Groundbreaking Quantum Physics Discoveries Show SOMETHING Is Traveling Faster Than Light

For a hundred years, physicists trumpeted the celestial speed limit. Einstein has shown, they said, that nothing travels faster than light. But for a generation now, there has been stunning experimental evidence that hints that some mysterious influences are traveling faster than light. Contemporary physics rests on two great pillars. Einstein's theories describe the large-scale structure of space and time. Quantum theory describes the small-scale behavior of matter within space and time. The behavior of molecules, atoms and other particles. Roughly, one describes the container and the other the contents. Although research continues, the two traditions are so much at variance that no one has been able to combine them into a single unified theory, or theory of everything. Quantum theory emerged piecemeal over many years, and its development was driven by experimental results and mathematical guesses. Like most committee efforts, quantum theory was a patchwork of conflicting motivations and strategies. There is one central obstacle to unification. Even today, no one really understands quantum theory. For many years, relativity and quantum theory led a peaceful coexistence. The mysteries of quantum theory were dramatized by a series of paradoxes, but the theory worked very well and never threatened to contradict and overthrow its rival. But now things are changing. Recent experiments are revealing that quantum theory is even more strange than expected. Sometimes it appears as a great conceptual black hole that sucks down into an every attempt to clarify the foundations of physics. Now, Einstein is threatened with Newton's fate. The theories of classical physics worked well at low speeds, but failed for objects traveling near the speed of light. Newton's theories got the predictions right in a limited domain, but were not fundamentally correct. In the long run, Einstein's theories may be celebrated for a host of startling true predictions, but relegated to history for their partial vision. The experiments that directly threatened Einstein's celestial speed limit involved measurements on pairs of particles some distance from each other. In short, the measurement on the first particle on the left mysteriously influences the other particle on the right. Wiggling the particle on the left produces a jiggle on the right. But the experiments show that any influence would have to travel faster than light. That is, the particles are far enough apart that a beam of light from the left-hand measurement cannot reach the right-hand apparatus until after it has completed its measurement and found the jiggle. What could cause this? Could some influence be traveling faster than light? The interpretation of every experiment in science rests on assumptions, and these claims are so astonishing that it is best to examine what lies behind them extremely carefully. In general, when an association or correlation between two events or measurements is found, there may be three explanations. First, there may be a mistake. Perhaps the association was merely an accident, a chance or spurious occurrence. If so, further repetitions of the experiment should reveal no further associations. Secondly, there may be a direct link. Measurements may reveal an association simply because the first event affects the second. Thirdly, however, there may be an indirect link between the events. Perhaps some third event occurring earlier sent out influences that created the later association between the pair of measured events. Philosophers say such events have a common cause. This momentous conclusion threatens to topple our understanding of relativity theory. The second argument reveals that it rests on several key premises. The first, B, seems safe. The second, that the association is not spurious, is also simple. The experiments were repeated at a dozen universities and the associations were consistently found. The last two, however, are quite strong and require comment. Everything depends on them. There is now a strong consensus among both physicists and philosophers that there is no common cause. The basis for this is a famous mathematical proof published by John S. Bell. His result was perhaps the most important development in the foundations of physics between Einstein and the current period of frenetic activity. Indeed, more than anyone else, John Bell triggered the progress now being made. All but a tiny minority of physicists now accept that his proof shows that no possible common cause could produce the observed measurements. The next premise gained dramatic support in experiments performed by Aspect and others at the Institute of Optics in Paris. Pairs of distant measurements within the laboratory were made extremely closely in time. Any cause, any force or wave traveling from one to the other could not complete the trip within the small interval of time between the measurements. Yet the associations between the pairs of measurements were still observed, just as in other experiments. Aspect's and succeeding experiments have provided direct evidence that no signals traveling slower than light could produce the associations. If the premises based on Bell's theorem and Aspect's experiments are as secure as they seem, there is no choice but to accept the revolutionary conclusion that something is traveling faster than light. Oddly, mainly mainstream physicists accept both Bell's and Aspect's work but resist this conclusion. How can this be? At first, there was