A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

Pope Francis greets the crowd from his popemobile in downtown Rio de Janeiro. Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil, home to the world's largest Roman Catholic population. (Photo by Ueslei Marcelino/Reuters)

“Sperm whale opening it's huge mouth, Ogasawara Islands, Japan. Sperm whales are the biggest carnivorous animals on the planet. Each teeth in the mouth of adult specimen weights more than 1 kilogram. Interestingly enough that modern marine biologists believe that these teeth despite being fearsome play little role in capturing and eating giant squid – with their main function being mainly ritual aggression between males!”. (Photo by Alexander Safonov)

Men carry others, so they do not soil their shoes and clothes, through a mudslide caused by Tropical Storm Erika in Carries, Haiti, August 29, 2015. Erika, a tropical storm that killed 20 people on the Caribbean island of Dominica and at least one person in Haiti, fell apart on Saturday over eastern Cuba, the U.S. National Hurricane Center said. (Photo by Andres Martinez Casares/Reuters)

A little boy shouts “Earthquake!” during a shouting contest, part of the annual evacuation drill on the National Disaster Prevention Day on September 1, 1986. The contest was aimed at teaching youngsters the importance of telling neighbors quickly and loudly of a disaster when it hits. The drill is annually conducted through out the country on the day marking the anniversary of the Great Kanto Earthquake that hit the Japanese capital and its vicinity on September 1, 1923, killing more than 104,000 people. (Photo by Sadayuki Mikami/AP Photo)

Karis, a one month old lion cub being weighed at Blair Drummond Safari Park near Stirling, Scotland, Thursday October 10, 2013. Weighing in at 5kg, the cub will stay with her mother, Teekay until she is 12 weeks old before they are returned to the pride. (Photo by Andrew Milligan/AP Photo/PA Wire)

Framed by the setting sun, an American Bison grazes at the Tallgrass Prairie National Preserve on Tuesday, April 28, 2015, near Strong City, Kan. The buffalo herd at Tallgrass is one of the few herds of wild bison left in the United States. (Photo by Travis Heying/The Wichita Eagle via AP Photo)

Undated UK Ministry of Defence handout photo of an RAF Tornado GR4 which has been painted in Gulf War “desert pink” paint scheme to honour the aircraft type's almost continuous operational service since the Royal Air Force helped liberate Kuwait from Saddam Hussein's forces, taken by SAC Rose Buchanan, which has been shortlisted for the general public to pick their favourite RAF Image of the Year. (Photo by SAC Rose Buchanan/MoD Crown Copyright/PA Wire)