Knocking on Heaven's Door - Lisa Randall [1]
79. DAMA results.
80. PAMELA results.
81. Nine-dots problem.
82. Thinking outside the box.
INTRODUCTION
We are poised on the edge of discovery. The biggest and most exciting experiments in particle physics and cosmology are under way and many of the world’s most talented physicists and astronomers are focused on their implications. What scientists find within the next decade could provide clues that will ultimately change our view of the fundamental makeup of matter or even of space itself—and just might provide a more comprehensive picture of the nature of reality. Those of us who are focused on these developments don’t anticipate that they will be mere post-modern additions. We look forward to discoveries that might introduce a dramatically different twenty-first-century paradigm for the universe’s underlying construction—altering our picture of its basic architecture based on the insights that lie in store.
September 10, 2008, marked the historic first trial run of the Large Hadron Collider (LHC). Although the name—Large Hadron Collider—is literal but uninspired, the same is not true for the science we expect it to achieve, which should prove spectacular. The “large” refers to the collider—not to hadrons. The LHC contains an enormous 26.6 kilometer1 circular tunnel deep underground that stretches between the Jura Mountains and Lake Geneva and crosses the French-Swiss border. Electric fields inside this tunnel accelerate two beams, each consisting of billions of protons (which belong to a class of particles called hadrons—hence the collider’s name), as they go around—about 11,000 times each second.
The collider houses what are in many respects the biggest and most impressive experiments ever built. The goal is to perform detailed studies of the structure of matter at distances never before measured and at energies higher than have ever been explored before. These energies should generate an array of exotic fundamental particles and reveal interactions that occurred early in the universe’s evolution—roughly a trillionth of a second after the time of the Big Bang.
The design of the LHC stretched ingenuity and technology to their limits and its construction introduced even further hurdles. To the great frustration of physicists and everyone else interested in a better understanding of nature, a bad solder connection triggered an explosion a mere nine days after the LHC’s auspicious initial run. But when the LHC came back on line in the fall of 2009—working better than anyone had dared anticipate—a quarter-century promise emerged as a reality.
In the spring of that same year, the Planck and Herschel satellites were launched in French Guiana. I learned about the timing from an excited group of Caltech astronomers who met May 13 at 5:30 A.M. in Pasadena, where I was visiting, to witness remotely this landmark event. The Herschel satellite will give insights into star formation, and the Planck satellite will provide details about the residual radiation from the Big Bang—yielding fresh information about the early history of our universe. Launches such as this are usually thrilling but very tense—since two to five percent fail, destroying years of work on customized scientific instruments in those satellites that fall back to Earth. Happily this particular launch went very well and sent information back throughout the day, attesting to just how successful it had been. Even so, we will have to wait several years before these satellites give us their most valuable data about stars and the universe.
Physics now provides a solid core of knowledge about how the universe works over an extremely large range of distances and energies. Theoretical and experimental studies have provided scientists with a deep understanding of elements and structures, ranging from the extremely tiny to the very large. Over time, we have deduced a detailed and comprehensive story about how the pieces fit together. Theories successfully describe how the cosmos evolved from tiny constituents that formed atoms, which