“As the nineteenth century drew to a close,” writes Bill Bryson in A Short History of Nearly Everything, “scientists could reflect with satisfaction that they had pinned down most of the mysteries of the physical world: electricity, magnetism, gases, optics, acoustics, kinetics, and statistical mechanics, to name just a few, all had fallen into order before them. They had discovered the X ray, the cathode ray, the electron, and radioactivity, invented the ohm, the watt, the Kelvin, the joule, the amp, and the little erg. If a thing could be oscillated, accelerated, perturbed, distilled, combined, weighed, or made gaseous they had done it, and in the process produced a body of universal laws so weighty and majestic that we still tend to write them out in capitals: the Electromagnetic Field Theory of Light, Richter’s Law of Reciprocal Proportions, Charles’s Law of Gases, the Law of Combining Volumes, the Zeroth Law, the Valence Concept, the Laws of Mass Actions, and others beyond counting. The whole world,” says Bill Bryson,” clanged and chuffed with the machinery and instruments that their ingenuity had produced. Many wise people believed that there was nothing much left for science to do.” Physics department chairmen were literally telling their graduates to go study something else more exciting. All the important discoveries had already been made. All that remained was the need for more and more precise measurements. That’s all.
But the world never ceases to surprise. It’s like a poem by Gary Snyder entitled “The Trail is Not a Trail”:
I drove down the Freeway
And turned off at an exit
And went along a highway
Til it came to a sideroad
Drove up the sideroad
Til it turned to a dirt road
Full of bumps, and stopped.
Walked up a trail
But the trail got rough
And it faded away—
Out in the open,
Everywhere to go.
The story of physics in the nineteenth century and then what happened next is the story of a path that seems like it’s narrowing down to a dead end, but then from nothing comes everything and everywhere to go and it blows your mind. You have a before, and then you have an after. Before, it’s an eminent physicist like Sir William Thompson saying very comfortably and very boringly that “future truths of physical science are to be looked for in the sixth place of decimals.” After, you have a next generation of eminent physicists saying things that are the exact opposite of comfortable and boring:
“Physics is very muddled again at the moment; it is much too hard for me anyway, and I wish I were a movie comedian or something like that and had never heard anything about physics!” (This from Wolfgang Pauli)
From Erwin Schrödinger: “I do not like it [he’s talking about quantum mechanics], and I am sorry I ever had anything to do with it.
For his part, Albert Einstein said, “I can’t accept quantum mechanics because] I like to think the moon is there even if I am not looking at it.”
Acknowledging this is Daniel M. Greenberger: “Einstein said that if quantum mechanics were correct then the world would be crazy. Einstein was right—the world is crazy.”
One more quote, from Michio Kaku: “It is often stated that of all the theories proposed in this century, the silliest is quantum theory. In fact, some say that the only thing that quantum theory has going for it is that it is unquestionably correct.”
These are unsettled voices, perplexed voices, nervous voices, even disgusted voices…. If this isn’t a story of before and after, I don’t know what is. A story of a path that’s become comfortably boring which suddenly—on a dime, in the blink of an eye—turns stranger than you even imagined possible and we are out in the open, unprotected, everywhere to go…
The story of quantum mechanics. This morning, I want to share a little about what quantum mechanics has to say about the world of the very small and then explore how this knowledge might be relevant to our human-sized world of everyday experience. That’s our goal for today—extremely modest, as always 🙂
Start with a basic lay of the land observation. You have the classical physics of Newton, which works perfectly well when dealing with objects much larger than atoms. But it soon became clear that classical physics had nothing to say about the atoms themselves and their component particles. “Things on a small scale,” says physicist rock star Richard Feynman, “behave nothing like things on a large scale.” This is not to say that today we have two separate systems of physics. What quantum mechanics does is dethrone the classical physics of Newton and reveal it as limited in scope—and then it steps up to the throne itself. Quantum mechanics, says Bruce Rosenblum and Fred Kuttner in their book The Quantum Enigma, “is at the base of every natural science from chemistry to cosmology. We need quantum theory to understand why the sun shines, how TV sets produce pictures, why grass is green, and how the universe developed from the big bang.” In more practical terms, no less than one third of our economy depends on technologies based on quantum mechanics (like lasers and transistors). Newtonian physics used to be king, but now there’s a new king in the house.
