Bici Palermo Tuning – a group of teenagers from the Sicilian capital Palermo – spend anything up to €1,300 customising their bikes with car batteries and multiple speakers to develop thunderous sound systems. The police are not impressed. (Photo by Matteo de Mayda/Cosimo Bizzari/The Guardian)

These Filipino icons of ingenuity were originally re-crafted from abandoned US army jeeps after the second world war, and helped to establish a new system of urban transportation. Jeepneys are being phased to help ease city congestion, but the move will also cause unemployment for experienced drivers – and higher fares for commuters. (Photo by Claudio Sieber/Barcroft Media)

Revelers gather on a commuter train platform of the HVV city public transportation system to drink alcohol on September 30, 2011 in Hamburg, Germany. Thousands of people participated in the event dubbed the “HVV Abschiedstrinken” (HVV Farewell Drink) that was organized through Facebook and is meant to celebrate the last day before a ban on alcohol consumption goes into effect on the city's public transport. (Photo by Joern Pollex/Getty Images)

Waves triggered by Typhoon Hato are seen in Hong Kong, China on August 23, 2017. A powerful typhoon barreled into Hong Kong on Wednesday, forcing offices and schools to close and leaving flooded streets, shattered windows and hundreds of canceled flights in its wake. Typhoon Hato came within 60 kilometers (37 miles) of Hong Kong, close enough to be considered a direct hit under Hong Kong's storm warning system. It was headed toward the western side of mainland China's Pearl River Delta. (Photo by Tyrone Siu/Reuters)

NASA space shuttle Atlantis is prepared on the Vehicle Assembly Building floor at the Kennedy Space Center May 18, 2011 in Cape Canaveral, Florida. The space shuttle program ends with Atlantis mission STS-135 scheduled for early July. Space shuttle Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. Atlantis also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module. (Photo by Roberto Gonzalez/Getty Images)

The land-robot “teleMAX” of German company telerob stands next to soldiers during a trial at the German army base on May 18, 2010 in Hammelburg, Germany. ELROB provides an overview of the current state of affairs in European unmanned system technology and to evaluate commercial off-the-shelf products for military use. It is to show what is feasible in robotics, to support technological developments in Europe, and to find solutions for the current military challenges. (Photo by Ralph Orlowski/Getty Images)

A member of the “Exit Point” amateur rope-jumping group jumps from a 44-metre high (144-feet high) waterpipe bridge in the Siberian Taiga area outside Krasnoyarsk, September 28, 2014. Fans of rope-jumping, a kind of extreme sport involving a jump from a high point using an advanced system of amortization including mountaineering and rope safety equipment, attended the Golden Autumn group's jumping season. (Photo by Ilya Naymushin/Reuters)

A sculptural artwork depicting former Chilean dictator Augusto Pinochet and headless presidents shot by a hooded high school student (not pictured) is seen at the Contemporary Art Museum in Santiago, December 2, 2014. The artwork, part of the “El ladrillo angular” (The angular brick) exhibition, portrays a student fighting against the ongoing continuity of dictatorship because of a political and economic system which has been impossible to destroy, according to “Papas Fritas” the artwork's creator. (Photo by Ivan Alvarado/Reuters)