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.

“Lofoten Glow”. I was desperately searching a good sunrise spot this particular morning. Normally Storvatnet Lake is completely covered in snow, so you can only imagine my surprise when I saw these crazy ice formations almost being shot out of the frozen lake. I put my crampons on and took a big risk walking out. I could hear the ice cracking underneath my feet, and when you’re all alone in a fjord/canyon like this – the cracks are echoed and sound really frightening. Was it worth it? I sure think so! Photo location: Storvatnet, Lofoten Islands in Northern Norway. (Photo and caption by Stian Klo/National Geographic Photo Contest)

A young girl plays on the glass bottom platform of the Oriental Pear TV Tower as she travels with her family on the second day of the Chinese Lunar New Year holiday, also known as Spring Festival, in Shanghai, China on February 18, 2018. Some 287 million tourists travelled in China during the first four days of the week-long Chinese Lunar New Year holiday, up 11.1 percent from the same period last year, new data showed Sunday. (Photo by Imaginechina/Rex Features/Shutterstock)

Aerial view of tourists cooling off at a water park in summer on June 27, 2023 in Zhengzhou, Henan Province of China. Zhengzhou Meteorological Observatory on June 27 issued an orange alert for high temperatures. (Photo by VCG/VCG via Getty Images)

A worker works at a plant of Hyundai Motor in Asan, South Korea, January 27, 2016. (Photo by Kim Hong-Ji/Reuters)

A man dressed as Santa Claus sits at a bus stop before an annual race in Belgrade, Serbia December 27, 2015. (Photo by Marko Djurica/Reuters)

A businesswoman Maha Shalaby paints ostrich eggs in Cairo, Egypt November 27, 2016. (Photo by Mohamed Abd El Ghany/Reuters)

A participant takes part in a “Zombie Walk” parade in Kiev, Ukraine on October 27, 2018. (Photo by Gleb Garanich/Reuters)