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)

A woman takes cover as shots are fired by police officers as they face off with stone-throwing protesters, during an anti-government demonstration in Bujumbura, Burundi, 20 May 2015. Police officers fired shots and teargas canisters in running battles with protesters who demonstrated against Burundi's President Pierre Nkurunziza's bid for a third term. Presidential spokesman man said on 20 May that the country will postpone its parliamentary and local council elections, previously scheduled for 26 May, to 05 June 2015. According to the United Nations' refugee agency, more than 105,000 Burndians have fled the country to seek refuge in neighbouring countries such as Rwanda, DR Congo, and Tanzania. (Photo by Dai Kurokawa/EPA)

A woman holds-up a white T-shirt trying to prevent being shot, as Palestinians flee Gaza City to the southern Gaza Strip on Salah al-Din street in Bureij, Tuesday, November 7, 2023. (Photo by Mohammed Dahman/AP Photo)

Two young women huddle up in their coats as they brave the cold in Newcastle, England on February 1, 2019. Women in skimpy dresses and men in t-shirts enjoyed a drink and a dance as they celebrated January finally being over. (Photo by Will Walker/North News and Pictures)

A General Atomics MQ-9 Reaper stands on the runway during “Black Dart”, a live-fly, live fire demonstration of 55 unmanned aerial vehicles, or drones, at Naval Base Ventura County Sea Range, Point Mugu, near Oxnard, California July 31, 2015. (Photo by Patrick T. Fallon/Reuters)

People participate in a wet t-shirt contest on a stage while people party and celebrate on the beach at Clayton's Beach Bar and Grill in South Padre Island, Texas, USA, 11 March 2018. Spring break draws thousands of kids from all over the country to many different locations to celebrate each year. (Photo by Larry W. Smith/EPA/EFE)

(L-R) Recording artists Ally Brooke, Normani Hamilton, Dinah-Jane Hansen, Lauren Jauregui and Camila Cabello of Fifth Harmony attend the 2016 Billboard Music Awards at T-Mobile Arena on May 22, 2016 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)

(L-R) Miss Universe 2015 Pia Wurtzbach, Miss USA 2015 Olivia Jordan and Miss Teen USA 2015 Katherine Haik attend the 2016 Miss USA pageant at T-Mobile Arena on June 5, 2016 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)