KILLING THE EXPERIMENTER
IN MY HIGH SCHOOL CHEMISTRY CLASS, THE MOST EXCITING MOMENTS always came when the teacher performed an “explosive” experiment to get the class’s attention. One such experiment that I recall fondly involved slicing a bit of metallic sodium from a bar of sodium immersed in a murky fluid and then dropping it into a flask of water. The reaction immediately separated the water molecules into their components, hydrogen and oxygen. It also generated a lot of heat. What made the experiment memorable was that the teacher obviously miscalculated the amount of sodium to be used, as the heat in the reaction, together with the oxygen, ignited the hydrogen, leading to a big explosion that broke the glass containing the water and put a huge circular burn mark on the ceiling of the lecture hall. Luckily, no one was hurt in this experiment gone awry. But it was the end of that type of attention getter for the remainder of the semester and serves well to illustrate the idea of an experiment that might easily have killed the experimenter.
While small potatoes as an existential threat, a high school chemistry lab experiment like this going astray is a good example of how complexity can rise up to bite you with potentially disastrous consequences when you’re not looking. In this case, we see the butterfly effect in action whereby a small miscalculation on the part of the teacher as to the amount of sodium to be used in the experiment led to a runaway reaction that didn’t quite either blow up the lab or kill the teacher but quickly sobered up everyone in the room.
So just like the ice-nine experiment in Vonnegut’s book Cat’s Cradle, which I detailed in Part I, playing with forces of nature that you don’t quite understand can be very dangerous to not only your own health, but to that of everyone on the planet should things go totally off the track.
Another such experiment on a vastly greater scale was the first atomic bomb test at Trinity site near Alamogordo, New Mexico, on July 16, 1945. As early as summer of 1942 in Los Alamos, Edward Teller, one of the scientists developing the bomb, expressed concern that the enormous temperatures generated by the explosion might set fire to the earth’s atmosphere. Just envisioning this gigantic, two-hundred-yard-wide mushroom cloud might well convince a person to take seriously the idea that the entire planet might just possibly be consumed in such a monumental fireball.
Despite the fact that the blast would generate temperatures hotter than those at the core of the sun, most of Teller’s colleagues felt his idea of a self-sustaining fire being ignited in the atmosphere was a very remote possibility. The director of the Manhattan Project, J. Robert Oppenheimer, called for a study of the matter. The report, publicly available only since 1973, confirmed the skeptics’ view that a nuclear fireball cools down far too rapidly to set the atmosphere aflame. But there was another threat hidden in that test.
Little was known about the dangers of radiation exposure in the 1940s, so local residents near the Trinity site were not warned or evacuated in advance of—or even following—the test. As a result, people in surrounding areas were exposed to radiation by breathing contaminated air, eating contaminated foods, and drinking affected water and milk. Some ranches were located within fifteen miles of ground zero, and commercial crops were grown nearby. At some of these ranches, exposure rates were measured shortly after the blast showing levels of about 15,000 millirems per hour, more than ten thousand times greater than what’s now considered to be safe. Even today, a one-hour visit to the Trinity site will lead to an exposure level of 0.5 to 1.0 millirems, which is about the amount of radiation a typical adult receives daily from natural and human sources, like X-rays and radioactive elements in the soil.
Physicists expressed concerns of a similar nature when the first sustained nuclear reaction was established in December 1942 by Enrico Fermi’s group under the abandoned west stands of the football stadium at the University of Chicago. Fermi had convinced the scientists that there could be no runaway nuclear reaction and that the city of Chicago was “safe.” Nevertheless, historians from the Atomic Energy Commission noted that it was still a “gamble” to conduct such an experiment with totally untested technology at the heart of one of the country’s largest cities.
