Tuesday, August 31, 2010
The fact that man’s intervention is driving the steady decline of the level of the dead sea informs us that additional intervention is in the cards in order to sustain the sea itself. Various options exist and some of the projects been contemplated are discussed here.
We have already posted on the Jordanian project that would lift water from the Red Sea to a desalination and power plant at the Dead Sea that would provide both power and fresh water, while dumping the strongly salinated waste water into the Dead Sea. An improvement on that may by to block part of the Dead Sea with a coffer dam to retain the waste water separate from the waters of the
Dead Sea. This may make good sense and allow the present nature of the Dead Sea to be retained for which there exist plenty of good additional commercial reasons.
However, the waste water will end up sitting on top of the present water for density reasons and simply preventing that from covering the whole lake is a good enough reason to use coffer dams.
There remains the simple option of lifting water from the
Mediterranean to operate a power plant. Again both plants are self sustaining and do replenish the waters of the dead Sea.
In time, restoration of forests and a local hydraulic regime may actually provide enough fresh ground water and precipitation to fully restore the
and provide for a large population, while also replenishing the Sea. Jordan River Valley
An extraordinary plan to revive the Dead Sea could ease tensions among
Israel, Palestine and . Or it could create an environmental disaster. Jordan
By Vince Beiser
August 23, 2010
Fathi Huweimel leans carefully over the edge of a jagged slab of broken asphalt, peering down into a 60-foot-deep crater that was level ground just yesterday. All around him sprawl the ruins of Ghawr al Hadithah, once a farming village in central Jordan but now a jigsaw of broken houses, shattered roads and abandoned tomato fields growing wild amid the massive holes pocking the earth. To the east, the village gives way to desert fringed by stark, sere mountains. To the west, a few hundred yards away, lie the glimmering waters of the Dead Sea.
“We’ve had about 75 holes open up in the last two years,” says Huweimel, a thickset man with a broad mouth and deep brown eyes who has lived all of his 45 years in the area. He works as a field researcher with Friends of the Earth-Middle East, an environmental organization. “Everyone is leaving,” he continues. “Those who stay are staying because they have no choice.”
The holes first started appearing in the 1980s, but the pace at which new ones open up has increased dramatically in recent years. Miraculously, no one has been killed by a cave-in yet, though there have been some close calls. A group of seven women — including Huweimel’s aunt — were harvesting tomatoes together one day when the ground collapsed with a roar just 2 meters in front of them. A small salt factory that employed about 100 people was evacuated before it collapsed.
The cause of all this destruction is water — or, rather, the lack of it. The ground is collapsing into sinkholes because the water beneath it is retreating. And the water is retreating because the
Dead Sea, a storied feature of the landscape since at least biblical times, is drying up.
The sea — actually a huge lake straddling the Israeli-Jordanian border at the lowest point on Earth, 420 meters below sea level — has been fed for millennia by the Jordan River. But today, so much water is siphoned out of the
Jordan to feed farms and cities that practically nothing is left to replenish the Dead Sea.
Over the past three decades, the sea’s level has fallen by some 25 meters and continues to drop by an average of another meter every year. Its surface area is dwindling apace; the sea’s shore has retreated as much as a mile. That is dealing a severe blow to the hotels and spas dotting what used to be the sea’s beaches. Moreover, as the water retreats, it destabilizes the ground around it, spawning the sinkholes that have devoured Ghawr al Hadithah. Underground freshwater springs that feed nearby oases rich in wildlife are also being dragged down.
“It’s a time bomb,” Huweimel says. “It will only get worse if nothing is done.”
It’s an extraordinary problem that has generated an extraordinary response. The governments of the three peoples that live along the Jordan River and the Dead Sea — the Israelis, Jordanians and Palestinians — are working together to promote a potential solution: a conduit to bring ocean water from the Red Sea to the Dead Sea. It’s being touted as a triple win: The water would replenish the
Dead Sea, and in the process generate hydroelectric power, which would in turn run desalination plants to make potable water for the region. As a not-inconsiderable political bonus, it would constitute the first major project ever undertaken by all three nations.
There’s just one problem. The conduit might make things even worse.
