A tour group wanders through block 7 of Eastern State Penitentiary in Philadelphia, Pennsylvania April 30, 2014. Opened in 1829, with the original corrective system of “confinement in solitude with labor”, the penitentiary housed about 75,000 inmates in its 142 years of operation. At Eastern State reunions, former inmates, staff and guard gather to share memories and trade stories and get a chance to describe their experiences in question-and-answer sessions with the public. (Photo by Mark Makela/Reuters)

Raissa Floriano whose father is hospitalized with CCOVID-19, cries during a protest amid the new coronavirus pandemic outside the 28 Agosto Hospital, in Manaus, Brazil, Thursday, January 14, 2021. Scores of COVID-19 patients in the Amazon rainforest's biggest city will be transferred out of state as the local health system collapses and dwindling stocks of oxygen tanks begin to falter. (Photo by Edmar Barros/AP Photos)

Visitors look at photographs in the exhibition “Lisette Model Street Life e Horst P. Horst Syle and Glamour” at the art gallery “Camera – Centro Italiano per la fotografia” in Turin, Italy, 27 April 2021. Culture venues reopened to the public as several Italian region are back to COVID-19 yellow zone in the country's tier system. (Photo by Alessandro di Marco/EPA/EFE)

David Sharp, an engineer with Lockheed Martin, displays the “Samurai Flyer”, an aviation design inspired by the maple seed, during the Association for Unmanned Vehicle Systems International Conference August 16, 2011 in Washington, DC. Lockheed Martin unveiled the new design and demonstrated vertical takeoff and landing, stable hover, and on-board video streaming of the aircraft during their demonstration. (Photo by Win McNamee/Getty Images)

Musician Simon Desorgher walks his giant sphere on the foreshore of the River Thames after a rehearsal for a performance of “Water Cycle for flute and sound system” on the river on September 11, 2009 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Crocoite is a mineral consisting of lead chromate, and crystallizing in the monoclinic crystal system. It is identical in composition with the artificial product chrome yellow used as a paint pigment.

Members of the “Exit Point” amateur rope-jumping group jump from a 44-metre high (144-ft) waterpipe bridge in the Siberian Taiga area outside Krasnoyarsk, September 13, 2015. Rope-jumping, an extreme sport, involves jumping from a high point using an advanced leverage system combining mountaineering and rope safety equipment. (Photo by Ilya Naymushin/Reuters)