Luis Hernan was always curious about how wireless technologies like radio are transmitted through the air. So after finishing up his studies in architecture, computer science, and design, Hernan decided to research these invisible signals through a PhD at Newcastle University. Hernan set up a system that turned the wireless signals around him into colourful, ghostlike images using long-exposure photography, allowing people to see the strength of the signals around them. (Photo by Luis Hernan)

Moraine Lake is a glacially-fed lake in Banff National Park, 14 kilometres (8.7 mi) outside the Village of Lake Louise, Alberta, Canada. It is situated in the Valley of the Ten Peaks, at an elevation of approximately 6,183 feet (1,885 m). The lake has a surface area of .5 square kilometres (0.19 sq mi). The lake, being glacially fed, does not reach its crest until mid to late June. When it is full, it reflects a distinct shade of blue. The colour is due to the refraction of light off the rock flour deposited in the lake on a continual basis.

Tibetan monks create an intricate picture made from coloured sand at St. Mungo Museum of Religious Life and Art on November 23, 2011 in Glasgow, Scotland. The monks, from the Panchen Lama's Monastery, are creating a Sand Mandala as part of a Tantric Buddhist ritual, invoking the presence of the Buddha in a design representing the palace of the deities. (Photo by Jeff J Mitchell/Getty Images)

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)

Alex Prager is an American art photographer and filmmaker based in Los Angeles. Her photographs primarily use staged actors, models and extras to create “meticulously designed mise en scène”, often described as film-like and hyperreal. “Alex Prager: Silver Lake Drive” is at the Photographers’ Gallery, London, 15 June – 14 October 2018. Here: The Big Valley, Susie and Friends, 2008. (Photo by Alex Prager Studio/Lehmann Maupin Gallery)

A woman sweeps an alleyway adorned with murals painted by artists from “Delhi Street Art” group at the Raghubir Nagar slum in New Delhi on December 2, 2019. A New Delhi slum has been given a colourful makeover thanks to a street artist collective, drawing art lovers and selfie-snappers to a rundown area that they would never normally visit. (Photo by Sajjad Hussain/AFP Photo)

A man walks in the early morning to start his day picking tea leaves at a plantation in Nandi Hills, in Kenya's highlands region west of capital Nairobi, November 5, 2014. Emerald-coloured tea bushes blanketing the rolling hills of Nandi County have long provided a livelihood for small-scale farmers, helping make Kenya one of the world's biggest tea exporters. But ideal weather and bigger harvests, instead of producing bumper earnings, have led to a glut of Kenya's speciality black tea. (Photo by Noor Khamis/Reuters)

Factory landlord Lawrence Taylor (L), portraying a Colour Sergeant from the King's Royal Rifle Corps, part of the Rifles Living History Society, performs a drill with Connor Young (R) of the Queen's Own Royal West Kent Regiment Living History Group as they recreate the life of a First World War soldier at the Eden Valley Museum in Edenbridge in southeast England May 10, 2014. Lawrence has always had an interest in military history and specifically “The Rifles” – his veteran father's WWII regiment. When he became a re-enactor he chose not to re-enact WWII as many of the veterans are still alive, and he felt uncomfortable as he remembers his father would have flashbacks and nightmares about the war. United by a fascination with military history and a fondness for dressing up, groups such as the Rifles Living History Society and the Queen's Own Royal West Kent Regiment Living History Group get together to recreate aspects of life during the First World War. Reuters photographer Luke MacGregor photographed members of the groups, both as they took part in living history events and at their day jobs. (Photo by Luke MacGregor/Reuters)