Spooky Action at a Distance: The Phenomenon That Reimagines Space and Time--and What It Means for Black Holes, the Big Bang, and Theories of Everything

Long-listed for the PEN / E.O. Wilson Literary Science Writing Award Short-listed for Physics World' s 2016 Book of the Year Ten Physics Books of 2015, Symmetry Magazine The Science Books We Loved Most in 2015, Gizmodo Best Astronomy and Astrophysics Books, Space.com “An important book that provides insight into key new developments in our understanding of the nature of space, time and the universe. It will repay careful study.” ―John Gribbin, The Wall Street Journal “Musser deftly traces the history of our quest to understand this curious phenomenon, covering an ambitious breadth of challenging topics from string theory to the multiverse to the unification of physics.” ― Science “[An] enlightening (and highly entertaining) book, one that takes us beyond earlier popular treatments into the speculative thickets of contemporary physics.” ―Jim Holt, The New York Review of Books “A good science writer has to show us the fallible men and women who made the theory, and then show us why, after the human foibles are boiled off, the theory remains reliable. No well-tested scientific concept is more astonishing than the one that gives its name to a new book by the Scientific American contributing editor George Musser, Spooky Action at Distance . The ostensible subject is the mechanics of quantum entanglement; the actual subject is the entanglement of its observers. Musser presents the hard-to-grasp physics of 'non-locality,' and his question isn't so much how this weird thing can be true as why, given that this weird thing has been known about for so long, so many scientists were so reluctant to confront it.” ― Adam Gopnik, The New Yorker “A highly enjoyable tour-de-force . . . Amid the superb writing here is a lot of information that will bring you up to date on everything you should know about this compelling mystery . . . this book will be one of the reading highlights of your year.” ―David Eicher, Astronomy magazine “Ambitious . . . the author has done a monumental job of translating recondite theory into laymen's terms.” ―Laurence A. Marschall, Natural History “In this polished study of the concept that Albert Einstein dubbed 'spooky action at a distance', science writer George Musser tours the entangled research, history and philosophical speculation surrounding it . . . proving that this is one of the most engrossing disputes in science.” ― Nature “Musser explores the history of humans grappling with nonlocality and what these strange effects are teaching quantum mechanics researchers, astronomers, cosmologists and more about how the universe works ― and while doing so, showing the messy, nonlinear and fascinating way researchers push forward to understand the physical world.” ―Sarah Lewin, Space.com “The journalistic style of this book is smooth and pleasing, rich with personal interviews that touch on the inner workings of researchers, and vignettes from contributors’ lives to add colour. Musser is a witty writer . . . As an experimental physicist, I certainly learned a lot, and am armed with new visual metaphors and fresh insight into an often perplexing field.” ―James Millen, Physics World “I join many others in regarding Musser as one of the best science writers covering cutting-edge physics research . . . His book contains fascinating, mind-expanding ideas, and I’ve been thinking about them for days on end.” ―Ben P. Stein, Inside Science “An endlessly surprising foray into the current mother of physics' many knotty mysteries, the solving of which may unveil the weirdness of quantum particles, black holes, and the essential unity of nature.” ― Kirkus Reviews (starred review) “Accessible and imaginative . . . Clarity and humor illuminate Musser’s writing, and he adroitly captures the excitement and frustration involved in investigating the mysteries of our universe.” ― Publishers Weekly “Can two subatomic particles on opposite sides of the universe truly be instantaneously connected? Or is any theory that predicts such a connection necessarily flawed or incomplete? Are the results of experiments that demonstrate such a connection being misinterpreted? Such questions challenge our most basic concepts of spatial distance and time. In Spooky Action At A Distance , George Musser beautifully navigates through the history, science, and philosophy of these mind-boggling conundrums, and expounds cutting edge thinking.” ―Mario Livio, astrophysicist and bestselling author of Brilliant Blunders and The Golden Ratio “George Musser gives us a fascinating tour of the latest attempts on the frontiers of physics to answer one of the oldest questions in science: What is space? And the wonderful lesson