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 vendor sleeps as his son waits for customers at their roadside vegetable shop in New Delhi, February 12, 2019. (Photo by Adnan Abidi/Reuters)

Israeli police officers are about to push away a demonstrator during a protest against Israel's Prime Minister Benjamin Netanyahu outside his residence in Jerusalem, Israel, early Sunday, August 9, 2020. (Photo by Ariel Schalit/AP Photo)

Visitors to West Midlands Safari Park in Bewdley, UK on October 17, 2023 are enjoying the bright October sunshine ahead of the storms to come. A curious giraffe meets eye to eye with a car full of happy visitors while licking the car windscreen with his long tongue. (Photo by Lee Hudson/Alamy Live News)

A child in colorful kimono walks at Tokyo's Asakusa district on the occasion of Shichigosan celebration Thursday, October 22, 2020. The festival celebrates children aged three, five and seven for their well-being. (Photo by Eugene Hoshiko/AP Photo)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

A child dressed in an imitation dress of army soldier enjoys a cold drink during a religious procession in Amritsar, India, 15 December 2015. The religious procession was taken out on the eve of the martyrdom day of the 9th Guru or Master of the Sikhs Sri Guru Tegh Bahadur Ji. Guru Tegh Bahadur was executed for not converting to Islam on the orders of Mughal Emperor Aurangzeb in Delhi in 1675 AD. The place of this occurrence is called Gurudwara Sis Ganj at Delhi. Guru Tegh Bahadur the youngest of the five sons of Guru Hargobind was born in Amritsar in 1621. (Photo by Raminder Pal Singh/EPA)

Models present creations during the PARIA/FARZANEH catwalk at London Fashion Week Men's in London, Britain June 10, 2019. (Photo by Henry Nicholls/Reuters)