widespread confusion and misunderstanding about Bell's theorem in the physics community. Many physicists had not studied the issue in detail and simply refused to believe that Einstein could be wrong. Even as younger physicists began to realize that quite profound progress of some sort had been made, they tended to give two sorts of reasons for discounting the above argument. First, everyone agrees that no energy or mass travels between the particles from one measurement to the other. Physicists tend to believe, with good reason, that everything that exists has mass and energy. Thus, they argue that if no mass or energy is transferred, nothing at all is transferred. This objection is countered by other physicists who argue that these experiments are very, very strange. They may be telling us that there are indeed things in the universe with no mass or energy, so-called pilot waves or information. No one has a clear idea about what these might be but clearly, the proponents say, something is producing the associated measurements in the experiments. Secondly, everyone agrees that no messages can be sent from one thing being measured to the other. Usually, a cause traveling through space, like a radio wave, is ideally suited to send messages and signals. But in these key experiments, no message can be sent. Many physicists believe that this is evidence against the existence of any faster-than-light causes. But this objection is mistaken. In quantum theory, the results of measurements are fundamentally random. These experiments cannot be used to input and output messages because the results of the first measurement is random. Since we cannot control the input to the system, we cannot control the output. It is a garbage in, garbage out, gigo effect. Thus, the failure to transmit the messages is due to quantum randomness and not necessarily to the absence of faster-than-light causes. Many or most mainstream physicists still deny that these experiments threaten relativity theory, but for reasons that seem weak. Philosophers tend to divide into two camps, some such as Arthur Fein and Bas van Fransen, except the curious associations but crudely put, say there is simply no explanation for them. They give various arguments but essentially say that explanation has here reached a limit. Nothing travels faster than light and nothing slower than light could produce the associations. And that is the end of the story. This position is made plausible by their general philosophical views but is obviously frustrating in this special case. Other philosophers hold that something is indeed traveling faster than light. The position was defended for years by the respected but eccentric physicist David Bohm and was carefully analyzed by Jim Cushing. In its various incarnations, this view has won serious reconsideration by philosophers and young physicists. The EPR experiments have momentous implications for the interpretation of relativity theory. In short, they favor Lorentz's minority interpretation. According to the mainstream interpretation, faster-than-light causation is impossible. There are several reasons for this. One is that the formula for mass increase suggests that anything approaching the speed of light would acquire infinite mass and energy. If the EPR measurements do instigate faster-than-light influences, then there is a lot of explaining to do here. Another reason is that faster-than-light influences would seem to make the paradoxes of time travel a real possibility. On the other hand, the minority interpretation can comfortably accommodate such influences. It says that only the present, only the absolute now of the ether exists. It, therefore, immediately rules out the time paradoxes. The past cannot be changed if it no longer exists. The minority interpretation insists that the relativity of simultaneity is merely apparent, an artifact of our measuring processes, and faster-than-light influences would favor this view. For a century now, Lorentz has been belittled for clinging to his deeper explanatory interpretation of relativistic physics. Physicists favored economy and observability over intuitive understanding. These EPR experiments may mark the rehabilitation of his more philosophical approach. The EPR debate has, however, produced one significant shift in recent presentations of the mainstream interpretation. It used to be common to assert flat out that nothing can travel faster than light. They say that no cause or no signal can travel faster than light. This sounds like a minor change, but actually opens up a loophole. The possibility that some things that do not transmit signals travel faster than light. I conclude this chapter with an odd historical footnote. These historic experiments, which provide the first credible evidence against the mainstream interpretation of relativity theory, were first proposed in 1935 by Einstein himself. As Einstein was developing his theory of special relativity, he also published some papers on the behavior of atoms and electrons. He also published some papers on the behavior of atoms and electrons. Some historians, like Thomas Kuhn, now say that these papers were the real start of quantum theory. Before Einstein, Planck had groped towards the basic concept, but it was Einstein who should be regarded as the founder of quantum theory. Einstein is thus credited by some historians with launching both the quantum and relativity revolutions. Later in his life, however, Einstein became quite disenchanted with the odd patchwork of ideas that the quantum theory had become. In 