Warriors from the Suri tribe in Ethiopia still stage the savage “Donga” battles – even after many fighters have been died from their injuries. Donga stick fights take place after the harvests, the Surmas count days owing to knots on a long stem of grass or jags on the trunk of a tree dedicated to that specific use. Here: A tribeswoman sporting a huge lip plate and wearing a skinned animal carcass on her head. (Photo by Eric Lafforgue/Exclusivepix Media)

A Hawker Hurricane Mk XIIa 5711 (G-HURI) fighter aircraft prepares to perform an aerobatic display at the IWM Duxford on October 18, 2012 in Duxford, England. The aeroplane, similar to those that defended British shores during the Battle of Britain in World War II, is due to be auctioned by Bonhams in their sale of “Collectors' Motor Cars and Automobilia” at Mercedes-Benz World Brooklands on December 3, 2012. The plane was built in 1942 and joined the Royal Canadian Air Force the following year, where it remained for the duration of the war, it is expected to fetch up to 17 million GBP. (Photo by Oli Scarff)

Photographers gather to take pictures of pilot Andre Borschberg (C) ahead of the take off of Solar Impulse 2-a solar powered plane- in Nanjing, China, May 31, 2015. The world's largest solar-powered airplane, Solar Impulse 2, took off from eastern China's Nanjing on Sunday to continue its round-the-world voyage. The Swiss-made plane left Nanjing's Lukou International Airport at 2:39 in the early morning, with former fighter pilot Borschberg at the controls alone for the entire 8,200-kilometer flight from Nanjing to Hawaii, the toughest leg of its marathon adventure. (Photo by Reuters/Solar Impulse)

Wrestler known as Gio Malkriado (top) fights with a fluorescent tube with wrestler Ciclope during an extreme wrestling fight at a temporary wrestling ring inside a car wash in Tulancingo Hidalgo, Mexico October 8, 2016. When the time comes for the so-called Extreme Star Fight, six wrestlers climb into the ring. Once the fighting begins, anything goes. They bash each other with chairs and long neon lights, causing small explosions and scattering tiny pieces of glass everywhere. (Photo by Carlos Jasso/Reuters)

Children clean the interior of a granary in preparation for grain storage in Odek village, north of Uganda capital Kampala February 14, 2015. Odek is the birthplace of Joseph Kony, founder and leader of the rebel group Lord's Resistance Army. The LRA rose up against the government in northern Uganda under the leadership of Kony in the late 1980s and has been accused of abducting children to serve as fighters and s*x slaves. (Photo by James Akena/Reuters)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

Military policemen try to open a path ahead for the funeral of 21-year-old Mohamed Adel, one of the army officers who died in yesterday's Sinai attacks, in Al-Kaliobeya, near Cairo, Egypt, July 2, 2015. Egypt launched air strikes on Islamist militant targets in the Sinai peninsula on Thursday, killing 23 fighters a day after the deadliest clashes in the region in years, security sources said. The sources said those killed had taken part in Wednesday's fighting in which 100 militants and 17 soldiers, including four officers, were killed, according to the army spokesman. (Photo by Mohamed Abd El Ghany/Reuters)

“Solar Impulse is a European long-range solar powered plane project being undertaken by Bertrand Piccard and André Borschberg. The project eventually hopes to succeed in the first circling of the earth with a piloted fixed-wing aircraft using only solar power. The first aircraft, bearing the Swiss aircraft registration code of HB-SIA, is a single-seater, capable of taking off under its own power, and intended to remain airborne up to 36 hours. This aircraft first flew an entire diurnal solar cycle, including nearly 9 hours of night flying, in a 26-hour flight on 7–8 July 2010”. – Wikipedia


Photo: Workers prepare the Solar Impulse airplane HB-SIA for a first runway test on November 19, 2009 in Dubendorf, Switzerland. Solar Impulse chairman Bertrand Piccard, psychatrist and aeronaut, who made the first non-stop round-the-world balloon flight, and CEO and former fighter pilot Andrй Borschberg plan a round-the-world flight, driven only by solar energy, for 2012. (Photo by Johannes Simon/Getty Images)