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)

A competitor drives his homemade vehicle without an engine during the Red Bull Soapbox Race in Amman, Jordan on September 20, 2019. (Photo by Muhammad Hamed/Reuters)

A staff member sets up a ROBOTLEO robot at the Global Mobile Internet Conference (GMIC) 2017 in Beijing, China April 28, 2017. (Photo by Jason Lee/Reuters)

This week's full Moon as photographed from on board the International Space Station by NASA astronaut Jeff Williams on August 19, 2016. Jeff is currently Commander of the Space Station for the Expedition 48 crew. (Photo by Jeff Williams/NASA)

An innovative artist has camouflaged nude bodies by painting them into the worlds most expensive artworks. New York body artist, Trina Merry picked the 20 top dearest paintings, then photographed naked models disguised as part of the piece. Here: Titled 8,100,000 after the price paid for Bal du moulin de la Galette. (Photo by Trina Merry/Caters News)

In 1994, after the fall of the Soviet Union, all Ukrainians had to get a new passport – and photographer Alexander Chekmenev was on hand to take their photos. The snatched extra shots he took are remarkable in their honesty and tenderness. (Photo by Alexander Chekmenev/The Guardian)

Parts of the Royal Chariot, which will be used during the late King Bhumibol Adulyadej's funeral later this year is seen at the National Museum in Bangkok, Thailand, February 6, 2017. (Photo by Chaiwat Subprasom/Reuters)

Andrey Karr from Western Riders Slacklines at sunset above big waves in Nazare, Portugal on December 27, 2017. (Photo by Aidan Williams/National Geographic Travel Photographer of the Year Contest)