Even though the nuclear test in New Mexico did not really threaten life on Earth, at least not by burning up the atmosphere, the consideration that that might happen is the first time in history that scientists seriously looked at whether their work might destroy the planet. As technology has moved forward at an ever-accelerating pace, these same sorts of fears continually appear and reappear. Their most recent manifestation is that the planet might be sucked into a man-made black hole or disappear in a shower of even stranger particles emerging from the gigantic particle accelerators at Brookhaven National Laboratory in the United States and at the European Nuclear Research Center (CERN) on the Swiss-French border outside Geneva. The basic question that arises whenever a new machine is built, generating ever more violent collisions of the elementary particles circulating inside its rings, is whether those violent collisions could spawn some kind of particle or event that would somehow “vacuum up” the earth—or even the entire universe. In particular, the fears circulating around the Large Hadron Collider (LHC) that went into service at CERN in late 2009, were that a particular form of a really strange particle aptly called a “strangelet” would just appear and a moment later the earth would just disappear.
Before digging just a bit deeper into why some feared such an outcome from the LHC, it’s of more than passing interest to examine why we build such potentially dangerous and definitely expensive “toys” like these particle accelerators in the first place. They are without doubt the most expensive laboratories ever created, and they represent the leading edge of technology. So what are we expecting to gain from such a gigantic investment in brainpower, engineering dexterity, and just plain hard cash?
SOMETHING—OR NOTHING?
THE 1960S WAS AN ESPECIALLY ACTIVE DECADE FOR THEORETICAL physicists advancing models to encompass all that was known about matter, energy, and everything else. Further development of this work has led to what today is termed the “theory of everything,” which is meant to embrace in one compact mathematical theory the workings of the many particles and forces that govern the universe, explaining how it began and how it will end. But there is still a missing link in this so-called Standard Model, an as-yet-unobserved elementary particle called the Higgs boson, which explains how matter comes to have its mass.
When British physicist Peter Higgs postulated such a particle in the early 1960s, his suggestion was met with derision by most of his colleagues. Today, the betting odds are that one of the triumphant products of the LHC will be the first actual observation of this elusive object. If CERN physicists can really find the Higgs boson, the Standard Model that the vast majority of physicists believe in today will be confirmed—and Higgs himself, who is now pushing eighty years of age, will have his crowning moment of personal and professional vindication.
Higgs developed his theory to explain why mass disappears as matter is broken down to its elementary constituents. His theory claims that at the very moment of the Big Bang, matter had no mass at all. And then it instantly gained it. The question is, How did this process work? Higgs argued that the mass must be due to an energy field that clung to the particles as they passed through the field of the Higgs particle and that gave them mass. That mysterious particle is now often termed the “God particle,” a label Higgs himself dismisses, especially as he professes to be an atheist. But without such a particle, stars and planets would never have formed since the matter created at the Big Bang would simply have moved off into space and never gravitated together to form massive objects, or for that matter, into organisms like you and me.
So confirmation of the existence of the Higgs boson is the first order of priority for the LHC. But scientists caution that even if the God particle is actually there, we may not see it. The process by which the particle gives mass to matter happens so fast that it may be buried in the data collected from the LHC and could take many years of “data mining” to find.
But the Higgs boson is not the only treasure that may pop up from the LHC once it’s up and running at full strength. Another possibility is that the collider will turn up evidence supporting the most theoretical of theoretical ideas in modern physics, string theory. There is a vocal community in the world of physics who argue that the entire universe consists of ultramicroscopic “strings” of matter-energy. That’s it. It’s strings of one type or another that form the entire universe as we know it. The problem is that no one has ever found a single solid piece of experimental evidence to support this theory! The whole notion is pure mathematical speculation.
To make any of the string theories work requires the universe to possess unseen dimensions beyond the normal three dimensions of space and one dimension of time that we’re familiar with from everyday experience. Most string theorists believe in a world of ten dimensions, and they hope that the LHC will uncover those extra dimensions. How might this happen?
One way the LHC might establish the existence of new dimensions would be if it creates micro black holes. The decay rates of the subatomic particles that such a black hole creates can be analyzed to see whether hidden dimensions actually exist. A closely related way to establish the existence of these “missing” dimensions would be for the LHC to produce gravitons, particles that carry the gravitational force, disappearing into these other dimensions. Anything of this sort would be nothing but sweet music to the ears of string theorists, lending some actual experimental evidence to their flights of mathematical fancy. Preliminary results, though, look distinctly unpromising.
