There are Beanie Babies, plush, tiny stuffed animals with heart-shaped tags. And then there are subatomic particle plushies, the stuffed versions of the constituents of Beanie Babies--soft, cuddly representations of the hadrons and leptons that make up all matter in the universe.
Really, what budding young scientist wouldn't want to take one to bed instead of a Teddy bear?
That's what Julie Peasley was betting on, sort of, when she designed the Particle Zoo line of plushies after seeing hand-made stuffed animals at craft shows.
"I love physics and I love crafts, so I thought why not combine them," she says. "I was sure someone had done it already, but they hadn't."
To maintain the scientific accuracy of her artwork, she strives to learn about particle physics and the people that make it their livelihood. So recently, she visited two of the top-ranking high-energy particle detectors in the world: the CMS experiment at CERN and the CDF experiment at Fermilab. While at Fermilab, she also got a tour of the NuMI tunnel, where a neutrino beam starts its path to the underground MINOS detector in Minnesota.
"I have an art degree," she says. "All my physics knowledge has come from popular science books and science communicators helping expand my understanding."
At CERN, she toured the CMS cavern and walked the platform that put her eye-level with the top portion of the seven-story detector. It was awe inspiring, she says.
At Fermilab, what the CDF detector--at a mere four stories--lacked in stature was made up by its up-close and personal viewing. Peasley's visit coincided with the detector's maintenance checkup, which occurs every one or two years. The detector was pulled apart so crews could make repairs, which also allowed Peasley to view the thousands of wires and layers of metal and scintillating plastic needed to record the data and possible signals of new physics out of millions of proton-antiproton collisions a second. She got to stand next to the muon chamber and peer inside the open detector to see the beam pipe and central tracking chamber.
"Here it is more intimate, more enclosed and smaller, but, honestly, bigger than I thought it would be," she says. "It does seem more complex up close."
Heidi Schellman, a professor at Northwestern University who works with the DZero collaboration at Fermilab, gave Peasley a tour of Fermilab from top to bottom. Schellman had commissioned Peasley to make a strange bottom meson plushie as gifts for three of her PhD students who were studying the particle.
Schellman also asked for a plushie to commemorate the first observation of the single top quark, announced in March by DZero and CDF scientists. The single top quark decays into a bottom quark and a W boson, which in turn decays into an electron and a neutrino or a muon and a neutrino. Peasley created a top quark that decays to its final state by unzipping it, revealing two smaller plush toys: an antimuon and a neutrino. The top quark then can be reversed into a bottom quark. You can see this "decay" in this video.
Special requests such as these have been on the rise, Peasley says.
She has branched off from the basic Standard Model particles to include theorized particles, including, of course, the Higgs boson and antiparticles. Also new is an astrophysics line that includes a brane with five strings attached and a cosmic microwave background plushie that resembles a blob of lava.
Arguably, Peasley chose one of the more visually abstract fields of physics to turn into art. But it was that very nature that of high-energy particle physics that captured her imagination.
"I think it is the most interesting science out there right now because of the mystery," Peasley says. "It is all impressive. CERN is impressive. This is impressive."