This human-scale lab rat cage is parked near a skate park in Denver, Colo., to make a point about the lack of science on marijuana. Richard Feldman Studio/Sukle Advertising and Design hide caption

itoggle caption Richard Feldman Studio/Sukle Advertising and Design

Tom Murphy, San Francisco, 1948 gelatin silver print The Minor White Archive, Princeton University Art Museum hide caption

itoggle caption The Minor White Archive, Princeton University Art Museum

Neonta Williams (left) shares family letters dating back to 1901 with preservationist Kimberly Peach during the Smithsonian's Save our African American Treasures program at the Birmingham Civil Rights Institute. Peach advises her to use archive-quality polyester sleeves to protect the fragile papers, rather than store them in a zip-lock bag. Debbie Elliott/NPR hide caption

itoggle caption Debbie Elliott/NPR

Zhang Kechun. Under the Abandoned Pier, 2013-2014. Zhang, 34, spent years shooting photos along the Yellow River. Zhang Kechun/Courtesy of Three Shadows +3 Gallery hide caption

itoggle caption Zhang Kechun/Courtesy of Three Shadows +3 Gallery

All folded up and ready to magnify: The Foldscope weighs less than two nickels, is small enough to fit in your back pocket and offers more than 2,000-fold magnification. TED/YouTube hide caption

itoggle caption TED/YouTube