Since the beginning of time, artists have been fascinated by the patterns of nature. Today, many artists are taking on nature -- not just as subject, but as medium -- employing natural materials, living organisms, even the wind itself, in their work. Sculptor Ned Kahn uses industrial methods to engineer vast machined installations, revealing the beauty of wind and water in motion. Engineer/artist Natalie Jeremijenko plants 100 pairs of cloned trees throughout San Francisco, rendering the pattern of differences between neighborhoods and microclimates. Bill Dan, also known as the "Rock Man of Crissy Field," takes on nature with his bare hands, creating improbable and striking rock sculptures that mesmerize bystanders.