One morning in late spring, Gidon Bromberg, Israeli director of Friends of the Earth-Middle East, takes me to the Lido Café at the northern end of the sea on the
side. For decades, the Lido was an elegant open-air restaurant where well-heeled residents of Israel Jericho and Jerusalem would come to have a leisurely lunch, smoke nargileh water pipes and step right off the patio for a dip in the Dead Sea. Today, weeds push through the patio’s broken tiles, and paint is peeling off the parts of the walls that are still standing. A hunched, leafless tree sulks by steps that once led to the water but now stop abruptly 3 feet above trash-strewn desert. The Dead Sea is barely visible in the distance, across a half-mile of bare, dun-colored earth.
“This place died because the Dead Sea ran away,” says Bromberg, an athletically built Israeli lawyer who still speaks with a trace of an accent betraying his boyhood in
. He’s looking slightly disheveled today in a rumpled polo shirt, his short hair uncombed. Bromberg knows this area like he knows the neighborhood in Tel Aviv where he lives. He’s been bringing legislators, activists, journalists and pretty much anyone he can get interested out here for more than a decade now to witness the crisis facing the Australia Dead Sea.
Bromberg, 46, founded Friends of the Earth-Middle East in 1994, in the heady days after Israel and the Palestinians signed the Oslo accords, when it seemed that peace might finally be within reach. As thrilling as that prospect was, Bromberg also saw a potential downside, one which he investigated in his master’s thesis at the American University in Washington, D.C. “I concluded that the peace process would contribute to the demise of the environment,” Bromberg says. “It was all about building hotels, industrial estates and highways. There was no discussion on improving or even protecting the environment.”
That finding inspired him to seek out like-minded Jordanian and Palestinian activists to help create FoEME, the first civil organization to bring representatives from all three peoples together in common cause. The idea was to address environmental issues that cross borders, water chief among them.
Of course, the region’s bitter politics haven’t made things easy. Within a few years of the group’s founding, the peace process collapsed into the bloody second Intifada. With the body count of both Palestinians and Israelis rising daily, anyone working with the other side risked being seen as a traitor. Bromberg’s car tires have been slashed, his Jordanian counterpart has been shot at, and Palestinian FoEME workers have been kidnapped by hard-line militias — but the group has not only survived, it has grown and now boasts 50 paid staff and offices in Tel Aviv, Bethlehem and Amman. Funding comes from the
and European governments as well as private foundations. Time magazine declared the group “environmental heroes” in 2008, and last year the Skoll Foundation gave it an award for social entrepreneurship. “I don’t accept everything the Israeli government does, but there has to be a dialogue between the people,” says Baha Afaneh, a Palestinian who works in FoEME’s U.S. branch. “We’re trying to work together on issues that affect us all.” Amman
Dead Sea was the very first project the group took on. “We did an inventory back in 1995,” Bromberg says, “and we saw that the Dead Sea faced the gravest threat.”
Dead Sea earns its name from the composition of its waters, which are so dense with minerals and salt — 10 times as much as ordinary seawater — that nothing but microbes survives in them. The sea has no channel out. Water comes in mainly from the Jordan River and leaves by evaporating under the sweltering desert sun, which routinely drives temperatures up to 120 degrees.
For thousands of years, that input/output equation remained more or less in balance. But in recent decades, the region’s booming population has thrown it completely out of whack. Jordanians, Palestinians and especially Israelis pull so much water from the
Jordan that only a heavily polluted trickle now reaches the Dead Sea from the north. Meanwhile, at the sea’s southern end, enormous factories pump out water to extract minerals. What’s left behind in the sea is evaporating as fast as ever, but almost no new water is coming in to replenish it.
Dead Sea has shrunk before. Throughout its long history, there have been low-rainfall years that reduced the Jordan River to a dribble. “The sea has been even lower than it is today in previous centuries, but it would always come back when precipitation picked up,” Bromberg says. “The difference today is that the Dead Sea is on a one-way ride. It can’t come back as it has before.”
The sea is unlikely to ever disappear completely. Small underground springs and rain provide enough water that even if the
were to dry up altogether, the sea would eventually stabilize — but as an ultra-briny puddle of about one-third its original size. If that were to happen, it would mean the loss of a world historic site and incalculable damage to the region’s economy and ecology. Jordan
Tourists flock to the area from all over the world for the spectacular desert scenery and history. Masada, the mountaintop fortress where Jewish zealots held out for years against conquering Romans, is nearby, as is the cave where the Dead Sea scrolls were found. But the main attraction is the sea itself, with its mineral-rich, ultra-salty waters, which are reputed to have therapeutic powers and offer the giddy experience of effortless floating.
