When scientists last September heard and recorded the sound of two black holes colliding a billion light-years away, they did it with a high-performance cluster of computers designed and built by Nor-Tech, a Burnsville firm that is a relative newcomer in the supercomputing industry.

Nor-Tech has been working for a decade with California State University, Fullerton and the University of Wisconsin-Milwaukee, two of the universities involved in the research, on the cluster that made the detection of gravitational waves possible.

The announcement Thursday of the successful discovery by the Laser Interferometer Gravitational-wave Observatory, a $1.1 billion facility in Louisiana known as LIGO, confirmed a theory expressed by Albert Einstein more than a century ago: that a merging of black holes would cause a ripple in space and time.

“When Dr. Bruce Allen [a leading researcher at LIGO] started looking for a supercomputer 10 or 11 years ago, we became married to him,” David Bollig, Nor-Tech’s founder and chief executive, said in an interview. “We’ve been selling them storage space and their computer modeling,” Bollig said.

Nor-Tech’s Orca computing cluster was also used for the simulations and movies shown Thursday at the news conference in Washington at which the discovery was announced.

A computing cluster is formed by linking dozens or hundreds of high-performance PC servers together so their combined processing power can take on a complex task.

Nor-Tech designs and sells such systems, chiefly using servers from Dell, Hewlett-Packard and Lenovo, and sells them to businesses, government agencies and research facilities like LIGO.

Bollig started the company in 1998 as Northern Computer Technologies, a distributor of computer parts. After the 2001 recession sent the firm’s revenue plunging, Bollig reoriented it as a manufacturer called Nor-Tech. For a time, it focused on niches in computing systems that run audio and video equipment and point-of-sale systems at restaurants and retailers.

Today, its prime product is the high-performance computing clusters that have emerged as a cost-effective form of supercomputing. One of its systems is being used by the Federal Aviation Administration to model commercial space travel.

Bollig said he thinks the detection of gravitational waves by the researchers at LIGO was “cool, pretty crazy.”

“They’ve thrown so much money at it that a whole slough of things may open up,” he said.