Two Miles Straight: SLAC and the Long Patience of Basic Science

Drive along Sand Hill Road toward the foothills and you pass, almost without noticing, one of the most remarkable structures ever built by a university. It is long, low, and ruler-straight, running for roughly two miles through the rolling grassland west of the main campus. Its builders called it Project M. The scientists who conceived it called it, affectionately, “the Monster.” Today it is the spine of SLAC National Accelerator Laboratory, which Stanford operates for the U.S. Department of Energy.

Construction began in 1962. The goal was to accelerate electrons to nearly the speed of light and slam them into targets, then study the debris for clues to the structure of matter. Research began in 1966, and within a few years the machine was producing results that would reshape physics. According to the laboratory’s own count, four Nobel Prizes have been awarded to six scientists for research carried out at SLAC.

What the Monster Found

The roll of discoveries is worth reciting, because each item represents years of patient, uncertain work. In 1968 experiments at SLAC produced the first evidence that protons and neutrons are made of smaller constituents, the particles now called quarks. That work earned the 1990 Nobel Prize in Physics for Richard Taylor of SLAC, shared with Henry Kendall and Jerome Friedman of MIT.

In 1974 a SLAC team led by Burton Richter discovered the particle now known as the J/psi, a finding announced simultaneously by a group at Brookhaven led by Samuel Ting; the two shared the 1976 Nobel Prize. In 1975, after years of persistent effort in the face of widespread skepticism, Martin Perl identified the tau lepton, the first member of a third family of fundamental particles. He shared the 1995 Nobel Prize. And in 2006 Roger Kornberg received the Nobel Prize in Chemistry for work on how DNA’s instructions are transcribed, research carried out partly at SLAC’s synchrotron facility.

The list illustrates something that the word “laboratory” can obscure. SLAC was not built to solve a particular problem. It was built to ask questions whose answers no one could predict, and the most consequential of those answers arrived years after the machine was switched on.

The most consequential answers arrived years after the machine was switched on, which is exactly how basic science is supposed to work.

A Machine That Reinvents Itself

Perhaps the most instructive feature of SLAC’s history is that the same physical infrastructure has been repurposed again and again. The laboratory has gone by three names: Project M, the Stanford Linear Accelerator Center, and, since 2008, SLAC National Accelerator Laboratory. The change reflects a broadening mission. Particle physics remains part of the work, but the lab now also serves chemists, biologists, materials scientists, and astrophysicists.

Sections of the original linear accelerator now drive the Linac Coherent Light Source, which began operating in 2009 as the world’s first hard X-ray free-electron laser. Its ultrafast, ultrabright pulses allow researchers to watch chemical reactions and molecular motion on timescales that were previously inaccessible. SLAC also built the main instrument for NASA’s Fermi Gamma-ray Space Telescope, which began mapping the sky in 2008, and contributed technology to the ATLAS experiment at CERN that helped discover the Higgs boson in 2012.

There is a small, lovely footnote in the laboratory’s lore: its first scientific discovery predated any experiment. During excavation for the accelerator in 1964, workers uncovered the fossil of an ancient marine mammal, a reminder that the ground beneath the foothills has its own long history.

Why Patience Is the Point

It has become fashionable, in Silicon Valley and beyond, to measure research by its time to market. SLAC is a standing rebuke to that habit. The discovery of quarks did not produce a product. The tau lepton has no consumer application. Yet the instruments, techniques, and trained people that emerged from this work have seeded fields from medical imaging to materials design, and the X-ray science now practiced at the lab is directly relevant to drug discovery and energy research.

The deeper lesson is about institutional temperament. A university that hosts a facility like SLAC is making a commitment measured in decades. It must tolerate long stretches without headlines, fund work whose payoff cannot be forecast, and resist the temptation to judge a two-mile machine by last quarter’s results.

That temperament is increasingly rare, and increasingly valuable. In a region that prizes speed, the straight line in the hills is a reminder that some of the most important things are built slowly, and pay off on a schedule no one can set in advance. This section of The Stanford Chronicle will return often to research of that kind: work whose value lies precisely in its patience.