Amateur astronomer Bill Snyder has been involved with astrophotography since 2007. Photo: The Cygnus Wall is in the southern area of NGC7000 also known as the North America Nebula. It is approximately 1800 light years from Earth, and is in the constellation Cygnus. The Wall is an energized shock front and contains the most concentrated star formations in the nebula. The size of the North America Nebula is about 4 full moons. (Photo and caption by Bill Snyder)

Relatives of the Afghan Army soldiers, who are trapped in Obde district of Herat while fighting against Taliban militants, protest to demand the government evacuate the injured soldiers, in Herat, Afghanistan, 17 June 2021. Afghan authorities said they are in the process to arrange the evacuation of Army soldiers from the restive district soon. There has been a particularly bloody spike in violence in the country in recent weeks, following the start of the withdrawal of US troops from the country, a process due to be complete by September 11. (Photo by Jalil Rezayee/EPA/EFE)

Girls stand on the rocks consulting a magazine as they carry their trays with fruits for sell, in Dakar, Senegal on February 28, 2021. (Photo by Zohra Bensemra/Reuters)

This long exposure picture shows vehicles on roads during rush hour on the eve of the National Day holidays in Shanghai on September 30, 2014. According to local media, police checkpoints will be set up at highways, elevated roads and business hubs to tackle drunk driving during the National Day holiday. (Photo by Johannes Eisele/AFP Photo)

Sinabung mountain spews volcanic smoke in Tiga Pancur Village, Karo, North Sumatra, Indonesia, 09 June 2019. According to BNPB, Mount Sinabung erupted, blowing volcanic ash more than 7,000 meters high. Sinabung is one of the most active volcanos in Indonesia. It erupted in 2010 and since then killed 17 people in eruptions in 2014 and another nine people in 2016. (Photo by Sarianto Sembiring/EPA/EFE)

A model practices her walk ahead of Dakar fashion week on Goree Island in Dakar, Senegal, on December 03, 2022. The 20th anniversary of Dakar fashion week is held in a preserved colonial era fort on Goree island, which was one of Africas biggest slave trading centres during the 15th and 16th century. (Photo by John Wessels/AFP Photo)

Indian Air Force soldiers toss their rifles as they perform during the full-dress rehearsal for Indian Air Force Day at the Hindon air force station on the outskirts of New Delhi October 6, 2015. (Photo by Anindito Mukherjee/Reuters)

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.