This photo taken on October 20, 2018 shows tourists posing for a photo on a middle of a railway track passing through an old residential district in central Hanoi. (Photo by Nhac Nguyen/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.

The world's longest moustache (belonging to one Ram Singh Chauhan of Rajasthan, India) measures a staggering 11.5 feet, or nearly 4 metres.

Mercedes Russell #21 of the Seattle Storm defends Aliyah Boston #7 of the Indiana Fever during the first quarter at Climate Pledge Arena on June 22, 2023 in Seattle, Washington. (Photo by Steph Chambers/Getty Images)

From left, Cierra Fraser, 28, Los Angeles, a nanny, and Joslin Farley, 28, Los Angeles, a barista, poses in the outfits they wore to see the movie “Barbie” at TCL Chinese Theater in Los Angeles, California, on July 22, 2023. “I just knew that it was in good hands. I knew we were not gonna get a stereotypical barbie movie. I knew it was gonna be exactly what the people needed”, said Farley. (Photo by Jenna Schoenefeld for The Washington Post)

“Winter Climbing from inside Ben Nevis”. The view from inside the mountain, as a winter climber passes through the cave on Minus Three gully. Photo location: Ben Nevis, Fort William, Scotland. (Photo and caption by Daniel Wildey/National Geographic Photo Contest)