She seemed reengaged, and asked, “Well, where did all of this come from?” So I went on to explain a little about “creation,” as scientists see it, the “big bang,” “matter-antimatter asymmetry,” the “nucleosynthesis” part of it by which ordinary matter is created in the big bang, etc., and that most of the primordial matter is hydrogen and helium, and it all was here within three minutes—that's before a considerable amount of processing that subsequently happened in stars to make the heavier elements, the stuff we're made of. But, I explained, the raw materials were established in the big bang, and many mysteries abound, like “where did the antimatter go?”
She seemed engaged in this and she asked a number of intelligent questions, finally getting to: “But what about life on Earth?” I explained that people weren't around at all for about thirteen and half billion years, and that we ultimately descended from microbial life-forms that arose, well, from large molecules, and eventually evolving into worms, vertebrates, primates, and then, “us.”
At this point the woman looked utterly horrified, turned, and hastily beat an exit from the building, returning to a large bus parked outside with the name of a church in Missouri on its side panel. I am sure she felt that while, perhaps, he has no particle of his own, she had surely just met Satan, or one of his many cacodemons, incarnate.
Leon Lederman, unflapped by all of the controversy, sits charmingly and serene as ever in his oversized leather desk chair with a smile on his face and a glowing sense of humor about all of it, the Einstein bobble-head doll on his desk bobbling in approval. The “God Particle” moniker has become a standard by-line in the latest newsworthy updates on the Higgs boson around the world, from Tibet to Timbuktu. “Timbuktu?” says Leon with a twinkle in his eye, “I have an uncle who sells bagels in Timbuktu…”
In any case, for the purposes of this book we'll assume that Leon had the iconic Norse god Wotan (Odin) in mind when he named the “God Particle.” And, in fact, the Higgs boson is not the end, or the “ultimate,” or even the “Götterdämmerung” of nature and science, but rather it all goes way beyond the Higgs boson. A Higgs boson represents the entry into a new domain of nature, the beginning of a new set of puzzles, and the beginning of our quest to discover something completely and radically new. The story always seems to turn out to be much bigger and grander than we may think it is at any given time.
Indeed, a curious parallel to the Norse myth continues: After its fabrication, Wotan (Odin) donned the Nibelungen's ring and went forth in his earthly wanderings, eventually ceding the ring to Siegfried, who slew dragons and rescued the beautiful Brunhilde from her eternal sleep on the fiery top of a volcano. Ultimately, in Götterdämmerung at the end of the Ring Cycle, the gods perish through their own perfidy and tomfoolery with the golden ring, ceding the future world down to the humans.
The message is clear: we must progress beyond a belief in demi-gods, dwarves, trolls, and selfish and angry gods—beyond the fairy tales we are taught as little children. The world ultimately belongs to and is stewarded, for better or worse, by humans. Perhaps the present moniker “Beyond the God Particle” fits all of this. Humans are continually making progress in learning how the universe really works, beyond fairy tales and myths, and through such profoundly successful international collaborations as at Fermilab and CERN, learning how to work and live together across national boundaries and cultural frontiers. It's all about collaboration on the largest scales of human endeavor. It's ultimately all about the future of people.
And so, we'll now abandon the term “God Particle” and look in greater detail at the Higgs boson, at the science of the smallest things in nature and what we are actually trying to do, and in many ways are succeeding in doing now—what we will achieve with the LHC, and what we hope to do, and must do, in the future. We are also looking beyond the Higgs boson, both as a thing and as an idea. With the Higgs boson in hand, physicists now have a powerful new insight into how nature generates its fundamental patterns and its properties of the elementary particles, and a new, powerful way to understand the remaining mysterious puzzles of the physical world.
The most fundamental of questions we are asking today concern the smallest objects, objects that lie far beyond the atom, the quarks, the leptons (“matter”) and gauge bosons (“force carriers”), the Higgs boson, and whatever lies beyond these things. Here we are exploring a strange new world—a world of the smallest things. No one has ever been here before, to examine what is happening at the smallest distances that are now probed by the Large Hadron Collider (LHC). This is not entirely blind exploration, for we actually have an inkling of what we are trying to understand—but surprises may be around the next corner.