At a physics meeting in Mumbai in late summer 2011, experiments were presented by Dr. Tara Spears of CERN, who stated that researchers failed to find evidence of so-called supersymmetric particles. This result puts one of the most popular theories in physics, superstring theory, on the spot. If the conclusions presented by Spears hold up, then physicists are going to have to find a new “theory of everything.” Interestingly, earlier results from the Tevatron in Chicago suggested just the opposite, which is why researchers asked CERN to employ the LHC to examine the process in more detail. Professor Jordan Nash of Imperial College in London, one of the researchers on the CERN project, states the matter this way: “The fact that we haven’t seen any evidence of it [supersymmetry] tells us that either our understanding of it is incomplete, or it’s a little different to what we thought—or maybe it doesn’t exist at all.” Before declaring supersymmetry a dead duck, though, we have to bear in mind that there are many other versions of the theory, albeit more complicated ones, that have not been ruled out by the LHC results. Superparticles may just be a lot harder to find than physicists originally thought.
As an interesting glimpse into the sociology of science, the downfall of supersymmetry would be a heavenly vision to a generation of younger theoretical physicists, who would then find the field wide open again for them to invent new theories, rather than being saddled with something invented by the older generation. As Max Planck once stated the matter, new theories are never accepted, they just have to wait for their opponents to die off. In this case, the “opponent” may well turn out to be supersymmetry. The next few years should pretty much settle the matter. But possibly there’s other bounty to be obtained from the LHC besides supersymmetry.
Probably the most puzzling fact we’ve observed about the universe as we see it is that there simply doesn’t appear to be nearly enough visible objects—stars, planets, asteroids, and so on—to account for the gravitational forces holding the galaxies and the universe itself together; to do the job, there must be a lot more gravity-generating matter than we currently observe. Enter “dark matter,” a form of matter that can’t be seen but makes up much more of the universe than all the visible matter taken together.
If (and it’s a huge if ) dark matter exists and has the right interaction strength with visible matter, some theories predict that the particles produced by collisions in the LHC will decay into dark matter that could actually be observed. But it’s not known whether it’s even possible to create dark matter by putting enough energy into a small enough space, so it might not show up in a collider yet more powerful than the LHC. And if it does appear, we know so little about the properties of such matter that it could be there and we’ll never see it because we don’t really know how to look. The only thing physicists seem confident about is that if it exists, it interacts very weakly with known particles. This means it would be hard to separate dark matter from background noise in the LHC experiments. So it’s a long shot, at best. But if the LHC can create particles that are even good candidates for being dark matter, that would lend encouragement to the whole idea. Last, but not least, there are the strangelets.
IN 1993, TWO MYSTERIOUS EXPLOSIONS SHOT THROUGH EARTH AT nearly a million miles an hour. Whatever the objects were, on October 22 they set off earthquake detectors in Turkey and Bolivia that noted an explosion in Antarctica packing a wallop of several thousand tons of TNT. Just twenty-six seconds later, whatever that object was exited the floor of the Indian Ocean near Sri Lanka. One month later on November 24, a second event was detected. Sensors in Australia and Bolivia showed an explosion off the coast of the Pitcairn Islands in the South Pacific, and an exit of the object in Antarctica nineteen seconds later.
According to physicists, both explosions are consistent with an impact by strangelets, bizarre particles that are postulated to have been created during the Big Bang and are still being formed inside very dense stars. Unlike ordinary matter, though, strangelets contain “strange” quarks, particles that are normally seen only in the shower of particles generated inside huge particle accelerators. The team investigating the 1993 events says that two strangelets just one-tenth the width of a human hair could account for the observations.
Smashing protons together at the energies reached by the LHC could create new combinations of quarks, the particles that form protons. It’s just possible that the kind of strange quark(s) that make up a strangelet will be produced in these collisions, as well.
The impact of a mini black hole created in a particle accelerator like the LHC has been explored extensively in the so-called hard science-fiction literature, since that’s the only place physicists can give expression to their imagined fears of an event that to the best of our knowledge has not yet occurred. Unfortunately, these Hollywood-style venues for exposition of the effects of a mini black hole are strongly at odds with the reality of what we actually know about such objects, assuming they even exist.
To cut to the chase, here is the situation with mini black holes as we understand them today:
So the bottom line is that mini black holes are not any kind of threat to humankind.
