A reveller of the Salgueiro samba school performs during the second night of Rio's Carnival at the Sambadrome in Rio de Janeiro, Brazil, on February 13, 2018. (Photo by Mauro Pimentel/AFP Photo)

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 child watching the sea while residents try to clear the bed of a river that has been blocked by debris left by Hurricane Matthew, in the commune of Roche-a-Bateaux, in the south west of Haiti, on October 21, 2016. At least 546 people were killed and more than 175,000 people lost their homes when Hurricane Matthew roared ashore on October 4, packing winds of 145 miles (230 kilometers) per hour. (Photo by Hector Retamal/AFP Photo)

This March 1, 2013 file photo shows a worker selecting cigars at the H. Upmann cigar factory, where people can take tours as part of the 15th annual Cigar Festival in Havana, Cuba. (Photo by Ramon Espinosa/AP Photo)

A coach wipes away tears and comforts a girl who was feeling tired during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, May 4, 2016. (Photo by Aly Song/Reuters)

An employee controls the arms of a manned biped walking robot “METHOD-2” during a demonstration in Gunpo, South Korea, December 27, 2016. It stands 13-feet (3,96 m) tall, weighs 1.3 tons and wields a pair of 286-pound (129,73 kg), motion-tracking metal arms. (Photo by Kim Hong-Ji/Reuters)

Cheerleaders wait to perform before the New Year's Day parade in London, Britain January 1, 2017. (Photo by Neil Hall/Reuters)

Yuri Gagarin does not always show up in full-scale astronautics. In this picture he smiles during his summer vacation in Sochi, Russia in 1961 with sunglasses and sunhat in the camera. (Photo by Imago/Eastnews)