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.

A photographer has weathered some of Americas most violent storms to capture these stunning snaps. Storm chaser Mike Mezeul II, 30, has travelled all over the US to shoot the likes of mammoth thunderstorms and surreal cloud patterns. His incredible collection of storm images are the result of more than 15 years of photography and thousands of miles of travel. The photographer, from Frisco in Texas, USA, became interested in storm chasing aged 16 when he got his first car. He has since shot ferocious storms as far north as the Canadian border and as far south as Mexico. (Photo by Caters News)

Reem Fawzy (L), the director of the Pink Taxi company, stands with her drivers in a parking lot in Cairo, Egypt, September 6, 2015. Pink uniforms, a pink logo on the cars, and even pink nail polish – it's all part of the look of women-drivers working for Egypt's first women-only taxi service. The Pink Taxi company hires only women drivers and gives rides to only female passengers. The company was started in an effort to provide a safe taxi service for women in a country with high rates of sexual harassment, said Reem Fawzy, the director of the company. (Photo by Amr Abdallah Dalsh/Reuters)

Photo taken on September 19, 2015 shows a baby Brazilian opossum at the “Parque Estoril” zoo in Sao Bernardo do Campo of Sao Paulo, Brazil. According to local press, the “Parque Estoril” zoo houses currently 23 orphan cubs of wild animals rescued in the south region of Sao Paulo, victims of illegal wildlife trade or problems caused by urban growth. According to the zoo, all the animals arrived in the last three months, and many of them, not being able to be reintroduced to their natural habitat, will be used as examples in environmental education classes. (Photo by Rahel Patrasso/Xinhua via ZUMA Wire)

Some people think of trolls as nothing but savage beast, yet others realize that beneath their rock-hard skin hides a gentle kind heart. Ivar Rodningem is one of the people who knows the true nature of trolls. Though these creatures look unruly, it is just the way they were born. Trolls come in all shapes and sizes. Some are small, some are large, and some are simply enormous. They help each other out, though elders tend to be loners, preferring the company of their own thoughts to anybody else. You shouldn’t run for your life if you ever meet a troll, though we wouldn’t recommend pestering them, as they are mighty strong, even the little ones.

This is the remarkable moment a group of skydivers performed a world record breaking feat in honour of their friend who died while skydiving. Known as a “Bigway”, the daring jump involves 57 people holding hands in a predetermined design as they hurtle towards the ground, head first. After making the first shape, the group then break away before coming back together to form a second shape all in a single skydive. Captured using a GoPro camera by Alaskan skydiver, Ben Nelson, 36, the topsy-turvy footage shows the adrenalin junkies soaring through the air at around 160mph before banding together twice in mid-air, making the stunt a world first. (Photo by Ben Nelson/Caters News)

Runner-up. “The heavens opened and the streets around Shibuya, Tokyo, were suddenly drenched in even more colour and movement. I was taking photos (my friend was holding the umbrella) when I noticed this woman at the crossing. I’m pleased with the futuristic feel of the image”. (Photo by Katherine Bridgestock/The Guardian)

This might quite simply be the oddest skydive youll ever see – as a pair of daredevils simulate a rodeo ride as they hurtle towards earth. In the bizarre pictures, skydiver Robyn Young managed to straddle co-jumper Oliver Miller, as they plummet through the sky – and amazingly, pal Jeff Donohue caught it all on camera. The pair managed to perform the stunt before going their separate ways and pulling their parachute cords during the skydive over recibo, Puerto Rico, last month. Here: Robyn Young surfs on the back of Oliver Miller as they descend upon Arecibo, Puerto Rico. (Photo by Jeff Donohue/Caters News)