Dr. Curt Stager took students to Walden Pond, the retreat of philosopher and citizen scientist Henry David Thoreau, to take sediment samples and compare modern observations with the meticulous records kept in Thoreau's journals.They found evidence of a changing climate and a lake ecology that has been altered by human use. The graphic novel that records the expedition might have bemused and amused the famed transcendentalist. Curt talks about the work with Martha Foley.