“Some physicists would prefer to come back to the idea of an objective real world whose smallest parts exist objectively in the same sense as stones or trees exist independently of whether we observe them. This however is impossible.”
— Werner Heisenberg
Quantum mechanics grew out of classical physics’ failure to account for the observed interaction of light with atoms (a beam of light shining on an object caused the object to emit particles, which classical physics could not explain). QM is widely held to be the most successful scientific theory ever developed and is batting 1,000 with experimental confirmation: there are no known examples of experimental results that are not consistent with quantum theory.1 To be clear: this is a brief and hugely over-simplified summary of just one small corner of quantum mechanics (QM). I have no doubt pushed the envelope of technical soundness in an attempt at simplicity. My goal is only to convey a sense of QM and a few of the issues it has raised over the century since its inception (particularly related to consciousness and how we perceive reality). If this arouses your interest or curiosity to find out more, so much the better. As always, I appreciate any comments, criticisms, or suggestions that might improve this.
There are many dimensions and principles associated with QM, but the foundation of it all is the fact that any bit of matter (Nick Herbert coined the term “quantumstuff” in his book Quantum Reality) can act as either an object or a wave. Whether it is an object or a wave basically depends on how you measure it. The term “wave” must be qualified, however. A quantum object’s wave form is at once a physical phenomena (like all waves, it has a frequency) and a probability function (which has absolutely no physical meaning).
Physical waves radiate in all directions. In two dimensions, a stone dropped into perfectly calm water creates a concentric pattern of waves; in three dimensions a loud noise can be heard in any direction. Physical waves from a single source can be measured at many different locations at the same time. The waves actually exist independent of their measurement. (Well, at least that’s what most of us believe– see Quantum Realities for other perspectives.) But a bit of quantumstuff only has a probability of existing at any given point. Once you measure it, the probability “collapses” and that bit of quantumstuff can be measured. However, if you measure it as a particle you can only measure either its momentum or its position; by measuring the position you change the momentum and vice versa (Werner Heisenberg’s Uncertainty Principle).
A quantumstuff wave is actually a probability function, not a physical wave. Although quantum wave functions are typically discussed in terms of the sub-atomic level, the mathematics are the same for any size object. According to QM, electrons and elephants can both be described either as particles waves. The only difference is the frequency of the waveform, which is inversely related to the an object’s size: the frequency of an electron’s waveform can be measured, but the frequency of an elephant’s waveform is far too small to measure.
The essence of QM is demonstrated by the famous (albeit with a rather small audience) double-slit experiment. The basic setup is quite simple: an electron gun fires electrons at a screen with one or more slits (openings) in front of a photo-sensitive plate. If the screen has one slit, the electrons register on the photo plate as point impacts, just like individual bullets. But if a the screen has two slits, the electrons register on the photo plate as an interference pattern, just like light waves would if they passed through a pair of openings. And– this is the spooky part– the interference pattern is created even if the electrons are fired one at a time. Remember, there are two slits in the screen. There is no way to explain this.
Richard Feynman, renowned physicist from Berkeley, stated categorically that the double-split experiment is “impossible, absolutely impossible, to explain in any classical way.”2 The Feynman Lectures is perhaps the most widely-read text on physics. Feynman earned a more general popularity during the Senate hearings on the space shuttle Challenger disaster– dropping a piece of material that the infamous O-rings were made of into his glass of ice water, pulling them out later and snapping them into pieces. Unless you grew up with a physics book in your cradle, the best way to picture all of this may be to watch a video: Dr. Quantum’s Double Slit Experiment. And if you want to learn more about what is probably the most famous experiment in the history of physics, an excellent source is the 2002 Physics World article “The Double Slit Experiment,” available at PhysicsWorld.com.
https://www.youtube.com/watch?v=Q1YqgPAtzho https://physicsworld.com/a/the-double-slit-experiment/
https://www.youtube.com/watch?v=Q1YqgPAtzho
Quantum theory has proven to be true in every instance it has ever been tested. The physical universe is fundamentally quantum even though it appears to us as the single monolithic system described by classical physics. Quantum theory diverges from classical physics in many ways, but a few areas in particular stand out in relation to the philosophical middle ground contemplated in this essay.
Complementarity, for example, is the idea that any object— an electron, for example, but theoretically applicable to an object of any size— can be viewed either as a particle or as a wave function, depending on how the experiment is set up. Quantum theory holds that electrons, and all other sub-atomic objects, are neither particles nor waves but rather a probability function of both that collapses into one or the other when measured. The nature of an electron— and by extension all of matter— is not a static thing but, somehow, a function of consciousness. Observed and observer are not separate things but rather inextricable parts of a system that requires both. Moreover, although the effects of quantum mechanics are only demonstrable at Panpsychism 1at sub-atomic level, at least with current technology, the fundamental principles are not a function of scale— they apply as equally to an an elephant or a planet as they do to an electron.
