Beyond the God Particle Page 2

  However, with the mounting federal budget deficit (not to mention severe pressure from my majority whip), it has become increasingly difficult over the past couple of years for fiscal conservatives such as myself to vote for any expensive scientific endeavor. We'll support better technologies for oil drilling, but a Super Collider is just too hard for me to support. (I really haven't a clue what one is.) Federal spending has to be prioritized, and this has been steadily eroding my support for the SSC. We have to get on with starving the beast of a federal government that has such a voracious appetite.

  Voting against the Superconducting Super Collider is, for me, a very difficult decision. Much of the SSC's research and development is being conducted in colleges and universities in my own district. Nevertheless, I feel strongly that this is a prudent and responsible vote. If other nations will benefit from discoveries and technology produced by the SSC, why shouldn't they contribute to its construction? Or build their own? The Superconducting Super Collider is simply too expensive for the United States to build on our own. And I will not raise taxes on my overburdened wealthy constituents. The economy can only grow by the efforts of American businessmen. In fact, I'm planning to sign a brand new “pledge,” crafted by my dear friend, Mr. Grover Norquist, that I will never vote to raise taxes again.

  Our country has been a world leader in technology, and we must continue to support our nation's scientific research programs. The SSC, however, is a program that we simply cannot responsibly fund. Although proponents have argued that the potential scientific benefits outweigh the high costs and that the SSC should be an immediate priority, I'd just like to see a few more roads in my district and a lot more oil drilling and coal mining. And, I might add that if humans were meant to see quarks and “God Particles,” God would have given them tiny eyeballs.

  The final vote to support the continuation of funding for the SSC in the House of Representatives was 159–264, the nays having their way with it. The construction of the tunnel for the Superconducting Super Collider was about a third complete, and more than two billion dollars had already been spent.

  It wasn't just Congress's fault. There were many problems in the management and attempted execution of the SSC project and plenty of blame to go around. It's very hard to pinpoint exactly what killed the SSC because it was a mélange of reasons. We don't want to indulge in dredging it all up, and the interested reader can read about it at any of the numerous websites provided to you by high-energy physics and Mr. Tim Berners-Lee and associates.4

  But for science, all of science, and as an engine of economic growth and prosperity in the US, the termination of the Superconducting Super Collider was an unmitigated disaster. If Congress was truly a body of leaders, it would have moved forward on the SSC and found a way to make it happen.

  The massive drilling machines of the SSC were abandoned in the half-completed tunnel where they stood. The tunnel itself carved in the frail Austin chalk, its sump pumps unplugged, has now filled with water, its walls soggy and collapsing, the heavy equipment dissolving away like some far-off shipwreck. Sage brush once again rolls in the wind through the downtown streets of Waxahachie, as plywood panels creak and shutters clap against walls, like some late-night replay of The Last Picture Show.

  IS IT RECOVERABLE?

  Over the years big science has increasingly fallen victim to the political process. Sadly, in the US, it seems not to be recovering. Particle physics in the US has not enjoyed the construction of a new cutting-edge particle accelerator since Fermilab's Tevatron was built in the 1980s (expanded with its Main Injector in the early 1990s). Big science in other fields, such as nuclear fusion and astrophysics, has also lost many similarly large-scale projects. Today, many people now question whether modern American-style democracy can ever manage grand science endeavors again. They wonder, are Americans, through visionless leadership, endless partisan bickering, and Machiavellian ultra-rich special interests and their lobbyists now destined only to sit watching TV in their devalued homes, fearing the mortgage collector, their jobs threatened, with their devalued currency, fighting multifront wars, making a mess of the planet with their fossil fuels, while the grand discoveries and exploration of the ultimate frontiers—and the burgeoning future economies this will bring—happen in Europe, China, India, and elsewhere? With the discovery of new phenomena, such as the Higgs boson at CERN in Geneva, Switzerland, will indeed come direct and indirect applications that can resuscitate moribund economies. But is this is now less likely to happen in America?

  Fortunately, at least for American scientists, the US does significantly participate in the big experiment collaborations that do their physics at the LHC, and the US significantly contributes technology and manpower to build it. Particle physics has grown up to become a truly international activity, and no large particle accelerator will likely ever be built again without full international collaboration. Even the use of the Fermilab Tevatron, which was the leading particle accelerator for two decades prior to the LHC, was an international collaborative effort, and Fermilab, like CERN, flies the colorful flags of its collaborators’ nations in front of the main building.

  But there's no place like home, and not having such a large-scale project on American soil makes the economic gain diffuse and less powerful in the long run. Schoolchildren in the Chicago area can now only visit a museum showcasing a past great particle accelerator at Fermilab—not an operating facility collecting never-before-seen data about the inner universe of matter.

  Yet, as regards the future of Fermilab and the US particle physics program, we're eternally hopeful. We'll discuss what we could and should plan to do to change this and move forward. There is a pathway back for American science, but we'll certainly have to refresh our American aspiration for greatness and find our old our “get up and go” that seems to have “got up and went.”

