Festivalgoers watch two actors of the Wasteland Warriors movement fight in a cage at the world's largest heavy metal festival, the Wacken Open Air 2019, in Wacken, Germany on August 3, 2019. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Wolfgang Rattay/Reuters)

Patients from Rady Children's Hospital hug a bottlenose dolphin after being invited to swim and interact with dolphins at Sea World in San Diego, California August 27, 2015. Sea World has hosted Dolphin Interaction Program for seven years. It was started by dolphin trainer Joy Soto who battled and overcame non-Hodgkin’s lymphoma. (Photo by Mike Blake/Reuters)

Born 29 December 1990 in Cambridge, UK. Lives and works between London and Essex. Spending the first 6 months of 2013 living in America, currently residing in New York. (Photo by Jack Davison)

Participants in costumes attend the first day of the annual Wave-Gotik Treffen, or Wave and Goth Festival, on May 17, 2013 in Leipzig, Germany. (Photo bilderkiste)

Jewels Lewis poses as the first customer to purchase the new Apple iPad 2 at Apple Store, Regent Street on March 25, 2011 in London, England. The latest iPad went on sale in the UK at 5:00pm.

Racing driver J. Gaal at the wheel of car number 26 at the RAC Tourist Trophy, run, for the first time, over the Four Inch Course on the Isle of Man, 17th September 1908. Gaal is racing in waterproofs. (Photo by Topical Press Agency/Hulton Archive/Getty Images)

Sumatran tiger Jumilah is seen with one of her cubs on display at Taronga Zoo on October 25, 2011 in Sydney, Australia. The Sumatran tiger cubs, born in August to mother Jumilah, will meet the public for the first time this week. (Photo by Mark Kolbe/Getty Images)

Google has built its first self-driving car prototypes and hopes to test hundreds more models this summer. If all goes well, the company is planning a pilot program in California over the next few years.