Afghan police recruits undergo training at the Afghan Police Academy October 5, 2010 in Kabul, Afghanistan. (Photo by Majid Saeedi/Getty Images)

Members of the South Korean Special Weapons and Tactics team exhibit their skill during anti-terrorism exercises at a training camp on May 30, 2005 in Seoul, South Korea. (Photo by Chung Sung Jun/Getty Images)

Cuban soldiers receive combat training at the Cadets School “Antonio Maceo” November 28, 2001, 30 kilometers East of Havana. (Photo by Jorge Rey/Getty Images)

Travellers stop to take a second glance at a model of a giant lady with her head stuck in a photo booth being exhibited in Victoria train station on September 21, 2007 in London, England. (Photo by Cate Gillon/Getty Images)

An instructor from the Tianjiao Special Guard/Security Consultant Ltd. Co, smashes a bottle over a female recruit's head during a training session for China's first female bodyguards in Beijing January 13, 2012. (Photo by David Gray/Reuters)

A female referee counts as member of Uganda's Soft Ground Wrestling is pinned to the ground during a training session at their camp in Mukono on February 28, 202. Uganda's Soft Ground Wrestling is getting attention worldwide and becoming an Internet sensation. Members showcase their wrestling skills on their YouTube channel, performing inside makeshift bamboo ring posts with string ropes and soil. Currently, Soft Ground Wrestling has 200 members, most of them from unprivileged backgrounds, and include both men and women training vigorously as they dream of becoming professional wrestlers. (Photo by Badru Katumba/AFP Photo)

Throughout time, people invented and reinvented rollerblades. Of course everyone’s dream was to combine them with regular footwear, so that at one moment you’re riding down the road, and in 5 seconds you’re walking into a shopping mall, without the mall cop chasing after you. The most resent inventions were heelys (sneakers with a wheel located in the heels) and Xsjados (aggressive skates, the exterior of which could be removed to reveal regular sneakers). In the past, people made similar attempts, however, these inventions were very inefficient and the trend never caught on. Omnia’C has found and made photos of one of such inventions: pop out roller skate sandals all the way from 1970s. Though their design is pretty cool, it seems like they would be very uncomfortable, since they totally lack ankle support.

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.