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.

A tree covered with hoarfrost casts a shadow on a snowy field, shot with a drone in Sieversdorf-Hohenofen, Germany on January 31, 2021. (Photo by Patrick Pleul/dpa)

Lake Assal is a crater lake in central-western Djibouti. It is located at the western end of Gulf of Tadjoura in the Tadjoura Region, touching Dikhil Region, at the top of the Great Rift Valley, some 120 km (75 mi) west of Djibouti city. Lake Assal is a saline lake which lies 155 m (509 ft) below sea level in the Afar Triangle, making it the lowest point on land in Africa and the third-lowest land depression on Earth after the Dead Sea and Sea of Galilee.

A woman poses next to a giant mining truck at the entrance of the Dakar Rally camp in Calama, Chile. The truck operates in copper mines near the city. (Photo by Victor R. Caivano/Associated Press)

Dancers pose for a photo as they prepare during Festival Cilung or “Love the Environment” Festival, where boats made from recycled materials, mostly plastic bottles, sail on the Ciliwung River, one of the most polluted rivers in the world, to raise public awareness about river pollution, in Jakarta, Indonesia, on September 28, 2025. (Photo by Willy Kurniawan/Reuters)

Turkish guard police take special training, lasting 316 hours, for carrying out their job at best at Police Training Center Directorate of Guarding Training Academy of Turkiye on June 1, 2022. in Ankara, Turkiye. (Photo by Evrim Aydin/Anadolu Agency via Getty Images)

Commandos of the “Underwater Defence” (SAS), the special operation unit of the Turkish Navy take part in a military training in Istanbul, Turkiye on June 13, 2022. (Photo by Ali Atmaca/Anadolu Agency via Getty Images)