Tuesday, February 12, 2013

A Pleasing Disruption: Fusion equations pop up on popular TV show


Above, in a scene from a recent episode of the top-rated CBS TV comedy, The Big Bang Theory, lead character Sheldon, a theoretical physicist, works on an equation describing turbulent diffusion in fusion devices. The equation closely resembles another included in a talk by PPPL physicist Greg Hammett at the Kavli Institute in Santa Barbara (inset left). (Graphic by Greg Czechowicz, PPPL)

Greg Hammett, a physicist at the Princeton Plasma Physics Laboratory, was minding his own business one recent evening, chilling, watching a TV show popular with Lab folks and many others – the top-rated CBS comedy, The Big Bang Theory (Episode14, titled “The Cooper-Kripke Inversion”.) Suddenly he saw it: Jim Parsons, the actor playing one of the show’s lead characters – a brilliant, though socially awkward theoretical physicist named Sheldon Cooper – was at work in front of a whiteboard. Scrawled across the board in red-orange magic marker were letters and digits representing an idea that Hammett knew quite well. To his great pleasure, Hammett spied an equation he had helped derive in his research on fusion energy. “This equation describes turbulent diffusion in fusion devices and also describes how performance can be improved by sheared flows that can reduce the turbulence,” Hammett said. “The ovals at the bottom of Sheldon’s whiteboard are meant to illustrate this stabilization mechanism – which we are studying as a possible way to improve fusion reactors – and this is an illustration that I’ve used in my talks.” 

Many researchers in the field of plasma physics have contributed to the development of this theory, fondly known to its adherents as “gyrokinetic turbulence theory.” The key people who developed this particular equation as well as the computer simulations backing them, in addition to Hammett, include: Bill Dorland at the University of Maryland; Mike Kotschenreuther, University of Texas; Mike Beer, Johns Hopkins University; and Ron Waltz of General Atomics. Dorland and Beer were former PhD students who worked with Hammett. Kotschenreuther also earned his doctoral degree from PPPL. And Hamid Biglari, who also played a significant role in the development of the turbulence improvement mechanism in this equation, earned his PhD from PPPL. He is now enjoying a prominent career on Wall Street.

PPPL Physicist Greg Hammett

For Hammett, and other fans of The Big Bang Theory at the Lab, it was a thrill to see fusion science touched upon in the show, which often intertwines high-level scientific conversations on topics such as Einstein’s quest for a unified field theory with young adult obsessions such as finding an attractive date for a Saturday night.

Another important Princeton connection is the show’s science writer-consultant, David Saltzberg, a UCLA physicist and Princeton University graduate who ensures that the show’s scientific content – including all equations -- is accurate. He obviously is very well read!

Hammett isnt sure exactly where Saltzberg found the formulas and illustrations because they have appeared in many talks he and others have given over the years that are available online, such as a talk Hammett gave in 2005 at the Kavli Institute for Theoretical Physics in Santa Barbara.

But Hammett is thinking broadly, looking to see whether the fusion strand will be woven into future installments. Late in this episode, the character Sheldon speaks with a colleague about ideas for a new fusion reactor design. He starts to explain an approach for reducing turbulence, one of the major research issues for plasma physicists at the moment, but is interrupted. "I don't know if we'll ever learn what brilliant ideas Sheldon had," Hammett said.

We can always hope!

Fusionista Kitta MacPherson is the director of communications at the Princeton Plasma Physics Laboratory and an award-winning science writer. 


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