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)

Deadwood is pictured in the onetime spa and resort town Epecuen, November 5, 2015. Over the past few years the town of Epecuen, located 550 km (341 miles) southwest of Buenos Aires, has been attracting tourists with its eerie apocalyptic atmosphere after a flood submerged it in salt water for more than two decades. Photo by Enrique Marcarian/Reuters)

Inmates sleep on the steps of a ladder inside the Quezon City jail at night in Manila in this picture taken on July 21, 2016. There are 3,800 inmates at the jail, which was built six decades ago to house 800, and they engage in a relentless contest for space. Men take turns to sleep on the cracked cement floor of an open-air basketball court, the steps of staircases, underneath beds and hammocks made out of old blankets. (Photo by Noel Celis/AFP Photo)

Hisakata Hiroyuki, a talented photographer from Japan, has managed to snap a group of mortal tomcats in a variety of high-flying kung fu poses. Using his own rapid-fire reactions, he photographs the lovable cats flying through the air, their legs and paws outstretched, like something out of an action movie. (Photo by Hisakata Hiroyuki/Caters News Agency)

A shrine maiden walks in the snow at the Tsurugaoka Hachimangu Shrine in Kamakura, near Tokyo, Thursday, November 24, 2016. Tokyo residents have woken up to the first November snowfall in more than 50 years. An unusually cold air mass brought wet snow to Japan's capital on Thursday. Above-freezing temperatures kept the snow from sticking, but forecasters said there could be an accumulation of up to 2 centimeters (1 inch). The last time it snowed in central Tokyo in November was in 1962. (Photo by Shizuo Kambayashi/AP Photo)

In this March 7, 1991 file photo, a U.S. Marine patrol walks across the charred oil landscape near a burning well during perimeter security patrol near Kuwait City. Twenty five years after the first U.S. Marines swept across the border into Kuwait in the 1991 Gulf War, American forces find themselves battling the extremist Islamic State group, born out of al-Qaida, in the splintered territories of Iraq and Syria. The Arab allies that joined the 1991 coalition are fighting their own conflicts both at home and abroad, as Iran vies for greater regional power following a nuclear deal with world powers. (Photo by John Gaps III/AP Photo)

Indonesian residents look at the Mount Sinabung volcano as it spews volcanic ash near the Tiga Pancur village in Karo, North Sumatra on August 3, 2016. Volcanic eruptions in Indonesia in recent days have forced the closure of two airports and disrupted some flights to the holiday island of Bali, officials said August 3. Mount Sinabung, a volcano on the western island of Sumatra which has been rumbling for some time, also erupted violently on August 2, although its ash clouds did not disrupt any flights. (Photo by Y.T. Haryono/AFP Photo)

A girl rides a donkey as another walks by at the Shawqaba camp for internally displaced people who were forced to leave their villages by the war in Yemen's northwestern province of Hajjah March 12, 2016. In northwest Yemen, one of the poorest countries in the Middle East, about 400 families uprooted by the war have been stuck in the Shawqaba camp in Hajjah province for the past year. Residents live in poorly built huts that protect them neither from summer heat nor winter cold in a camp that lacks the most basic services. (Photo by Abduljabbar Zeyad/Reuters)