Turning to the question of dark matter, the impact in the short term would be simply one of aesthetics. Our theories of the universe as we know it today require a lot more matter than what’s been seen. Discovery of this “missing” matter would tidy up our theories and give us some confidence in forecasting the ultimate fate of the universe. Either the current expansion will continue indefinitely, or there will eventually be a Big Crunch consisting of a contraction back to a single point. Finally, the third, but unlikely possibility, is a steady state in which things are balanced just right so that there is no cosmic oscillation between the Big Bang and the Big Crunch, but only a Big Yawn. So there is no immediate threat to our human way of life from dark matter, either.
That’s the menu: mini black holes, strangelets, dark matter, the Higgs boson, hidden dimensions. And those are just the things that physicists know about or postulate that might turn up in the debris of the LHC collisions. Detection of one or another of these objects would validate one model of particle physics over the competitors.
The real prize, though, would be something that we don’t know about—a kind of Unknown Unknown! If such an event should occur, the entire world might vanish, and with that disappearance the world of physics, along with everything else. Or maybe such an X-event would just turn the world of physics upside down and force us to rethink everything we believe we know about the mysterious ways of the material world.
The opposite end of this spectrum is the booby prize: We find nothing! Years of smashing particles together yield nothing that we don’t already know about. Should this occur, we would probably also have to rethink our theories of the universe. So the two extremes, something totally new or just plain nothing, might end up being the most exciting discovery of all.
FEAR OF PHYSICS
IN ITS MARCH 1999 ISSUE, THE POPULAR-SCIENCE MAGAZINE SCIENTIFIC American ran an article titled “A Little Big Bang,” which signaled the second phase of concern that physics would/could destroy the planet, if not the entire universe. The focus of concern in that article was that the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory on Long Island outside New York City would create strange particles of matter that might either blow up the planet or perhaps suck the entire universe into a hole from which it would never return.
The RHIC consists of two circular tubes, 2.4 miles long. Electrons from gold atoms are isolated and then accelerated to 99.9 percent of the speed of light. When these electrons collide, incredibly dense matter is created having a temperature ten thousand times greater than at the center of the sun. These are conditions that haven’t existed since the creation of the universe in the Big Bang, a moment twelve billion years ago when all the laws of physics known today broke down. So it’s natural to wonder what the effects might be of such an experiment. In fact, that very question is the reason the RHIC was built in the first place.
Following the Scientific American article, numerous letters from concerned readers flooded into the magazine’s offices expressing anxieties over the possibilities that the collider would destroy us all. Typical was the letter from Mr. Walter Wagner, a former nuclear safety engineer turned botanist in Hawaii, who said Stephen Hawking’s work argued that a miniature black hole would have been created moments following the Big Bang that started the universe. He wanted to know “for certain” that this would not happen when the RHIC was fired up. The magazine printed this letter, along with a reply by Nobel Prize–winning physicist Frank Wilczek, who stated that physicists are very leery of using the word impossible (that is, “for certain”), but that the whole idea of a black hole coming from the RHIC and gobbling up the planet was an “incredible scenario.” Here Wilczek used the term “incredible” in its literal meaning: incredible = simply not believable.
Never to be left behind when it comes to sensationalism, the general news media jumped on this possibility with relish. One reporter called the RHIC the Doomsday Machine and said that a physicist told him that its construction was “the most dangerous event in human history.” Another account claimed that a grade-school student in Manhattan wrote a protest letter to Brookhaven officials, saying she was “literally crying” as she wrote the letter. The machine was even blamed for creating a black hole that swallowed the airplane that crashed in 1999 killing John F. Kennedy Jr.
This expression of public concern over what might come out of a particle accelerator began some years earlier when Paul Dixon, a psychologist at the University of Hawaii, picketed Fermilab outside Chicago because he feared its Tevatron collider might trigger a collapse in the quantum vacuum that could “blow the whole universe to smithereens.” (I wonder if Dixon knows Walter Wagner, as there seems to be something in the air of Hawaii that brings out these kinds of protests!)
