
Visitors walk through artist Fujiko Nakaya’s Fog Bridge, an artificial fog exhibit, on Thursday, Feb. 13, 2014, at the Exploratorium in San Francisco. (AP Photo/Marcio Jose Sanchez)
Visitors walk through artist Fujiko Nakaya’s Fog Bridge, an artificial fog exhibit, on Thursday, Feb. 13, 2014, at the Exploratorium in San Francisco. (AP Photo/Marcio Jose Sanchez)