American free climber Dean Potter walks on a 41-meter-long and two-centimeter-wide slackline over Enshi Grand Canyon at an altitude of 1,800m on April 22, 2012 in Enshi, Hubei Province of China. Potter successfully finished the lone slackline walk in about three minutes without taking any protective measures. (Photo by ChinaFotoPress/ChinaFotoPress)

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

Russian Tu-95MS strategic bombers fly in formation during rehearsals for the Victory Day military parade, with St. Basil's Cathedral seen in the foreground, in central Moscow May 5, 2015. Russia will celebrate the 70th anniversary of the victory over Nazi Germany in World War Two on May 9. (Photo by Tatyana Makeyeva/Reuters)

Two ancient bronze coins, which according to Israel Antiquities Authority archaeologists were struck by the Roman procurator of Judea, Valerius Gratus, in the year 17/18 CE and recently were revealed in excavations beneath the Western Wall in Jerusalem's Old City are exposed to the media' on November 23, 2011 in Israel. (Photo by Lior Mizrahi/Getty Images)

Firefighters extinguish a fire in Kampar, Riau province on Indonesia's Sumatra island on August 13, 2019. Indonesian authorities are deploying thousands of extra personnel to prevent a repeat of the 2015 fires, which were the worst for two decades and choked the region in haze for weeks. (Photo by Wahyudi/AFP Photo)

Actress Tiffany Haddish sits on top of two garbage cans after getting shoved down by passerbys with a scraped knee only to have Billy Crystal come to her rescue filming “Here Today” in Brooklyn, New York on October 28, 2019. (Photo by Christopher Peterson/Splash News and Pictures)

A male Philippine eagle named Geothermica is seen in an exclosure at Jurong Bird Park in Singapore on November 27, 2019. Singapore unveiled two Philippine eagles at its main aviary November 27, the first breeding pair of the critically endangered raptors to be brought outside their native country as part of a conservation plan. (Photo by Roslan Rahman/AFP Photo)

A robot, developed by start-up firm Asimov Robotics, holds a tray with face masks and sanitizer after the two robots were launched to spread awareness about the coronavirus, in Kochi, India, March 17, 2020. (Photo by Sivaram V/Reuters)