Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)

Located in Kunshan, eastern China, the restaurant relies on over a dozen machines for tasks such as greeting customers, waiting on tables and cooking basic meals. The eatery becomes the third café in the world to rely on the use of robot employees, potentially giving a glimpse into how future businesses could operate. Photo: This photo taken on August 13, 2014, shows a robot carrying food to customers in a restaurant in Kunshan. It's more teatime than Terminator – a restaurant in China is electrifying customers by using more than a dozen robots to cook and deliver food. (Photo by Johannes Eisele/AFP Photo)

Children watch their classmate pour cold water on herself under the watch of a fitness coach at a local kindergarten in Russia's Siberian city of Krasnoyarsk, March 11, 2015. The program, which also involves sports training and sauna usage, has been practiced by the kindergarten for more than 15 years as they believe it has health benefits and keeps the children fit. Children start pouring cold water on themselves outdoors after about three years of training and undergoing medical tests, and the kindergarten is the only one in the region that practices these exercises, according to employees. (Photo by Ilya Naymushin/Reuters)

A government employee reacts as she is sprayed with disinfectant before entering a government office building to curb the spread of COVID-19 on March 19, 2020 in Pasig city, Metro Manila, Philippines. The Philippine government has sealed off Luzon, the country's largest and most populous island, to prevent the spread of COVID-19. Land, sea, and air travel has been suspended, while government work, schools, businesses, and public transportation have been ordered shut in a bid to keep some 55 million people at home. The Philippines' Department of Health has so far confirmed 217 cases of the new coronavirus in the country, with at least 17 recorded fatalities. (Photo by Ezra Acayan/Getty Images)

Lido cabaret dancers perform during a demonstration outside the cabaret as dancers, other employees and union activists are gathering to try to save their jobs and the history of the cabaret, known for its dinner theater and its “Bluebell Girls” revue, Saturday, May 28, 2022 in Paris. Amid financial troubles and changing times, the venue's new corporate owner is ditching most of the Lido's staff and its high-kicking, high-glamour dance shows – which date back decades and inspired copycats from Las Vegas to Beirut – in favor of more modest musical revues. (Photo by Thomas Padilla/AP Photo)

A 20 metre high spiral staircase in a tower used as an emergency exit, is seen inside a Federal Reserve bank (Bundesbank) bunker, prior to the bunker's official opening to the public in Cochem, Germany, March 18, 2016. West Germany's Central Bank (Deutsche Bundesbank) stored some 20 billion German marks of emergency notes in two underground bunkers, one in Frankfurt the other in Cochem, between 1964-1988 during the cold war. (Photo by Kai Pfaffenbach/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.

A preparatory model of the Imperial State Crown of India worn in 1911 by King George V stands next to original ledgers dating from 1735 in Garrard's flagship store in Mayfair on April 6, 2011 in London, England. Garrard is the world's oldest jewellers having been founded by George Wickes in 1735 and soon after appointed as goldsmith to the Prince of Wales. For over 160 years Garrard held the title of Crown Jeweller, bestowed by Queen Victoria in 1843, Garrard have served six successive monarchs. They have produced several royal crowns as well as the engagement ring presented to Kate Middleton by Prince William and formerly Princess Diana's engagement ring. (Photo by Oli Scarff/Getty Images)