A guest arrives before the Blumarine show during Milan Fashion Week Spring 2019 in Milan, Italy, September 21, 2018. (Photo by Stefano Rellandini/Reuters)

A female rebel in Kabul, Afghanistan, circa 1979. Photo taken at a parade in Kabul in honor of the pro-Communist Saur Revolution. She was from the women’s battalion of the people’s militia (one of the anti-imperial groups that participated in the coup d’etat). (Photo by Viktor Khabarov)

American singer-songwriter Ashley Nicolette Frangipane, known professionally as Halsey is seen in Midtown on October 07, 2021 in New York City. (Photo by Gotham/GC Images)

A new type of tandem at Alexandra Palace, London. (Photo by Fox Photos/Getty Images). June 1936

Two men using an electric power saw to fell a tree circa 1940's. (Photo by Keystone View/FPG/Getty Images)

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

Libyan leader Muammar Gaddafi attends the inauguration ceremony of Jacob Zuma on May 9, 2009 in Pretoria, South Africa. Jacob Gedleyihlekisa Zuma is South Africa's fourth President since the end of apartheid. (Photo by Foto24/Gallo Images/Getty Images)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)