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)

Kate O'Connor of Team Northern Ireland celebrates during the Women's Heptathlon High Jump on day five of the Birmingham 2022 Commonwealth Games at Alexander Stadium on August 02, 2022 in the Birmingham, England. (Photo by Matthew Lewis/Getty Images)

Wearing a protective mask to curb the spread of the new coronavirus a man attends a memorial for those who have died from COVID-19 worldwide, at Rio's Christ the Redeemer statue in Rio de Janeiro, Brazil, Wednesday, July 1, 2020. (Photo by Leo Correa/AP Photo)

Brandy Shelton of Greensboro, North Carolina, “twerks” for a group of bikers on Ocean Boulevard during the 2015 Atlantic Beach Memorial Day BikeFest in Myrtle Beach, South Carolina May 22, 2015. After three people were killed and seven wounded in shootings during 2014 Bikefest, State officials called for an end to the event that draws thousands to the family-friendly beach town.Their efforts were unsuccessful. Bikers returned to Myrtle Beach – just a week after a bloody motorcycle gang shootout in Waco, Texas. But this time authorities are more prepared, with dozens of new surveillance cameras and a police force three times the size of last year's. (Photo by Randall Hill/Reuters)

Giant panda Xiao Qi Ji plays at his enclosure at the Smithsonian National Zoo in Washington, Thursday, September 28, 2023. (Photo by Jose Luis Magana/AP Photo)

Bikini Contest in Daytona Beach, Florida, USA. (Photo by Evan Hurd/Sygma/Sygma via Getty Images)

A couple throw themselves into an energetic jive at a studio in London.

“Amphilophus citrinellus is a large cichlid fish endemic to the San Juan River and adjacent watersheds in Costa Rica and Nicaragua. In the aquarium trade A. citrinellus is often sold under the trade name of Midas cichlid. A. citrinellus are omnivorous and their diet consists of plant material, molluscs and smaller fish”. – Wikipedia

Photo: Two Midas Cichlid (lat: amphilophus citrinellus) fish are seen in an aquarium at Hellabrunn zoo on December 23, 2009 in Munich, Germany. (Photo by Alexandra Beier/Getty Images)