is that the deeper we look into the question, the more captivating it becomes.” ―Lee Smolin, founding faculty member at the Perimeter Institute for Theoretical Physics and author of The Trouble with Physics “With clever metaphors and dry humor, acclaimed science communicator George Musser is the perfect tour guide on this wild ride through wormholes and emergent dimensions to the cutting edge of physics. This quest to understand the ultimate nature of space may forever transform how you think about the very fabric of reality.” ―Max Tegmark, physicist and author of Our Mathematical Universe “Modern physics is in the process of dismantling the very space all around us, and the universe will never be the same. In this engaging book, George Musser leads us through the thickets of science and philosophy and takes us to the brink of a very different view of the world.” ―Sean Carroll, theoretical physicist at the California Institute of Technology and author of The Particle at the End of the Universe “Locality has been a fruitful and reliable principle, guiding us to the triumphs of twentieth-century physics. Yet the consequences of local laws in quantum theory can seem 'spooky' and nonlocal-and some theorists are questioning locality itself. Spooky Action at a Distance is a lively introduction to these fascinating paradoxes and speculations.” ―Frank Wilczek, winner of the Nobel Prize in Physics and author of The Lightness of Being and A Beautiful Question George Musser is an award-winning journalist, a contributing editor for Scientific American , and the author of The Complete Idiot's Guide to String Theory . He is the recipient of a Jonathan Eberhart Planetary Sciences Journalism Award from the American Astronomical Society and the 2011 American Institute of Physics Science Communication Award for Science Writing. He was a Knight Science Journalism fellow at MIT from 2014 to 2015. He has appeared on Today , CNN, NPR, the BBC, Al Jazeera, and other outlets. He lives in Glen Ridge, New Jersey, with his wife and daughter. Excerpt. © Reprinted by permission. All rights reserved. Spooky Action at a Distance The Phenomenon that Reimagines Space and Time–and what It Means for Black Holes, the Big Bang, and Theories of Everything By George Musser Farrar, Straus and Giroux Copyright © 2015 George MusserAll rights reserved.ISBN: 978-0-374-29851-7 Contents Title Page, Copyright Notice, Dedication, Introduction: Einstein's Castle in the Air, 1. The Many Varieties of Nonlocality, 2. The Origins of Nonlocality, 3. Einstein's Locality, 4. The Great Debate, 5. Nonlocality and the Unification of Physics, 6. Spacetime Is Doomed, Conclusion: The Amplituhedron, Notes, Bibliography, Acknowledgments, Index, A Note About the Author, Also by George Musser, Copyright, CHAPTER 1 The Many Varieties of Nonlocality Enrique Galvez's lab at Colgate University is about the size of a two-car garage and, like most people's garages, jammed with stuff. Along the walls are workbenches loaded with toolboxes, electronic gear in various stages of disrepair, and, on the left side as you enter, the most frequently used piece of equipment: the coffee pot. In the middle of the room are a pair of optical benches: industrial-strength steel platforms, each the size of a dining-room table, covered with a pegboard-like grid of holes for attaching mirrors, prisms, lenses, and filters. "It's like playing with Erector sets all over again," says Galvez, a mellow Peruvian who looks remarkably like Al Franken. If anyone has taken it on himself to show the world what quantum entanglement looks like, it's Galvez. Entanglement is the best known of several types of nonlocality that modern physicists have observed, and the one that spooked Einstein. The word "entanglement" has connotations similar to a romantic entanglement: a special and potentially troublesome relationship. Two particles that are entangled with each other are not literally intertwined, like balls of yarn; rather, they have a peculiar bond that transcends space. You can see this effect by creating, deflecting, and measuring beams of light — not ordinary flashlight beams, but beams of entangled photons. The earliest versions of the experiment, done in the 1970s at Berkeley and Harvard, involved mad-scientist contraptions of broiling-hot ovens, stacks of glass panes, and clattering teletypewriters. Galvez has taken advantage of Blu-ray lasers and optical fibers to miniaturize the setup, so that it now fits on a classroom desk. Most experimental physicists I've met are tinkerers at heart, as fascinated by cool stuff as by the mysteries of the universe. An experimentalist at the Centre for Quantum Technologies in Singapore told me that, in his lab, incoming students have to pass a test. There's not a single physics question on