British theoretical physicist Stephen Hawking, Cambridge University Professor and Fellow, circa 1985. Stephen Hawking, the brightest star in the firmament of science, whose insights shaped modern cosmology and inspired global audiences in the millions, has died aged 76. (Photo by Gemma Levine/Getty Images)

A demonstrator shows her arm with the name “Marielle” written on it, as she performs during a protest against the murder of councilwoman Marielle Franco in Rio de Janeiro, Brazil, Tuesday, March 20, 2018. Franco's murder came just a month after the government put the military in charge of security in Rio, which is experiencing a sharp spike in violence less than two years after hosting the 2016 Summer Olympics. (Photo by Leo Correa/AP Photo)

Kerry Katona (L) seen attending OK! Magazine's 25th anniversary party at The View from the Shard on March 21, 2018 in London, England. (Photo by Splash News and Pictures)

A woman falls to the beach after she was attacked by three white women segregationists, when she attempted a wade-in with several African American and white desegregationist demonstrators, June 23, 1964, St. Augustine Beach, Fla. The people in the photo are unidentified. (Photo by AP Photo/JK)

Victorious in 129 successive fights, including 40 as a pro, Ray Robinson falls through the ropes of a ring, under the impact of Jake LaMotta's fists on Olympia Stadium, Detroit, Michigan on February 5, 1943. Robinson got back in the ring, but lost the decision in ten rounds. LaMotta pummelled him for the rest of the fight, winning via a unanimous decision, giving Robinson the first defeat of his career.They fought again just 21 days later when Robinson regained his mantle winning in another 10-round fight, Robinson won the close fight by a unanimous decision. LaMotta stated the bout was gifted to Robinson because he would be inducted into the army the next day. (Photo by Bettmann Archive/Getty Images)

Palestinian man Mohammed al-Hoor, 23, demonstrates his street workout skills in Nuseirat refugee camp, in the central Gaza Strip on May 2, 2017. (Photo by Mohammed Salem/Reuters)

The Eiffel Tour-the body language of balance. I came across this group of young adults from Sarajevo, Bosnia, having fun testing their balance two nights ago in on the Esplanade de Trocadero. (Photo and comment by Peter Turnley)

Indonesian mahouts clean their Sumatran elephant in a river near the zoo in Medan, North Sumatra, Indonesia, 12 December 2014. According media reports, the smallest of the Asian elephants, Sumatran elephant (Elephas maximus sumatrensis) is facing serious pressures arising from illegal logging and associated habitat loss and fragmentation in Indonesia. The population has come under increasing threat from rapid forest conversion to plantations. (Photo by Dedi Sahputra/EPA)