Tourist Police sit in the shade on a road leading to the Coptic Cairo area on May 27, 2011 in Cairo, Egypt. Protests in January and February brought an end to 30 years of autocratic rule by President Hosni Mubarak who will now face trial. Food prices have doubled and youth unemployment stands at 30%. Tourism is yet to return to pre-uprising levels. (Photo by Peter Macdiarmid/Getty Images)

A recruitment drive during the First World War at Trafalgar Square, London. (Photo by Central Press/Getty Images)

People run along a street as rain caused by tropical storm Alberto, the first named storm of 2024 Atlantic hurricane season, falls, in Monterrey, Mexico. on June 19, 2024. (Photo by Daniel Becerril/Reuters)

These stunning photos act as postcards for one photographer, who has traveled all over the globe, braving freezing temperatures to create the ultimate time lapse video. Photographer Dustin Farrell, 36, spent four years perfecting his technique and traveling all over the world in his quest to capture the most beautiful time lapses of nature. (Photo by Dustin Farrell/Caters News)

Macro or Micro? Scientists’ pictures baffle our sense of scale. It began when Stephen Young, a geography professor at Salem State University in Massachusetts, tricked his biologist colleague Paul Kelly into thinking a satellite image was one of his electron microscope scans. Can you guess whether they are close-up or very far away? (Photo by Paul Kelly)

In this Thursday, June 14, 2018, file photo, students wear virtual reality goggles during a science class at Pyongyang Teachers' University, a teacher training college, in Pyongyang, North Korea. (Photo by Dita Alangkara/AP Photo)

A woman uses a face masks as a preventive measure against the spread of the new coronavirus, COVID-19, in Bogota, on March 19, 2020. Colombia will block all international flights from Monday for 30 days, President Ivan Duque announced on Thursday. (Photo by Raul Arboleda/AFP Photo)