The two pipes in which proton beams will travel. Credit: Guido Mocafico
On a summer day, you can ride your bicycle through the narrow lanes that bisect fields of grass on the outskirts of Geneva with no thought that, dozens of meters below, one of the most complex construction projects in human history is underway. The Large Hadron Collider (LHC), just one year from completion at CERN, will be the most powerful particle accelerator ever constructed, the largest and most technologically sophisticated machine ever built, and one of the greatest scientific endeavors humanity has yet undertaken.
The late Austrian-American physicist Victor Weisskopf described the grand particle accelerators that began to take shape around the world in the 1950’s and 60’s as the “Gothic cathedrals of the 20th century.” The comparison was, and is, apt. The medieval cathedrals pushed the limits of available technology, involved the craftsmanship of literally thousands of skilled workers, and took generations (and sometimes centuries) to complete. Modern particle accelerators require decades from conception to completion and involve scientists from about 80 countries, speaking dozens of languages, whose separate handiwork must mesh together perfectly on the scale of thousandths of millimeters. The physical magnitude of these distinct public works projects is similarly comparable—just one of the LHC’s four detectors is large enough to house the Notre Dame Cathedral.
But the true comparison that probably drove Weisskopf to make his claim is more subtle. Cathedrals were designed to celebrate the glory of God as manifested through the human spirit in words, music and art. The LHC has been engineered to celebrate and proclaim the glory of the natural world, and of our remarkable ability to comprehend it, as manifested through experimental science. It will probe the structure of matter on scales 10 billion times smaller than anything “nano,” creating fleeting elementary particles that, since the Big Bang, have existed almost exclusively in the imagination of theoretical physicists. The issues it will seek to address range from the origin of mass to the origin of matter; from surpassing the near-complete Standard Model of physics, that precisely governs particle interactions on a subatomic scale, to unveiling the very fundamental mathematical symmetries that guide the structure and makeup of the natural world.
Weisskopf’s comparison is also worth reflecting upon as we recall that Gothic Cathedrals, like their modern counterparts, strained the purse strings of the communities where they were built. The LHC’s cost will exceed $8 billion. In a practical world, particularly one in which government deficits and basic human needs abound, one may reasonably ask whether such public largesse can be afforded to such a minority of special interest, particle physicists.
One argument is that the cost of the LHC, built as part of an international collaboration over a decade, pales in comparison to the cost of other government outlays, including maintaining the war in Iraq for a few months. But it is disingenuous to compare apples and oranges in this way. The real question is whether we as a culture can afford not to pursue the questions about the universe that have baffled us for millennia, especially now that we may have the capability to discern the answers. Science is often celebrated as the source of technology, but I believe that celebration is misplaced. Science is a vital part of our culture. Like any lasting piece of art, music or literature, it compels us to reassess our place in the universe—to question where we come from, and where we are going. To turn our back on these questions is to dismiss our cultural inheritance.
Indeed, when Robert Wilson, the first director of the Fermi National Accelerator Laboratory near Chicago was summoned before a US House of Representatives committee to justify the exorbitant cost of his accelerator, he was asked whether it would aid in the defense of the nation. He answered, “It has nothing to do directly with defending our country, except to make it worth defending.”
High school students today do not study the plumbing of the ancient Greeks, but we hope they still marvel at the elegance of Plato and Socrates. When we think of the great civilizations that have come before us, we associate their greatness with the ideas that drove their culture forward. We remember their efforts to confront the mysteries of the natural world, from the astronomy of the Chinese to the mathematics of the Arab masters, to the natural philosophy of ancient Greece and Rome. The Large Hadron Collider, and the discoveries it may make, are a part of our legacy for future generations.
An internal view of the CMS detector. Credit: Guido Mocafico
Will the LHC live up to our hopes? The particle physics community has every reason to believe new discoveries will be made at the LHC to reinvigorate a field that has, for too long, been starved of data that might point beyond the Standard Model. Major discoveries—ranging from the observation of new “superpartners” of ordinary particles, to new forces and the more exotic possible disappearance of energy into hypothesized extra dimensions—tease the imaginations of theorists. But it could also be that the hoped-for new phenomena may elude us; indeed, they may not exist. As unfavorable as this might appear to be for the prospects of a new generation of accelerators, even this worst case will teach us something of fundamental importance about nature. Indeed, a lack of new phenomena may be the most unexpected and exciting discovery of all. We have nothing to lose. Null experiments may not be as exciting as positive discoveries, but they can change a field. (One need only recall the Michelson-Morley experiment, whose failure to detect the aether helped pave the way for Einstein’s Theory of Relativity). The LHC could tell us that the machinations that have occupied particle theorists for the past two decades, and have been source material for books and television shows, may have been misplaced—to be supplanted by even more exciting ideas yet to be born.
The effort to understand the natural world is not a humble enterprise, and neither should it be. It represents the very best of what we celebrate about being human, and provides the otherwise unimaginable insights that illuminate our brief existence here on this lonely planet. The LHC is the next immodest step in the noble tradition of unlocking the mysteries of the heavens, seeking to capture their haunting grandeur while firmly on the ground. That is its ultimate justification. The shared motivation and hubris that have propelled us from Galileo’s first sight of Jupiter’s moons, to the Hubble Space Telescope’s intimate vision of deep space, are its impetus, and it is this intellectual endeavor—to explore the unknown possibilities of existence—that justifies pushing hard at the edges of our knowledge and ultimately defines what we call civilization.
Lawrence M. Krauss is Ambrose Swasey Professor of Physics, Professor of Astronomy, and Director of the Center for Education and Research in Cosmology and Astrophysics at Case Western Reserve University. His latest book is Hiding in the Mirror: The Mysterious Allure of Extra Dimensions, from Plato to String Theory and Beyond.
Originally published May 30, 2006