PROVIDENCE – Using pulses of high-intensity sound, two Brown University physicists have succeeded in making a movie showing the motion of a single electron. Humphrey Maris, a physics professor at Brown, and Wei Guo, a Brown doctoral student, were able to film the electron as it moved through a container of superfluid helium.
To observe the motion of an electron – an elementary particle with a mass that is one billionth of a billionth of a billionth of a gram – had previously been considered impossible. The images, which were published online on May 31 by the Journal of Low Temperature Physics, show scattered points of light moving down the screen – some in straight lines, some following a snakelike path.
“We were astonished when we first saw an electron moving across the screen,” said Maris. “Once we had the idea, setting it up was surprisingly easy.”


