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)

Young devotees carry oil lamps in the early morning of the tenth day celebrations of Hindu Nepali festival “Dashain” at a temple in Bhaktapur on the outskirts of Kathmandu on October 24, 2023. (Photo by Prakash Mathema/AFP Photo)

This image released by Paramount Pictures shows Taron Egerton as Elton John in a scene from “Rocketman”. (Photo by David Appleby/Paramount Pictures via AP Photo)

A child holds a gun at the National Rifle Association (NRA) annual convention in Indianapolis, Indiana, U.S., April 15, 2023. (Photo by Evelyn Hockstein/Reuters)

A schoolgirl stands next to the Kenya-Uganda railway line during the partial reopening of schools, after the government scrapped plans to cancel the academic year due to the coronavirus disease (COVID-19) pandemic, in Kibera slums of Nairobi, Kenya on October 12, 2020. (Photo by Thomas Mukoya/Reuters)

Most people know Nikon as a purveyor of pro and consumer-grade digital cameras. But the company's expertise with optics bleeds over into related markets – it's one of the science community's major suppliers of microscopes. And each year the company asks the community to send it some of their favorite images of tiny objects. A panel of scientists and journalists have chosen the best of this past year's submissions, which Nikon has placed on its Small World site.

Photo: Honorable Mention. “Snow crystal, illuminated with colored lights (5x)”. (Photo by Dr. Kenneth Libbrecht, California Institute of Technology (Caltech), Department of Physics, Pasadena, California, USA)

Former US President Donald Trump's impersonator Neil Greenfield gestures outside Trump Tower in New York City on March 22, 2023. With barricades set up near Trump Tower and police on high alert, New York was holding its breath March 22, 2023 for the likely indictment of Donald Trump, but the timing remained uncertain. (Photo by Timothy A. Clary/AFP Photo)

U.S. Secretary of State John Kerry stands inside the historic Shackleton hut near McMurdo Station, Antarctica, Friday, November 11, 2016. Kerry became the highest-ranking American official to visit Antarctica when he landed for a two-day trip on Friday. He's been hearing from scientists about the impact of climate change on the frozen continent. Kerry's aides described the trip as a learning opportunity for the secretary of state. He has been receiving briefings from scientists working to understand the effects of climate change on Antarctica. Kerry has made climate change an intensive focus of American diplomacy during his term, and had previously spent decades working on the issue as a U.S. senator. Trump has called climate change a hoax and said he would “cancel” U.S. involvement in the landmark Paris Agreement on global warming. (Photo by Mark Ralston/Pool Photo via AP Photo)