1935, he co-authored a now-famous paper with two younger physicists, Boldulsky and Rosen, which came to be known as the EPR paper. Clearly, this conclusion is an attack on quantum theory. Essentially, they're saying that because quantum theory conflicts with relativity, quantum theory must be nonsense. Most remarkably, however, they detail specific experiments in which quantum theory seemed to predict faster than light causation. These experiments are now known as EPR experiments. Partly because of his public attack on quantum theory, which was then both successful and fashionable, Einstein became a sad and isolated figure. For the last 30 years of his life, he was often regarded by other physicists as a has-been and became the subject of widespread jokes. Even his attack on quantum theory was misunderstood and trivialized. The story circulated widely that Einstein had an old-fashioned mental block against randomness in physics. His line that God does not play dice served as a caricature for his views. In hindsight, Einstein knew long before others that the key issue was these spooky faster-than-light influences. But even his best friends, like Max Born, could not follow Einstein's reasoning and chided him for being so confused. In 1964, 30 years after the EPR paper, it was John Bell who revived Einstein ideas and crucially pushed physicists towards conducting the experiments that Einstein had proposed. Even then, however, Bell's paper was lost by the journal and not published for two years. Almost 15 years passed before Siric's experiments were performed in the early 1980s. These EPR experiments proved that Einstein's premise A was probably correct. Although Einstein has had the last laugh, it may be small comfort. In the long run, quantum theory may undermine relativity theory. We will remember Einstein not for positively creating his own theories, but for his penetration into the quantum theory's mysterious destructive power. The most exciting and profound new physics, the first glimpses of 21st century physics, are now coming from astronomy. Stunning new, super-sensitive instruments and dazzling theoretical models have combined to squeeze revolutionary data from the faintest observations. From satellites in outer space and camps 800 meters from the South Pole, astronomers are mapping the shape of space and reaching back to the birth of time. Despite its many successes, the Big Bang model led to some new, deeply perplexing puzzles. Suppose our telescopes look at very distant objects in opposite directions. They might be so remote that nothing could travel from one to the other. Even at the speed of light, the journey would take longer than 15 billion years since the Big Bang. Yet the universe in opposite directions looks pretty much the same. In fact, it is exceedingly uniform. The cosmic microwave background, for example, comes to us from the farthest corners of the universe, but is the same whichever way we look, to within one part in 10,000 or more. This is suspicious. What could have coordinated or matched conditions and regions so far from each other? Since this coordination seems to have extended beyond the horizon that light could reach, it was called the horizon problem. There are other big problems. Imagine throwing a stone straight up into the sky. Three things might happen. Ordinarily, the stone will rise upward, slow down and fall back to Earth. If it were thrown up with enormous speed, however, it would escape Earth's gravitational pull and zip out to infinity. Balanced between these two possibilities, there is a third. If the speed were exactly right, the rock might be slowed down by gravity, but never quite enough to make it fall backwards. Its speed would be slower and slower. Far above Earth, where its gravitational field becomes even weaker, the rock would barely crawl upwards, but still manage to continue on toward the stars. Like someone traveling at one kilometer per hour, then a half, then a quarter, and then an eighth of a kilometer per hour, the rock would go slower and slower, but never stop altogether. Obviously, this third scenario is extremely unlikely, and depends on the stone's initial speed being exactly on the knife edge between falling back and escaping to infinity. The Big Bang hurled all the matter and energy of the universe outwards, and, likewise, there are three possibilities for what might happen next. First, the matter might expand outwards and then fall back. The Big Crunch. Second, it might expand outwards, forever, until all the matter and energy were thinly dispersed in a cold and dark infinite space. Heat Death. Thirdly, if the critical balance were exactly right, the universal expansion might slow down to a crawl, but never quite fall back. In this case, the universe would become more and more stable. As the mass-energy became more evenly distributed, the curvature of space would become flatter and flatter. The Flat Universe. The problem is that this last scenario is extremely unlikely, but astronomical observations indicate that our universe is indeed flat. How could a huge, violent, turbulent explosion be so finely poised between the Big Crunch and Heat Death? Some call this the Fine Tuning Paradox. In 1981, Alan Guth, a young physicist, then at Stanford University, proposed a wild theory that would resolve both these and other outstanding problems with the Big Bang in one fell swoop. In a word, he proposed that, early in the first second of the universe's existence, the framework of space-time expanded extremely quickly. Like a balloon suddenly inflated to