JAPAN: A businessman stands at a pond in the Kyu-Shiba-rikyu Garden on a warm and sunny day in Tokyo, Japan, March 18, 2016. (Photo by Thomas Peter/Reuters)

VIETNAM: A Vietnamese woman, wearing the traditional “ao dai” long dress, poses for photos along peach blossom flowers ahead of the Vietnamese “Tet” (Lunar New Year festival), in a field in Hanoi, Vietnam, February 2, 2016. (Photo by Reuters/Kham)

Iranian-Kurdish female fighters hold their weapons during a battle with Islamic State militants in Bashiqa, near Mosul, Iraq on November 3, 2016. (Photo by Ahmed Jadallah/Reuters)

A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

Soap Bubble Structures by Kym Cox. Bubbles optimise space and minimise their surface area for a given volume of air. This phenomenon makes them a useful tool in many areas of research, in particular, materials science and “packing” – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom, which interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst. (Photo by Kym Cox/2019 Science Photographer of the Year/RPS)

India's Central Reserve Police Force personnel take part in a rehearsal for the Republic Day parade on a cold winter morning in New Delhi January 8, 2014. (Photo by Ahmad Masood/Reuters)

A Filipino fan lines up for the One Direction concert Saturday, March 21, 2015 in the suburban Pasay city south of Manila, Philippines. One Direction's “On the Road Again” tour will continue with upcoming performances in Manila, Philippines, and Jakarta, Indonesia, despite the absence of one of its members Zayn Malik, who flew back to London due to “stress”. (Photo by Bullit Marquez/AP Photo)