Now as you listen to me talk about the sheer weirdness of quantum mechanics, keep reminding yourself about one thing: it is the most successful theory in all of science. It’s been subjected to challenging tests for eight decades and no prediction, however crazy-sounding, has ever been proven wrong. “It is the most battle-tested theory in all of science” (Rosenblum and Kuttner). So here’s what the king says. At least some of it.
First, atoms are made up of all sorts of weird things. You have protons and neutrons making up the atomic core, and then you have electrons which create the charged field around the nucleus. But did you know about quarks? Quarks are the building blocks of protons and neutrons, and they come in six flavors: up, down, charm, strange, top and bottom.
Then there’s the Higgs boson, which is what gives mass to all the particles. Without the Higgs boson, everything is insubstantial, everything is ghostly, there is no creation, there is nothing (which is why one physicist calls this “the god particle.”)
But don’t forget antimatter. All normal particles are thought to have antimatter partner particles with the same mass but opposite charge. When matter and antimatter meet, the two annihilate each other. The antimatter partner particle of the proton, for example, is the antiproton, while the antimatter partner of the electron is called the positron, and the antimatter partner of the particle Obama is called Romney (just kidding about this last part!)
And did you know about sparticles? Sparticles are predicted by supersymmetry theory, which posits that for every particle we know of, there is a sister particle that we have not yet discovered. For example, the superpartner to the electron is the selectron, the partner to the quark is the squark and the partner to the photon is the photino. (I just wish that this prediction worked for dollars in the bank. For every dollar you have, you got a dollarino in Switzerland waiting for you to come claim it…)
Sheer weirdness. But wait! There’s more… Listen to what physicist Werner Heisenberg says about these particles: “[They are] themselves are not real; they form a world of potentialities or possibilities rather than one of things or facts.” It’s only when we make a measurement that the world of possibilities snaps out of it and becomes something definite.” What we have here, in other words, is a straight up denial of the existence of a physical world independent of its observation. To the question, “If a tree falls in a forest and no one is around to hear it, does it make a sound?,” quantum mechanics replies, “Forget about sound. You should worry more about the tree itself existing!”
It’s crazy, and to make this craziness crystal clear, Erwin Schrödinger told a hypothetical story involving a cat. Schrödinger’s cat. Bill Bryson describes it as follows: “Schrödinger offered a famous thought experiment in which a hypothetical cat was placed in a box with one atom of a radioactive substance attached to a vial of hydrocyanic acid. If the particle degraded within an hour, it would trigger a mechanism that would break the vial and poison the cat. If not, the cat would live. But we could not know which was the case, so there was no choice, scientifically, but to regard the cat as 100 percent alive and 100 percent dead at the same time.” That’s quantum logic for you: both/and. Only when someone actually looks in the box does the “wave function collapse” (that’s the fancy way of putting it) and we have one and only one actuality: the cat alive, or the cat dead. Either/or and not both.
By the way, know where Schrödinger got his idea for the thought experiment? His dog. 🙂
Now keep reminding yourself: quantum mechanics is the most successful theory in all of science. Quantum mechanics is the most battle tested theory in all of science. Repeat as necessary.