But it gets harder every year for visitors to actually reach the water. When
Israel’sEin Gedi Spa, a health-tourism complex offering massages and sulphur pools, was built in the 1980s, the Dead Sea came right up to the wall around its outdoor swimming pool. Now, guests have to ride a tractor-pulled tram through a mile of mud flats to reach the constantly receding shore.
And as the water retreats, more and more sinkholes open up. Kibbutz Ein Gedi, which runs the spa, has had to close a nearby campground because half of it has been swallowed up by the earth. Sinkholes have also made it too dangerous to work a date plantation across the road, where the palms have been left to dry up and double over on themselves, as though they’ve abandoned hope. The sinkholes have also forced the Israeli government to scrub plans for 5,000 new hotel rooms in the area. All told, the Dead Sea’s shrinkage is costing
some $60 million per year in lost tourism revenues, according to an estimate by the Samuel Neaman Institute, an Israeli public policy research outfit. Israel
Eli Raz knows more about the sinkholes than anyone. Raz is a sinewy, silver-haired Ben-Gurion University geologist who lives at Kibbutz Ein Gedi, where he works out of a windowless office surrounded by glossy photos of desert rocks, flowers and salt formations. He has been studying the holes since they first started appearing in the late 1980s. A few years ago, on one of his regular research expeditions, he fell into a 30-foot sinkhole and was trapped for 14 hours until rescue workers pulled him out. “Now I have documented sinkholes from the inside as well as out,” Raz deadpans.
Raz estimates there are more than 3,000 sinkholes just on the Israeli side. They are the result of a shift in underground currents caused by the sea’s drop. Subterranean
Dead Sea water has built up a layer of salt rock under the soil in many areas. As that water withdraws, new water takes its place, slowly dissolving the salt layer — until the ground above gives way.
Sinkholes are just one side effect of the shift in the underground water flow. As the groundwater chases the receding seawater, it is changing the course of the underground springs that feed nearby oases. Sizeable swathes of vegetation are dying as a result. That threatens the ibex, leopards and other rare animal and plant species that live in the oases, as well as the hundreds of millions of birds that stop to rest in them on their migration routes.
“If you disturb this ecosystem, it could have a big chain reaction,” Raz says. “That’s my biggest concern.”
But concerned as he is about the damage being done by the Dead Sea’s shrinkage, Raz is deeply skeptical of the plan to save it by bringing in water from the
The idea of digging a waterway from the ocean to the
Dead Sea has been bandied about for centuries. Athanasius Kircher, a renowned German-Jesuit scholar, proposed it in 1664 as a transportation route; an English admiral named William Allen seconded the notion in 1855. Theodor Herzl, the founder of Zionism, imagined a canal from the Mediterranean to the Dead Sea in his seminal 1902 bookAltneuland (The ). Old New Land
The Israeli government took a serious look at digging a canal in the 1970s and 1980s, hoping it could yield hydroelectric power that would leave the country less dependent on foreign oil. But the Red-to-Dead project really began gathering steam in the 1990s, amid the exuberance of peacemaking between
Israel, and the Palestinians. Former Israeli Prime Minister Shimon Peres is the idea’s foremost champion. In his book, The New Middle East, Peres writes: Jordan
“Politically, this earthshaking enterprise can help maintain peace and establish mutual long-term interests. … The water will flow along the Arava (the desert valley in which the sea sits), the power stations will give light, and the wasteland will bloom with life. The region will experience peace, serenity and progress. People from other countries will use the seaport and airport, visit the spas and vacation centers and enjoy the products of our flourishing desert.”
The second Intifada bumped the Red-Dead project to the back burner, but finally, in 2006, the governments of
Israel, Palestine and jointly convinced the World Bank to get on board. Everyone involved agrees saving the sea is a priority, but each side gives different weight to the project’s other expected benefits. For Jordan , which faces a chronic and deepening shortage of water, developing new, potable supplies is paramount. For Jordan , a major engineering project in partnership with an Arab country would constitute a long-sought political milestone. The mere fact that it and its Arab neighbors are talking about such an undertaking earned the participants a pat on the head from the Israel U.S. Senate, which passed a resolution in 2007 applauding “the cooperative manner” in which all three sides were working to save the Dead Sea. For the Palestinians, who were originally excluded from the planning for the conduit, it’s crucial just to be given a role in the project, to bolster their political standing in general and their claims to the region’s water resources in particular. “Though we are occupied by Israel, the Jordan River runs along our land,” as does part of the Dead Sea, says Shaddad Attili, head of the Palestinian Water Authority. “It’s important that we be brought in as partners.”
