Penny Farthing cyclists ride near Tower Bridge on June 9, 2011 in London, England. The riders have cycled from Paris ahead of the IG Markets London Nocturne cycling event on June 11, 2011. (Photo by Peter Macdiarmid/Getty Images)

Two attendees compete in the biggest vape cloud competition at the Vape Summit 3 in Las Vegas, Nevada May 2, 2015. According to new research provided to Reuters, youngsters say that performing tricks is one of the top two reasons they began using e-cigs. (Photo by David Becker/Reuters)

“Mr Big Dipper”, Nicholas Roemmelt (Denmark). A stargazer observes the constellation of the Big Dipper perfectly aligned with the window of the entrance to a large glacier cave in Engadin, Switzerland. This is a panorama of two pictures, and each is a stack of another two pictures: one for the stars and another one for the foreground, but with no composing or time blending. (Photo by Nicholas Roemmelt/National Maritime Museum/The Guardian)

Nekama, a baby North Chinese leopard, emerges from a basket at her official presentation to the media at Tierpark zoo on March 15, 2011 in Berlin, Germany. Nekama was born on January 7, 2011 and currently weighs 4.5 kg.

Models pose backstage ahead of the Gary Bigeni show during Rosemount Australian Fashion Week Spring/Summer 2011/12 at Overseas Passenger Terminal on May 4, 2011 in Sydney, Australia. (Photo by Matt King/Getty Images)

Wladimir Klitschko (L) and David Haye attend a press conference on June 27, 2011 in Hamburg, Germany to preview the heavy weight title fight between them which will be held on the 2nd July 2011 at the Imtech Arena. (Photo by Scott Heavey/Getty Images)

Visitors photograph an animatronic Tyrannosaurus Rex at the National Museum of Scotland, July 29, 2011. (Photo by David Moir/Reuters)

“Unexpected x2 (a.k.a. “how much is that doggie in the window”)”. Taiwan, 2011. (Photo and caption by Asian (Street) Impressions)