In short: we are attempting to answer the vexing question: What is the origin of mass? Mass is one of the most important defining quantities of matter. But where does it come from? What makes mass happen? Will we ever become skillful enough to calculate the mass of the electron or the muon or the top quark from a “first principle”? What shapes and controls and sculpts the elementary constituents of matter and their masses?
This is a bit like trying to answer the deep biological question “What and where is the genetic code of life?” The answer to that question came in the 1950s—it turned out to be encoded into a very long and durable molecule called DNA. And from that has come an entirely new set of capabilities, as DNA can be “read” and “reread” and, eventually, we think, “rewritten.” All structure and function and ultimately all diseases of living organisms are controlled by DNA and its associated processes. Understanding DNA and its evolution is the foundation of understanding all life on Earth. Our open physics questions today are much like the biological ones before the 1950s: “What causes the phenomenon of mass?” Put another way, “What is the DNA of matter itself?”
To get some insight into the process of the exploration of nature, let us ask, what deep questions were our ancient ancestors asking over the past three millennia? Like newborn babies, our ancient ancestors awoke with rational minds and conscious awareness into a world with a “reality” of its own. It was difficult initially for them to shake off primitive prejudices, notions and fears, unwarranted or otherwise, about things that seemed to happen or were only imagined to happen. There was an internal reality to the human mind in the early dawn of intelligence, voices that spoke in the night, apparent demigods lurking behind every tree, making all things, good or bad, happen. This led to peculiar notions, for example, that one must dance in strangely ostentatious ways, while wearing bizarre make-up and costumes, in order to make good things happen, perhaps to make it rain. Indeed, most appeals for divine intervention are just a variation on a rain dance and are motivated by something like the mortal fear of crop failure. It was difficult to discard that and to create a distilled “objective reality.”
But gradually there emerged a coherent understanding and philosophy of objective reality. Questions could now be posed and answers sought without reference to mythical beings and magic, without the fear of offending the particular gods that brought the rains. One learned to do “experiments.” And one learned that the reproducibility of an experimental result was far more important than the mere opinions of the witch doctors and high priests. Does it really rain when we put on our costumes and dance about? No. But there are certain crops that can grow better in a dry climate than others, and certain clever ways to grow them. At some point the issue of understanding reality became “science.”
Eventually people asked the deeper questions: “What are all things made of?” “What are their properties?” “How do they interact with one another?” “What are the fundamental laws of nature that govern these objects?” These are practical questions, but they are also the biggest questions. They deal with profound issues: “What constitutes physical reality?” and “What is the nature of physical substance?” and “What is physical force, motion, space, and time?” The answers hold deep secrets, and perhaps the key to a better fire, a better sword,
a cure for illness, perhaps a way to make the rains come or prevent them from leaving, or to make the best of what the conditions are, and how not to mess things up. By the end of the nineteenth century, here on Earth, the question: “What is the nature of matter?” was framed within the province of chemistry: All matter is formed from the basic atoms that comprise the chemical Periodic Table of the Elements—where “periodic”’ refers to their chemical properties. The elements form chemical compounds and enter into chemical reactions according to specific empirical rules. The laws of physics are those of Galileo and Newton, embellished by Maxwell, Gibbs, Boltzmann, etc.
Many thinkers from antiquity had previously developed a rudimentary concept of “elements.” These would be the basic, irreducible components out of which things are made. Among the earliest ideas were the so-called “classic elements,” as described by Plato: “Air,” “Fire,” “Earth,” and “Water,” as well as mysterious “Quintessence.” The latter was considered to be an all-universe-filling “ether.” This view of the nature of matter reduced every question to the five classic elements and offered a (very) tiny hint of an underlying order, but it certainly didn't get into the details. It was more of a dismissive answer to questions about the inner nature of matter.