a gargantuan size, the universe puffed outward in an instant. This process was dubbed inflation. It is not a rival to the Big Bang theory, but a modification and addition to it. Guth suggested that the distance between any two points would expand at a rate faster than the speed of light. This does not mean that anything, any mass or energy, traveled faster than light. At each point, light would still travel along at 300,000 kilometers per second, but there might suddenly be much more space between it and its source. The distance between any two points would be stretched extremely quickly. After this brief burst during the initial explosion, the universe would settle down into the steady expansion discovered by Hubble. Inflation would solve the horizon problem because things that are now extremely far apart and mysteriously coordinated were once cozy neighbors. This would also solve the flatness problem. Just as any region on a balloon's surface becomes flatter as it inflates, the process of inflation drives the curvature of space to near-perfect flatness. Although it would solve several puzzles about the Big Bang, many cosmologists were skeptical about this extravagant idea. Although Guth had been led to the idea by applying accepted physics to the early universe, the whole seemed rather speculative. The world keeps surprising us. The great advantage of the inflation hypothesis is that it not only predicts that far-flung regions of the universe will be uniform, but it makes quantitative predictions about the minute residual departures from uniformity. Extremely tiny fluctuations in the microwave background radiation were measured in the early 1990s by the COBE satellite and were an astonishingly close fit to the predictions. There were still many doubts about inflation among physicists, but in 2000 there were several new and historic reports of observations that further supported the inflation model. Astronomers and physicists triumphantly celebrated the combined achievement of their far-reaching theories and high-precision measurements. Inflation is now probably accepted by most of them and will be taught as part of the standard Big Bang theory. Just as it seemed as if contemporary physics were penetrating the innermost secrets of nature, in 1998 astronomers made a preposterous announcement. The observations were so bizarre and so unexpected that most scoffed at them. It was widely expected that more data or more careful analysis would expose some mistake, when in 2000 and 2001 more observations were reported. However, they in fact strengthened the case for the first, absurd claim. There is no agreement yet about how to explain these mysterious observations, but if correct, they throw the foundations of physics into turmoil. Physicists have been heard to whisper that to make sense of it all, we need a new Einstein. Imagine that our stone is again thrown overhead, arches high into the sky and then accelerates out of sight. That would be absurd. Gravity is pulling the stone downward. It should be losing energy. How could it speed up? But astronomical teams based at the University of Berkeley and Harvard University have announced just this. The Big Bang threw all the matter in the universe outwards. Both Newton's and Einstein's theories of gravity predict that the expansion must be slowing down to some degree. The mutual gravitational attraction of all the matter in all the galaxies should be pulling them inwards. But measurements of distant supernovae show just the opposite. All the matter in the universe appears to be accelerating outwards. Its speed is picking up. This new acceleration is entirely different from inflation. Inflation is a brief expansion of space-time that lasted for an instant during the primordial fireball. If the galaxies are even now accelerating away from each other, some new force acting over long distances is at work. This new force would apparently be as permanent and real as the other known forces. But what force could be strong enough to push all the matter in the whole universe outwards? Are there new kinds of forces that our physics knows nothing of? Where would the energy come from? Could there be something outside the universe that is attracting our galaxies? Is general relativity just wrong altogether and a misleading guide to the interpreting these observations? Since ordinary mass produces gravitational attraction, and since mass is energy, physicists say that energy produces attraction. Thus, the new mysterious repulsion, the new push outwards must, they say, be produced by negative energy. The paradoxical name is really just a label for the mystery. There is no consensus about what new physics will be needed to explain our accelerating universe, and some perhaps still hope that the observations are some kind of error. We return to Einstein again. In 1917, two years after completing general relativity, Einstein applied the theory to the question of the shape of the universe. At that point, however, he believed that the universe was more or less stable. This was a holdover from the traditional belief in the fixed stars. His theory kept contradicting this belief. As the mass and energy in the universe moved around, the shape and curvature of the universe altered too. Einstein's theory was predicting that the universe would evolve and change over time. Reluctantly, Einstein published a paper showing how his theory, born of so many difficult years of struggle, would have to be modified. In brief, he showed that the theory could be tweaked or fudged to counteract any expansion