A silicon rug in the form of Adolph Hitler on display during an exhibition by Israeli artist Boaz Arad, at the Center for Contemporary Art February 22, 2007 in Tel Aviv, Israel. Arad is an Israeli artist who is dealing with the Holocaust in a provocative way. He uses the Holocaust to discuss human evil and contemporary Israel, which he says is torn and crumbling. (Photo by David Silverman/Getty Images)

The Enigma coding machine used by the Germans in WWII on display at Bletchley Park National Code Centre, November 25, 2004 in Bletchley, England. (Photo by Ian Waldie/Getty Images)

Katy Perry attends the premiere of “The Smurfs” at the Ziegfeld Theater on July 24, 2011 in New York City. (Photo by Jemal Countess/Getty Images)

Lightning streaks across the sky as lava flows from a volcano in Eyjafjallajokul April 17, 2010. (Photo by Lucas Jackson/Reuters)

NEPAL: A devotee is smeared with a vermillion powder while celebrating the “Sindoor Jatra” vermillion powder festival at Thimi, in Bhaktapur, Nepal, April 14, 2016. (Photo by Navesh Chitrakar/Reuters)

A vendor holds a fried spider along a street in Phnom Penh, Cambodia, April 10, 2017. (Photo by Samrang Pring/Reuters)

Two sheep fight in a competition in Zhangjiakou, Hebei province, China on August 1, 2017. (Photo by Reuters/China Stringer Network)

A robot named “Robovie-II”, developed by Japanese robotics research institution ATR, moves around at a grocery store during a shopping assisting experiment by utilizing the robot in an ubiquitous network technology platform in Kyoto, western Japan January 6, 2010. (Photo by Yuriko Nakao/Reuters)