Because here’s something else you need to know. One word: Entanglement. Einstein hated it, called it “spukhafte Fernwirkung”: spooky action at a distance, like what happens when you put a pin in a voodoo doll that looks like me and I say OUCH! Note how sharply this violates the common sense assumption of separability or locality in nature—that hunks of matter (molecules, people, planets) interact only if they impact each other directly, only if there’s some kind of direct contact. But apparently not. Bill Bryson describes it well: “Perhaps the most arresting of quantum improbabilities is the idea, arising from Wolfgang Pauli’s Exclusion Principle of 1925, that the subatomic particles in certain pairs, even when separated by the most considerable distances, can each instantly ‘know’ what the other is doing. Particles have a quality known as spin and, according to quantum theory, the moment you determine the spin of one particle, its sister particle, no matter how distant away, will immediately begin spinning in the opposite direction and at the same rate. It is as if, in the words of the science writer Lawrence Joseph, you had two identical pool balls, one in Ohio and the other in Fiji, and the instant you sent one spinning the other would immediately spin in a contrary direction at precisely the same speed. Remarkably,” adds Bill Bryson, ”the phenomenon was proved in 1997 when physicists at the University of Geneva sent photons seven miles in opposite directions and demonstrated that interfering with one provoked an instantaneous response in the other.”
“Spukhafte Fernwirkung” indeed. Spooky. Even spookier, when you consider how scientists are detecting entanglement effects (or creating them) in macroscopic objects. In 2009, physicists at the University of California in Santa Barbara directed a pulse of microwaves at an electronic circuit chip holding two different superconducting loops, each with a current flowing within them. The current flow in each of the loops should be completely independent of each other, and why not—they aren’t touching at all. But direct a pulse of microwaves at them, and all of a sudden, the currents flow in exact opposite direction. They are in tune, in other words: in sync, in harmony, entangled. Sounds all esoteric I know, but creating quantum effects like this in the human-sized realm is what’s required in order to create quantum computers, and quantum computers are on their way. It’s gonna happen.
Experiments like this are just making it harder and harder for physicists to avoid dealing with the strangeness of quantum mechanics. The usual thought process is that because the micro realm of the sub-atomic differs by so many orders of magnitude from the macroscopic, human-sized realm, what happens in one need not imply anything about what happens in the other. This is why most physicists today practice a “shut up and calculate” philosophy which focuses on just crunching numbers and producing empirical evidence that may support technological innovation. But as for the larger philosophical and theological questions: best not talked about. Keep the skeleton in the closet. Is the universe more like a great thought than a great machine? Must there be consciousness in order for there to be a world? Is our shared reality something we create together through our thoughts and attitudes? Is Emerson literally right when he says, “What lies behind us and what lies before us are small matters compared to what lies within us”? Questions all easy to avoid, if we insist upon the sharp divide between the micro and macro realms. But now the divide is starting to crumble, and I’m not talking about movies like What the Bleep Do We Know or books like The Secret. I’m talking hardcore laboratory science. It’s happening.
Consider this study published in the prestigious journal Science. Dean Radin summarizes: “That study reported that the EEGs of pairs of separated identical twins (two such pairs out of 15 pairs tested) displayed unexpected correspondences. When one twin was asked to close his or her eyes, which causes the brain’s alpha rhythms to increase, the distant twin’s alpha rhythms were also found to increase. The same effect was not observed in unrelated pairs of people.” Sounds a lot like entanglement, doesn’t it? If it can happen in circuit chips, then why not in brains? And when we start thinking along these lines, how much of what we take for granted in our lives is in truth as weird as anything quantum mechanics throws our way? Feelings of deep connectedness with loved ones. Finishing each other’s sentences. You hear the telephone ring and you know exactly who’s calling. This kind of stuff happens all the time. Love is the nearest and dearest thing to our hearts. Yet it turns out (perhaps!) to be just a different kind of sheer weirdness. Love as a quantum phenomenon. Who knew?
We are a long way from the comfortable and boring pronouncements of the establishment physicists of the nineteenth century. That was before. Now is after. We are immersed in sheer weirdness. The world we only thought we knew is now suddenly strange. Tales from the subatomic realm are wonder tales. Science fact sounds like science fiction. Quarks and antimatter and sparticles and everything else. And isn’t it great? The path which seemed like it was dead-ending has opened up, and where to go is everywhere….