
In the past few years at least three experiments have been proposed to test whether or not consciousness is necessary to collapse the wavefunction. The first is a thought experiment due to
Bedford and Wang from University of Natal in South Africa. Instead of a cat, B & W imagine a situation in which a quantum system either opens slit A or slit B in an optical interference experiment. In the case where the quantum odds are 50/50 both slits are open at the same time in the same manner as the cat is 50/50 alive and dead. Because both slits are open, an interference pattern should be observed. However if someone looks at the slits, the wave function collapses, only one slit is open at a time and no interference is observed. If B & W are correct, this setup unlooked at produces optical interference but when a mind intervenes the interference vanishes.
A bunch of us including Amit Goswami, Saul-Paul Sirag, Casey Blood and Ludvik Bass (Schrödinger's last graduate student) considered this problem for many months. We called our quest the
AMY Project. After much discussion and calculation, the AMY team concluded that Bedford & Wang were wrong. No matter what happened in their experiment--looking or not--no interference would ever be observed. The B & W experiment, we decided, fails as a crucial test for mind-created reality.
A second approach to catching the mind in the act is due to
Abner Shimony and his students at Boston University (see "the Boston Experiment" in
Elemental Mind) and
Dick Bierman at the University of Amsterdam. Shimony and Bierman propose the existence of a perceptual difference between you personally collapsing the wavefunction and you merely witnessing a wavefunction that some other mind has previously collapsed. To test this conjecture, they set up an experiment (see diagram below) in which two observers are looking at identical detectors and a hidden switch decides which observer gets to see (and presumably collapse) the quantum event first. This imaginative test of the mind-created reality hypothesis has so far yielded inconclusive results. If minds create reality, these minds apparently do not find it easy to perceive what this creation process feels like.
A third approach to testing the mind-created reality hypothesis is due to
Roger Carpenter &
Andrew Anderson at
Cambridge University (pdf). In the C & A test, two observers both look at the same quantum system but Observer A gets a random output and Observer B gets an output that tells whether Observer A's result is true or false. Thus the putative mind-created reality does not come into existence UNTIL BOTH OBSERVERS SHARE THEIR DATA. So C & A have two separate channels by which consciousness can create reality: 1. break the code by sharing data or 2, directly observe the quantum system. In a wholly quantum world, there is no reason why these two separate methods of looking should lead to the same reality. But they always did--which led C & A to conclude in favor of an objective collapse model of reality.
To this trio of mind-matter experiments I should probably add my own work with the
metaphase typewriter which was a quantum system (Geiger counter and radioactive source) coupled thru speech statistics to an electric typewriter. Inspired by Jane Roberts'
Seth Speaks, I had hoped that the MT might operate as a quantum spirit medium and function as a clear communication channel for a discarnate entity as talkative as Seth. But no spirits ever took over my metaphase device during the year or so that it was in operation.
Does consciousness create reality? So far there is NO EXPERIMENTAL EVIDENCE from quantum physics that supports this bold conjecture.
On the other hand, so far there is NO EXPERIMENTAL EVIDENCE for
the Higgs boson or for even one of the many, many new particles predicted by the
Supersymmetry conjecture. Yet physicists continue to look for these things.
I hope this brief review of experiments designed to test the quantum mind hypothesis will inspire others to improve on them. Coincidentally the primary quantum system in every one of these tests was a radioactive source and a
Geiger counter, a 100-year-old technology which seems as primitive as a flint ax when compared with the sophisticated quantum systems now routinely available in today's physics labs. Seems to me it's time for the mind-created reality hypothesis to be probed by light-sensitive CCDs, electron-tunneling flash drives, Bose-Einstein condensates, phase-entangled photons and the Heisenberg-uncertain qubits in quantum computers. Physicists, put on your hi-IQ thinking caps. Ladies and gentlemen, start your quantum engines.
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Diagram of the Shimony-Bierman Experiment