In the early 1990s, psychiatrist Thomas Wehr conducted an experiment in which a group of people were plunged into darkness for 14 hours every day for a month.

It took some time for their sleep to regulate but by the fourth week the subjects had settled into a very distinct sleeping pattern. They slept first for four hours, then woke for one or two hours before falling into a second four-hour sleep. […]

In 2001, historian Roger Ekirch of Virginia Tech published a seminal paper, drawn from 16 years of research, revealing a wealth of historical evidence that humans used to sleep in two distinct chunks. […]

Much like the experience of Wehr’s subjects, these references describe a first sleep which began about two hours after dusk, followed by waking period of one or two hours and then a second sleep. […] During this waking period people were quite active. They often got up, went to the toilet or smoked tobacco and some even visited neighbours. Most people stayed in bed, read, wrote and often prayed. Countless prayer manuals from the late 15th Century offered special prayers for the hours in between sleeps.

And these hours weren’t entirely solitary - people often chatted to bed-fellows or had sex.

A doctor’s manual from 16th Century France even advised couples that the best time to conceive was not at the end of a long day’s labour but “after the first sleep”, when “they have more enjoyment” and “do it better”.

Ekirch found that references to the first and second sleep started to disappear during the late 17th Century.

{ BBC | Continue reading }

The kings of the Spanish Habsburg dynasty (1516–1700) frequently married close relatives in such a way that uncle-niece, first cousins and other consanguineous unions were prevalent in that dynasty. In the historical literature, it has been suggested that inbreeding was a major cause responsible for the extinction of the dynasty when the king Charles II, physically and mentally disabled, died in 1700 and no children were born from his two marriages, but this hypothesis has not been examined from a genetic perspective. In this article, this hypothesis is checked by computing the inbreeding coefficient (F) of the Spanish Habsburg kings from an extended pedigree up to 16 generations in depth and involving more than 3,000 individuals. […]

It is speculated that the simultaneous occurrence in Charles II of two different genetic disorders […] could explain most of the complex clinical profile of this king, including his impotence/infertility which in last instance led to the extinction of the dynasty.

{ PLoS | Continue reading | Read more: Nature }

photo { Erich Heckel, Fränzi Reclining, 1910 }

Modern humans are estimated to be about 200,000 years old, but 99% of progress has occurred in the last 10,000 years. What were we doing before that?

[…]

Low Population: Until about 10000 BCE, world population never exceeded 15 million and mostly was around 1 million. Urban World History The present population of the world is 7 billion and 1 million is comparable to the population of a medium size city. When you have just a couple of million people spread in this big wide world, there is little that humanity could collectively build. Even if we assume that early human being could be as productive as us, their civilization could produce less than 1/1000 of what our society could do.

Life Expectancy: From that point until 20th century, we had a very low life expectancy (about 30 years). Imagine if we all died by the time we reached 30, how much could we learn from our parents and how much can we teach our kids. Given the low life expectancy of early humans, there was not much time to learn and teach. We just started randomly doing whatever we could to survive.

{ Quora | Continue reading }

installation { Jannis Kounellis, Untitled, 2005 }

Researchers at the University of Leeds may have solved a key puzzle about how objects from space could have kindled life on Earth.

While it is generally accepted that some important ingredients for life came from meteorites bombarding the early Earth, scientists have not been able to explain how that inanimate rock transformed into the building blocks of life.

This new study shows how a chemical, similar to one now found in all living cells and vital for generating the energy that makes something alive, could have been created when meteorites containing phosphorus minerals landed in hot, acidic pools of liquids around volcanoes, which were likely to have been common across the early Earth.

“The mystery of how living organisms sprung out of lifeless rock has long puzzled scientists, but we think that the unusual phosphorus chemicals we found could be a precursor to the batteries that now power all life on Earth. But the fact that it developed simply, in conditions similar to the early Earth, suggests this could be the missing link between geology and biology,” said Dr Terry Kee, from the University’s School of Chemistry, who led the research. […]

“Chemical life would have been the intermediary step between inorganic rock and the very first living biological cell. You could think of chemical life as a machine –a robot, for example, is capable of moving and reacting to surroundings, but it is not alive. With the aid of these primitive batteries, chemicals became organised in such a way as to be capable of more complex behaviour and would have eventually developed into the living biological structures we see today,” said Dr Terry Kee.

{ University of Leeds | Continue reading }

Last week I discussed a way of preserving bodies almost indefinitely in some cases: embalming. On the other side of this is decay, the process of bodily decline and biological breakdown of the flesh. If you’ve ever watched any of the forensics crime shows, you know that understanding decay and changes in the body can be a key factor in determining when the individual died and how the body was treated after death. But it’s also important for archaeologists dealing with remains that are ancient.

