Authors: Steve Volk
In what's known as the classic, double-slit experiment, photons, electrons, or any atom-sized objects are shot at a screen, impervious but for two tiny slits. A photographic plate sits on the other side of the screen, there to record where each photon lands. Close one slit and the plate will record a logical pattern of photons, with the bulk of them cropping up right across from the open slit. Open both slits and the plate will record bands of photons landing in a pattern of varying intensity, consistent with a wave. So far, so good. Newton rules. But this is where things get well and truly weird: Because if just one photon is emitted into the apparatus at a time, while both slits remain open, scientists would expect to see two regular patterns of photons striking the photographic plateâone behind each slit. But, that isn't what happens. Instead, after shooting lots of photons, one at a time, toward the slits, we find the same interference pattern we saw when the photons were emitted in a flood. The scientific conclusion is that each photon individually travels through both slits at the same timeâmeaning, every individual particle behaves
as a wave
.
In any case where photons are being emitted individually, then literally speaking, wave interference cannot take place. But wave interference is precisely what is observed. The same experimental results hold true not just for photons, but neutrons, electrons, and protons as well. No one particularly
liked
this conclusion. But it was staring them in the face: photons act as a wave when they aren't being measured, and as particles when they are.
It is true that the act of measuring a quantum particle involves striking it with another particle of comparable energy and size. So it isn't just the act of
looking
at the wave function that causes it to collapse into a particle. Failure to make this distinction is responsible for much of the controversy surrounding QM. Still, even when properly understood, QM remains a challenge to our philosophy. The role of the experimenter in consciously choosing when and how to measure a particle
does
directly influence its behavior and in this sense creates a dramatic link between the person doing the observing and the quantum particle being observed. Unless you've read up on the quantum for yourself previously, and perhaps even if you have, you're feeling a bit lost right about now. In a sense, so is modern physicsâlost, that is, and found. Because the strange reality of the quantum realm is precisely what underpins our own more predictable, billiard ball lives.
Physicist John Wheeler added an extra measure of crazy to our understanding of the quantum by formulating a “delayed-choice” design. In this experimental variation on the double-slit exercise described, either slit can be closed
after
the photon has passed the initial screen but before the photon reaches its final destination, where its location is recorded. The Wheeler experiments confirm a single photon will behave like a wave if both slits are allowed to remain openâa particle if one is closed. The result suggests the particle “knows,” after it passes through the slits, that one of the slits will ultimately be shut. Later.
Don't even worry about the voice in your head shouting it can't be true. (That's just your amygdala talking its oft-untrustworthy paranoia.) Just accept, for now, that it is true, and that these experiments raise a host of issues, both philosophical and scientific, including the nature of the relationship between the observer and the observed. I've long accepted, as a reporter, that my presence on the scene with a notebook and a pen causes the behavior of my sources to change, often dramatically. In fact, I sometimes have to hang around my subjects for hours or even days before they begin to let down their guard and behave as they normally do. I would never expect the fundamental building blocks of reality, however, to behave in the same seemingly conscious manner as the politicians, cops, and criminals I interview. Yet the results of these experiments suggest that is precisely what happens. This aspect of quantum mechanics has spawned a host of analyses, including the Copenhagen interpretation, which claims that quantum waves of energy “choose” a particular state only under observation. The other, leading contender is the many-worlds interpretation, which gets around this idea that we somehow create reality by measuring it by arguing that all the possibilities of a wave are realizedâin separate universes. As you might imagine, mystics are among those who love the Copenhagen argument, and no matter how irrational it sounds, many rationalists dig many-worlds.
I find the many-worlds interpretation most intriguing for what it says about the many scientists who in their love for this theory arguably stop practicing science at all. The idea that our universe is one of a seemingly infinite number, splitting off into still more “copies” of the universe (or perhaps just copies of quantum wave functions, depending on who's doing the talking) as different possibilities are realizedâas in one universe the electron spins
up
, in another it spins
down
âis pretty tough to accept outside the Cineplex. And so the many-worlds interpretation of quantum mechanics is in a sense modern science's great Achilles' heelâthe evidence of what desperation can do to us all. Because in trying to reconcile a mechanistic picture of the world with the vagaries of quantum mechanics, a surprisingly large number of scientists endorse the seemingly unscientific idea of an infinite number of parallel
some
things operating unseen alongside ours.
I don't call the many-worlds theory unscientific just because it sounds like something out of a science fiction plot. I call it unscientific because more than fifty years after it was first introduced, by a theoretical physicist named Hugh Everett, no one has devised an experiment to test whether the many-worlds theory is so. Of course, the scien
tific
method calls for scien
tists
to construct testable hypotheses. And in fact, if a theory isn't testable it's normally not considered sound science. Some scientists rail against many-worlds for these very reasons, yet the idea has largely been granted a pass.
In a poll conducted by political scientist L. David Raub of leading cosmologists and other quantum field theorists, in fact, 58 percent responded, “Yes, I think [the] Many-Worlds Interpretation is true.”
Proponents of many-worlds include some of science's greatest luminaries, like Stephen Hawking, Murray Gell-Mann, and Richard Feynman. Supporters seem to like this theory, no matter how far-out it sounds, because it allows them to go on looking at
this
universe exactly the way they already do. These many universes, the theory goes, don't interfere with each other in any way that might force us to refigure our current understanding of physics. But this lack of direct observation, from any one universe to another, is also what nudges the idea from the empirical confines of science toward philosophy.
There is some hypocrisy here: mental telepathy, which we discussed in chapter 2, is dismissed by the scientific mainstreamâdespite mountains of well-controlled scientific research suggesting
some
thing small but real is going on there. In contrast, an untestable idea like many-worlds, unencumbered by the stigma surrounding the paranormal, can win wide acceptance from these very same people.
