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)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)

Best portfolio winner. Roseate Spoonbill, Platalea ajaja, by Petr Bambousek, Czech Republic. (Photo by Petr Bambousek/2018 Bird Photographer of the Year)

Scared of Heights. “Taken from the highest residential building in Asia: the Zenith in Busan. This was taken with official permission (which took me months to get) and safety measures were taken. I had to hang myself over the edge to get this shot. Not for the faint of heart! But when you’re at a height like this, the world below you just seems different. It takes away the fear one would normally have, and gives a sense of peace instead”. (Photo by Albert Dros/NatGeo Cities Travel Photographer of the Year 2017)

“Mr Big Dipper”, Nicholas Roemmelt (Denmark). A stargazer observes the constellation of the Big Dipper perfectly aligned with the window of the entrance to a large glacier cave in Engadin, Switzerland. This is a panorama of two pictures, and each is a stack of another two pictures: one for the stars and another one for the foreground, but with no composing or time blending. (Photo by Nicholas Roemmelt/National Maritime Museum/The Guardian)

Two women wearing nun outfits drink beer while watching the 2014 Tim Hortons Brier curling championships in Kamloops, British Columbia in this March 8, 2014 file photo. Although some people might conclude that a curling event could produce a dull atmosphere, it is actually far from it. Some of the most energetic and loyal fans are committed to showing their colours at tournaments around the world. There was a lull in the games that were being held on this day and I remember spotting these nuns sitting in their seats earlier. Although them just sitting there didn't produce a picture, I kept my eye on them for the entire match. As soon as I spotted them with beer in their hands, I slowly turned my camera towards them and waited for them to take a drink. One of the challenges of shooting this image was to not have everyone notice me taking the photo. I had a longer lens on and was right in the middle of the rink. I slowly turned my lens, not to make my intentions too obvious, and waited until they drank from their beers together. (Photo and caption by Ben Nelms/Reuters)

Smoke rises from a house days after part of the ground it was resting on collapsed into Lake Whitney, Texas in this June 13, 2014 file photo. I was covering the controlled burn of a house slowly falling into Lake Whitney due to the decaying cliff underneath. Asked to take photos from an aerial perspective, an instructor and I took off from Grand Prairie Municipal Airport around 9am. The burn, scheduled to start an hour later, was delayed. I love flying, but patience proved challenging as circling for nearly three hours gets boring fast. Once the fire started we only had 15 minutes to take photos because the plane was booked at 1pm. The owners invested their retirement savings in the house and were even advised by geologists that the ground was stable. To watch your investment literally go up in flames must take its toll emotionally. The owners said they don't expect their insurance to cover the loss. (Photo and caption by Brandon Wade/Reuters)

1st Place in Wildlife: A male orangutan peers from behind a tree while crossing a river in Borneo, Indonesia. (Photo by Jayaprakash Joghee Bojan/National Geographic Nature Photographer of the Year contest 2017)