A herd of wild monkeys ask for food from passing vehicles along a mountain road after a snowfall on October 20, 2020 in Luhuo County, Sichuan Province of China. (Photo by Jin Shujie/VCG via Getty Images)

A boy makes his way on a bicycle along a flooded road near the Ganges River in Allahabad on August 23, 2022, as water levels rose following monsoon rainfalls. (Photo by Sanjay Kanojia/AFP Photo)

A man wades through a water-logged road after rains ahead of Cyclone Yaas at Digha in Purba Medinipur district in the eastern state of West Bengal, India, May 26, 2021. (Photo by Rupak De Chowdhuri/Reuters)

A man carrying vegetables is stopped by police at a barricade on a road during a 21-day nationwide lockdown to limit the spreading of coronavirus disease (COVID-19) in Chennai, India, March 25, 2020. (Photo by P. Ravikumar/Reuters)

A goose walks on the road as Belarusian villagers take part in the Yurya religious rite to bring a good harvest in the village of Lutki, some 270 km south of Minsk, on May 6, 2019. (Photo by Sergei Gapon/AFP Photo)

If we were to burn NH4Cr2O7 with HgSCN in the Dark Ages in Europe and show it to anyone, it is us who would be burning next on a fiery cross of Inquisition. And it’s no wonder, since this experiment produces a truly marvelous result. At first, as you ignite the mixture of NH4Cr2O7 and HgSCN, all you can see is that it is slowly burning with a reddish flame. After a while, however, a crater is formed in the middle of the burning pile, and then, suddenly, tentacle-like appendages start sprouting from the burning mixture. And you can almost hear the scream of the mad occultist – “Come forth, Kraken! Come forth!” But of course, this is simply a chemical reaction that is called the "Pharoah's Serpent". It was also often sold in firework stores until people realized that it was toxic.

People and Nature category winner: Why did the sloth cross the road? by Andrew Whitworth (Osa Conservation and University of Glasgow), taken in Osa Peninsula, Costa Rica. “I was driving out from the Osa Peninsula, located on the southern Pacific coast of Costa Rica on a dark, stormy day. This female three-toed sloth (Bradypus variegatus) had luckily just about made it across the road, and the drivers of the Toyota on this occasion had spotted her in good time”. (Photo by Andrew Whitworth/2019 British Ecological Society Photography Competition)

An isolated five-floor building stands in the middle of a new road on November 22, 2012 in Wenling, Zhejiang Province of China. Zhejiang Province of China. 67-year-old Luo Baogen and his 65-year-old wife from Xiazhangyang village still live in the half-demolished residential building, because they are dissatisfied with the relocation compensation. The road, which leads to the Wenling Railway Station, has not been put into use. (Photo by China Foto Press)