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)

“Touring the Koko-en Gardens adjacent to the Himeji castle was an unexpected highlight of our visit”, wrote Jeff Solar, 64, of Silver Spring, Md., about his trip to Japan. “The fall colors were outstanding and the gardens were both amazing and a bargain (just a few Yen added to the cost of the Himeji Castle admission)”. (Photo by Jeff Solar/2017 Washington Post Travel Photo Contest)

The Elf on the Shelf balloon floats down Sixth Avenue during the 88th Annual Macy's Thanksgiving Day Parade in New York November 27, 2014. (Photo by Andrew Kelly/Reuters)

In this publication you can see some best pictures of photographer Chris Hondros, who was killed on April 20, 2011 by a rocket-propelled grenade (RPG) in Misrata, Libya.

Photo: “Getty Images” photographer Chris Hondros (1970–2011) walks the ruins of a building August 21, 2006 in southern Beirut, Lebanon. (Photo by Getty Images)

An exterior view of Rauceby, an abandoned mental asylum in Lincolnshire, UK. These haunting photos show the collapsing remains of a derelict mental asylum. The pictures show the ruined former hospital building and chapel, now covered in dust and graffiti. Few signs remain that reveal the site as a former home of mentally ill adults and children. (Photo by Simon Robson/Caters News)

ESA astronaut Samantha Cristoforetti on the International Space Station 3 February 2015 during her Futura mission. Samantha is living and working on the Station as part of the Expedition 42 crew. Picture released on February 10, 2015. (Photo by ESA/NASA)

A child walks to an installation made from fallen leaves by college students, in shape of a sofa, to call for people's attention to environment protection, in Hangzhou, Zhejiang province, China, December 6, 2016. (Photo by Reuters/China Daily)

Natan Dvir, an Israeli photographer, focuses on the human aspects of political, social and cultural issues. For his “Coming Soon” series, Dvir says that in recent years, a kaleidoscopic net of huge billboards has enveloped the commercial hubs of New York. Seen here, a man looks at a Juicy Couture billboard while passing it on 52nd street close to 5th Avenue in New York, June 5, 2012. (Photo by Natan Dvir/Polaris)