  LONG LIVE THE KING

  The LHC is operating superbly today. It is a particle accelerator that hurls protons at enormous energies head-on into one another, at the highest energies ever achieved by humans. Within every trillion collisions of the protons at the LHC there emerges a mysterious new form of matter—shards of matter that exist for only a billionth of a trillionth of a second—yet enough time to be recorded in the two great eyeballs of the LHC, the particle detectors known as ATLAS and CMS. The market value of this form of matter cannot be assessed—it's meaningless—its value is determined by the cost of the entire project of the LHC and, per ounce, it is literally trillions of trillions of trillions times greater than that of gold.

  With the demise of the SSC, the US walked off the playing field of the highest energy particle accelerators. The US has essentially outsourced this, perhaps the most important science, to someone else. And that “someone else” is CERN, and the Europeans know what they are doing and they are doing it well.

  So, what is this place called CERN?

  Western science began in Europe. It began with the ancient Greeks, but the modern era traces to Galileo, who divined the law of inertia by studying balls moving on inclined planes. Newton encoded this into his laws of nature and discovered that gravitation is a universal force that permeates the universe, holds the earth in its orbit about the sun, and controls the fall of an apple in a garden.

  This was the birth of the Age of Enlightenment. It ultimately led to the summation of the laws of electricity and light by Faraday and Maxwell, to Max Planck and Albert Einstein and the twentieth century leap forward with the discovery of the quantum behavior of all small things. Countless phenomena that were opaque and mysterious could now be attacked scientifically. The atom, the chemical bond, and the chemical basis of life as well as the properties of materials and properties of the elementary building blocks of all matter could now be understood. But the political climate in Europe shifted toward horror, with the rise of fascism in the twentieth century, and many of the greatest European scientists had to leave, including Einstein, Fermi, Emmy Noether, and many others.

>   By the end of the Second World War, European science had lost its leadership role held for the three and half centuries since Galileo to the United States of America. However, a small group of the leading European scientists, including most notably Niels Bohr of Denmark and Louis de Broglie of France, envisioned creating a new center for physics in Europe. Such a laboratory would stimulate European scientific research but would also permit sharing the increasing cost burdens of the large-scale facilities required for nuclear and particle physics.

  French physicist Louis de Broglie (one of the founding fathers of the quantum theory) put the first official proposal for the creation of a European laboratory forward at the European Cultural Conference in Lausanne in December 1949. A further push came at the fifth UNESCO General Conference, held in Florence in June 1950, where the American Nobel laureate physicist, Isidor Rabi, tabled a resolution authorizing UNESCO to “assist and encourage the formation of regional research laboratories in order to increase international scientific collaboration…” In 1952, 11 countries signed an agreement establishing a provisional Council—the acronym “CERN” was born and Geneva was chosen as the site of the future Laboratory. The CERN Convention, established in July 1953, was gradually ratified by the 12 founding Member States: Belgium, Denmark, France, the Federal Republic of Germany, Greece, Italy, the Netherlands, Norway, Sweden, Switzerland, the United Kingdom, and Yugoslavia. On 29 September 1954, following ratification by France and Germany, CERN officially came into being.5

  In 1957 CERN built its first particle accelerator, a comparatively low-energy machine that provided particle beams for CERN's first experiments. It evolved into a machine that was used for research in nuclear physics, astrophysics, and medical physics, and was finally closed in 1990, after 33 years of service. The original synchrotron had given way to a more powerful “Proton Synchrotron” (PS) by late 1959, which still operates today.

  Conventional particle physics experiments are identical in configuration to those of a biologist's microscope—a point we'll be harping on throughout this book. Think of a microscope in a typical high school biology lab. Here you have an incoming light source (the particle beam) colliding with some material that you've placed on a glass slide, perhaps containing a drop of pond water (the target), in which there might be a paramecium or an amoeba swimming around (the “quarks” you want to see). The incoming light scatters off the target and is collected in an optical system with lenses that magnify the image and present it to your eyeball (the detector). In this way you can see the little microbes swimming around in their drop (data!). So, in summary we have (1) a particle beam; (2) a target; and (3) a detector that collects (4) data. That's it—very simple indeed—these powerful accelerators and their detectors are microscopes.

  There's one key point, however, about particle physics that you must grasp: the smaller the thing you want to see in the target, the higher the energy you must impart to your beam particles. The reasons for this will be explained later, but it is our basic operating principle. This is also true for microscopes, and it's why electron microscopes, which use higher-energy beams of electrons instead of low-energy beams of visible light, “photons” are better than optical microscopes. This is actually where microscopes really do become particle accelerators—it's more than just a powerful metaphor because it's really true, and all the issues and challenges of building powerful microscopes hold as well for particle accelerators, and vice versa.