First, let’s look at the early stages of decay. […] The first stage consists of the ‘mortis‘ phases. The blood isn’t being pumped through the body so due to gravity it pools in certain areas, and this is known as livor mortis. Shortly after this, the muscular tissue becomes rigid and incapable of relaxing, a state called rigor mortis. Next the body loses heat and cools in a process called algor mortis. Second, the body goes through bloat, in which means that microbes are rapidly growing and forming gases within the body. […]

Bones are also subject to continued decay, the study of which is known as taphonomy and is extremely important for archaeologists.

{ Bones Don’t Lie | Continue reading }

photo { Bobby Doherty }

Baerg was challenged by a Cornell colleague to investigate whether black widows were harmless or poisonous. […] He made extensive observations of black widow behavior and its venom’s effects on rats. Baerg used himself as an experimental subject to test the effects of the venom on humans. He induced a black widow to bite the third finger of his left hand, but the bite was apparently superficial, and he suffered no symptoms besides a “slight, sharp pain.” Baerg repeated the test the following day, this time allowing the spider’s fangs to remain inserted for five seconds. During the next three days, Baerg recorded his symptoms and reactions, creating the first account of the effects of the black widow spider bite on humans; it was published in the March 1923 edition of The Journal of Parasitology (vol. 9, no. 3). Baerg observed the swelling and pain that followed the spider’s bite, noting that, as the symptoms spread to his shoulder, chest, and hips, he had problems with breathing and speech. He also noted that the “doctor advises that I go to bed.” He recalled the experience later, saying that the pain was severe and different from anything he had ever experienced. Baerg induced numbers of arachnids to bite or sting him over the successive years and recorded the resulting effects.

{ Encyclopedia of Arkansas | Continue reading }

art { Joan Miró, Painting (Head and Spider), 1925 }

Why does the alphabet’s 24th letter designate the nameless?

[…]

It probably starts with the 17th-century French philosopher and mathematician René Descartes, who in his 1637 book “La Géometrie” first systematically used a lower-case “x,” together with “y” and “z,” to signify an unknown quantity in simple algebraic equations. […] We now jump […] from 1637 to 1895, when Wilhelm Röntgen discovered a new type of radiation. Röntgen, who wasn’t sure just what he had come across, named his find in German X-Strahlen, using the algebraic symbol for something unknown. […] “X-ray” has remained our English word and has also contributed, with the help of the term “X-ray vision,” to x’s ability to evoke the uncanny.

{ Forward | Continue reading }

previously { XXX, XXY, XYY }

photo { Adam Broomberg & Oliver Chanarin }

There are good reasons for any species to think darkly of its own extinction. […]

Simple, single-celled life appeared early in Earth’s history. A few hundred million whirls around the newborn Sun were all it took to cool our planet and give it oceans, liquid laboratories that run trillions of chemical experiments per second. Somewhere in those primordial seas, energy flashed through a chemical cocktail, transforming it into a replicator, a combination of molecules that could send versions of itself into the future.

For a long time, the descendants of that replicator stayed single-celled. They also stayed busy, preparing the planet for the emergence of land animals, by filling its atmosphere with breathable oxygen, and sheathing it in the ozone layer that protects us from ultraviolet light. Multicellular life didn’t begin to thrive until 600 million years ago, but thrive it did. In the space of two hundred million years, life leapt onto land, greened the continents, and lit the fuse on the Cambrian explosion, a spike in biological creativity that is without peer in the geological record. The Cambrian explosion spawned most of the broad categories of complex animal life. It formed phyla so quickly, in such tight strata of rock, that Charles Darwin worried its existence disproved the theory of natural selection.

No one is certain what caused the five mass extinctions that glare out at us from the rocky layers atop the Cambrian. But we do have an inkling about a few of them. The most recent was likely borne of a cosmic impact, a thudding arrival from space, whose aftermath rained exterminating fire on the dinosaurs. […]

Nuclear weapons were the first technology to threaten us with extinction, but they will not be the last, nor even the most dangerous. […] There are still tens of thousands of nukes, enough to incinerate all of Earth’s dense population centers, but not enough to target every human being. The only way nuclear war will wipe out humanity is by triggering nuclear winter, a crop-killing climate shift that occurs when smoldering cities send Sun-blocking soot into the stratosphere. But it’s not clear that nuke-levelled cities would burn long or strong enough to lift soot that high. […]

Humans have a long history of using biology’s deadlier innovations for ill ends; we have proved especially adept at the weaponisation of microbes. In antiquity, we sent plagues into cities by catapulting corpses over fortified walls. Now we have more cunning Trojan horses. We have even stashed smallpox in blankets, disguising disease as a gift of good will. Still, these are crude techniques, primitive attempts to loose lethal organisms on our fellow man. In 1993, the death cult that gassed Tokyo’s subways flew to the African rainforest in order to acquire the Ebola virus, a tool it hoped to use to usher in Armageddon. In the future, even small, unsophisticated groups will be able to enhance pathogens, or invent them wholesale. Even something like corporate sabotage, could generate catastrophes that unfold in unpredictable ways. Imagine an Australian logging company sending synthetic bacteria into Brazil’s forests to gain an edge in the global timber market. The bacteria might mutate into a dominant strain, a strain that could ruin Earth’s entire soil ecology in a single stroke, forcing 7 billion humans to the oceans for food. […]

