A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

Each year Nikon Small World recognizes the excellence of photography taken under the microscope. The contest showcases the beauty and complexity of life. Anyone interested in microscopy and photography can enter the contest and in its 42nd year, Nikon Small World received 2,000 entries from 70 countries. Here: 11th Place; Scales of a butterfly wing underside (Vanessa atalanta). (Photo by Francis Sneyers/Nikon's Small World 2016)

Swiss police officers stand beside of mock gates of the NEAT Gotthard Base Tunnel inside the event hall for the upcoming opening ceremony near the town of Erstfeld, Switzerland May 31, 2016. The celebrations of the opening of the Gotthard Base Tunnel will start on June 1, 2016. With a length of 57 km (35 miles) crossing the Alps, the Gotthard Base tunnel is the world's longest train tunnel. (Photo by Arnd Wiegmann/Reuters)

A fragment of a Koran manuscript is seen in the library at the University of Birmingham in Britain July 22, 2015. A British university said on Wednesday that fragments of a Koran manuscript found in its library were from one of the oldest surviving copies of the Islamic text in the world, possibly written by someone who might have known Prophet Mohammad. Radiocarbon dating indicated that the parchment folios held by the University of Birmingham in central England were at least 1,370 years old, which would make them one of the earliest written forms of the Islamic holy book in existence. (Photo by Peter Nicholls/Reuters)

Shell, which is the replica of the biggest detonated Soviet nuclear bomb AN-602 (Tsar-Bomb), is on display in Moscow, Russia, August 31, 2015. The shell is part of an exhibition organized by the state nuclear corporation Rosatom. (Photo by Maxim Zmeyev/Reuters)

Hollywood actress Malin Akerman helps King Digital Entertainment set the Guinness World Record for the World's Largest Hammock to celebrate the launch of its new game Paradise Bay on Wednesday, September 2, 2015, in Jersey City, N.J. (Photo by Charles Sykes/Invision for King World Entertainment/AP Images)

A street side fruit vendor has his face covered as a precaution against the coronavirus in Kolkata, India, Tuesday, July 21, 2020. With a surge in coronavirus cases in the past few weeks, state governments in India have been ordering focused lockdowns in high-risk areas to slow down the spread of infections. (Photo by Bikas Das/AP Photo)

A cat stretches on top of dried seafood in a shop in the Sheung Wan district of Hong Kong on August 7, 2020. International Cat Day, celebrated on August 8, is a day to raise awareness for cats and learn about ways to help and protect them. (Photo by Isaac Lawrence/AFP Photo)