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.

Dutch artist Maxim Gazendam works on his sand sculpture during the third edition of the European Championship Sand Sculpting 2014 in Zandvoort aan Zee, The Netherlands, 08 August 2014. Eight sculptors from different European countries will each create an impressive sculpture on the main theme “Music and Dance”. (Photo by Remko De Waal/EPA)

A golden huddle by Minqiang Lu, China. Two females and a male golden snub-nosed monkey huddle together to keep warm in the extreme cold. Threatened by forest loss and fragmentation, this endangered species is confined to central China. Restricted to living high up in the temperate forests, these monkeys – here in the Qinling mountains in Shaanxi province – feed mostly in the trees, on leaves, bark, buds and lichen. In heavy wind and snow, Minqiang walked up the mountain carrying his equipment. He stayed for half an hour in temperatures of –10C opposite the tree where the group was huddled before achieving this eye-level composition. (Photo by Minqiang Lu/Wildlife Photographer of the Year)

A freediver uses weights, yoga and camera tricks to create the illusion of walking underwater for a film which took three years to shoot and was completed in 2013 in El Hierro, Canary Islands. Like a scene from a Hollywood science-fiction movie, this trick footage shows a man apparently walking on water. The underwater film was shot by biologist Armiche Ramos and brothers Armando and Francisco del Rosario, who used their expertise in freediving to create the illusion. No computer graphics were involved in the production, with the team relying solely on their own skills – and a few hidden secrets. (Photo by Ocean Brothers/Barcroft Media/ABACAPress)

For more than a century, the Barcelona skyline has been graced (or marred, depending on who’s talking) by the spectacle of the Basilica designed by Anton Gaudi, first started in 1882. If you want to know what it’ll look like when finished, don’t fret — 2026 is right around the corner. Or you can watch this video, released last week on YouTube by Basílica de la Sagrada Família and titled simply “2026 We Build Tomorrow,” a 3-D artists’ rendering of the building stages through completion.
(If 144 years sounds like a long time to finish a cathedral, keep in mind that there were decades that they didn’t work on it — and that Notre Dame de Paris took 182 years, although the 13th century Parisians didn’t have diesel-powered industrial cranes.) Now, if only the video could show us what the admission and hours will be in 2026 (and how to avoid the inevitable long lines).

Mates Jimi Hunt and Dan Drupstee dug the 650m slippery slide on a property at Helensville, northwest of Auckland and opened it this weekend as part of a festival to help combat depression.

Alligator trapper Mark Whitmire prepares an alligator he caught in a lagoon on a golf course to relocate it to a more natural environment in Orlando, Florida, U.S., June 19, 2016. (Photo by Carlo Allegri/Reuters)

Normally, pictures can be worth a thousand words but these images of some horrifyingly brilliant face paint art will give you the shivers. The fascinating photographs will make your head spin and your stomach churn as the life-like illustrations leave you shocked. Nikki Shelley, 34, from Rugby in Warwickshire, has built a career out of face painting after she started practicing on her children. Here: The Devil inside by Nikki Shelley. (Photo by Nikki Shelley/Caters News)