or contraction of the universe. By adding an entirely new variable, he could stabilize the universe. He called this the cosmological constant. When Hubble discovered the expansion of the universe a decade later, in 1929, Einstein was red-faced. If he had believed his beloved theory, he could have predicted Hubble's historic discovery. He deleted the cosmological constant from his equations and said it had been the biggest mistake of my life. What goes around comes around. Now that physicists are struggling to make sense of our new inflating and accelerating universe, the cosmological constant is suddenly back in vogue. By reinserting the constant in the general theory of relativity and twiddling it up and down, physicists can make their theory match both inflation and the new acceleration. As one physicist said, the constant has become a panacea, a universal cure for all cosmological puzzles. In fact, to counteract a contracting universe, the cosmological constant would represent just the sort of negative energy needed to explain the observed acceleration. Thus, it may be possible, by restoring the constant to Einstein's theory, to extend the theory to handle the new observations. Einstein's biggest mistake may be the new physics of the 21st century. Time will tell. Anyone hauling a boulder to the top of a skyscraper and dropping it to the street below would expect the catastrophic impact. Flying shards of rock and road, streaks of spark and smoke, the clap and crack of the reverberating bang. Similarly, when a planet, comet, or any other material falls into a star, the resulting explosion is often dramatic. It can produce blinding flashes, bursts of high-energy X-rays, and gigantic glowing flares of fiery gases. But, in early 2001, astronomers observing a strange object 6,000 light-years from Earth with the orbiting Hubble telescope reported that they had seen the opposite. Massive clumps of hot gases, many times larger than Earth, were being sucked down into a large, invisible object. As they raced downward, the accelerated adjostling heated them, and they glowed and pulsed with incredible energies. Then, nothing. The gases just disappeared. There was no explosion, no flashes, no flares, just nothing. Einstein's theory of general relativity predicts the existence of black holes, bodies so dense that their gravity captures everything close by and prevents it from escaping. Not even light, the fastest and most nimble signal known, can climb up and away from a black hole. They are colorless, invisible, wholly black patches in the sky. For this reason, physicists doubted for many years that black holes could ever be seen at all, and if they could not be observed, they doubted they were a serious part of a empirical science. For many, they were just science fiction. Since the 1970s, evidence has slowly accumulated that black holes do exist. Nonetheless, all the observations were necessarily indirect and circumstantial, and skeptics insisted that other interpretations of the data could not yet be excluded. In the past few years, however, the richness and variety of observations have sharply strengthened the case. Many people feel there is now overwhelming evidence that black holes exist and are common throughout the universe. The Hubble observations of the disappearing gases were, for one recent example, widely regarded as the tell-tale signature of a black hole. Nothing else could have so completely swallowed and contained such a violent explosion. The formation of black holes can be understood in a simple way. The parts of any body attract each other with a very tiny gravitational force. Usually, other forces keep the parts apart and ensure that bodies remain stable. But consider a star shining in the night sky. It is mostly a kind of gas composed of very simple atoms. In its dense center, these atoms bump into each other and fuse together in many nuclear explosions. These generate the heat and light that make stars so hot. Since heat causes expansion, the energy release pushes the atoms in the stars outward. Thus, the star is stable because of a certain balance. Gravity pulls the atoms together. Some of them collide and explode, and the resulting energy pushes the atoms away from each other. The inward and outward forces are in equilibrium. Over billions of years, however, the star will burn up all its atomic fuel and become dim. With fewer explosions inside, gravity will gradually win the war and compress the star further and further. In very large stars with enormous numbers of atoms pulling each other inwards, no other processes are able to resist the force of gravity, and the star will shrink until it is very tiny. Although the gravitational pull of a single atom by itself is very weak, many atoms concentrated in a small space exert gigantic forces. These would be so strong on our tiny star that nothing could escape its grasp. It has become a black hole. Even light cannot be reflected off such an object. A portion of any light that struck it might bounce off and begin to race away. But the gravitational pull would be so great that, like a ball arcing upwards and falling down again, the light would gradually turn around and be reabsorbed. This is what makes black holes invisible. Even though general relativity predicts black holes, Einstein always denied their existence. He repeatedly sought to find physical principles that would block their formation. We can get a glimpse of his reasoning by returning to the rubber sheet analogy for curved space. A weight on the rubber sheet will bend the rubber downward