You’re not sure where to look first as John Cohn takes center stage at the TEDx event in Delft, Netherlands. Perhaps at the wreath of colored lights that flash in sequence like a movie-theater marquee around his head? How about at the rainbow-tie-dyed lab coat the IBM researcher is wearing?
If that’s not enough to distract you, add to those special effects the natural halo of his joyously white hair and beard, and you can’t help but think you’ve encountered a mad scientist—albeit one with a decidedly hippie bent.
Your first impression of craziness doesn’t falter much when he announces that he’s about to melt iron in a microwave. “Isn’t that stranger than fact?” he chortles ever so slightly as he places a small bundle of steel wool into a microwave. Through the door, you can see the steel wool ignite and glow like the embers of a campfire. “Isn’t that just gorgeous?!” Cohn says, adding drolly, “I would suggest you do it in someone else’s microwave.”
It’s a deft display of changing states of matter, but hardly a dry lecture on physics. (In fact, “Do Try This at Home” is the talk’s title.) With a broad smile and a lively cadence to his voice, Cohn talks about the importance of bringing a playful spirit to work. You must take the time to play to be creative, exhorts a PowerPoint slide flashed on the wall behind him.
It just so happens that his best playfulness revolves around the marvels of science. Cohn (E’91) is a renowned scientist—one of 63 acting IBM Fellows, the most senior technical rank in IBM’s 200,000 person technical community. His specific role there is Chief Scientist for Computer Aided Design. The group he leads helps create chips for everything from camcorders to video games to supercomputers. “I love these chips,” he says. “Just getting the physics to work so that you can get a billion transistor chips to run at over three billion operations per second without melting is a huge challenge.”
In his free time, he happily takes to the stage, like at a TEDx ([technology, entertainment, and design event), presenting an outreach program he calls “Jolts and Volts.” The theatricality reflects his desire to hold an audience in rapt attention, and it works even with the toughest audiences—elementary schoolchildren.
His science outreach began two decades ago. “I wasn’t a sports dad. I was a science dad,” he says. As his sons Max, Sam, and Gabe were growing up, Cohn learned how to make play out of homespun experiments. The appeal of science is ultimately visceral, he says. It has the power to dazzle and delight if properly presented. In other words, make things spark, burn, and explode. “When my kids got older, I found that they really liked blowing things up in the backyard and making sparks,” he says, with something of an understatement.
He has a natural flair for showmanship and “goofiness.” He describes his eccentric look as somewhere between Dumbledore and a vagabond: “I love that image, and I try to live up to it.” Yet the look is preamble to the content, for the goal is to provide the spectacle and the education. “Jolts and Volts” is essentially an overview of electricity from microvolts to megavolts. The demonstrations are fast-paced and definitely off the beaten path. For instance, Cohn runs electricity through a pickle propped up on two forks to demonstrate electrical conductance. Resistance is apparent, too—and futile—as the pickle burns away in the middle like a blown fuse. Other demonstrations include paper towels shot from a cannon and a small robotic car, all delivered to hold even the shortest attention spans.
By his own admission, he likes “going for the big spark, the big zap, the big flame.” He doesn’t necessarily expect that everyone will become a scientist. His goal is to awaken an appreciation for science and engineering. He has presented to tens of thousands.
For this work and his career achievements, Carnegie Mellon has chosen him as the recipient of its 2014 Alumni Distinguished Achievement Award.
His motivation to share the marvels of science has a tragic backstory. His middle son, Sam, died at the age of 14 in a pedestrian accident. Cohn does not sensationalize or glamorize the loss, but it keeps him focused on what genuinely matters. He continues to present his outreach program as a way to honor Sam: “When you light that fire in somebody, it’s all worth it. It’s hard to get excited about stuff that isn’t important.”
Ultimately, his message extends beyond science. It’s about approaching life with joy and creativity. Our most productive and happiest times come when we’re playing, he believes: “The people who actually keep that sense of play are really, really lucky.” He adds, “It’s hard but important!”
Nurturing playfulness, he points out, often requires courage of the I-should-know-better-but variety. For example, one day a few years ago, he was wrestling with a creative block. His boys, who were now young men, took him to a bridge. His youngest son, Gabe, said, “Here, Dad, this will help your creativity,” just before he jumped off the bridge into the river below. Of course, Dad had to follow. How did that plunge help him with his work? His answer: To forget about fear and hesitation—to be bold.
That boldness helps explain how an IBM scientist can be so comfortable wearing, in public, a headband of synchronized lights.