Other philosophers of antiquity, however, were actually quite modern from our perspective. The foremost of these was Democritus of Athens, one of most advanced thinkers in all of human history, considered by some to be the “father of modern science,” certainly the Galileo of his age. Democritus was born around 470 BCE, and died around 370 BCE, thus living to the ripe old age of about 100.1 He was often viewed as an eccentric fellow and largely ignored in his home town of Athens, and was supposedly detested by Plato, who denied ever meeting him (though this was unlikely since Plato allegedly wanted all of Democritus's books burned).
Democritus inherited the moniker “the laughing philosopher,” as he evidently found most of the ideas of other contemporary philosophers to be rather humorous, if not ridiculous. We can imagine him heckling Plato during a lecture in some curia, circa 400 BCE, perhaps asking a subtle and detailed question about a certain chemical reaction about which Plato could not begin to answer:
P: And the natural order and simplicity of nature is simply that all things can be resolved to the five “elements,” the “air,” the “fire,” the “water,” the “earth,” and the “quintessence,” and that's all of it.
D: Master, are these elements transmutable into one another?
P: No, truly not, sir, for as I say, they are elemental.
D: But of what element is the brilliant light of the sun?
P: (pause) I suppose…a form of quintessence as it does flow though space which is filled of quintessence and so it must be such.
D: And, master, of what element is papyrus?
P: Surely, papyrus is a form of the earth as it comes from the earth.
D: So, master, if I place a gem of spherically shaped quartz between the position of the sun, and that of a papyrus scroll, which you say is a form of the earth, I can direct, or “focus,” the sun-light, a form of quintessence, upon the papyrus and I can produce a fire. Have I not converted the quintessence into the fire or the earth into the fire?
P: I do not believe this can happen, sir.
D: I have set up the experiment here, master (Democritus directs Plato and the audience to a window at which he has an apparatus. With the apparatus he focuses sunlight onto a piece of scroll paper, and it shortly smokes then bursts into flames).
P: (impatiently) Well, if this is not a ruse then perhaps…perhaps light is really a form of fire, so you have not converted anything into anything else.
D: But if I should send the light, that you now say is fire, into an urn of oil, it becomes dark…where has the fire now gone? Has it become the oil which you would say is the earth?
P: Indeed…(pause, stammer) well, perhaps it is as we said quintessence…
D: Then as I burn the papyrus (the paper continues to smolder), which is a form of the earth, in the fire, and the smoke rises into the air, and the papyrus disappears, have I not converted the earth into air?
P: (long indignant pause)
D: Bbbbwwwaaahahahaha…(Democritus bursts into a sneering and callous laughter).
Democritus wanted real and detailed answers to scientific questions. From Democritus we got a conceptual basis of the elements. These elements, he reasoned, must have certain complex dynamical properties that cause them to ultimately shape and define the behavior of matter. The multitude of various properties of ordinary matter are reduced to the more fundamental properties of atoms. Some elements were envisioned to be little spherical balls that could freely flow (e.g., liquids), while others had hooks and could form stiff structural bonds (metals), and still others had block-like shapes that might make regular crystalline arrays (diamond or quartz). The theory had to explain all known phenomena correctly, perhaps even predict new observable phenomena, the standard to which science holds all theories.
Of course, this was an ultra-ambitious undertaking in those days. Democritus had no microscopes, or particle accelerators, to test and validate his hypothesis. But his reductionist hypothesis implied rules and organizing principles for chemistry. Democritus dubbed the basic constituents of matter “atoms” from the Greek atmos (indivisible). Out of these basic building blocks we can construct more complex objects and the forms and shapes of all that we see. The behavior of the large-scale physical world is thus emergent from the fundamental properties of atoms.
This is a wholly modern view of the physical world, as well as one of the tasks of science. While, in Democritus's theory, certain materials could change and rearrange their structure under chemical reactions (e.g., burning them, letting them rot, or dissolving them in water), the underlying atoms were immutable, unchangeable, invariant. His theory was useful and offered a prescription for further research. Here was the basic tenet of “fundamental particles,” and their role as the irreducible components of all things throughout the universe, which sculpt and shape the world through their own intrinsic properties.
