San Diego Ballet School students wear protective masks backstage during a performance of “The Nutcracker”, presented by the San Diego Ballet in a drive-in performance at a parking lot in San Diego, California, December 5, 2020. (Photo by Bing Guan/Reuters)

A woman dances during a rehearsal by the group “Tambores de Olokun” in Rio de Janeiro, Brazil, Sunday, April 17, 2022. The Brazilian municipalities of Rio de Janeiro and Sao Paulo postponed the traditional parades of the carnival samba schools to April 22 - 23, as a result of the COVID-19 pandemic. (Photo by Bruna Prado/AP Photo)

In this Thursday, October 3, 2019 photo, a female black bear sleeps with its tongue out high up in a Ponderosa pine tree near Clark Fork School in the Rattlesnake neighborhood of Missoula, Mont. The bear's cub, not pictured, was snoozing on a nearby branch. (Photo by Tommy Martino/The Missoulian via AP Photo)

A member of Viradouro samba school performs during the first night of Rio's Carnival parade at the Sambadrome Marques de Sapucai in Rio de Janeiro, Brazil on April 22, 2022. (Photo by Carl de Souza/AFP Photo)

Dennis Hong a professor of Mechanical & Aerospace Engineering at UCLA Samueli School of Engineering attempts to impede the movement of ARTEMIS, a full-sized humanoid robot with first-of-its-kind technology in Los Angeles, California, U.S., April 13, 2023. (Photo by Mike Blake/Reuters)

The lightest material ever made has been produced by a team of scientists in China, a Chinese university announced.

In this September 10, 1977, file photo, from left, Hua Guofeng, Chinese Communist Party (CCP) chairman and Mao Zedong's immediate successor; Ye Jianying, CCP vice chairman and future ceremonial head of state; Deng Xiaoping, no formal titles at the time but soon to emerge as paramount leader during the reform era; Li Xiannian, CCP vice chairman and future president; Wang Dongxing, head of the leadership bodyguard unit who helped topple the Gang of Four, view the body of later Chinese leader Mao Zedong in Beijing. (Photo via AP Photo)