In the stillness and noise of the M.R.I., I picture what the magnet is doing to my brain. I imagine hydrogen protons aligning along and against the direction of its field. Bursts of radio waves challenge their orientation, generating signals that are rendered into images. Other than the sting of the contrast agent, the momentary changes in nuclear spin feel like nothing. “Twenty-five more minutes,” the radiologist says through the plastic headphones. Usually, I fall asleep.
I’ve had more than 50 scans since 2005, when I received a diagnosis of multiple sclerosis, and I now possess thousands of images of my brain and spine. Sometimes I open the files to count the spinal-cord lesions that are slowly but aggressively taking away my ability to walk. On days my right leg can clear the ground, it feels as if a corkscrew is twisting into my femur. I take halting steps, like a hapless robot, until it’s impossible to move forward. “Maybe in 10 years there will be a pill, or a treatment,” a doctor told me.
For now, even a sustained low fever could cause permanent disability, and medications that treat the disease have left me immunosuppressed, making fevers more likely. I quarantined before it was indicated, and what I miss most now, sheltering in place, are walks through my neighborhood park in Los Angeles with my dog, who gleefully chases the latest bouncy ball I’m hurtling against the concrete. Her current favorite is the Waboba Moon Ball, which comes in highlighter fluorescent yellow and Smurf blue, among other colors. Technically Moon Balls are spherical polyhedrons. They sport radically dimpled surfaces, as if Buckminster Fuller had storyboarded an early pitch for “Space Jam.” Moon Balls are goofy, but they bounce 100 feet.
The golden age of bouncy balls began in 1965, with the introduction of the SuperBall. Wham-O claimed the toy was made of Zectron, an atomic-age label for synthetic rubber that was cured with sulfur and compression molded at high temperatures. The result was an “ultraelastic” solid sphere that, unlike most every other type of rubber ball, barely deformed upon collision and consequently returned to the bouncer with hard-to-discern spin, often at punitive speed. “It’s almost alive!” went an old slogan. Wham-O sold millions of them for 98 cents apiece, a high price considering the fundamentally unsporty nature of ultraelasticity. Lots of people bounced their SuperBall only once, high above the treetops, before losing it to tall grass, a crawl space beneath a house, a sewer. One beautiful arc.
It was Norman Stingley, the SuperBall’s chemist-inventor, who discovered the closest thing to a replicable trick shot. Thrown without spin between two horizontal parallel surfaces, like the underside of a dining table and the floor, a SuperBall reverses direction after the second bounce, only to return to the hand of the thrower after the third, like magic. Around 1967, the Nobel Prize-winning physicist Luis Walter Alvarez showed the “table trick” to his colleague Richard Garwin, who at age 23 had designed the first hydrogen bomb. Garwin had a day job at I.B.M. but found time to write a five-page paper describing the mechanics of the SuperBall’s “bizarre behavior.” SuperBalls became the darlings of physics professors, who took them to classes and circumscribed their bounces in equations and matrices at just the moment when cheap Zectron knockoffs were hitting gumball machines worldwide.
The technology continues to advance. One newer ball contains compressed helium; others skip uncannily across the surface of water. The patent of one of my favorites describes a ball meant to bounce with “limited unpredictability,” which is also great shorthand for the state I want to embrace. The scholarship has also advanced. Bouncy balls, scientists learned, spin faster than other balls and change spin more readily. In a 2004 paper, Todd Hefner at the University of Washington’s Applied Physics Laboratory demonstrated how an ultraelastic ball bounced into a narrow vertical channel may come bounding back out, as if in protest. “The superball problem has always been a diversion and welcome distraction,” Hefner told me.
Garwin was also a creator of an early form of computer memory that used liquid as a storage medium. The technique didn’t make its way into personal computers — but it did solve a hard problem of nuclear magnetic resonance, and the underlying technology is used in all M.R.I. machines. During my last scan in February, after the hospital’s parking attendants had begun wearing face masks, I thought about this, as well as Garwin’s research on pandemics, which found that personal protections like distancing were the best means to change the trajectories of outbreaks. Like the textbook spins of protons and SuperBalls, these pandemics can be modeled with precision. But the models are only models.
To bounce a ball at the dog park, in the full bleed of morning sunshine, is to hear its optimistic pop, to embrace a state of not knowing. The first bounce goes so high that it leaves me with enough time to put down my coffee, take the phone out of my pocket and unlock the camera before the ball hits the ground again. Time slows, and by then, the dog has caught it. It’s a tantalizing suspension. To not have to think about anything else is a temporary relief from the known laws of the universe, the ones that will repeat to me, again and again, that what’s coming my way is inevitable.