Where Big Ideas Take Shape
Situated inconspicuously on the south side of campus is a cavernous building that has witnessed some of the most influential developments in the history of astronomy and physics. Called the Synchrotron Building, the 48-foot-tall structure, originally dubbed the Optical Shop, was constructed in the 1930s as a place to polish and grind the giant 200-inch mirror of Palomar Observatory’s Hale Telescope. In 1949, the building was renamed the Synchrotron Building when construction began on Caltech’s synchrotron, a particle-smashing experiment that sped electrons up to nearly the speed of light. Shown here are a handful of the many projects to have been developed in the Synchrotron Building over the years.
Over the decades, the Synchrotron Building has been a hothouse in developing novel instruments to measure the cosmic microwave background, the glowing relic radiation from the Big Bang. Pictured above is the latest instrument, the BICEP (Background Imaging of Cosmic Extragalactic Polarization) Array, which, like its predecessors, will carry out observations at the South Pole in search of primordial gravitational waves from the Big Bang.
This giant thermos bottle–like vessel currently being built in the Synchrotron Building will be incorporated into the nEDM experiment, which will make precise measurements of the neutron’s electric dipole moment. The experiment, planned to begin at Oak Ridge National Laboratory in Tennessee in about five years, will seek to answer the question: What happened to all the antimatter in our universe?
Eight 10-meter radio dishes, designed by the late Caltech physics professor Robert Leighton (BS ’41, MS ’44, PhD ’47), were constructed in the building at the end of the 1970s. Six of these would go on to be used for studies of the cosmos at Caltech’s Owens Valley Radio Observatory (OVRO); another dish became Caltech’s Submillimeter Observatory in Hawaii; and the final dish went to the Raman Research Institute in India.
At the time of its operation in the 1950s and ’60s, Caltech’s synchrotron was the most powerful atom smasher ever built, operating at energy levels of 1 billion electron-volts. Today’s largest atom smasher, the Large Hadron Collider (at CERN), reaches energy levels up to 14 trillion electron-volts.
The 4,500-pound MOSFIRE instrument now at W. M. Keck Observatory in Hawaii was assembled in the Synchrotron Building over a period of seven years. The near-infrared spectrometer is an astronomy workhorse and has been observing the cosmos since its installation in 2012.
LIGO research took place in the Synchrotron Building in the 1990s and early 2000s. To accommodate the westward extension of a necessary beam tube, a tunnel was dug under the bridge between the Guggenheim and Firestone buildings. Today, one may notice a gentle bump in the pavement directly under the bridge; this is where the tunnel was built.
To prevent Palomar’s 200-inch mirror from being scratched while it was being ground and polished, workers constantly swept and mopped the floor, and even washed the walls of the room. Upon entering the space, workers were required to remove their shoes and clothes, and don rubber-soled shoes and uniforms. A magnetic sweeper was also kept in constant operation on the floor.