Bloody Arrowhead Reveals Maya 'Life Force' Ceremony

An ancient arrowhead with human blood on it points to a Maya bloodletting ceremony in which a person’s “life force” fed the gods, two researchers say.

The ceremony took place around 500 years ago in Guatemala at a temple at the site of Zacpetén. During the ceremony someone was cut open — possibly through the earlobes, tongue or genitals — with an arrowhead made of obsidian (a volcanic glass), and their blood was spilled.

The Maya believed that each person had a “life force” and that bloodletting allowed this life force to nourish the gods. “The general consensus (among scholars) is that bloodletting was ‘feeding’ the gods with the human essential life force,” said Prudence Rice, a professor emeritus at Southern Illinois University in Carbondale.

“We know Mayas also participated in bloodletting as a part of birth or coming-of-age ceremonies,” said Nathan Meissner, a researcher at the Center for Archaeological Investigations at Southern Illinois University. “This practice served to ensoul future generations and connect their life force to those of past ancestors.”

Whoever gave their blood may have done so voluntarily and probably survived the ceremony, Rice said.

Bloody finds

This life force ceremony was one of many discoveries made in a study published recently by Meissner and Rice in the Journal of Archaeological Science. For the study, they examined 108 arrowheads from five sites in the central Petén region of Guatemala. All the sites had been excavated within the last 20 years and all the arrowheads date to between A.D. 1400 and A.D. 1700.

Using a technique called counter-immunoelectrophoresis they were able to detect the remains of ancient blood on 25 of the arrowheads and identify the types of species they came from. Two of the arrowheads had human blood, while the others held blood from a mix of animals, including rodents, birds, rabbits and large cats.

During the lab procedure, proteins are removed from the arrowheads and tests are conducted to see if the proteins react to serums containing the antibodies of different animals. If a reaction occurs, then it means the proteins from the arrowhead may be from the animal whose antibodies are being tested.

This technique “has been used occasionally in the last decade, but has some limitations because of cost, its potential for contamination, and its success rate,” Meissner said. Quite often, ancient proteins don’t survive the passage of time and the reactions don’t always allow scientists to identify the precise species. For instance, while the researchers were able to tell that four of the arrowheads were coated with the blood of rodents, they couldn’t identify what type of rodents were killed.

Combat casualty?

In the study, the researchers found that two arrowheads had human blood on them. The second arrowhead with human blood was discovered inside an old house near a fortification wall at Zacpetén. Impact damage on the arrowhead suggests it hit a person.

The researchers aren’t clear on the story behind this arrowhead. A wounded individual (perhaps someone who was defending the site) may have been carried into the house, where the arrowhead was removed. “There are multiple accounts of Mayas surviving arrow injuries, which could mean they were brought back embedded in living individuals,” Meissner said.

Read more at Discovery News

Wormhole Wonders: Hunting Down Spacetime Shortcuts

Science fiction literature is full of stories in which tunnels in space-time — known as wormholes — are used for time travel. How much fact lies within the fiction? The answer is, more than you might think. Scientists are looking at ways to use traversable wormholes (if they exist) to travel faster than the speed of light — and even to travel through time itself.

"A traversable wormhole is a hyperspace tunnel, also called a throat, that connects together two remotely distant regions within our universe, or two different universes — if other universes exist — or two different periods in time, as in time travel, or different dimensions of space," physicist Eric Davis told Space.com by email.

Davis specializes in the field of space-time as a member of the Tau Zero Foundation, where he uses equations from Einstein's general theory of relativity to think about possible (or impossible) designs for traversable wormholes, warp drives and time machines.

Building a Wormhole

Wormholes were first proposed in 1916 by mathematician Ludwig Flamm, who was toying around with equations from Einstein's theory of general relativity that describe how gravity can curve space-time, which refers to the fabric of physical reality. While these tunnels through space-time are a fascinating theoretical possibility, according to physicist Kip Thorne, a professor emeritus at the California Institute of Technology, scientists have not yet come up with an agreed-upon way that wormholes could form in nature, and no wormholes have ever been detected.

