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.

Sofia Evangelia Malkogeorgou and Evangelia Platanioti of Greece perform in the duet technical routine of the artistic swimming event during the Paris 2024 Olympic Games at the Aquatics Centre in Saint-Denis, north of Paris, on August 9, 2024. (Photo by Gonzalo Fuentes/Reuters)

China’s new tallest building has received unexpected publicity thanks to Russian free climbers Vadim Makhorov and Vitaly Raskalov. The pair took two hours to climb 650 metres up the unfinished Shanghai Tower. They did not use safety equipment on their ascent to the top of a crane attached to the tower, from where they took these extraordinary pictures of Shanghai. Photo: Vitaly Raskalov's feet dangle from the top of the Shanghai Tower, high above the Shanghai World Financial Centre. (Photo by Vitaly Raskalov/Caters News Agency)

This is a portion of the first color 360-degree panorama from NASA's Curiosity rover, made up of thumbnails, which are small copies of higher-resolution images. The mission's destination, a mountain at the center of Gale Crater called Mount Sharp, can be seen in the distance, to the left, beginning to rise up. The mountain's summit will be imaged later. (Photo by NASA/JPL-Caltech/MSSS)

Barcelona-based visual effects/3D animation company Big Lazy Robot brings us a beautiful animated video that uses an alternate robotic world to satirize our dependence on technology.

On Set with David Bowie and Tilda Swinton. A photo taken by Director Floria Sigismondi on set of The Stars (Are Out Tonight), featuring Tilda Swinton.

These stunning sand sculptures are being used to encourage youngsters to explore their surroundings and play in the dirt. (Photo by OMO Lowe)