The average human brain can juggle seven discrete chunks of information simultaneously; geniuses can sometimes manage nine. Either figure is extraordinary relative to the rest of the animal kingdom, but completely arbitrary as a hard cap on the complexity of thought. If we could sift through 90 concepts at once, or recall trillions of bits of data on command, we could access a whole new order of mental landscapes. It doesn’t look like the brain can be made to handle that kind of cognitive workload, but it might be able to build a machine that could. […]

To understand why an AI might be dangerous, you have to avoid anthropomorphising it. […] You can’t picture a super-smart version of yourself floating above the situation. Human cognition is only one species of intelligence, one with built-in impulses like empathy that colour the way we see the world, and limit what we are willing to do to accomplish our goals. But these biochemical impulses aren’t essential components of intelligence. They’re incidental software applications, installed by aeons of evolution and culture. Bostrom told me that it’s best to think of an AI as a primordial force of nature, like a star system or a hurricane — something strong, but indifferent. If its goal is to win at chess, an AI is going to model chess moves, make predictions about their success, and select its actions accordingly. It’s going to be ruthless in achieving its goal, but within a limited domain: the chessboard. But if your AI is choosing its actions in a larger domain, like the physical world, you need to be very specific about the goals you give it. […]

‘The really impressive stuff is hidden away inside AI journals,’ Dewey said. He told me about a team from the University of Alberta that recently trained an AI to play the 1980s video game Pac-Man. Only they didn’t let the AI see the familiar, overhead view of the game. Instead, they dropped it into a three-dimensional version, similar to a corn maze, where ghosts and pellets lurk behind every corner. They didn’t tell it the rules, either; they just threw it into the system and punished it when a ghost caught it. ‘Eventually the AI learned to play pretty well,’ Dewey said. ‘That would have been unheard of a few years ago, but we are getting to that point where we are finally starting to see little sparkles of generality.’

{ Ross Andersen/Aeon | Continue reading }

Two generations on, the 1946-1947 Moldovan famine remains a highly contentious and emotive issue in Moldova itself. […] One aspect of the Moldovan famine that makes its memory more fraught is the gruesome suggestion that ‘the eating of corpses took place on a large scale.’ The authorities were aware of the practice— they even showed Alexei Kosygin, then a candidate politburo member and sent from Moscow to investigate, a corpse that had been prepared for eating—and sought to stamp it out. There were stories of murder-cannibalism, including one of ‘a peasant woman from the village of Tambula’, who had ‘killed two of her four children, a girl of six and a boy of five, with a view to eating them’, and ‘another peasant from the village of Cajba’ who had‘ killed his 12-year-old grandson who had come to visit and ate him’.

Cannibalism is famine’s darkest secret, a taboo topic. How common was it in the past?

{ SSRN | Continue reading }

photo { Joe Shere, Jayne Mansfield and Sophia Loren at Romanoff’s, Beverly Hills, c. 1958 }

The Tunguska event was an enormously powerful explosion that occurred near (and later struck) the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, on June 30, 1908. The explosion is believed to have been caused by the air burst of a large meteoroid or comet fragment at an altitude of 5–10 kilometres (3–6 mi) above the Earth’s surface.

Although the meteoroid or comet appears to have burst in the air rather than hitting the surface, this event still is referred to as an impact. Estimates of the energy of the blast range from 5 to as high as 30 megatons of TNT, with 10–15 megatons of TNT the most likely—about 1,000 times more powerful than the atomic bomb dropped on Hiroshima, Japan.

The Tunguska explosion knocked an estimated 80 million trees down over an area covering 2,150 square kilometres (830 sq mi) (i.e. circular area of 52km in diameter). It is estimated that the shock wave from the blast would have measured 5.0 on the Richter scale.

{ Wikipedia | Continue reading }

Interest in sensations from removed body parts other than limbs has increased with modern surgical techniques. This applies particularly to operations (e.g., gender-changing surgeries) that have resulted in phantom genitalia. The impression given in modern accounts, especially those dealing with phantoms associated with penis amputation, is that this is a recently discovered phenomenon. Yet the historical record reveals several cases of phantom penises dating from the late-eighteenth century and the early-nineteenth century. These cases, recorded by some of the leading medical and surgical figures of the era, are of considerable historical and theoretical significance. This is partly because these phantoms were associated with pleasurable sensations, in contrast to the loss of a limb, which for centuries had been associated with painful phantoms. We here present several early reports on phantom penile sensations, with the intent of showing what had been described and why more than 200 years ago.

{ Taylor & Francis | Continue reading }

related { Study of a rare disease making people look like a woman but having male genitals under study }

{ Thanks Tim }