Alchemists over the subsequent centuries went to work. They never succeeded in turning the element lead (Pb) into the element gold (Au), or achieving any other elemental transmutation, for that matter. In countless attempts to do so they merely rearranged elements within the many exotic compounds, but they provided the service of amassing an enormous empirical “database” of recipes and processes and properties of chemicals that formed the foundation of the science of chemistry. In this sense, Democritus's theory was tested, found to be correct, but has been so significantly enlarged in detail by later science that it ultimately proved to be more of a philosophy, a prescription to actually do the hard work of science, and not to be merely contented with a dismissive shake of the wrist, invoking “air,” “fire,” “earth,” “water,” and “quintessence,” panacea for lack of a deeper understanding.
What we come into contact with on a daily basis, the “everyday matter,” is the first layer of the “onion of nature.” It is comprised of “molecules,” which are either large or small groupings of atoms. Salt (NaCl), water (H2O), oxygen in the air we breathe (O2), and methane (CH4), the gas we use to heat our homes, etc., are all molecules, composed of combinations of the more fundamental elements or atoms. Molecules can be broken down chemically into their constituent atoms, which can then be rearranged into other molecules. Just light a match to a certain mixture of oxygen molecules and methane molecules, and these will rapidly rearrange to form water molecules and carbon dioxide molecules, releasing a lot of heat.2 On the other hand, sodium (Na), chlorine (Cl), hydrogen (H), oxygen (O), carbon (C), and so on, are all atoms, or “elements.” These are invariant, or unchanging, in chemical reactions—they are the “fundamental particles” of chemistry.
The total numbers of these atoms never change in chemical reactions—the atom of gold (Au) cannot be changed into lead (Pb) by chemical reactions. The atoms
cannot be further subdivided without doing things that aren't possible in a high school chemistry lab. To smash atoms apart, into “smithereens,” takes us beyond the realm of chemistry. It takes us into a deeper layer of the onion of nature, the realm of atomic and nuclear physics, eventually into the realm of quarks, leptons, and gauge bosons. These are, today, the true “fundamental particles” of nature, perhaps to be replaced by smithereens in some science of the future.
By the mid-nineteenth century, based upon the accumulated knowledge of all the known chemical processes, the elements, or atoms, were classified according to their properties by the great Russian scientist Dmitri Mendeleev. This classification scheme is called the Periodic Table of the Elements. The Periodic Table was a stunning summary of the thousands of years of alchemy, chemical science, and simply messing around with matter. It represented the reduction of the virtual infinity of molecules into a simple list of approximately 100 atoms found in nature (slightly more than 100 atoms is today's count; it was significantly fewer at the time of Mendeleev; many elements, such as helium, were discovered later, and many of the heaviest elements are so radioactively unstable that they must be artificially produced in particle accelerators and are not to be found on our old high school chemistry classroom wall charts). The Periodic Table represented a pattern of repetitive chemical behavior in the properties and forms of atoms as one goes to heavier and heavier atoms. By its complexity, however, it suggested that atoms may, themselves, be further reduced and may have internal structure, and that a deeper layer of subatomic matter must exist.
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THE “PHYSICS AS AN ONION” METAPHOR
Mendeleev's table was the beginning of the modern era of the science of matter. To understand this, one must appreciate that nature is, empirically, organized much like an onion. Nature has different layers of phenomena and structures as one descends to smaller and smaller distance scales. And, going downward to shorter distances, we discover, is equivalent to going to higher and higher energy scales (higher “energy per particle”; we'll define this more carefully momentarily). Although all of nature is governed by the same underlying fundamental laws of physics, the structures of complexity that we see in nature seemingly occur at different “strata” of phenomena, like an onion, and each stratum of nature is characterized by the energy needed to probe it.
Beyond the God Particle Page 4