Hugh Pickens DOT Com writes: Things to pack in your golf bag: clubs, balls, tees, beverages and a fire extinguisher. The NYT reports that scientists have determined that striking a rock while swinging a titanium club can create a shower of sparks that are hot enough, and last long enough, to start a brush fire. The finding, by researchers at the University of California, Irvine, clears up what fire officials in Southern California have seen as a mystery: the origin of two recent golf course fires in Irvine and Mission Viejo including one that burned 25 acres and injured a firefighter in 2010. “That was hard for anybody to believe,” says Steve Concialdi, a captain with the Orange County Fire Authority. “We were thinking they were started by cigars or cigarettes.” Most clubs come with stainless steel heads, but a significant number have recently been produced with a titanium alloy, which makes them lighter and easier to swing. The only problem is that, when struck against hard surfaces — like rocks or concrete — the impact with the rock abrades the titanium surface, producing small particles — up to about one-fiftieth of an inch in diameter — that burned for up to a second, at temperatures high enough to cause dry vegetation to ignite. Given the drought in California and the extreme fire danger, Concialdi says the fire department is asking golfers using titanium-coated clubs to move their balls away from rocks and dry vegetation and onto the irrigated fairways. He says while golfers may complain it's making the game easier, it's too risky to do otherwise this season. "Talk about a hazard," says Concialdi. "We are looking at a severe fire season because of the drought, and no one should take chances with titanium clubs on dry ground."