it. Instead, they have to tell the story of how they took apart some household appliance and managed to get it back together, hopefully before their family found out. Apparently, clothes washers are a popular choice. Galvez, for his part, says his childhood passion was chemistry — of the blowing-up variety. Growing up in a middle-class neighborhood in Lima, he and some friends once tried to make gunpowder. All they got was a smoke bomb, which is perhaps just as well. "It was much more fun than something exploding," Galvez recalls. "It probably wasn't very healthy." Galvez says he found his calling as a nonlocality crusader almost by accident. In common with the majority of physicists, he didn't give much thought to the phenomenon until the late 1990s, when a colleague stopped by his office with some dramatic news: the Austrian physicist Anton Zeilinger and his lab mates had used entanglement to teleport particles from one place to another. Teleport?! No fan of Star Trek could fail to be impressed. Although Zeilinger's team had beamed only single photons rather than an entire starship landing party, the coolness factor rivaled that of smoke bombs. And the procedure was straightforward. Suppose you want to teleport a photon from the left side of your lab to the right. First, you prime the teleporters by creating a pair of entangled photons and positioning one on each side of the lab. Then, you take the photon you want to beam and let it interact with the left particle. Because the entangled particles have a special bond between them, the interaction is immediately felt on the right, allowing the photon to be reconstituted there. (Some quibble whether the procedure should really be called teleportation; they consider it closer in spirit to identity theft. The experimentalists strip the left particle of its properties and thrust those properties onto the right particle. But a particle is nothing more than the sum of its properties, so these two characterizations amount to the same thing.) Galvez and his colleague already had all the gear, and before long, they were beaming particles across their lab, too. "We were trying to figure out teleportation just for the fun of it," Galvez says. Another colleague suggested they design an entanglement experiment that even a physics-for-poets class could do. It doesn't do teleportation, but achieves the first and most important step in the process — namely, creating and distributing the entangled photons. As simple as the apparatus looks now, the team sweated over it for two years. Galvez began to run summer workshops for ALPhA, a physics-education group, to show teachers how to do the experiment, and he posted his instruction manuals online so that do-it-yourselfers can entangle particles in their basements. The former president of ALPhA, David Van Baak, exclaims: "We're past the stage where entanglement is a research-university-only affair. It's getting out to the masses." On the day I visit Galvez's lab, one of his optical benches is given over to the entanglement experiment, the aim of which is not only to demonstrate entanglement, but also to explore what might be causing it. I recognize the setup as basically a high-tech Rube Goldberg coin flipper in which photons assume the role of coins. They are either "heads" or "tails" depending on whether they pass through a filter or not. The system is tuned so they have a 50-50 chance of getting through, like flipping a fair coin. The basic plan is to create a pair of these coins, flip both at the same time, see which sides they land on, create another pair, flip them, and so on. Repeat thousands of times and add up the statistics. It seems like a lot of effort for a predictable result, until you remember that we're talking about quantum coins. Clearly, thinking of particles as coins is a metaphor, but as long as you don't take it too literally, it's completely kosher. Physicists themselves understand phenomena in terms of metaphor. To set the apparatus into motion, Galvez fires an ultraviolet laser through a series of optical elements that ensure proper alignment of the light. The beam strikes a small crystal of barium borate, a material discovered by Chinese scientists in the early 1980s, which splits the ultraviolet beam into two red beams. The splitting occurs particle by particle: if you could zoom in and view the beam as a stream of photons, you would see some of the ultraviolet photons hit the crystal and divide their energy into identical twin red photons. Voilà, coins. Located just upstream of the crystal is an optical element known as a waveplate, which Galvez uses to control the output of the crystal. Depending on how he sets the waveplate, the red photons are either entangled or not. Once the red beams diverge, they cease to interact. Galvez aims each