and produce a deep well. Crucially, if the same weight is compacted into a smaller space, it creates an even deeper well with steeper sides. This is because there is less rubber directly under the weight and supporting it, and less rubber that needs to be stretched downward. This can be compared to pushing down on a thin sheet with the flat of your palm and your fingertip. The latter creates a deeper hole with the same force. According to general relativity, gravity will compress some stars into even smaller and smaller spaces. This means that the wells in the rubber sheet get even deeper and narrower. Eventually, as a star shrinks, the curvature of the well will become infinitely steep. Thus, a black hole is called a singularity, which means that the numbers describing it have all gone off the scale and become infinite. When the numbers in their equations blow up and become infinite or develop other pathologies, mathematicians say they have become singular. What does it mean to say the curvature of the well in the rubber sheet has become infinite? The short answer is that no one really knows. We can imagine this as a rip or rupture in the rubber sheet, a place where it is no longer smooth but suddenly has no definite depth, no steepness that we can measure and assign a finite number to. This is probably what set Einstein so firmly against black holes. His theory made the curvature of the space-time the most basic thing in the world. He pictured the curvature of a continuous and smooth and gave equations that precisely described its flexing. A black hole is not only physically bizarre, but it also represents some kind of breakdown in general relativity. Although the theory predicts that large stars will be endlessly compressed and form black holes, it cannot describe their ultimate infinite state. Einstein's theory cannot reach into the central core of a black hole. Zeno's paradoxes entangle Greek philosophy and paradoxes of the infinite. Here we see infinity rearing its head again in our most advanced science. Einstein believed that if black holes were real, if actual infinities infested his space-time curvature, his theory would be wrecked. They would show that space-time curvature was not basic, or that it came to an end where it was not defined, or that there was something beyond space-time. He died believing that predictions of black holes were some kind of miscalculation, some minor misunderstanding that future generations would put right. Thus, the confirmation of the existence of black holes has created an important mystery for interpreters of general relativity. If black holes are real and physical, then probably actual infinities are too. In fact, the physicists Stephen Hawking and Robert Penrose proved theorisms in 1970s that roughly say that singularities are inevitable and unavoidable. Since then, physicists have begun to grapple with the meaning and mathematics of these infinities more seriously. Einstein is surely right that whatever the technical details of a definition of space-time singularity, it should follow that physical laws, insofar as they presuppose space and time, are violated or, perhaps more accurately, do not make sense of singularities. This is good reason for holding that singularities are not part of space-time. Harriman goes on to say, however, that singularities are not a breakdown in general relativity. The theory works well in ordinary smooth space-time. Singularities can be regarded as the boundary of space-time, as its endpoints, and perhaps we should not hold it against general relativity that it fails there. Contrary to Einstein, I do not think the fact that general relativity predicts space-time singularities is necessarily a cause for alarm, and I certainly do not think the prediction of singularities is a signal that the theory self-destructs. In sum, Ehrman argues that singularities can be quarantined. They exist and are predicted by general relativity, but will not infect those regions of space-time free of infinities. Einstein believed that his theory described the ultimate reality. Thus, suggestions that general relativity works only in certain portions of the universe are catastrophic. Ehrman reflects the views of many contemporary physicists. They expect that general relativity will someday be superseded just as Newton's theories were. Both Einstein and Newton were correct, but only in limited domains. Someday, they believe, a quantum theory of gravity will replace general relativity and, they hope, make sense of singularities. In the meantime, the hunt for black holes has produced new and breathtaking evidence that they exist, are common, and are sometimes unimaginably huge. Astronomers distinguish between black holes that weigh about as much as our sun and supermassive black holes. For example, there is a powerful source of X-rays called Cygnus X-1. This system wiggles and gyrates in a way that suggests it is a pair of bodies rotating around each other. One of them, however, is invisible. Observations suggest that it is a black hole weighing about 10 times the size of our sun. This is puny, however, compared to the monsters detected at the centers of galaxies. Galaxies are great, swirling collections of stars that are brighter and more concentrated near their centers. In recent years, compelling evidence has emerged that stars attracted down into the centers of galaxies conglomerate into black holes. These weigh a million or a billion times as much as our sun. The black hole at the center of our own Milky Way galaxy is 3 million times as massive as the sun.