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.

Members of Japan's idol group “Virtual Currency Girls” wearing cryptocurrency-themed masks perform in their debut stage in Tokyo, Japan, January 12, 2018. Japanese female idols have teamed up to form the ‘Virtual Currency Girls’ group to promote the knowledge of cryptocurrencies through entertainment. Each of its 8 members represents a cryptocurrency: bitcoin cash, bitcoin, ether, neo, nem, ripple, mona, and cardano. (Photo by Kim Kyung-Hoon/Reuters)

Chief priest Gbenga Saala raises a cutlass to kill a dog during an annual prayer and sacrifice celebration of the iron god Ogun in Abuja, Nigeria, June 23, 2015. Every year worshippers offer a dog as sacrifice to Ogun, a traditional Nigerian deity, in hope of an auspicious year ahead. Taxi drivers, blacksmiths, panel beaters and mechanics – trades that depend on metal for their livelihood – pay homage to Ogun, led by high priest Gbenga Saala. As part of the ceremony, the priest pours the dog’s blood on symbols of these workers’ trade: keys, spanners and other tools piled up in a metal barrel. (Photo by Afolabi Sotunde/Reuters)

Are you one of those people who like to keep everything in order? If you do, you’re going to love the project The Art of Clean Up, created by Ursus Wehrli. This guy will perfectly organize the most unusual of places! Do you hate how unorganized the parking lots are, or how your haphazardly your grandma hangs the laundry to dry in the sun? Welcome to the perfect world where everything is in its rightful place. Every little detail is kept in check; every color is placed where it belongs, just like you love it. Did you ever think that your Christmas tree is not orderly enough? Well, Ursus will take it apart and put it in near little piles. (Photo by Ursus Wehrli)

Local residents receive food from federal authorities in Xalacahuantla, Mexico, on Thursday, October 16, 2025. Hundreds of communities in central and eastern Mexico were cut off by deadly landslides and flooding caused by torrential rains. (Photo by Alfredo Estrella/AFP Photo)

Dennis Hong a professor of Mechanical & Aerospace Engineering at UCLA Samueli School of Engineering attempts to impede the movement of ARTEMIS, a full-sized humanoid robot with first-of-its-kind technology in Los Angeles, California, U.S., April 13, 2023. (Photo by Mike Blake/Reuters)

Gong Yan of Team China flies out of the gate at the Para Alpine Skiing Men's Super Combined Super-G Standing at Yanqing National Alpine Skiing Centre during day three of the Beijing 2022 Winter Paralympics on March 07, 2022 in Yanqing, China. (Photo by Joel Marklund for OIS/PA Wire)

A gallery worker poses with work by artist Elinor Stanley during a press preview of The RA Schools Show 2023 at the Royal Academy of Arts in London, Britain, 08 June 2023. The RA Schools Show 2023 runs from 08 to 25 June 2023 at the Royal Academy of Arts in London. (Photo by Neil Hall/EPA)