Mario Huettenhofer, chief of the German company 3D Fab, presents his own face as 3d print during the international fairs FabCon 3.D and Rapid.Tech in Erfurt, Germany, Thursday, May 15, 2014. 130 exhibitors from all over the world present the entire world of 3D printing. The trade fairs are accompanied by specialist programs featuring 80 scientists, practitioners and trend analysts from ten countries, who will explain the latest findings, trends and applications for additive processes in industry and for 3D printing in the private sector to newcomers, experts and consumers alike. (Photo by Jens Meyer/AP Photo)

Dhruva Aliman does a back somersault as he dismounts from a slackline on the beach at Santa Monica, California on October 19, 2014. Slackline is a balance sport where a line of webbing is adjusted at different levels of tension between two anchor points and participants (called slackers) perform tricks and stunts including somersaults. (Photo by Mark Ralston/AFP Photo)

A young man, who says he is part of a local criminal gang, poses for a picture holding a gun in the neighbourhood of Korogcho in Nairobi, Kenya, March 19, 2015. Around 2 million people live in the shantytowns packed in around Kenya's capital. Crime is high amid chronic unemployment levels, while basic services and sanitation are scarce. Residents try to make the best of things, eking out a living and picking up work where they can. (Photo by Siegfried Modola/Reuters)

Far from the fancy throngs who gather at the Pebble Beach Concours d'Elegance every year, another collection of car enthusiasts strive to cough up the worst cars imaginable. The Concours d'Lemons gathers the Edsels, Yugos and Azteks of yesteryear to give the freaky and foul their day in the sun. Photo: The 1973 Electra-King three-wheeler, the dead evolutionary branch of today's electric cars. (Photo by Robert Kerian/Yahoo Autos)

Pablo Holcer tests out a VR system made by Neurable that allows the user to control with their thoughts as the EEG headset interprets thoughts into actions in the VR environment at SIGGRAPH 2017 in Los Angeles, California, July 31, 2017. (Photo by Mike Blake/Reuters)

English fashion modelDaisy Lowe performs a DJ set for Badoos #DateOfTheDead party at La Bodega Negra on October 26, 2017 in London, England. (Photo by Tabatha Fireman/Tabatha Fireman/Getty Images for Badoo)

Graduates dance as they take part in a “Last school bell” ceremony at a school in Minsk, Belarus on May 30, 2018. (Photo by Vasily Fedosenko/Reuters)

Cardi B attends the Fanatics Super Bowl Party at College Football Hall of Fame on February 2, 2019 in Atlanta, Georgia. (Photo by Shareif Ziyadat/WireImage)