by Bob Berman
Old textbooks say that the sun and Earth move together through space at just thirteen miles a second. That’s because, not too long ago, we were only aware of our motion relative to the stars surrounding us. Imagine a group of floating leaves rushing down a river’s rapids. One leaf has a bit of a slow, sideways drift relative to the others. That’s what those old books talked about. Like adjacent horses on a carousel, the stars in the night sky—which on average are just 150 light-years away—partake of the same motion we do. So they don’t seem to move much, relative to us. Observing them, we seem to be slowly drifting at thirteen miles per second toward the star Vega (some authorities peg it as the constellation Hercules in that same part of the sky). However, we know now that we, Hercules, and Vega all simultaneously rush crazily forward at 140 miles a second in the direction of the star Deneb, which we’ll never reach, because it’s moving ahead at the same rate.
Although this ultimate sensible motion of our world unfolds ten times faster than our best rockets, it’s still just one-thousandth the speed of light.
CHAPTER 17: Infinite Speed
When Light’s Velocity Just Won’t Get You There
I could be bounded in a nutshell, and count
myself a king of infinite space,
were it not that I have bad dreams.
—WILLIAM SHAKESPEARE, HAMLET (CA. 1600)
There’s fast, and then there’s infinite.
Plenty of things are fast. All the atoms around us vibrate trillions of times a second. Photons in fiber-optic cables completely circle the earth in a literal eyeblink. Distant galaxies whoosh 150,000 miles farther away each second.
Infinitely fast is a different ball of wax. It would mean that something leaving the farthest galaxy just as you reach this point of the sentence is now already in Kansas. We always thought such superluminal speeds were impossible. We were wrong.
Infinity’s exploration requires a quick peek into the intriguing realm that surrounds light speed, which seemed like the absolute limit when many of us went to school.
In 1905, Einstein explained a wild observation made two decades earlier by Hendrik Lorentz and George FitzGerald. They had realized that light travels at a constant speed and understood how profoundly remarkable this is.1
It means photons from the landing lights of an approaching jet strike you at light’s unwavering rate of 186,282.4 miles per second, as if the plane weren’t moving at all. Right from the get-go, light starts out as unique and nonintuitive.
Moreover, Einstein showed that objects that have weight can never quite reach light’s speed. In a hypothetical ultrapowerful rocket, as you accelerate your mass increases. You magically get heavier and heavier. At just below the speed of light, even an object that started out lighter than a feather would outweigh the entire universe. The energy needed to accelerate it the final tiny amount would be infinite. Hence you could never achieve that speed.
After Einstein set forth his two relativity theories in 1905 and 1915, light’s sovereignty in a vacuum was no longer seriously challenged. Yet bizarre escape clauses started to show up during the ascension of quantum mechanics in the 1920s.
This is a Wonderland realm where objects don’t quite exist until they’re observed. There are two main competing theories attempting to make logical sense of this. The first is the “many worlds” explanation for quantum phenomena. This maintains that each option in life creates a separate universe that then carries on. The moment an alternative possible action exists for anything—even if you observe a falling leaf landing here but not an inch away—the cosmos divides into separate realities to accommodate both outcomes.
If you measure an electron, you’ve deliberately or unintentionally forced it to appear in a particular place with particular properties, such as an upward spin versus a downward spin. Or, to be more accurate, you have suddenly joined the universe where it exists in the state you observe it to be. But different yous also exist, inhabiting separate universes, where they each observe the electron in all the other places or states that were then possible.
By this reasoning, some other version of you really did take the prettiest cheerleader to the prom. Unfortunately, one analogue of yourself was a jerk that night (remember, if it could happen, it did happen), and she never spoke to that version of you again.
Most theorists and science professionals do not buy into all these simultaneous realities. Instead, the majority prefers the Copenhagen interpretation. This does away with multiple realities but says that the universe is filled with particles and bits of light that have no definite existence, location, or motion until they are observed. Only then does their wave function collapse, and only then do they materialize in a statistically determined place and continue to exist there happily from that moment on.
Einstein didn’t like any of this. In 1935, he and two colleagues, Boris Podolsky and Nathan Rosen, wrote a now-famous paper in which they essentially bad-mouthed quantum theory as fundamentally incomplete and thus seriously flawed and addressed an aspect of quantum theory that was bizarre even by quantum standards. They pondered what happens to particles created together, or “entangled.” According to quantum thinking, the pair of particles then shares a wave function, and each object knows what the other is doing. If one is observed, forcing it to leave its blurry, probabilistic wave-function state and collapse into an electron with an “up”-pointing spin, its twin—no matter where in the universe it happens to be—knows what its doppelgänger did, which causes its own wave function to collapse. It instantly becomes a particle with complementary properties, in this case a “down” spin.
