Models Miranda Kerr, Candice Swanepoel, Adriana Lima and Erin Heatherton attend The Reveal of the What Is s*xy? List celebrated by Victoria's Secret Bombshells at The Beverly on May 12, 2011 in Los Angeles, California. (Photo by Charley Gallay/Getty Images for Victoria's Secret)

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.

Photographer and artist Jill Greenberg poses at her home to promote her Exhibit “Glass Ceiling: American Girl Doll” And Billboard For LA on September 29, 2011 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images)

A group of young women have 'a bit of a do' for Oxfam at St Pancras International and enjoy a screening of the nation's favourite chick-flick Dirty Dancing on February 28, 2011 in London, England. Oxfam is calling on women across the UK to get together with their female friends in March to celebrate women's achievements for the 100th anniversary of International Women's Day (March 8, 2011) and raise money to support their work with women living in poverty. www.oxfam.org.uk/do (Photo by Ian Gavan/Getty Images for Oxfam). LONDON, ENGLAND – FEBRUARY 28

Berlin-based artist Sebastian Bieniek unfolds the story of a two-faced female in his series of photographs “doublefaced”. Using an eye pencil and lipstick, bieniek simply draws an image of a face onto the side of skin. The sketch includes only one eye: carefully placed hair hides the rest of the face from view, revealing one, moving eye of the model. Blue, brown, awake, and sleeping variations create portraits with unique expressions and an illustrative sensibility. The 22 photographs of the hybrid girl expose her daily routine – drinking coffee, traveling on the train, taking a shower, and smoking cigarettes – capturing the daily life of a female with two faces.

Pretty Girls, Ugly Faces is a photo fad in which girls take pictures of themselves while posing in an unflattering manner, making a silly face or performing a physically strenuous activity.

Some 300 girls and women in India still practise open defecation. Over half the country’s population, 800 million people, do not have access to a toilet that meets basic standards. (Photo by Poulomi Basu/WaterAid)