A new test of water ripples supports the idea of quantum heat in a vacuum
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.