A police officer holds a pistol during clashes with protesters near a burning tyre barricade in the Kariobangi slum of Nairobi, Kenya Friday, May 8, 2020. Hundreds of protesters blocked one of the capital's major highways with burning tires to protest government demolitions of the homes of more than 7,000 people and the closure of a major food market, causing many to sleep out in the rain and cold because of restrictions on movement due to the coronavirus. (Photo by Brian Inganga/AP Photo)

Spot, a robot with dog-like movements, walks past a dog in Cathedral Square in Erfurt, Germany on April 20, 2021. Security service provider Ciborius, a provider of robotic security solutions with artificial intelligence, presented its artificial employee with high-resolution 360-degree all-round camera, ultra-bright LED light and a light detection system on Domplatz. (Photo by Michael Reichel/dpa)

Lebanese students dance during “The Big Dance” event in downtown Beirut, near the parliament May 9, 2015. About 1000 students from all over Lebanon gather and take part in a joint dance with the aim of encouraging people to get into dance and increase fitness levels. This initiative is part of the British Council's project, Connecting Classrooms which aims at building links between schools in the UK and Lebanon. (Photo by Aziz Taher/Reuters)

A student works on her skills during an acrobatics class near the pier in Huntington Beach, CA on Monday, August 17, 2020. Instructors at the Orange County Performing Arts Academy decided to bring the class to the beach from Anaheim Hills to beat the heat and give the students an end of the summer treat. (Photo by Paul Bersebach/The Orange County Register via AP Photo)

Zimbabwe University students run away from police during a protest outside the magistrates courts in Harare, Monday, September 14, 2020. Police broke up the protest and arrested some students demonstrating in support of a university union leader who was making a court appearance following his arrest for protesting against human rights abuses in the country. (Photo by Tsvangirayi Mukwazhi/AP Photo)

A Filipino teacher checks a picture of a student shown on a tablet that is attached to robot during a graduation ceremony at a school in Taguig City, Philippines, 22 May 2020. At least 179 high school students received their diploma during an online graduation ceremony that was beamed live on Facebook as a measure to prevent the spread of the coronavirus and COVID-19 disease. (Photo by Francis R. Malasig/EPA/EFE)

A large Mantle or Desk Clock featuring a fossil ammonite at its center, carved from the South American wood Keolbra with radiating Walnut spines. The clock hangs on a round, Plexiglass back supported by a wood base (Bubinga). The clockworks is a quartz, high-torque movement that runs on a single AA battery.

An Occupy Wall Street protestor is arrested by the police during a march from Zuccotti Park to Union Square on March 24, 2012 in New York City. The Occupy Wall Street movement has seen a resurgence in recent weeks in part due to new protests over the killing of Florida teen Trayvon Martin. (Photo by Andrew Burton/Getty Images)