Seven-year-old Mimi Meade winces from the sting as Dr. Richard Mulvaney inoculates her April 26, 1954 in McClean, Va., with the new Salk polio vaccine. Mrs. John Lucas, a registered nurse, holds Mimi's arm steady as she gets one of the first injections of the countrywide test. (Photo by Harvey Georges/AP Photo)

Pfc. Remy Bouchard swaps a cigarette for an egg with a French Orphan near La Haye Du Puits, France on July 18, 1944, which was captured by American forces. The boy is only twelve years old. (Photo by Hugh Broderick/AP Photo)

Elementary school sumo wrestlers compete in the sumo ring during the Wanpaku sumo-wrestling tournament in Tokyo, Japan July 30, 2017. (Photo by Kim Kyung-Hoon/Reuters)

It’s enough to make your head spin. The photographer Katherine Young set out to shoot spiral staircases in London, England to great effect, including this shot she calls the Downward Spiral Part III. (Photo by Katherine Young/Rex Features/Shutterstock)

A balloon dips into Bald Eagle lake during the 36th Annual Hot Air Balloon Rodeo in Steamboat Springs, Colorado on July 9, 2017. (Photo by Jason Connolly/AFP Photo)

Hitler, Hirohito and Mussolini, in effigy, are about to take a mile-high plunge over Stone Mountain, near Atlanta, Georgia, June 21, 1942, as part of the scrap rubber drive. Private Elias Nour, who arranged the stunt as a farewell party on the eve of his entrance into the army, is on the running board. He guided as the “Axis” plunged to destruction. Spectators had to give a scrap of rubber as the price of admission to the spectacle. (Photo by AP Photo)

Princess Diana relaxes on the sand during a visit to the beach on the Caribbean Island of Nevis January 4, 1993. (Photo by Mark Cardwell/Reuters)

In this photo taken June 3, 2009, a female North Korean soldier looks out from behind a barbed-wire fence around a camp on the North Korean river banks across from Hekou, northeastern China's Liaoning province. North Korea's top court has convicted two U.S. journalists, and sentenced them to 12 years in labor prison, the country's state news agency reported Monday. (Photo by Ng Han Guan/AP Photo)