Thorne and some of his colleagues also showed that even if a wormhole appeared, it would likely collapse before an object (or person) could pass through it. To keep the wormhole open long enough to traverse it would require some kind of scaffolding, but normal matter wouldn't stand up to the job — it would require an "exotic material."

"Dark energy is one form of naturally occurring exotic matter whose negative pressure produces the gravitationally repulsive force that pushes the space inside our universe outward, thus producing the inflationary expansion of the universe," Davis said.

Along with dark energy, scientists also know of an exotic material called dark matter, which is five times more prevalent in the universe than regular matter. To date, scientists have been unable to directly detect either dark matter or dark energy, so much about them is still unknown. Scientists can learn about these materials, though, by examining the effect they have on the space around them.

According to Ali Övgün of Eastern Mediterranean University in Cyprus, it's possible that wormholes could form where dark matter is present, and thus that they could exist in the outer regions of the Milky Way, where dark matter lies, as well as within other galaxies. Övgün is working to prove that wormholes could exist in regions dense with dark matter. He and his colleagues have run simulations that show that wormholes in dense regions of dark matter found in galactic halos would satisfy the physical requirements scientists think the tunnels require.

"But it is only mathematical proof," Övgün said. "I hope one day it will be possible to also find direct experimental evidence."

So, what happens to a person or instrument traveling through a wormhole?

"Nothing! The space-time geometry of traversable wormholes requires that there be no nasty, intolerable gravitational tidal forces acting upon the spacecraft or its passengers while they move through the wormhole tunnel," Davis said. "They go into the throat at their departure location near Earth and get shunted through the tunnel to emerge out the other side near the destination star."

Because these theoretical tunnels cut through space-time, they would allow travelers to achieve speeds that appear to an outside observer to be faster than light (FTL). However, from the travelers' points of view, they would never actually outpace the speed of light — it would just seem that way to outside observers because the travelers would be taking a route that's shorter than they would have taken through ordinary space.

Before scientists could use wormholes, they would first have to find them. To date, wormholes have not been discovered. However, if they exist, locating a tunnel through space-time may not be as difficult as it sounds.

"As it is visualized in the movie 'Interstellar,' in the future, there will be some experiments to observe indirectly," Övgün said.

Based on certain wormhole theories, he compared peering through a wormhole to Alice's glimpse through the looking glass, in Lewis Carroll's novel of the same name. The region of space at the far end of the tunnel should stand out from the area around the entrance thanks to distortions that would be similar to the reflection in curved mirrors. Another indication may be the way light is concentrated as it moves through the wormhole tunnel, much as the wind blows through a physical tunnel.

Davis refers to what is seen at the near end of a wormhole as a "rainbow caustic effect." Such effects could be seen from a distance.

"Astronomers were planning to use telescopes to hunt for these rainbow caustics as a sign of a naturally occurring, or even an alien-made, traversable wormhole," Davis said. "I never heard if that project got off the ground."

Traveling Through Time

As part of his study of wormholes, Thorne also proposed a thought experiment in which a wormhole could be used as a time machine. Thought experiments about time travel often run into paradoxes. Perhaps the most famous of these is the grandfather paradox: If an explorer went back in time and killed his or her grandfather, that person could not be born, and would never have gone back in time in the first place. This seems to suggest that backward time travel is impossible, but according to Davis, Thorne's work opened up a new avenue for scientists to explore.

Read more at Discovery News

These Bacteria Could Live in Europa's Ocean

The idea of life existing in a buried sea inside a moon of Jupiter may seem strange, perhaps impossible. But a series of laboratory tests show that some terrestrial bacteria would adapt well to the salty and sulfate-rich ocean believed to exist beneath the hard icy shell of Europa.

In addition to a global liquid ocean, Europa, which is about one-quarter the diameter of Earth, has a metal-rich core and rocky interior, providing both the chemistry and possible energy sources to support life.

