Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

Team McLaren Mercedes drivers Lewis Hamilton (L) and Jenson Button unveil the new MP-27 Formula 1 car at the McLaren technology centre on February 1, 2012 in Woking, England. (Photo by Mark Thompson/Getty Images)

«Little Red Riding Hood». “The moment I pulled this sweater out of the drawer for Frankie I knew what I wanted for my picture today. I envisioned the look, the style, and the composition. When working with a 2 year old it is never easy to actually get the shot you want, especially when they decide to skip nap time. But I really like how this one turned out” – Rich. (Photo by Rich)

A student of the Orchestra of Recycled Instruments of Cateura holds an instrument made from recycled material by craftsman Nicolas Gomez, in Cateura, near Asuncion, May 9, 2013. The orchestra is the brainchild of its conductor Favio Chavez, who wanted to help the children of garbage pickers at the local landfill, and the instruments are made from salvaged materials by craftsman Gomez. The orchestra now involves 30 schoolchildren who have toured countries in Latin America, North America and Europe to play music ranging from Beethoven and Mozart to the Beatles and Paraguayan folk songs. (Photo by Jorge Adorno/Reuters)

The moon is seen in its waxing gibbous stage as it rises behind the helicopter from the original Batman television show, which people can ride at the New Jersey State Fair, Saturday, June 22, 2013, in East Rutherford, N.J. The moon, which will reach its full stage on Sunday, is expected to be 13.5 percent closer to earth during a phenomenon known as supermoon. (Photo by Julio Cortez/AP Photo)

In this October 14, 2013 photo, ecology professor Ricardo Freitas catches a broad-snouted caiman to examine, then release back into the water channel in the affluent Recreio dos Bandeirantes suburb of Rio de Janeiro, Brazil. Caimans are like tanks, a very old species with a remarkable capacity for renovation that allows them to survive under extreme conditions where others couldn't, said Freitas, who runs the Instituto Jacare, or the Caiman Institute, which aims to protect the reptiles. (Photo by Felipe Dana/AP Photo)

Jordan Matter showcases their athletic prowess in everyday situations such as a martial artist shaving with a samurai sword, an ice hockey goalie shopping and a gymnast balancing from a street sign. Photo: “River View” – Jacob Jonas & Jill Wilson – Acro Yoga Specialists. (Photo by Jordan Matter)