beam at a polarizing filter, much like the ones that photographers screw onto the front of their lenses to cut down on glare. The filter lets photons through or blocks them depending on their orientation — their polarization. Galvez can turn a dial on the side of the filter to control which photons make it. For this experiment, he sets both filters to the same setting, one that admits half the photons at random, thereby simulating coin flips. Photons that make it through the filters are sent to detectors that convert them to electrical pulses. These detectors are the you-break-'em-you-bought-'em part of the system. Being sensitive enough to pick up individual photons, they run $4,000 apiece and are easily damaged by bright light. Even with the room lights off, the detectors pulse wildly, because the minutest sliver of light will set them off. Watching them gives me a new appreciation for how bright a supposedly dark room can be. We have to make sure our phones and laptops are fully off; a single glowing LED might spoil the experiment. "A while back we had to put black tape over anything that lit in the lab," Galvez says. "You would be surprised how many of those lights there are." He drapes a black velvet cloth over the devices and draws a thick curtain around the entire bench. Finally, the detectors are wired into a meter with three digital readouts, located safely outside the curtain. Two show the number of photons that make it through the left and right polarizing filters. When Galvez switches on the laser, those numbers flash by like milliseconds on a stopwatch. The third readout shows the "coincidences" — when both photons in a pair make it through their respective filters. In terms of the coin metaphor, a coincidence means that both coins have landed on heads. These coincidences are Galvez's window into quantum nonlocality. Having given me the tour, Galvez is ready to take some data. To verify that everything is working properly, he first simulates flipping ordinary coins by setting the waveplate to produce unentangled photons. The meter reads about twenty-five coincidences per second. For comparison, you'd get one hundred coincidences per second if every single photon in every single pair made it through the filters. So, the coincidence rate is about a quarter of its maximum possible value. This is just what you'd expect from the laws of chance. If you take two coins and flip them, each will come up heads about half the time, so both will be heads about a quarter of the time. Now Galvez adjusts the waveplate to generate entangled photons. The coincidence rate jumps to about fifty per second. A change from twenty-five to fifty on a digital readout in a basement lab might not seem like much. But that's physics for you. It takes effort to peer beneath the surface of the world around us, and the clues are subtle, but they are no less dramatic for that. All those years of waiting and preparing for this moment have paid off, because when I see that fifty, I realize what I am seeing, and I shiver. The photons are behaving like a pair of magic coins. Galvez flips thousands of such pairs, and both always land on the same side: either both heads or both tails. That kind of thing doesn't happen by pure dumb luck. If a friend of mine did this trick at a party — flip pairs of coins so that both came up heads twice as often as they rightfully should — I'd assume it was a practical joke. My friend might have gone to a magic shop and bought double-sided coins, which look the same on both sides, making the outcome of a flip preordained. Could an equivalent stunt explain the pattern I was seeing in Galvez's lab? To test for such trickery, Galvez uses a tactic proposed by the Irish particle physicist John Stewart Bell in the 1960s. He turns one of the filters by an angle of 90 degrees, which, like flipping a coin with your left hand rather than your right, doesn't alter the probability of a particle getting through; if the outcome really is predetermined, nothing should change. But this seemingly innocuous change does have an effect on the photons. The coincidence meter drops nearly to zero — meaning that if one photon gets through, the other never does. In other words, the magic coins have switched from always landing on the same side to always landing on opposite sides. A practical jokester would need some extra sleight of hand to pull off this trick. By making further refinements, Galvez rules out any conceivable chicanery. I go over and look at the optical bench again. Those filters are separated by the width of my hand. Experiments by Zeilinger and others have stretched the distance to one hundred miles, and researchers at the Centre for Quantum Technologies are working on a space-based version that will go even farther. For a tiny particle, that