Measurements from NASA's Galileo mission to Jupiter indicate that Europa's ocean is rich in magnesium sulfate, among other salts. That got scientists curious about how well some bacteria that live in harsh environments on Earth would fare under even more extreme conditions that may exist on Europa.

Astrobiologist Sandra Ramirez, with Mexico's Universidad Autonoma del Estado de Morelos, and colleagues tested three strains of bacteria -- Bacillus pumilus, Halomonas halodurans and Salinibacter ruber -- under different concentrations of sodium chloride, magnesium chloride, sodium sulfate and magnesium sulfate.

The point of the experiment was to demonstrate whether the bacteria have the ability to grow not only in the presence of salty sodium chloride, but also but when "salts of astrobiological interest," as Ramirez puts it, are added.

The researchers found that all three strains of bacteria could adapt to a concentrated saline environment. But one, the extremophile Salinibacter ruber, showed a particular fondness for magnesium sulfate. "We found a very different behavior in the extreme bacteria," Ramirez said at the International Astronautical Congress in Jerusalem. "We're conducting experiments investigating the reason for this."

The initial experiments show that Europa's ocean may harbor life as we know it, despite a myriad of potentially extreme conditions, such as temperature, acidity, pressure and salinity, the researchers conclude.

Read more at Discovery News

Is Sitting Really That Bad? Yes.

Like smoking and overeating, sitting has joined the list of behaviors that seem likely to lead to an early death. In recent years, dozens of studies have linked prolonged sitting with higher risks for cardiovascular disease, cancer, type 2 diabetes and more.

A welcome dose of hope for office-workers and couch potatoes seemed to arrive last week, when a new study suggested that sitting might not be so bad, after all. Based on 16-years of data on more than 5,000 middle-aged adults, UK researchers found no link between prolonged sitting and the risk of death.

But, experts caution, the new findings don’t necessarily contradict or debunk growing evidence for the harms of sedentary lifestyle. One major reason is that participants in the new study were especially active, reporting an average of 15 hours of physical activity per week.

That’s drastically more than the 2.5 weekly hours recommended by many major medical groups. And that suggests that there might be some still-unquantified protective effect of exercise that counteracts the dangers of sitting. The study also looked only at death rates, and not at rates of diseases or other health measures.

Based on the bulk of accumulating data, experts say, a sedentary lifestyle still seems to carry real risks.

“There is a lot of very good research that is ongoing in research groups around the world, which is examining associations between sitting and disease in different populations and most importantly, the underlying biology behind these associations,” says Richard Pulsford, an exercise physiologist at the University of Exeter, and lead author of the new study in the International Journal of Epidemiology.

“When we understand what’s going on under the surface,” he says, “we will know far more about whether sitting or a lack of activity is the most important factor for promoting good health.”

Although scientists have long known that physical activity promotes health, the first clue that sitting could be detrimental for people came in 2009, when researchers looked at data on more than 17,000 Canadians and found that people who sat more were more likely to die from cardiovascular disease.

Since then, a number of large studies in a variety of countries have produced similar results, says Peter Katzmarzyk, an epidemiologist at the Pennington Biomedical Research Institute in Baton Rouge, Louisiana, and co-author of the 2009 study.

Accumulating findings have been both alarming and punctuated by unknowns. In general, studies have shown no “safe level” below which sitting is good and above which sitting becomes bad, Katzmarzyk says. Instead, it appears that progressively more sitting leads to progressively worse consequences. Even avid exercisers suffer more ill effects when they spend more of their non-workout time sitting.

But there is also evidence to suggest that sitters who exercise fare better than sitters who just sit. In a review of 47 studies published in the Annals of Internal Medicine earlier this year, researchers concluded that, among people who did not exercise, prolonged sitting raised risks for various diseases by about 40 percent, says  lead author David Alter, a cardiologist at the University of Toronto. Among avid exercisers, on the other hand, sitting raised risk by just five or 10 percent.

The new UK study supports the idea that the benefits from lots of physical activity can counteract the harms from lots of sitting.