That QM has driven a great many scientists into a claim that, like the supernatural, seems to lie beyond the current reach of science should not come as a surprise. The legendary physicist Richard Feynman knew what a challenge QM presented to our understanding. Often, this kind of talk is dismissed as hyperbole, scientists patting themselves on the back for understanding what mere mortals can'tâor in Feynman's case, a beautiful mind speaking off the cuff. But in a philosophical sense Feynman meant every word
.
In a lecture collected in
The Strange Theory of Light and Matter
, Feynman says of quantum mechanics: “It is my task to convince you not to turn away because you don't understand it. . . . I don't understand it. Nobody does.”
We should be clear here. In a
practical
sense, scientists
do
understand quantum physics.
Quantum mechanics enabled scientists to predict new kinds of particles, which they subsequently found. And quantum mechanics helped us discover the forces that bind atoms into moleculesâin short, chemistry. Quantum mechanics, or the science of subatomic particles, is the foundation of computers, televisions, all the electronics we consume. Our knowledge of the subatomic world
is
powerful, powerful enough to make it work for us. But what we don't understand about quantum mechanics is
what it means
for our philosophy. And so the iPod has also come with a terrible costâand I don't mean $250.
Traditionalists, including Einstein, thought the new uncertain foundation of the universe that had just been discovered was itself illusory, though he himself had helped to usher in this new understanding! If the strangeness of the quantum world was not somehow explained away, complained Einstein, “I would rather be a cobbler, or even an employee in a gaming house, than a physicist.”
There is something important to consider here about the human beings who practice science. Einstein, like many physicists and rationalists, simply liked the idea of a predictable world better. He chose to enter physics becauseâlike Hameroff, dreaming of standing at the edge of the universeâhe liked the idea of being able to explain how everything worked. And he was honest enough to admit his own disappointment in the world Quantum Mechanics described. Today, physicists and cosmologists remain embroiled in a controversy over whether the Many Worlds interpretation of QM even qualifies as science. This infinite number of hypothesized universes could turn out to be real. But for now, their reality seems largely subjective, a matter of preference.
The terrible cost of QM is that it has thrown up the shutters on us all; and in its mysteries, it has forced scientists to go beyond the evidence and data at hand to find some way of claiming the world they prefer is also the world that is so. This is the stormy, conflicted milieu into which Hameroff and Penrose reached to explain consciousness. In doing so, they immediately subjected themselves not just to scientific criticismâbut to scientific anger. That is in great part why Hameroff got the reception he did at the Beyond Belief conferenceâa reception that was at least as emotional as it was reasonable. And that is why so many scientists continue to castigate his quantum-based theory of consciousness, even though we have more reason than ever to believe QM might play some role in biological systems.
H
AMEROFF REMAINS PERHAPS BEST
known for his appearance in the surprise hit documentary film,
What the Bleep Do We Know?,
a New Agey treatment of quantum mechanics in which human beings are said to create their own reality. Critics of the 2004 film contend it got its science something less than half-rightâstretching the role of the observer in choosing whether to measure a particle into an almost Godlike power to succeed in life, love, and career merely by thinking it so. The movie has since become a kind of Exhibit A in arguments skeptics make against the invocation of what is often dubbed “quantum magic” or “quantum quackery.” But Hameroff, who was one of numerous talking heads in the film, isn't afraid to speak up for itâto a point. “I thought the movie was meant to entertain and inspire,” he says, “and on that score it succeeded. Look at how popular it is. I stand by everything I said in the film, and as for the rest, I had nothing to do with it.”
The things Hameroff says in and outside the film, however, are more than enough to earn him a spot in the skeptic's Hall of Shame. Telepathy, the afterlife, spirituality: Hameroff has claimed that a quantum origin for consciousness could open the door to all these things. Entanglement might explain telepathy and contribute to an afterlife spent roaming the cosmos in a tiny subatomic form. Crazy stuff, that. But it's safe to say, more than fifteen years after they first introduced their theory to the world, the jeering is loud but the jury is still out on the Penrose-Hameroff model of consciousness.
In sum, what became known as Orch-OR, or orchestrated objective reduction, would explain consciousness
and
the primary mystery of quantum mechanics in one shot. The observer effect, in which the waveform is said to “collapse” into a particle state,
is
consciousness; each conscious moment is a collapse. The particulars of how this happens are as complicated as you might wish them to be, revolving around a theory of quantum gravity. But essentially, the Penrose-Hameroff model relates collapse of the wave function/consciousness to fundamental components of the universeâlike the properties of space and time. They cannot be explained or reduced because there is nothing to reduce them to.
The most often cited argument against Orch-OR was given early on by physicist Max Tegmark, who argued that microtubules could not sustain quantum states for a long enough period of time to be relevant to neural processing. But Hameroff and a physicist named Jack Tuszynski countered by saying that Tegmark had improperly modeled the Orch-OR theory, rendering his calculations inaccurate. The state of play hasn't really changed since then, and so, in short, no one has yet falsified Orch-OR or completed an experiment that suggests Orch-OR must be so. For now, the theory's real value lies in the reaction it has provoked, demonstrating how desperate believers are to earn the scientific validation of quantum physics, and how deathly afraid materialists are of considering that quantum mechanics might validate some paranormal claims about the nature of the world or even influence our philosophy.
In fact, the most telling assault on Orch-OR was the one launched by philosopher Patricia Churchland
before
the Penrose-Hameroff model was even published. “She couldn't wait until it even came out to attack it,” Hameroff told me, smiling. “I meanâwhat is that?”