An Afghan woman walks with a child in the old city of Herat province, Afghanistan on October 15, 2018. (Photo by Mohammad Ismail/Reuters)

A medical worker in protective gear sprays mist on her colleague during a hot day at an outdoor clinic for coronavirus tests at a public health facility in the southwestern city of Gwangju, South Korea, 05 June 2020. (Photo by Yonhap/EPA/EFE)

Ballerina Kira Hilli of the Netherlands National Ballet dances in a tutu with a diameter of 3 meters for a video made for the 1.5 meter society, on the Prinsengracht in Amsterdam, The Netherlands, 04 June 2020 (issued on 12 June 2020). The so-called social distance tutu is made of denim fabric, specially made for the Safe Distance Ballet. (Photo by Remko de Waal/EPA/EFE)

Sеx worker Moira Mona wears a mask at her studio where she creates videos near Amsterdam, Netherlands on June 30, 2020. (Photo by Piroschka van de Wouw/Reuters)

Tengger tribe people make their way to the summit of Mount Bromo volcano to make offerings in Probolinggo, East Java province on July 7, 2020, as part of the Yadnya Kasada Festival. During the annual Yadnya Kasada festival, the Tenggerese climb Mount Bromo, an active volcano, and seek the blessing from the main deity by presenting offerings of rice, fruit, livestock and other items. (Photo by Juni Kriswanto/AFP Photo)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

Bikini-clad women sit as they operate a 3.6 metre-high custom-made female robot at the “Robot Restaurant” in Kabukicho, one of Tokyo's best known red light districts, August 15, 2012. (Photo by Tokyo Scum Brigade)

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