This RHIC brouhaha came and went as the machine was put into service in the summer of 2000 with no reported difficulties, at least not any involving the mysterious disappearance of aircraft or untoward corners of the earth being swallowed up in a cosmic vacuum cleaner. But that’s not the end of the public’s fear of physicists.
In 1994, work began at the European Nuclear Research Center (CERN) near Geneva, Switzerland, on an even more powerful particle accelerator, the LHC that I’ve already spoken of. After several start-up glitches, the machine went into full service in late 2009, although it won’t be ready to operate at its full design level until 2014. This project was the culmination of an idea that had been bandied about at CERN since the late 1980s. And just what was this idea? Nothing less than to build a Big Bang machine that could re-create those fleeting moments nearly fourteen billion years ago when the fundamental building blocks of the universe were put in place.
The engineers at CERN knew that to create the energies necessary to answer questions about the Higgs particle, dark matter, and the like, they had to build a machine more complex than any machine ever created by human beings. In this machine, beams of protons would be accelerated to 99.9999999 percent of the speed of light in an environment colder than interstellar space. The proton beams would then be crashed together in the hope that the particles created in these explosions would yield answers to the foregoing questions.
Another part of the conjuring trick is to actually see the “answers,” since the elementary particles created in the colliding beams would decay and disappear in less than a trillionth of a second. To capture these transient objects requires a detector larger than a five-story building, yet so precise it can pinpoint an object with an accuracy of one-twentieth the width of a human hair!
The design and construction of such an incredible device took over ten thousand scientists and engineers more than fourteen years, and an expenditure of more than six billion euros (more than eight billion US dollars), to build.
Just a couple of months before the LHC was supposed to “go live,” the same Walter Wagner who expressed concerns about the RHIC filed a lawsuit in Hawaii’s US District Court, calling for the US Department of Energy, Fermilab, the National Science Foundation, and CERN to slow down the LHC preparations for several months in order to reassess the collider’s safety. The suit asked for a temporary restraining order on implementation of the LHC and called upon the US government to carry out a full safety study of the machine, including a renewed consideration of the doomsday scenario.
More specifically, the scenario outlined in Wagner’s lawsuit includes the following possibilities:
Runaway Black Holes: Millions of microscopic black holes would be created that would persist and somehow coalesce into a gravitational mass that would consume other matter and ultimately swallow up the planet. Most physicists believe that these black holes, if they’re created at all, would have minuscule energy and quickly evaporate, thus posing no threat whatsoever.
Strangelets: According to current wisdom, all known matter is composed of various types of elementary objects called “quarks.” Wagner and others fear that smashing protons together at enormous energies might create new combinations of quarks, including a nasty version known as a stable, negatively charged “strangelet” that could turn everything it touches into strangelets as well. This is reminiscent of the so-called ice-nine scenario from Kurt Vonnegut’s novel Cat’s Cradle that I briefly described in Part I. Recall that Vonnegut imagined a strange form of matter, ice-nine, that was seeded into the oceans and immediately turned all normal water into a solid crystalline form.
Magnetic Monopoles: All magnetic objects that we know about have two poles, one pointing north, the other south. It has been suggested that high-energy collisions of the LHC variety might give rise to massive particles that have only a single pole, north or south—but not both. The fear is that such a particle might then start a runaway reaction that would convert other atoms into monopole form.
Quantum Vacuum Collapse: Quantum theory postulates that the vacuum between particles is in fact just brimming over with energy. Some argue that putting enough energy in one place could be enough to break down the forces that stabilize the quantum vacuum energy and allow its release. Calculations suggest that if this were to happen, an infinite amount of energy would be released, creating a massive explosion that would sweep across the universe at the speed of light. The more imaginative versions of this scenario even suggest that perhaps some of the huge explosions observed in other parts of the galaxy might be due to experiments performed by aliens with the quantum vacuum that have gone awry.
So what does the world of science put forth as arguments against these scenarios? Are any of them even faintly plausible? Do any carry a likelihood great enough to trump the innate curiosity of human beings about the universe around us? Let’s see some of the counterarguments the world’s physics community marshals against these imaginative, if perhaps fanciful, scenarios.
