Purdue University has opened an investigation into “extremely serious” concerns regarding the research of a professor who said he had produced nuclear fusion in a tabletop experiment.

The vibrations, they said, collapsed tiny gas bubbles in the liquid, heating them to millions of degrees, hot enough to initiate fusion. If true, the phenomenon, often called sonofusion or bubble fusion, could have far-reaching applications, including the generation of energy.

No other scientists have been able to reproduce the findings.