“The real health risks associated with sitting are among those folks who are both sitting for long periods of time and not exercising,” Alter says. “The magnitude of risk really diminishes and is marginal among folks who exercise.”

What science can’t yet offer are clear guidelines on how much exercise is enough in order to justify a long day behind a computer or a relaxing night of binge-watching shows on Netflix. For most people, two hours a day of activity is an unrealistic goal. And while less might still offer protection, the only way to know for sure is with trials that assess the consequences of various amounts and types of movement. That kind of data is not yet available.

Read more at Discovery News

Photo of Iceberg That Sank Titanic on Auction

A photo of the iceberg that likely sank the Titanic — along with a critical testimony about red paint seen on the side of the iceberg — has resurfaced after hanging for nearly a century on a boardroom wall, according to a BBC report.

The photo showing what may be the deadliest iceberg in history, was snapped by the chief steward of the German ocean liner Prinz Adalbert on April 15, 1912 — the morning after the Titanic struck the iceberg and sank, dooming the ship’s 2,200 passengers. While other photos of the iceberg exist, this is the only one that comes with its own testimony.

In the testimony, the steward wrote, “On the day after the sinking of the Titanic, the steamer Prinz Adalbert passes the iceberg shown in this photograph. The Titanic disaster was not yet known by us. On one side red paint was plainly visible, which has the appearance of having been made by the scraping of a vessel on the iceberg.”

The note was signed “M. Linoenewald, and three crewmen.”

The Titanic’s hull was painted red and the red paint on the iceberg most likely had come from the ship as the ice scraped into its side. The Titanic was on its maiden voyage crossing the Atlantic when it hit the iceberg, carrying just over 2,200 passengers and crew. Only 983 people survived the disaster.

The photograph hung for decades on the walls of the law firm representing the Titanic’s owners, White Star Line. The firm closed in 2002, and the four partners of the firm are now putting it up for auction, along with the note.

Read more at Discovery News

400-Year-Old Church Emerges as Reservoir Dries

As Mexico’s parched Nezahualcoyotl reservoir slowly succumbs to drought-like conditions, its receding waters have revealed a haunting relic from the past: a submerged 16th-century church not seen in over a decade.

Originally built by Dominican monks, the church was located in Quechula, a small town that church officials envisioned would eventually become a large population center. Quechula, however, was completely abandoned in the 1770s after a devastating plague ravaged the area.

In the 1960s, what remained of Quechula was completely submerged when Mexican authorities dammed the nearby Grijalva River.

Since then, the church has only been seen in such detail one other time. In 2002, the reservoir was reportedly so low that visitors were able to walk through the church's remains.

So far this year, the reservoir's water level has dropped 75 feet, exposing much of the resilient structure, which stands 48 feet tall at its highest point.

From Discovery News

Attraction Guided by Our Genes

Opposites attract. It’s a basic principle of magnetism that has long been applied to romance. But the problem is that research on relationships shows that this notion, which sounds all well and good in song form, doesn’t ring true in practice.

Instead, we tend to be attracted to people who are similar to us in one way or another. It’s a phenomenon known as assortative mating. Assortative mating can be seen across traits like race, age, facial characteristics and body type, all of which have a genetic basis.

Individuals in fact tend to seek out someone with similar DNA, finds a joint analysis of Latino communities in Mexico, Puerto Rico and the United States by researchers at the University of California – San Francisco, Microsoft Research, Harvard, University of California – Berkeley, and Tel Aviv University.

Couples who pair up in these communities often have similar genetic ancestry, which proves stronger in determining mate selection than other socioeconomic factors, such as education levels, which itself has shown to be a powerful predictor of attraction in previous research.

In fact, ancestry was so similar in the populations studied that the average couple was the genetic equivalent of between third and fourth cousins. This degree of genetic relatedness among mating pairs could have potential health implications, both positively and negatively, as recessive alleles are more commonly passed in partners with similar genetic profiles.