might as well be the other side of the universe. The photons manage to coordinate their behavior across that gap. They are not in contact, and no known force links them, yet they act as one. When Galvez dials the polarizer filter on the left side of his lab bench and a photon passes through, the photon will be polarized in the same direction as the filter. Its entangled partner follows in lockstep: it acquires the same polarization and will respond accordingly to its own filter. So, what happens on the left affects the photon on the right, even when there's no time for any kind of influence to cross the gap. Indeed, such an influence would need to travel from left to right instantly — that is, infinitely fast, which is plainly faster than light, in apparent defiance of the theory of relativity. This is one of the many mysteries posed by nonlocality. Physicists have commented that it is as close to real magic as they've ever seen. "Students love it," Galvez says. "The good students say, 'I want to figure this out.'" Shut Up and Calculate Is nonlocality just a carnival freak show — fun to ooh and aah over, but having no broader implications — or does it belong on the center stage of physics? For most of the twentieth century, physicists treated it as a freak show, and as a student I adopted this attitude, too. It wasn't until years later, when I delved into Tim Maudlin's book Quantum Nonlocality and Relativity, that I appreciated the depth of the mystery. Sitting in his George Nakashima–furnished living room, Maudlin tells me he'll never forget the moment he learned about quantum nonlocality. One day in the fall of 1979, while a physics major at Yale University, he opened up the latest issue of Scientific American magazine. The cover story was about dung beetles, but he flipped past it and landed on an article on the early entanglement experiments. For particles to act as if by magic stunned Maudlin. "I remember the day when I read that article," he says. "My roommates remember that day. I walked around and around my room. The world wasn't what I thought it was. It bugged the hell out of me." It also bugged him that his physics professors, like mine, had never once mentioned this phenomenon. When he probed them about it, they blew him off. Once, Maudlin recalls, he raised his hand in class and asked whether quantum theory might not give way to a deeper theory in which the seeming contradictions would make perfect sense. The professor dismissed the idea and went back to scribbling Greek letters on the blackboard. "He didn't offer any explanation at all of why not," Maudlin says. "So he shut down the question without answering it." * * * To appreciate the mind block that Maudlin and I ran into, you have to go back to the famous debates between Einstein and another of the founders of quantum mechanics, the Danish physicist Niels Bohr, in the 1920s and '30s. Einstein worried that nonlocality would contradict his theory of relativity and argued that it had to be a kind of illusion, reflecting our ignorance of some essential aspect of nature. Bohr argued ... well, nobody is quite sure what Bohr argued. His reasoning gave "tangled" a whole new meaning, and his missives have been interpreted as either championing or contesting nonlocality. To the extent that anyone does understand what he said, he was asserting that it didn't matter what weirdness lay behind the scenes, as long as the theory could predict what experiments saw. As anyone who has watched an American presidential debate knows, judgments about "win" or "lose" often have little to do with what the debaters actually say. Most physicists just wanted the Bohr-Einstein debate to be over, so they could get on with applying quantum mechanics to practical problems. Because Bohr promised closure, they rallied around him and wrote off Einstein as a has-been. One later wrote that Einstein's "fame would be undiminished, if not enhanced, had he gone fishing instead." Over the subsequent decades, physicists used quantum theory to do all sorts of useful calculations. They figured out transistors, lasers, and other mainstays of the modern world. So the collective decision to set aside questions about the theory's deeper meaning seemed justified. Whenever those conceptual questions did come up, physicists deemed them "philosophical," which wasn't intended as a compliment, but as a way to deny that the questions were even worth asking. The English physicist Paul Dirac wrote, "It is only the philosopher, wanting to have a satisfying description of nature, who is bothered." (Continues...) Excerpted from Spooky Action at a Distance by George Musser . Copyright © 2015 George Musser. Excerpted by permission of Farrar, Straus and Giroux. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site. Read more