The easy way to create such entangled pairs is to shoot a laser into beta barium borate or certain other crystals. Suddenly two photons emerge, each with half the energy (twice the wavelength) of the original, so there is no net energy gain or loss. These two then head off at the speed of light, possibly for billions of years, to lead seemingly independent lives. The same process holds true for entangled solid objects such as electrons and even whole atoms and clumps of material.
But let one member of the duo collapse into a particular state, and its twin knows this is happening and instantly does the same.
Einstein, Podolsky, and Rosen argued that such apparent parallel behavior must be attributable to local effects, a contamination of the experiment, rather than some sort of “spooky action at a distance,” as they called that aspect of quantum theory. Their paper was so celebrated that such synchronized quantum antics borrowed the physicists’ initials and became known as EPR correlations. And the line “spooky action at a distance” became the standard pejorative way of describing such an outrageous and silly belief—a put-down of true instantaneous behavior. It was repeated in dismissive fashion in physics classrooms for decades.
But recent experiments show that Einstein was wrong. In 1997, Geneva researcher Nicolas Gisin created pairs of entangled photons and sent them flying apart along optical fibers. When one encountered the researcher’s mirrors and was forced to go one way or another, its entangled twin, seven miles away, always instantaneously acted in unison and took the opposite, complementary option when encountering its own mirror.
Instantaneous is the key word. The reaction of the twin was not delayed by the amount of time light could have traversed those seven miles to convey the news. It happened at least ten thousand times faster, which was the experiment’s testing limit. Quantum mechanics tells us that the echoed behavior should indeed be perfectly simultaneous. Indeed, quantum theory predicts that an entangled particle knows what its twin is doing and instantly mimics its actions, even if the pair lives in separate galaxies billions of light-years apart.
This is so bizarre, with implications so enormous, it drove some physicists to a frantic search for loopholes. Some argued that Gisin’s testing apparatus had a bias and preferentially was detecting only those particles that exhibited the complementary properties expected of twins. Then in 2001, National Institute of Standards and Technology resea
rcher David Wineland eliminated these criticisms.
Wineland used beryllium ions and a very high detector efficiency to observe a large enough number of events to seal the case. So this fantastic behavior is a fact. It’s real. But how can a material object instantly dictate how another must act or exist when the two are separated by large distances? Few physicists think that some previously unimagined interaction or force is responsible. Striving to understand, I asked Wineland what he believed, and he expressed an increasingly accepted conclusion.
“There really is some sort of spooky action at a distance.”
Of course, we both knew that this clarifies nothing.
So particles and photons—matter and energy—apparently transmit knowledge across the entire universe instantly. Light’s travel time is no longer the limit.
Some physicists say that this does not violate relativity because we cannot exploit this to send information faster than light, since the “sending” particle’s behavior is governed by chance and not controllable. Moreover, nothing of any mass is making the journey. Indeed, nothing weightless, even a photon, is making that infinite-speed journey, either. But something is being conveyed instantaneously.
The scientific (not to mention philosophical and metaphysical) implications are astounding. Let’s say some of the atoms in your body originally formed in an entangled manner with other particles soon after the big bang. Since then, both have been flying apart, and now they are separated by billions of light-years. Your atoms make up pieces of your brain, which is physically located in Peoria. Those other particles have become part of an alien on a planet in the fashionable Aldebaran system.
Right now, some creature there is observing your twin’s atoms in a lab. Bingo, they collapse to exhibit specific properties. Instantly, with no delay whatsoever, your own brain’s atoms know this is happening five billion light-years away, and they, too, collapse into complementary objects. The effect is sudden and alters your thought processes, and you make a snap decision. You show up at your boss’s party wearing an embarrassing polka-dot tuxedo. You can’t explain why you acted so oddly, but your life is ruined. This seems like science fiction, but EPR correlations are real.
First it means that the entire universe is a single entity in some fundamental way. It means there are no secrets between locations here and those far away, no matter how distant—and that the information “exchange” happens simultaneously, at infinite speed.
It means that Einstein was dead wrong about locality.
Locality is important in any exploration of motion. After all, movement always implies that things are pushed, propelled, or jostled by other objects or forces, such as wind, water, and gravity. This is what Einstein believed—that an object is influenced only by its immediate surroundings. It’s called the principle of locality.
A kind of supplementary principle is local realism. This means that all objects have actual properties independent of any measurement of them. An atom, or the moon, is really “there” in some location, and with a definite motion, regardless of whether people are observing it. It’s our job, if we’re so inclined, to set up ways to learn about this object and to measure its properties.
