Going golfing during a drought is practically Gatsbian in its excess, even if the course uses recycled water. (“A ‘responsibly managed’ golf course still used 83 percent more water to irrigate its plants than was necessary,” writes Joel Makower of GreenBiz.) So it’s doubly insulting to us plebes that golf clubs might have started two recent fires in California.

In a new paper in Fire and Materials, UC Irvine researchers explain how relatively new, lightweight titanium golf clubs spark when they hit a rock, unlike traditional stainless steel clubs — and the sparks are hot enough to start a fire. Watch awesomely named UC Irvine professor James Earthman make sparks fly:

After two golfers confessed to starting fires, the Orange County Fire Authority asked if the researchers would investigate. Reports the New York Times:

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[Their research] clears up what fire officials in Southern California have seen as a mystery: the origin of two recent golf course fires, including one that burned 25 acres and injured a firefighter in 2010.

Steve Concialdi, a captain with the Orange County Fire Authority, in Irvine, said that in both incidents, golfers using 3-irons with titanium-alloy heads had said they hit the ground and created sparks that started the fires.

“That was hard for anybody to believe,” Concialdi said. “We were thinking they were started by cigars or cigarettes.”

Well, you probably shouldn’t toss your smoldering cigar into some dry grass during a drought, either. Probably best to stay in the basement watching Netflix.

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