Another bizarre conclusion of quantum theory is that the behavior of linked particles is independent of their position— a pair of entangled particles share a quantum state that cannot be described independently of each other, even if they are at opposite ends of the universe. The idea of such a connection between particles, referred to as non-locality, makes absolutely no sense in the universe of classical physics. It is simply not possible that a pair of particles can somehow be instantaneously linked over vast distances: the theory of relativity prohibits any communication that exceeds the speed of light. Einstein emphatically rejected “spooky action at a distance” and ardently defended locality, the principle that an object can be directly influenced only by its immediate surroundings, and the integrally related concept of realism, that the world exists independently of any observation of it. To paraphrase Einstein, the moon is there even if one is not looking at it. Einstein never believed in non-locality. He held that any connection between particles at different locations was a function of hidden variables, fundamental properties of matter that we had yet to discover.
This was not a small matter. Quantum theory appeared to shatter the foundational assumption of a one-to-one correspondence between an given element of physical reality and a mathematical description of it. It untethered the connection between physics and understandable explanations of the world. Einstein and many other physicists at the time didn’t buy it. They were convinced that physical reality was monolithic, that the universe existed independently of any awareness of it. So along with physicists Boris Podolsky and Nathan Rosen, Einstein proposed a thought experiment and mathematical basis for concluding that quantum theory was an incomplete description of reality, that hidden variables could account for its bizarre conclusions. Their 1935 paper “Can Quantum-Mechanical Description of Physical Reality be Considered Complete?” triggered an intense and public debate between Einstein and Neils Bohr, a principal founder of quantum theory.
Einstein never relented in his belief, going to his grave insisting that quantum theory was incomplete. But Einstein was wrong. In 1964 John Stewart Bell published a paper proposing a mathematical test for determining the presence of hidden variables. Bell’s Theorem was experimentally testable, and in the early 1980s experiments performed by Alain Aspect showed that hidden variables could not account for the results of those experiments. Aspect’s experimental setup retained some loopholes that kept open the possibility of alternative explanations with some form of hidden variables. But increasingly refined experiments performed over the ensuing decades have all confirmed Aspect’s initial conclusions. Physical reality is indeed nonlocal.
Although non-locality has some practical consequences, such as quantum computing, the most significant implications are philosophical, and they are enormous. Henry Stapp asserts that Bell’s Theorem is “the most profound discovery in the history of humanity”. Dislocations inevitable to the discovery of non-locality are only beginning to register in common thought, similar to the last centuries of the 15th century following Copernicus’ pronouncement of heliocentric cosmology. If non-locality is true, as appears to be certain, then the classical conception of a single, real universe completely knowable through measurable things cannot be true. That conclusion, of course, will eventually be a very big deal in several fundamental ways, at least two of which are pertinent to this essay. First, science has reached the limit of its explanatory power about the nature of reality. Science has many frontiers yet to conquer about the nature of physical reality, but it can no longer be looked to as the final arbiter of the ultimate nature of our world. Reductive explanations necessarily end with physics, and physics can no longer support meaningful conclusions that represent a true and complete understanding of reality. Wolfgang Pauli, a principal in the discovery of quantum mechanics, observed that “Since the discovery of the quantum of action, physics has gradually been forced to relinquish its proud claim to be able to understand, in principle, the whole world.”
Another fundamental consequence of non-locality is the realization that human consciousness is somehow an integral part of something immensely larger than we can even imagine. Historically the exclusive domain of philosophy, questions about consciousness are now central to the radical conclusions of quantum physics. Although the basic tenets of quantum physics have been known for almost a century, and key aspects have been known to be incontrovertible for many decades, contemporary academic philosophy has largely ignored their incredible implications for consciousness. As recently as 1998???, for example, the introduction to a summary of modern materialism stated that “there are currently no alternatives to the materialist paradigm.”
All objects are, simultaneously, both and neither a particle nor a wave function, but rather a potential to be either. Particle and wave are complementary aspects of the object; a complete description of the object requires both. This has led to what Neils Bohr referred to as a deep truth: “ It is the hallmark of any deep truth that its negation is also a deep truth.”
Another aspect of quantum physics that applies to the middle way are the related phenomena of quantum entanglement and non-locality, the fact that particles are connected in a way that is impossible in classical physics. When pairs of particles are generated or interact, the quantum state of particle cannot be described independently of the quantum state of the other. Among the many implications of this discovery is the realization that every particle in the universe is connected; separation is an imaginary condition imposed by human minds. Henry Stapp, a prominent philosopher of quantum theory, has called non-locality “the most profound discover in the history of humanity.”
Underlying the ideas of both non-locality and complementarity is the notion that mind is a fundamental property of the universe. Consciousness is, somehow, an inextricable aspect of reality.