People look at a loaded truck that got stuck in a sinkhole on a road in Guilin, Guangxi Zhuang Autonomous Region, January 7, 2015. No injury was reported, according to local media. (Photo by Reuters/Stringer)

Sunrise over Maridalsvannet in the forest areas near the outskirts of Oslo, the capital of Norway. Winter is approaching, the first snow covers the ground, and the water has already got a thin layer of ice. The temperature is significantly below the freezing point, the air is clear and the sun colors the morning clouds in deep tones. (Photo by Tore-Thiis-Fjeld/Getty Images)

A performer dressed as a Hello Kitty poses inside a Hello Kitty-themed Taroko Express train in Taipei, Taiwan March 21, 2016. Lucky fans of Hello Kitty were among the first to ride a train themed after the iconic fictional character on its inaugural run in Taiwan on Monday. The Hello Kitty-themed Taroko Express train, the first in Taiwan, set off from the Shulin train station and will travel to Taitung on the east coast route. The Taiwan Railway Administration, which will introduce Hello Kitty merchandise, said it plans to adds more themed trains to its fleet. (Photo by Tyrone Siu/Reuters)

In this March 13, 2015 photo, Yohan, 4, from left, Cristian, 7, and Angelo, 6, playfully toss coca leaves into the air, singing: “I have a lot of money, look at all the money I have”, in La Mar, province of Ayacucho, Peru. Hauling cocaine out of the remote valley is about the only way to earn decent cash in this region where a farmhand earns less than $10 a day. Beyond extinguishing young lives, the practice has packed Peru's highland prisons with cocaine backpackers while their bosses evade incarceration. (Photo by Rodrigo Abd/AP Photo)

Tippi aged 6 sitting on the back of Linda, a tamed ostrich in South Africa, 1996. Incredible pictures of the real life Mowgli, a girl who spent the first ten years of her life growing up in the African bush, have been released for the first time. The magical images chronicle the life of Tippi Benjamine Okanti Degré, who was brought up with wild animals, just like Rudyard Kipling's hero did in The Jungle Book. (Photo by Sylvie Robert/Barcroft Media)

A colony of penguins gather with the Bark Europa in the background, on March 05, 2015 in South Georgia Island. An adventurer has documented his 5,000 miles journey aboard a 100-year-old ship, sailing from Argentina to Antarctica to Cape Town. (Photo by Andrew Orr/Barcroft Images)

A busy rush hour sees thousands of commuters climbing on board a train – as well as holding onto its sides and sitting on the roof before it speeds off. Men, women and children climb and are pulled up onto the roof of the train, which is around 12ft (3.6m) high, as they try to find themselves a space. With no seats available inside, many commuters decide to take the risk and choose a rooftop view for their journey out of Dhaka city, in Bangladesh. (Photo by Yousuf Tushar/Solent News & Photo Agency)

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)