“SCIENTIFIC” FICTIONS
ACCORDING TO EINSTEIN’S FAMOUS EQUATION E = MC2, IF YOU PUT enough mass into a small enough space you could generate a black hole, a region of space with a gravitational field so great that nothing, not even light, can escape from it. Since the LHC will be smashing protons together at near light speed, and protons are made of many smaller particles, it’s not totally beyond reason to wonder if several of these pieces might find themselves crushed together into a small enough space to generate a black hole. Here are some reasons why that is very unlikely.
Extra Dimensions: Those worrying about the possibility of mini black holes being created by the LHC assume the energy required to do this is vastly less than what we think is actually required based on studies of the world as we find it. So the possibility of generating a black hole in the LHC arises only in theories that postulate “large extra dimensions.” Only in this way is there “room” in these extra dimensions for the type of interactions needed to build black holes at low energies.
Basically, the problem is that producing black holes requires an enormously strong gravitational attraction. But gravity is by far the weakest of the four known forces. So to remedy this difficulty, some theories assume extra spatial dimensions accessible to the carrier of the gravitational force, the graviton, but not accessible to other particles such as quarks, photons, and electrons.
If such extra dimensions really existed, then gravity might actually be a very strong force but still appear weak to us, since the gravitons would spend most of their time in the extra space and seldom visit our part of the universe. At present, though, there is no evidence for the reality of these extra dimensions.
Theory Versus Reality: Strictly speaking, no one has ever seen an actual black hole; it is simply a theoretical construct. Many objects have been observed in the galaxy that are candidates for being black holes. But, in fact, there are a lot of difficulties with the whole notion of a black hole, and we don’t really know for sure whether or not they actually exist.
An especially troubling aspect of the whole idea of a black hole is that the general theory of relativity states that time should slow down as an object approaches a heavy object like a black hole. This means that chunks of matter disappearing into a black hole should take an infinite amount of time to vanish, at least as seen from the perspective of an observer outside the so-called event horizon of the black hole. Such an observer would see an object, say a football, floating toward the black hole and then somehow just get “stuck” like a fly on a piece of flypaper at the event horizon. Of course, if you’re a quarterback with your hand on that football, you continue on through the event horizon, blithely unaware that anything special has occurred—until you turn around and try to go back out. Then you discover that it’s a one-way trip and you’ve crossed the point of no return. But an observer on the outside would see no such thing; that observer would see you stuck to the event horizon forever.
Cosmic Rays: As early as 1983, Sir Martin Rees of Cambridge University and Piet Hut of the Institute for Advanced Study in Princeton pointed out that cosmic rays have been smashing into things all over the universe for eons. Many of these collisions are at energy levels millions of times greater than the LHC can generate. Yet no planet-sucking black hole has appeared, and the universe is still here. As the world’s leading expert on strangelets, Robert Jaffe of MIT, says: “If it were possible for an accelerator to create such a doomsday object, a cosmic ray would have done it long ago.” He goes on to state, “We believe there are relevant cosmic ray ‘experiments’ for every known threat.”
So it would appear that until we have accelerators more powerful than the energy of the most energetic cosmic ray, we’re covered.
ADDING IT ALL UP
LOOKING AT THE WORLD OF PHYSICS AS SEEN FROM THE STANDPOINT of a theoretical elementary particle physicist, on the asset side of the experiments under way today in Geneva, Chicago, Long Island, and elsewhere, we see the possibility for validation of one of the many competing models of how the universe is put together or the possibility of having to entirely rethink our view of this literally cosmic question. The liability column, which is what the rest of the world mostly sees, contains the extremely remote, but still nonzero, possibility of destroying the earth.
Either of these possibilities is an X-event. Either confirmation or denial of the current Standard Model of physics would be an X-event within the community of physicists, something rare, with great social impact in that community and definitely surprising (especially if the end result is denial). The other case, destruction of the earth by a strangelet, is an X-event impacting a much broader social community, namely, the entire planet (including the physicists!), and would also definitely be a surprise. Of course, I say this partially tongue in cheek as the two X-events are hardly commensurable, the “X-ness” of the second vastly outweighing that of the first. Nevertheless, regardless of how these physics experiments turn out, the end result will without fail be an X-event as we employ that term in this book.