There is a limitation in this study in that the research, appearing the latest Proceedings of the National Academy of Sciences (PNAS), in that it focused on ethnically homogenous communities. Other studies have found similar results, however, when looking at different populations.

Last year, another PNAS study by University of Colorado – Boulder researchers examined the genetic profiles of 825 non-Hispanic white couples. The researchers looked at single-nucleotide polymorphisms, parts of DNA where humans differ from one another. What the scientists found was that married individuals were likely to be more genetically similar than two individuals randomly selected from the same population.

Assortative mating is common, some researchers argue, simply because of population stratification. Individuals tend to coalesce around like individuals, according to ethnic, racial or socioeconomic factors. But there is evidence as well of disassortative mating at a genetic level as well.

A 2009 study presented before the conference of the of the European Society of Human Genetics examined the major histocompatibility complexes (MHCs), a genetic region that plays a key role in immune response and reproductive success, in 90 married couples and compared them with 152 randomly matched pairs set up as control group. Married couples were more likely to choose a mate with diverse MHCs, likely an evolutionary strategy tied to successful reproduction.

Read more at Discovery News

Weird Woodworm-like Pits on Pluto Reveal Icy Puzzle

Like a woodworm-infested log, new photos from NASA’s New Horizons mission of dwarf planet Pluto have revealed a pockmarked terrain that is as puzzling as it is beautiful.

Imaged just before the NASA probe made close approach on July 14, this new view of Pluto’s icy Sputnik Planum region reveals hundreds of pits, a few hundred meters wide by a few tens of meters deep, swarming across the surface. Composed of ices such as nitrogen, planetary scientists are making an early guess that these features are caused by sublimation, but the alignment and location of the pits are a mystery.

Sublimation occurs when an ice turns directly into a vapor without turning into a liquid — like “dry ice” on Earth (carbon dioxide ice), the ice will change phase into a gas without passing through the liquid phase. As there is little atmospheric pressure on Pluto, sublimation is a dominant process; as the abundant surface ices are heated, they vent gases into the tenuous atmosphere, forming a surprisingly complex interplay between the surface and atmosphere.

Indeed, the surprising lack of impact craters on Sputnik Planum shows the surface is constantly being refreshed by new ice likely being layered from the atmosphere and these pits are physical evidence of this bizarrely active ice layer.

“Pluto is weird, in a good way,” said New Horizons project scientist Hal Weaver, of Johns Hopkins Applied Physics Laboratory in Laurel, Md. “The pits, and the way they’re aligned, provide clues about the ice flow and the exchange of volatiles between the surface and atmosphere, and the science team is working hard to understand what physical processes are at play here.”

It’s hard not to imagine what this landscape would look like if we could stand on the surface of Sputnik Planum. We already know that this region is pretty much flat, but the inclusion of these pits would make it look like an ocean of dramatic sinkholes in the ice stretching to the horizon.

Read more at Discovery News

Novel algorithm simulates water evaporation at the nanoscale

We are all familiar with boiling a pot of water--flame from a stove heats the base of a metal pot, the metal transfers the heat to the water, and the temperature goes up and up until the water boils. Professor Shalabh Maroo and graduate student Sumith YD are looking closer -- much closer. They are looking at heat transfer in water at the nanoscale, where the heat from the pot's atoms transfers to the atoms that make up water.

The evaporation of water that occurs when it meets a hot surface is understood in continuum theory and in experimentation. Before now, researchers were unable to study it at nanoscales in molecular simulation. YD and Maroo's algorithm has made that possible, and their paper, "Surface-Heating Algorithm for Water at Nanoscale," has garnished notable attention in the Journal of Physical Chemistry Letters.

Within their paper, the pair details their development of a new algorithm that simulates the evaporation of water at the molecular scale that matches theoretical, numerical, and real-world observations. In doing so, the team has provided a molecular dynamics tool that allows for the study of various heat transfer problems at the nanoscale, including understanding and utilizing passive liquid flows.