Contrast this with quantum theory, which denies locality. It insists that an atom can be influenced by events (such as its entangled twin’s wave function collapsing) that are not only utterly out of contact with it but on a different side of the universe. And that such influences occur instantaneously. No “carrier particle” is necessary to bring the news or effect the influence from one place to another, nor is the influence limited to some speed, even the speed of light. Instead it jumps in less than an eyeblink from distant empires.
As for local realism, quantum theory does away with that, too. Its popular Copenhagen interpretation insists that the entire universe is made of countless particles such as electrons that have no inherent location. Nor do they have any motion. In a real sense, they do not even enjoy any form of true existence. They instead dwell in a kind of blurry probability state of potentiality, with tendencies that are statistically decipherable. Upon observation, they materialize according to probability laws.
Einstein indeed hated this. It meant that nothing existed or moved unless observed. It also meant that no one could pin down the actual behavior of individual objects—we could only speak about them statistically as a group and assess the likelihood of them being here but not there or moving this way rather than that. This is what caused him to utter his famous antiquantum line, “God does not play dice.”
If we set up an apparatus that allows us to detect a particle’s location, the object obligingly materializes in a particular place. Yet it still doesn’t have a specific motion. But if we instead construct a device that can detect motion, we duly observe the entity to be moving, and yet its position at any given moment is blurry and poorly defined. We can’t precisely see its location and its motion.
At first scientists thought that this must be a result of some technological immaturity on our part—that if our equipment got better, we’d be able to pin down the motion and the location, the way we can with large bodies, such as Saturn. Eventually we came to see that the problem lies much deeper. The small entities that make up everything in the cosmos do not each have a location or a movement. Moreover, only our act of observation brings one or the other into existence.
The reason large macroscopic objects do appear to dwell in specific places and have motion is because they’re composed of so many countless small objects that the overwhelming probabilities of each yield a statistically certain collection in the spot we’re observing.
That statistical business is wild, too. While objects normally appear in the most likely places, there’s always a tiny statistical chance they’ll behave oddly. That they’ll materialize far from where they’re expected.
Consider a newly paved road with a fresh temporary covering of gravel. Passing cars cause each stone to jump into the air and land somewhere. There’s a fifty-fifty chance that a rock being popped up by a tire can go toward the road’s edge as opposed to bouncing toward the center. The ones that happen to go toward the edge now have a fifty-fifty chance of flying even farther toward the edge when they’re popped up by the next car. Over time, all these probabilities play out, and the road is totally clear of gravel. It’s all now entirely off the edge—because once a rock is removed from the road the game ends for that rock, which doesn’t move anymore. When enough tires have passed, even the pebbles that defied the odds and kept improbably bouncing back toward the center have finally yielded to a series of edge-oriented jumps. The proof is right there: a mere two weeks after the road opened to traffic, no gravel remains. Given enough time, all statistically possible events come to pass, even unlikely ones.
But look closely. Here is one rock that somehow caught the edge of a truck tire, was scraped by an adjacent stone in a very unlikely way, and was propelled hundreds of feet into someone’s bird feeder. This single act would probably not have been predicted. It was extremely unlikely. But it was possible. And given enough time, if there are enough objects involved, all possibilities, no matter how remote, come to pass.
In quantum theory’s Copenhagen interpretation, a milk container in your fridge contains particles whose locations are blurry and probabilistic. It’s made of many more atoms than the number of gravel stones on a road. (A one-gallon milk container contains the same number of atoms as there are lungfuls of air in Earth’s atmosphere.) When you next open the fridge, it is extremely likely that all the container’s atoms will be present and that the carton will be sitting where you placed it the night before. Even if one atom materializes somewhere else it would not affect the container’s existence on the same shelf as the one where you remember placing it. But it is possible, not impossible, that all the atoms will materialize in a most statistically unlikely location. If so, the container will be gone. Perhaps it will suddenly appear in a bedroom in Myanmar.
The chance of all those p
articles acting in unison in so statistically improbable a way is so small that it is unlikely to happen even in the five-billion-year bionic lifetime of the planet—the period from first bacteria to eventual sterilization. But the point is: it could happen. If it does, we see an apparent miracle. We have then observed motion without any apparent cause.
So this crazy stuff is true. The observer and the universe go together. And occasional impossible motion is not impossible after all.
Since quantum mechanical behavior and most of the motions discussed in this book involve random activity, it may be worth taking a moment to examine the power and limits of randomness. The usual clichéd example is the monkeys-and-typewriters thing. You’ve probably heard it: a million monkeys typing for a million years would eventually create the works of Shakespeare just by random chance. Is it true?
In 2003 a research team at a university in England placed a bunch of typewriters in front of a group of six macaques in a zoo enclosure for a month to see what would happen. The animals typed virtually nothing. Instead they pushed food and dirt into the keys, threw some of the machines on the ground, used them as toilets, and quickly rendered all the devices useless. They didn’t create any written wisdom whatsoever.