Nanoflowers, each smaller than the thickness of a dollar bill, sprout up spontaneously on a surface dipped in salts and silicon. Courtesy of Wim Noorduin/Harvard University hide caption

itoggle caption Courtesy of Wim Noorduin/Harvard University

Sonny Vaahn, 25, holds his family's refugee identification in Bronx, N.Y. The card was issued to them during their initial entry into a refugee camp along the Thai-Cambodian border after the "killing fields" atrocities ended in Cambodia. Courtesy of Pete Pin hide caption

itoggle caption Courtesy of Pete Pin

Swedish photographer Paul Hansen did not artificially manipulate his prize-winning picture "Gaza Burial," the World Press Photo Foundation said Tuesday. Critics had said the image was a composite of several photos. AFP/AFP/Getty Images hide caption

itoggle caption AFP/AFP/Getty Images

A sapeur poses for a photo while a crowd waits in line for a concert organized by KVV Mouzieto, an important sapeur who lives in Paris, to promote his first music album. The ministry of communication and many sapeurs were invited for the event. Hector Mediavilla/Picturetank hide caption

itoggle caption Hector Mediavilla/Picturetank

Ricardo Galvez, Giovanna Meneses Pisco and Arely Betzabe pose for a photograph in front of their former home El Ayllu. The family was back in the neighborhood to gather some of their belongings, and Giovanna spent the hours teary-eyed. As soon as families moved out, the Ministry of Transportation and Communications, with the help of paid community members, began to demolish the buildings. Courtesy of Elie Gardner hide caption

itoggle caption Courtesy of Elie Gardner

The elaborately tiled City Hall subway station in New York City — still extant but now closed to the public, alas — used the Guastavino touch to convince wary city dwellers to head underground for a train trip. Michael Freeman/National Buildling Museum hide caption

itoggle caption Michael Freeman/National Buildling Museum