Jim Beck, an earthquake engineering expert at the California Institute of Technology in Pasadena, wondered if the ring would be worth building if it couldn't protect a structure from different types of shaking, not just different wavelengths. The cloak might only work perfectly in special circumstances, he said.
"It sounds like an interesting idea, but I think there's a long way to go before they get to what they would like to see done," he said.
Guenneau said he hopes that others will take the idea and explore its promising applications. Last year, Guenneau and his colleagues made headlines by building a prototype tsunami invisibility cloak that uses ring-shaped channels to redirect water waves around an object. Now they're probing that idea further in a large-scale experiment.
The reality of making buildings seem invisible to the destructive forces of nature, be they the waves from earthquakes or tsunamis, "seems a bit crazy, but it's not science fiction," Guenneau said. "We gave the people the concept, now people can try to improve it to make it more tractable."