  In the usual way of doing their particle collision business, physicists make a particle beam strike an atom that is sitting at rest in a fixed target, like a block of lead or beryllium, just like the light beam striking the target on the glass slide under the microscope. However, physicists realized that in the subsequent particle collisions with the atoms in the block of material, much of the precious energy of acceleration of the incoming beam is wasted. The outgoing particles emerging from the collision acquire “recoil momentum,” which takes away the useful energy. However, if two particle beams could be fired at each other and made to collide head-on, then there need be no recoil momentum and all the energy is available to probe deep inside of matter. The full particle beam energy becomes available to make a detailed image, or to actually produce new and previously unseen and very short-lived elementary particles. This is the concept of the modern “particle collider.” The Fermilab Tevatron and the CERN LHC (previously CERN's LEP collider) were and are all-powerful and useful particle colliders. But what a challenge this is—to make infinitesimally small particles that are smaller than a millionth of a billionth of a golf ball in size, traveling almost at the speed of light, hit each other head-on!

  The world's first proton–proton collider, called the Intersecting Storage Rings (ISR), was built and came into operation at CERN in 1971. The ISR was a very small machine by today's standards, but there were daunting challenges to overcome just to make it work. The ISR produced the world's first head-on proton–proton collisions. It was actually constructed on French soil on land adjoining the original CERN site in Switzerland. At the same time, the first electron–positron collider was ramping up at Stanford Linear Collider laboratory.

  THE GRAND SYNTHESIS

  By the early 1970s theoretical physicists had sewn all the available data from a century of research together, much of it coming from the data produced at high-energy particle accelerators, and had developed a remarkable descriptive and predictive theory that has come to be known as the “Standard Model.” One of the great achievements of the Standard Model is that it united two of the known forces in nature into one unified entity. These two forces are electromagnetism, the force associated with ordinary electricity, light, and magnetism, together with a very feeble force, so feeble that it wasn't even noticed until the 1890s, called the weak interactions. Though this latter force is “weak,” without it the sun could not shine and we would not exist.

  The electromagnetic force is associated with particles, called photons, that are the particles of light. Likewise, the Standard Model predicted that the weak force must be associated with three previously unseen particles, called the W+, W–, and Z0 (these are called the “weak bosons”; “bosons” are defined in the Appendix). These three particles were predicted to be very heavy by particle physics standards (the W+ and W– are 80 times heavier than the proton, and the Z0 is 90 times heavier than the proton), and they have extremely short lifetimes, less than one trillionth of a trillionth of a second. But physicists realized that these particles could in principle be produced and detected in a sufficiently energetic collider experiment. Alas, no machines existed at the time the Standard Model was put together that were capable of producing the weak bosons, but indirect hints of their existence continued to emerge in various experiments. These “indirect” hints compelled the ultimate construction of a machine capable of directly producing and observing the W+, W–, Z0.

  In the early 1970s the first big accelerator at Fermilab (called the Main Ring) came into existence, while CERN had built, upon their existing PS, the Super Proton Synchrotron (SPS). Both the Fermilab Main Ring and the CERN SPS were a whopping four miles in circumference (approximately). Particle physics had become big science. These were powerful accelerators that could be used to produce very energetic beams that went off to various fixed target experiments. With fancy upgrades, however, they could in principle be converted to colliders, and with head-on collisions they could produce and “discover” the W+, W–, Z0.

  In the late 1970s Fermilab embarked upon an ambitious and long-term goal of building the Tevatron, a machine that would collide protons with antiprotons6 and that would ultimately become the world's first superconducting-magnet collider operating at the highest achievable energies for the four-mile circumference ring. CERN, on the other hand, took the bold decision to convert the SPS into a proton–antiproton collider to aggressively stalk the weak bosons, W+, W–, Z0, as quickly as possible. This was a risky gambit, but it paid off handsomely.

  The first proton–antip
roton collisions at the CERN SPS were achieved just two years after the project was approved. Two large experiments at the SPS, named UA1 and UA2, started to search the collision debris for signs of weak interaction particles, and in 1983, CERN announced its discovery of the W+, W–, and Z0 bosons. Carlo Rubbia and Simon van der Meer, the two key scientists behind the discovery and the SPS conversion into a collider, received the Nobel Prize in Physics within a year. Fermilab's Tevatron came online later. It should be noted, however, that throughout this period the Fermilab budget (in today's dollars) was about $300 million per year, while the CERN budget was more than $1 billion per year. Money may not buy happiness, but it does buy big science, quickly and effectively.

  Though scooped by the W+, W–, Z0 boson discoveries at CERN, the two Tevatron experimental collaborations, known as D-Zero and CDF, successfully discovered the elusive top quark, the heaviest of all known Standard Model particles, in the mid 1990s. All that remained to find in the Standard Model was its missing link—the Higgs boson. As the Tevatron assumed the role of the world's highest-energy particle accelerator, CERN began to build a new kind of collider, and the physically largest one ever. The new machine was a collider of electrons and their antiparticles, positrons. This was called the “Large Electron–Positron Collider (LEP).7