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 Bedouin rifleman hides behind his camel while he carefully takes aim in the Sahara desert. (Photo by Three Lions/Getty Images). Circa 1955

Women take part in Belarus Cup in bodybuilding and fitness in Minsk, October 24, 2015. (Photo by Vasily Fedosenko/Reuters)

Revellers take part in a zombie parade to celebrate Halloween in Kiev, Ukraine, October 31, 2015. (Photo by Valentyn Ogirenko/Reuters)

A Muslim boy takes part in Friday prayers on a street outside a mosque in Mumbai, India, June 24, 2016. (Photo by Shailesh Andrade/Reuters)

“Don't take the life too serious”. (Photo by David Olkarny)

Hillary Clinton waves to a selfie-taking crowd at a recent campaign event in Orlando, Florida on September 26, 2016. (Photo by Barbara Kinney/Hillary for America)

A participant takes part in a high heel race to protest in favor of gender equality in Monterrey, Mexico on May 12, 2019. (Photo by Daniel Becerril/Reuters)