By some accounts, the self-proclaimed "Angel of Death" killed upwards of 70 people in and out of hospitals across Kentucky and Ohio.Public Domain Donald Harvey’s mugshot from his arrest in 1987. Donald Harvey was an unassuming nurse’s aid in 1987 when he pleaded guilty to killing 37 people. The soft-looking man had been on a decades-long rampage of poisoning hospital patients driven by some God complex. He saw himself as an “Angel of Death” who meted out mercy killings to the terminally ill.

A strange fashion trend that caught on in the early 20th century: The baskets on the girls' heads are meant to act as umbrellas. Seoul. Circa 1900. Okinawa Sobo/Flickr In Pyongyang, the same fad was all the rage. Here, a wealthy Korean girl walks down the crowded streets of the city, her face covered with a basket. 1904. Okinawa Sobo/Flickr Porters make their way over the mountains, a mass of pottery strapped to their backs.

Stanford researchers have just pushed knowledge on the relationship between humans and robots one step further. Is robot sex in our future?Image Source: Sean Gallup/Getty Images A recent Stanford University study that saw researchers building on the idea of the “uncanny valley” has turned up some surprising results. The uncanny valley hypothesis describes the U-shaped relationship between how “human” a robot looks, and how comfortably humans receive them. The theory suggests that for a “familiar but distinctly non-human robot,” a natural human response would be “to look at them as a friendly, non-threatening computer,” according to the study’s press release.

From missing hikers to mangled corpses to theories about the Yeti, the Dyatlov Pass Incident remains one of modern history's most baffling mysteries.In February 1959, nine Soviet hikers disappeared in the Ural Mountains, never to be seen alive again. Their bodies were discovered weeks later with baffling injuries, including missing eyes and tongues, leaving investigators horrified and baffled. So what exactly happened during the so-called Dyatlov Pass Incident? To date, no one knows for certain.

A successful revolution hinges on not just how you wage war, but how you wield words. Fidel Castro — whose rhetoric helped turn the island of Cuba against its democratically-elected government — is a living testament to that. Castro, who held control over Cuba for half a century, is not known for his pithiness. Indeed, over the course of his life he has often given three-hour speeches, and will answer a simple “yes” or “no” question with an entire defense of the impoverished and a searing indictment of capitalism.