I need to preface this entry by saying two things. First, I'm no quantum physicist. This is intended to be an introduction for the lay reader. Readers who are well versed in particle physics will no doubt be alarmed by my reductionism. So be it. You have to start somewhere. I would encourage those of you interested in delving deeper to read Michio Kaku's 2006 book Parallel Worlds: A Journey Through Creation, Higher Dimensions, and the Future of the Cosmos.
Second, nothing bugs me more than getting hooked on a blog about, say, macramÃ© and finding that the author has suddenly become obsessed with third world politics. If I wanted to read about third world politics, I'd go to the BBC website, ya know. By writing about quantum physics, some readers will accuse me of committing a similar transgression. In my defense, I'll say only this, quantum physics in increasingly grappling with questions that were once considered the province of psychologists and theologians--questions like: What is the nature of self? And is there a god? I would argue that this line of inquiry qualifies as "psychology for the modern mind."
Okay, that was my apologia. Now for the good stuff.
In The End of Mr. Y, British novelist Scarlett Thomas presents the most concise, commonsense explanation of quantum physics I've ever run across:
Quantum physics deals with subatomic particles, in other words, particles that are smaller than atoms . . . But when physicists first began theorizing about these particles and observing them in action in particle accelerators and so on, they found out that the subatomic world doesn't act the way we'd expect.
All that common sense stuff--the past happening before the future, cause and effect, Newtonian physics, and Aristotelian poetics--none of it is applicable at the subatomic level. In a deterministic universe . . . you can always tell what's going to happen next, if you have enough information about what went before. And you can always know things for sure. It's always night or day, for example: It's never both at once. On a quantum level, things don't make sense in that way.
(The End of Mr. Y, 137-138)
This is a perfect jumping off point for our conversation. Try not to get discouraged by the phrases "Newtonian physics and Aristotelian poetics." Newtonian physics, for the scientifically challenged, is just capital 'P' physics--the kind you encountered in high school. As for Aristotelian poetics, this is just a fancy way of describing conventional notions of time. In our world, time behaves predictably. Every story has a beginning, a middle, and an end. This doesn't hold true in the world of subatomic particles.
The Wacky World of Subatomic Particles
Subatomic particles are a lawless bunch. They refuse to be hemmed in by traditional notions of time and space. You and I are constrained by the laws of the physical world. We can only be in one place and one time. Our ability to interact with other people is contingent on proximity. (If I want to hug my mother, she has to be in the same room. If she's on another continent, I'm forced to settle for a phone call.) And for us, the physical world is concrete. I may understand that I'm made up of the same stuff as my table on a philosophical level, but that doesn't make me Neo. I still have to walk around it rather than through it. These rules don't apply to quarks.
As Thomas writes, these "particles can go through walls just like that. There are pairs of particles that seem to be connected and stay connected in some way even when they are separated by millions of miles." And there's no three-act structure for these guys. They can be in multiple places at the same time. For them, beginning, middle, and end have no meaning. They exist in a state of never ending possibility known as a wavefunction.
Doing Cruel Things to Cats in the Name of Physics
The classic example of the dual nature of subatomic particles is, of course, Schrodinger's cat. In 1935, a physicist named Erwin Schrodinger devised a thought experiment that allowed people to wrap their heads around the idea of a wavefunction. He said, imagine you put a cat in a metal box. Then, imagine that before closing the lid, you inserted a small amount of some radioactive substance. Two possibilities exist: the atoms could decay, thus triggering the release of an acid, which would kill the cat; or the atoms could remain in tact and the cat would survive.
Schrodinger was trying to answer a question: "when does a quantum system stop existing as a mixture of states and become one or the other?" Put simply, when does the wavefunction give way to one reality? The answer: not until someone is there to observe the cat. The cat's fate will only be decided if someone pops the lid and checks in on it. If the cat remains in the box undisturbed, both possibilities will persist. The cat will be simultaneously dead and alive.
