Reflections on RHIC’s Summer Sunday
By Elizabeth Wade
My taste in scientific instruments tends toward the out-dated, arcane, and decommissioned—in a word, junk. Ever since my regular childhood visits to Berkeley’s Lawrence Hall of Science, where Ernest Lawrence’s first cyclotron is displayed in a circular room dedicated to its honor and a later, larger version of the device serves as a sculpture on the lawn outside, I’ve been intrigued by the stories of past physics experiments and the machines that made them possible.
Whether due to the relatively small scale of the experiments performed on them or the forgetfulness of history, these machines tend to be associated with the kind of blockbuster names that send chills down your spine when you think, “He (or, much more infrequently, she) stood right here and pressed that start button.” Also, they tend to be small enough to have things like start buttons, a touch that brings them out of the mythical status of the discoveries they helped make and back down to the human scale. And even the most groundbreaking of contraptions can let its hair down once it has been decommissioned—kids can climb on the Lawrence Hall of Science’s cyclotron “statue,” the piece of the cosmotron that adorns a Brookhaven lawn looks remarkably like Pac-Man, and when I returned from a summer at Fermilab with a picture of the lab’s old bubble chamber (below), a friend asked, “Where did you intern? Willy Wonka’s factory?”
But even after cyclotron hunting in Columbia University’s tunnels and decorating my room with bubble chamber tape and slide rules, I had yet to see the inner workings of a machine that hadn’t been retired well before I was born. So when John Haggerty invited me out to Brookhaven for RHIC’s Summer Sunday, I was particularly excited to see an accelerator and detectors that were not only operational, but exceedingly relevant—and best of all, temporarily shut down and opened up.
After a brief presentation about RHIC and an introduction to the laboratory by Derek Lowenstein, I was treated to personal tours of the PHENIX and STAR experiments, as well as a trip into the RHIC tunnel itself. All of my guides were eager to discuss their work and answer my questions about their experiments. And as fascinating as it was to hear about quark-gluon plasma from scientists who had worked to discover it, I was really charmed by details like a cardboard box sitting inside the STAR detector, or repairs to the PHENIX detector made with tape—signs of improvisation, resourcefulness, and most of all, hard work.
One of the attractions of the experiments done with a machine like RHIC is their grand scale—we can explore and understand the universe well beyond the limits of human perception and often, it seems, human imagination. Quark-gluon plasma is out of this world—literally. The fractions of a second after the Big Bang are the furthest away from the human scale you can get, and the fact that we learn about them by colliding unimaginably small atomic nuclei can make it difficult to identify with the quest to understand them. Add to that questions like dark matter, supersymmetry, and extra dimensions and you might as well be in the realm of science fiction.
While the experiments done on earlier machines may have seemed just as far-fetched during their time, the approachability of the machines themselves brings them back down to earth. Lawrence’s first cyclotron is small enough to hold in your hand, while I had to climb three stories of scaffolding to get to the top of the PHENIX detector. But from my new vantage point, I could see the small imperfections that gave the experiment its personality. The aluminum foil used to reduce background noise and the mind-boggling tangles of wires may go unmentioned in papers and press releases, but they are the details that tell the stories of the hundreds of people who worked together to build the machine, and continue to do so to keep it running.
The leap into the unbelievable that started with relativity and quantum mechanics is fuelled by curiosity but sustained by ingenuity. And while today’s experiments may be orders of magnitude more complicated than those able to be done with a cyclotron, the part of them that gives you chills is still their human touch.
Thank you to Derek Lowenstein, Ed O’Brien, Waldo MacKay, Timothy Hallman, and Achim Franz for giving me a unique look into the work they do, and a special thanks John Haggerty and his family for making my visit possible with their friendliness and hospitality.