Heather Larsen from Golden, Colorado, USA performs a split while walking the slackfline or highline across two towers in the Tower of David citadel complex overlooking the Old City of Jerusalem 02 May 2016. Larsen is one of the world's top female highliners, or slack liners and walked the lines as part of a Kickstarter campaign for an outdoor product. The tower at left was built by King King Herod some 2000 years ago. (Photo by Jim Hollander/EPA)

A woman takes part in a global March for marijuana in Medellin, Colombia, May 7, 2016. The Global Marijuana March (GMM) is an annual rally held at different locations across the planet. It refers to cannabis-related events that occur on the first Saturday in May, or thereabouts, and may include marches, meetings, rallies, raves, concerts, festivals and information tables. (Photo by Fredy Builes/Reuters)

Young people jump over a bonfire as they take part in the Ivan Kupala Night celebration, a traditional Slavic holiday, outside the small town of Turov, some 270 km south of Minsk, on July 6, 2016. People celebrate Kupala Night with bonfires that last throughout the night with some leaping over the flames as it is believed that the act of jumping over the bonfire cleanses people of illness and bad luck. (Photo by Sergei Gapon/AFP Photo)

A policeman controls traffic at 42nd Street and 7th Avenue as New York City remains without electricity caused by a blackout that affected the entire city and most of the eastern part of the nation August 15, 2003 in New York, New York. More than 50 million people were affected by the outage, in Toronto, Detroit, Cleveland and New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images)

Barbara Peacock is one of five recipients of the Getty Images annual Grants for Editorial Photography programme, which gives photojournalists an award of $10,000 as well as the agency’s support in pursuing projects of their choosing. American Bedroom is an ongoing series of portraits in which she explores the complexities and idiosyncrasies of contemporary American life. Here: Jessica, Milford, New Hampshire: “Sometimes life throws you in all sorts of directions. The most important part about life is to remember you are exactly where you need to be”. (Photo by Barbara Peacock/Recipient of the Getty Images Grant for Editorial Photography 2017)

Chieftain Japarupi Waiapi shows a roasted monkey -part of Waiapi's diet, also based in Manioc and fruits- at the reserve in Amapa state in Brazil on October 13, 2017. When Waiapis walks into the Amazon forest surrounding their village, they do not see trees, but a kind of shopping mall providing medicine, food, shelter, tools and weapons all under the eye of multiple spirits. (Photo by Apu Gomes/AFP Photo)

Four pillars of light from the 4 Laser Guide Star Facility on ESO's Very Large Telescope (VLT) are shown reaching into the Chilean night sky in this image from ESO Photo Ambassador Fred Kamphues, on September 2, 2016. The lasers are a key part of the adaptive optics system on the VLT. Adaptive optics allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy, including Paranal in Chile, the home of the VLT. (Photo by F. Kamphues/ESO)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)