Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

Enthusiasts gather for the Model Rail Scotland exhibition on February 24, 2012 in Glasgow, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

Police take part in a role play exercise as they clear a protest on top of a train during training on March 6, 2012 in Oxenhope, England. A new team of specialist officers set up to deal with searches and policing at a height, such as on top of a train, undergo training exercise in Oxenhope, West Yorkshire. (Photo by Bethany Clarke/Getty Images)

These images show a heart-warming moment between a loving couple as they’re lit up under a stunning starry night sky. Taken on the Crimean Peninsula, the images show couples posed up beneath a glorious midnight skyscape. (Photo by Andrei Sheliakin/Caters News Agency)

These stunning images show a group of aerial artists lighting up the night sky. Taken by photographer Casey Grimley, 37, the photos show pole dancers and aerial artists at various locations in Southern California, including the famed Joshua Tree National Park. (Photo by Casey Grimley/Caters News Agency)

Photographer Maurizio Pignotti, 46, spends all night in freezing temperatures painstakingly shooting the breathtaking crystal-clear stars. He uses a technique where he merges together anywhere between 80 and 450 shots to create what he describes as a “rainbow of stars”. Space-lover Maurizio, captures the star trails on the borders of the Adriatic Sea – including the Sibillini Mountains National Park, the Conero National Park, and the Gargano National Park. (Photo by Maurizio Pignotti/Caters News)

A life-size robot named “Mark 1”, built by product and graphic designer Ricky Ma, 42, is seen in Hong Kong, China March 31, 2016. Ma, a robot enthusiast, spent a year-and-a half and more than HK$400,000 ($51,000) to create the humanoid robot, which is modelled after a Hollywood star, to fulfil his childhood dream. The eyes of the robot include face and color tracking functions. (Photo by Bobby Yip/Reuters)

A couple who did not give their names walk in downtown Havana, February 2, 2015. (Photo by Alexandre Meneghini/Reuters)