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 (Scientific American/Farrar, Straus, and Giroux, 2015) 286 pages
I’ve been told—and by more than one person—that I have a kind of knack for explaining complicated concepts in a way that is understandable to people who are not familiar with them. So I have a real interest in how other writers attempt to accomplish this, because I know it’s not an easy thing to do. It has to look easy, but a lot of thought goes into this kind of exploration.
Musser is a general science writer of some note, and he’s won awards for his work with Scientific American magazine. This is a good thing, because what he is attempting to explain here is one of the trickiest concepts to modern physics for general readers and even physicists to grasp: the nonlocal aspects of the universe we live in.
Really? Physicists don’t even grasp nonlocality? That’s more or less what Musser claims (pages 3 and 20) when he notes that his own professors didn’t mention nonlocal “spooky action” once during classes. He had to hear about on the street (well, in a non-textbook) instead of in school.
So what is “spooky action at a distance” and nonlocality? And why is it so upsetting to many modern physicists? Nonlocality is the idea that what happens here, locally, depends not only on the things that can act on the space we have in front of us, but things that are impossibly far away, perhaps even at the edge of the universe. These effects occur faster than light, in fact, instantaneously, and so constitutes not only “action at a distance” such as the moon raising tides on earth, but “spooky action at a distance” because the space between here and there makes no difference in the size of the effect at all.
The “spooky” phrase and title comes from a comment by Einstein, who was disturbed that quantum theory allowed photons of light to become entangled and then separate much farther than any signal could travel between them (no information can be sent faster than the speed of light), yet still have measured values that were coordinated. In other words, if one photon is polarized in the up direction, the other must be polarized in the down direction.
Now, you’re probably thinking what I did when I heard about this phenomenon: what’s the big deal? Isn’t it like have a red and blue ball and putting them in boxes? If you take them to the opposite ends of earth, and open one box and find the blue ball, then the other one must be red, right? What’s the surprise in that? Ah, but if you think of it that way, you would be wrong. Quantum theory was needed because scientists realized that atoms and such could not be tiny versions of regular things like balls (page 8). Otherwise, atoms would explode and so on. To make theory fit with measurements, quantum theory had to take a radical step of proposing that certain physical characteristics, like polarity, could not have fixed values until they were measured.
So it’s not that one ball is red and the other blue from the start: both balls are a mix of “redness and blueness” until the measurement (the opening of and looking into the box) occurs. Then the observed ball “pops” (or quantum jumps) to red or blue and, of course, the other ball must “pop” to the opposite value.
But what does all this “nonlocal” talk mean? Well, Einstein and other physicists have long fretted that if we can’t isolate systems in space during experiments, and influences can travel across the universe in no time at all, then there is no point is doing physics at all (page 11). Something deeper than we know knits the fabric of the world together. But for now, we have no idea what this might be.
Musser uses “magic” coins as an example throughout the book: entangled coins, when flipped, will land both heads or both tails after they have been entangled and separated much more often than chance requires (page 103, among other places). This difference between chance and observation is known as “Bell’s inequality” because Irish physicist John Stewart Bell first formulated nonlocal effects for entangled photons and particles (pages 101-105).
I’m not sure coins are a good analogy for nonlocal effects. I read a very good explanation years ago that showed conclusively why there could be no “hidden variables” that explained the effect. In other words, Bell’s inequality showed that there can’t be little “arrows” attached to the photons that tell observers if the photon is up or down. The percentage of predicted matches in that case will not be the same as the observed percentage.
I realize I am being very opaque about these effects, but that’s because Muller is. There is a rule in publishing general science books today that you can’t mention math or show equations. You can talk about Bell’s inequality, but you can’t show it. I am not sure it’s possible to convey a real feel for “spooky action” without showing any math at all. But I guess it’s better than ignoring nonlocal effects and pretending that’s it’s not a problem for modern physics. (Some physicists shrug and say “it’s weird but who cares? It’s not like you can use it to communicate faster than light…” page 107.)
The real value of Musser’s book is that he not only tries to give readers a feel for the issue, but takes things a step further. He shows how nonlocality pops up not only in the case of purposeful entanglement, but in other contexts as well.
Once thought to be restricted to entangled photons and subatomic particles, Musser show how nonlocal effects seem to play a role in the way Black Holes operate. Black Holes cannot decay, it seems, by Hawking radiation without nonlocal effects making this energy escape possible (page 25). There’s no real surface to a Black Hole, which makes it difficult to decide what’s in and what’s out unless there are nonlocal effects. And without a nonlocal early universe, even with cosmic inflation, the Big Bang should not have left us with the pattern of cosmic microwaves that we see (page 33).
What would the new, nonlocal, physics look like? Musser spends the last sixty pages or so musing about a theory of “Quantum Graphity” (page 184) where space is more complex that a gird of points, and the the “Amplituhedron” (page 203), which bends time and space in new ways. A quote on page 206 from physicist Rafael Sorkin says “A star is closer than yesterday” and shows how far we have come from Newton’s mechanical universe.
Here’s something to think about when I talk about another popular scientist writing about physics next week: Maxwell’s equations. You don’t have to know anything about them for new, just know that the equations as we have them today are not the ones that Maxwell originally formulated (page 143). That’s because Maxwell originally allowed things like electric potential to get values from nonlocal effects. That bothered Hertz and others so much that they rewrote the equations as soon as they could to banish nonlocal aspects.
And that’s the thought I want to leave you with: nonlocal “spooky action” is scary to some, and they would rather “shut up and calculate” (page 20) and work around it than to address it head on and figure out what it is trying to tell us about the universe we live in.