Pooh, a one-year-old cat, who lost his hind legs in an accident and has been given bionic paws, walks in a vet clinic in Sofia on January 31, 2017. Pooh, who is thought to have lost his legs in a car or train accident last April, is back on the prowl thanks to Bulgarian veterinary surgeon Vladislav Zlatinov. He is the first vet in Europe to successfully apply the pioneering method of Irish neuro-orthopaedic surgeon Noel Fitzpatrick, who shot to fame in 2009 when making Oscar the first bionic cat by fitting him with new hind legs in Britain. (Photo by Nikolay Doychinov/AFP Photo)

Microsoft co-founder Paul Allen has spent the last six years working on a giant aircraft capable of launching rockets to space. Today, his company Stratolaunch Systems literally rolled that plane out of its hangar in the Mojave Desert for the first time ever.

These Arab recruits line up in a barracks square in the British Mandate of Palestine, on December 28, 1940, for their first drill under a British solider. Some 6,000 Palestinian Arabs signed up with the British Army during the course of World War II. (AP Photo)

First lady Michelle Obama (R), joined by daughters Sasha Obama (C) and Malia Obama, is presented with the official White House Christmas Tree on November 25, 2011 in Washington, DC. The tree, a 19-foot-tall balsam fir, was grown on Schroeder's Forevergreens farm near Neshkoro, Wisconsin. (Photo by Brendan Hoffman/Getty Images)

Participants learn how to survive in the wild, including tips on how to make it through a zombie invastion at a “Zombie First Responder” course March 11, 2012 in Sandy, Oregon. In an intensive 2-day curriculum participants train in everything from wilderness and urban survival, nerf or nerd weaponry, stealth and evasion, and proper zombie “disposal”. (Photo by Natalie Behring/Getty Images)

Three men display their tattoos during the International Malaysia Tattoo Expo in Kuala Lumpur on November 29, 2019. The international tattoo expo is held for the first ime in Kuala Lumpur celebrating that art of tattoo and gathering over a hundred tattoo artists from 40 countries. (Photo by Mohd Rasfan/AFP Photo)

Cheerleaders wearing face masks due to the outbreak of the coronavirus disease (COVID-19) are seen at the first professional baseball league game of the season at Taoyuan International baseball stadium in Taoyuan city, Taiwan, April 11, 2020. (Photo by Ann Wang/Reuters)

A woman in a face mask dances inside the club on the opening of the summer season for “Villa delle Rose”, one of the most famous clubs on the Adriatic Coast on June 20, 2020 in Rimini, Italy. The Villa delle Rose is among the first dance clubs to reopen in the Adriatic Riviera after the Covid-19 pandemic. (Photo by Max Cavallari/Getty Images)