Relativity Revealed

Physicists have observed a bizarre prediction of special relativity for the first time

- VICTORIA HELM, THOMAS JUFFMANN AND PETER SCHATTSCHNEIDER

IN HIS CLASSIC SCIENCE-FICTION STORY “THE NEW ACCELERATOR,” PUBLISHED in 1901, H. G. Wells describes a drug that speeds up a person's metabolism by a factor of 1,000. For the two protagonists who valiantly test the potion, the world appears strangely slowed down, almost frozen in movement. The story got one of us (Schattschneider) thinking: If we could slow down time, could we see single photons fly through space? Could we observe relativistic phenomena? In particular, could we ever glimpse a strange prediction called the Terrell-Penrose effect?

The Terrell-Penrose effect would make objects moving at nearly the speed of light look oddly rotated. The notion seems to go against another prediction of Einstein’s special theory of relativity known as Lorentz contraction, which holds that as things go faster they will shrink. Although the Terrell-Penrose effect had been tested in thought experiments and simulated on computers, it had never been demonstrated in real life.

The prospect of real-world testing lay dormant until recently, when one of Schattschneider’s colleagues, quantum scientist Philipp Haslinger of the Vienna University of Technology, mentioned to him an experiment called the SEEC project, which aims to visualize the way light moves across surfaces. He shared a video in which a laser pulse seems to move at a speed of meters per second, only about one billionth of the speed of light. There it was again: the idea of slowing down time—Wells’s New Accelerator, this time in the form of not a magic potion but ultrafast photography.