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)

A quirky cartoonist challenged his own creation to a fight – but he could only draw. US artist Alex Solis, 31, from Chicago, Illinois, drew his skull t-shirt-wearing alter ego, who he calls Chuck, smashing his phone and stabbing his finger in his Inkteraction pictures. But Alex got his own back with a punch to Chucks jaw before squashing him against the bottom of the page. The ink man tried to get under Chucks skin to win the fight by stretching and pulling the cartoons face as the drawings became more bloody. (Photo by Alex Solis/Caters News)

Mount Sinabung volcano erupts, as seen from Tiga Pancur village, Karo Regency in Indonesia's North Sumatra province, in this October 8, 2014 file photo. (Photo by Y. T. Haryono/Reuters)

Convicted murderer Hector Alvarado Mazariegos, right, drops to the ground as he is hit by bullets of a Guatemala firing squad in the public cemetery at Mazatenango, June 28, 1975. His companion, Rocael Ortiz, met the same fate a few seconds later. Both were convicted of murder. (Photo by AP Photo/Anzueto)

A follower of the Afro-Brazilian religion Umbanda pays tribute for Iemanja, goddess of the sea, in Copacabana Beach in Rio de Janeiro, Brazil December 29, 2017. Hundreds of practitioners of Brazil's Afro-Brazilian Candomble and Umbanda faiths have gathered at Rio de Janeiro's Copacabana beach to honor Yemanja. Worshippers were mostly dressed in white as they launched their offerings to Iemanja: small boats with flowers and bowls with candles and fruits. (Photo by Ricardo Moraes/Reuters)

Number 10. BELL H-13 SIOUX was a two-bladed, single engine, light helicopter built by Bell Helicopter. Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT. In 1947, the United States Air Force ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. The United States Army first ordered Bell 47s in 1948 under the designation H-13. These would later receive the name Sioux. The Bell-built H-13 B is seen airborne in this April 29, 1951 photo. The helicopter is equipped with a 173 horsepower engine, cruises at 85 miles per hour, climbs 900 feet in a minute and has a service ceiling of 11,500 feet. (Photo by AP Photo)

A woman reacts as she lays flowers outside the Perm State University following a campus shooting in Perm, about 1,100 kilometers (700 miles) east of Moscow, Russia, Tuesday, September 21, 2021. A student opened fire at the university, leaving a number of people dead and injured, before being shot in a crossfire with police and detained. Beyond saying that he was a student, authorities offered no further information on his identity or a possible motive. (Photo by Dmitri Lovetsky/AP Photo)

Russia's Kamila Valieva performs during the Exhibition Gala at the Rostelecom Cup 2021 ISU Grand Prix of Figure Skating in Sochi on November 28, 2021. (Photo by Dimitar Dilkoff/AFP Photo)