This in-the-lab analog of the Unruh effect matches expectations for accelerated motion in space
Empty space might feel hot to a traveler zipping through at a rapidly increasing clip — or so some physicists predict. And a new experiment provides a hint that they might be right.
That idea, known as the Unruh effect, seems to be supported by an analogous effect that appears in a tank of rippling water. Patterns in the waves, when analyzed as if seen by an accelerating observer, appear to re-create the expected signature of the effect, researchers report September 7 at arXiv.org. If it holds up to further scrutiny, the result would mark the first time a version of the Unruh effect has been spotted.
It’s a counterintuitive concept: To an observer moving at a constant velocity, a perfect vacuum would be frigidly cold. But someone accelerating through that empty space might work up quite a sweat. “The Unruh effect is basically saying that if you are accelerated enough in the vacuum, you can burn to death,