"By capturing realistic differential thermal gradients in water heated at the surface, our algorithm can be an incredibly valuable tool for studying a range of heating and cooling problems. It's also simple enough to be easily integrated into various molecular simulation software and user codes," describes Maroo.

This research is part of Maroo's CAREER award research, in which he is investigating the fundamental physics associated with nanoscale meniscus evaporation and passive liquid flow to remove large amounts of heat from small surfaces in very short amounts of time. This work aims to provide rapid and efficient cooling of next-generation computer chips and energy conversion devices.

From Science Daily

Dates for cataclysms on early moon, Earth questioned

This highly shocked zircon, from the Vredefort Dome in South Africa, shows thin, red bands that are a hallmark of meteorite impact. Uranium-lead dating from this zircon matched the age of the rocks exposed at Vredefort, not the more recent age of impact (2 billion years).

Phenomenally durable crystals called zircons are used to date some of the earliest and most dramatic cataclysms of the solar system. One is the super-duty collision that ejected material from Earth to form the moon roughly 50 million years after Earth formed. Another is the late heavy bombardment, a wave of impacts that may have created hellish surface conditions on the young Earth, about 4 billion years ago.

Both events are widely accepted but unproven, so geoscientists are eager for more details and better dates. Many of those dates come from zircons retrieved from the moon during NASA's Apollo voyages in the 1970s.

A study of zircons from a gigantic meteorite impact in South Africa, now online in the journal Geology, casts doubt on the methods used to date lunar impacts. The critical problem, says lead author Aaron Cavosie, a visiting professor of geoscience and member of the NASA Astrobiology Institute at the University of Wisconsin-Madison, is the fact that lunar zircons are "ex situ," meaning removed from the rock in which they formed, which deprives geoscientists of corroborating evidence of impact.

"While zircon is one of the best isotopic clocks for dating many geological processes," Cavosie says, "our results show that it is very challenging to use ex situ zircon to date a large impact of known age."

Although many of their zircons show evidence of shock, "once separated from host rocks, ex situ shocked zircons lose critical contextual information," Cavosie says.

The "clock" in a zircon occurs as lead isotopes accumulate during radioactive decay of uranium. With precise measurements of isotopes scientists can calculate, based on the half life of uranium, how long lead has been accumulating.

If all lead was driven off during asteroid impact, the clock was reset, and the amount of accumulated lead should record exactly how long ago the impact occurred.

Studies of lunar zircons have followed this procedure to produce dates from 4.3 billion to 3.9 billion years ago for the late heavy bombardment.

To evaluate the assumption of clock-resetting by impact, Cavosie and colleagues gathered zircons near Earth's largest impact, located in South Africa and known to have occurred 2 billion years ago. The Vredefort impact structure is deeply eroded, and approximately 90 kilometers across, says Cavosie, who is also in the Department of Applied Geology at Curtin University in Perth, Australia. "The original size, estimated at 300 kilometers diameter, is modeled to result from an impactor 14 kilometers in diameter," he says.

The researchers searched for features within the zircons that are considered evidence of impact, and concluded that most of the ages reflect when the zircons formed in magma. The zircons from South Africa are "out of place grains that contain definitive evidence of shock deformation from the Vredefort impact," Cavosie says. "However, most of the shocked grains do not record the age of the impact but rather the age of the rocks they formed in, which are about 1 billion years older."

The story is different on Earth, says zircon expert John Valley, a professor of geoscience at UW-Madison. "Most zircons on Earth are found in granite, and they formed in the same process that formed the granite. This has led people to assume that all the zircons were reset by impact, so the ages they get from the Moon are impact ages. Aaron is saying to know that, you have to apply strict criteria, and that's not what people have been doing."

The accuracy of zircon dating affects our view of Earth's early history. The poorly understood late heavy bombardment, for example, likely influenced when life arose, so dating the bombardment topped a priority list of the National Academy of Sciences for lunar studies. Did the giant craters on the moon form during a brief wave or a steady rain of impacts? "It would be nice to know which," Valley says.

Read more at Science Daily