Athough quantum mechanics has been around since before World War II, many scientists refer to it as the new physics. They suggest that it conveys deep insights into the nature of consciousness, insights that confirm the mystical teachings of yogis and herald a new age of enhanced awareness.
   But does quantum mechanics (or QM) truly reveal anything about consciousness and its role in nature? A close look at the theory shows that it doesn’t. Attempts to analyze the role of “the observer” in QM show that the theory is plagued with persistent conceptual problems. And when we try to bring consciousness into the picture, those problems simply get worse.
   To see why this is so, let’s consider an idealized experiment, the simple “delayed-choice split-beam experiment” proposed by physicist John Wheeler. . . . According to Wheeler’s analysis, whether we see interference or see photons coming on separate paths still depends on the position chosen for the photodetectors.
   Does this mean that the photon has split or stayed single as a consequence of a choice made later? Wheeler says no. He concludes, “No phenomenon is a phenomenon until it is an observed phenomenon.” In other words, one can’t say anything about the photon before the observation, which, so to speak, brings the observed phenomenon into existence. Wheeler generalizes on this by saying, “The universe does not ‘exist, out there.’ . . . It is in some strange sense a participatory universe.”

   Now, this might seem to tell us something profound about consciousness. It might seem to suggest that consciousness somehow plays a crucial role in the phenomena of nature.
   But this is not the case. First of all, what is an “observer” in QM? In every case the observer is a physical device. Here the observer is a photodetector, which might consist of a photographic plate, an electronic photocell, or even the retina of someone’s eye. Wheeler’s analysis doesn’t mention whether or not a conscious human being ever becomes aware of what the photodetectors are doing. We don’t think of a photodetector itself as conscious (even when it is a retina), and in analyzing the experiment the idea of consciousness plays no role. The strange phenomena predicted by Wheeler’s theory tell us nothing about consciousness. . . .
   According to QM, a phenomenon is not a phenomenon until physical devices “observe” it. If we posit a nonphysical observer who can see things independently of the physical apparatus, we get into trouble with the quantum theory.

So what can we say about quantum mechanics and consciousness? Even though QM has an excellent record of accurately predicting certain physical phenomena, it is a physical theory afflicted by serious conceptual difficulties. I would propose that QM is not a fully correct description of physical reality, and a better theory may eventually replace it. Wheeler declares that he is sticking with the standard quantum theory because it is “battle-tested.” But classical mechanics is also battle-tested, and in the late nineteenth century many expert physicists thought it was approaching perfection. Then, in the twentieth century, physics was revolutionized, first by relativity theory and then by quantum mechanics. . . .

Copyright © 2004 by Richard L. Thompson