Both the Observor and the Observed
I like to think of quantum particles as wayward teenagers. When they're on their own, it's total mayhem. They're doing drugs; they're having sex; they're generally thumbing their nose at "the man." But once you get them in a room with their grandmother, they're totally different creatures. Well-groomed, polite, and eager to please. In this analogy, we are the grandmother. When we're there to watch how quarks conduct themselves, the hijinks come to end. No more walking through walls, or existing in multiple places at once. They begin to behave the way we expect them to.
But here's where it starts to get really complicated. Because you are made up of these rebellious particles, you're not just the grandmother. You're also the wayward teen. And so is everything else. The tree outside your bedroom window. The chicken you cooked for dinner last night. The computer you're browsing on. The question then becomes, why are we so constrained? If our subatomic particles are capable of walking through tables and being at the opera and the gas station at the same time, why aren't we?
The answer, simply put, is that there's always a grandmother watching us, keeping our behavior in check. 'But that's just not true,' you say. 'If I'm locked away in my studio apartment watching The Sopranos on my own, there's no grandmother.' And you're right. But according to quantum theory, when you're in a witness-free environment, you're just like the cat. You exist in a state of pure possibility and that won't change until the pizza delivery guy shows up at your door and forces your quarks to cleave to reality. Weird, no? Well, brace yourself, because it gets even weirder.
The Problem with The Big Bang
If you buy into the idea that a quantum system exists as a mixture of states until an observer comes along and forces its hand, it brings up some profound questions about the beginning of life. According to quantum physics, the Big Bang wouldn't have been possible without an observer to tip the scales. The explosion that gave rise to life on earth would simply have been one possibility floating around in a sea of possibilities. This realization has prompted some of the more romantic physicists out there to say there was an observer: God. Others aren't satisfied with this explanation, thus was born the many-worlds interpretation.
The many-worlds interpretation says that because there was no observer to bring about the Big Bang, we essentially exist in a giant wave function. The Big Bang did not "happen" in a deterministic sense. It's just one of a gazillion possibilities existing side by side. And we, humans, happen to live inside that possibility.
What does this mean for you and me? It means that we don't exist in a deterministic sense either. The consciousness I'm experiencing is just one expression of the possibility that is called Orli. In this particular expression, I've made it to the age of 32. I live in a comfortable 1-bedroom apartment in Brooklyn. And I'm preparing to heat up a bowl of turkey soup. But on parallel planes, there are Orlis who decided to wait to eat; Orlis who opted to go to the gym instead of sitting down in front of the computer. There could also be Orlis who never made it out of childhood, and Orlis who opted to become hemp farmers in Santa Cruz instead of writers.
And, of course, it's not just about us piddling humans. The many-worlds interpretation also implies the existence of parallel worlds: Worlds where humans never bested the Neanderthals; where America was never colonized by Westerners; where the Holocaust never happened; and the atom bomb was never invented.
Contemplating the many-worlds interpretation always gives me a pleasant sense of vertigo. Being commitment-phobic by nature, I love the idea that all the possibilities this version of Orli has turned her back on still exist somewhere on an alternate plane. Others find the idea crazy-making. Not only does it require you to relinquish god, it also necessitates the abolishment of the soul. According to the many-worlds interpretation, you aren't a unique flower destined to meet your maker in a giant park in the sky. You're just one of an infinite number of possibilities.
I don't know about all this. Don't get me wrong, it's not the first time I've encountered these concepts, its just that they don't seem right at all. My gut feeling says that 50 years down the line, these sort of notions are going to be downright laughable. But still, you've written very well on the topic-- I'd be interested to see you take it to the next level, and introduce readers further into these topics. When you referred to Noam Chomsky in a different entry, I've got to say that I partially agree with him-- take the entry on false pregnancy, for instance. You do a marvelous job of essentially telling us a story. It's very interesting, and as a layperson, certainly arouses many fascinating questions. However, I could get a neat story from the headlines at Yahoo as well: "one-eyed kitten born", etc... Once I'm done reading about what happened, I'm ready for the next step. What is the treatment of such an affliction? When did false pregnancy first come to be realized? What is a modern treatment? Have the psychological causes for false pregnancy decreased in modern days? How about a link to a study that I could actually read without a subscription to a n academic journal?
Anyhow, I'll be bookmarking your blog. Thanks for writing. --DaveX