The World Bank has rounded up $16.7 million from the
U.S., France, and other countries for a series of studies on the feasibility and environmental and social impacts of what is now formally known as the Red Sea-Dead Sea Water Conveyance Study Program. The project could ultimately take any of several forms — a canal, a tunnel, a pipeline or some combination. In any case, the engineering is fairly straightforward. Red Sea water would have to be pumped over or piped under the hills around Aqaba, Jordan’s sole port, which offers the most promising access point to the Sweden Red Sea. But after that, it would simply flow downhill to its sub-sea-level destination. Hydroelectric stations along the way would harness the flow to generate power for desalination plants. Estimated cost: anywhere from $5 billion to $15 billion.
And that’s the just the basic version. Peres and Israeli industrial magnate Yitzhak Tshuva want to take things even further by building a Vegas-style strip of desert resorts along the waterway. At a recent conference in
, Tshuva presented a plan to line the conduit with parks, lagoons, entertainment centers and 200,000 hotel rooms. Jerusalem
It sounds great: Save the
Dead Sea, get freshwater, promote regional cooperation, maybe even generate thousands of jobs. But Friends of the Earth-Middle East and other environmental groups are deeply concerned that the conduit might do more harm than good.
There are potential problems all along the route the water would travel. The conduit would suck as much as 2 billion cubic meters — or a little more than half a trillion gallons — of water every year out of the Gulf of Aqaba, a narrow finger of the Red Sea. Pulling out that much water could alter the currents and temperatures in the Gulf, warns the Samuel Neaman Institute, potentially harming the highly sensitive coral reefs and the 1,000-plus species of fish that live there. Those reefs are a world-class diving destination; losing them would certainly cost
some of the nearly half-million visitors that come to Aqaba every year. The massive, noisy machinery required to pump the water out certainly won’t help the tourist trade, either. Jordan
The waterway is planned to run through the
, which sits on the border between two tectonic plates. That makes the area prone to earthquakes that could damage the conduit and send salt water spilling into the surrounding desert, which is home to rare palm trees, gazelles, hyrax and other species. “It’s a totally unique ecosystem,” Bromberg says. “We’re not so worried about a rupture — that would be a one-time thing. It’s a consistent leak that is the biggest worry. They’re going to be moving nearly 2 billion cubic meters of water through here every year. A leak would mean a constant slow seep of a lot of water.” Arava Valley
Mixing regular seawater with that of the
Dead Sea, which has a different chemical composition, could also be bad news. Research by the Geological Survey of Israel suggests that the Dead Sea’s calcium-rich brine could react with sulphates in the seawater to form gypsum, which would turn the Dead Sea white. The influx of less-salty water could also stimulate the Dead Sea’s microorganisms, causing an algae bloom that would turn the water red. And diluting the sea’s salinity would likely also reduce its famous buoyancy.
“We think the solution is dealing with the root causes of the sea’s demise,” Bromberg says, “not some technological fix that will give rise to a new set of problems.”
The main cause shrinking the Dead Sea is the emaciated, immiserated
Jordan River. In 1847, the Jordan was so big and wild that U.S. Navy Lt. W.F. Lynch had to battle rushing rapids and waterfalls on an exploratory expedition down the river to the Dead Sea. Today, the storied waterway, featured in the holy books of Judaism, Christianity and Islam — the river “deep and wide” in which John baptized Jesus — creeps into the Dead Sea as a trickle composed mostly of sewage. According to a FoEME study released in May, the river’s annual inflow to the sea has been squeezed from 1.3 billion cubic meters to an estimated 20 to 30 million cubic meters — a 98 percent drop.
People are to blame. Since 1970, the combined population of
Israel, and the Palestinian territories has more than tripled from 5.3 million to some 17 million. Over the last several decades, they, along with their neighbor to the north, Jordan Syria, have tapped, dammed and diverted almost all of the water in the and the springs and tributaries that once fed it. Jordan
Originating in the mountains between
Israel and Syria, the river runs down into theSea of Galilee and from there through the Jordan Valley to the Dead Sea. But Israel and Jordan now take so much water out of the Sea of Galilee that almost none flows out into the riverbed.
About a half-mile south of the
Sea of Galilee, what little river water does escape comes up against an earthen berm, forming a large pool rimed with scum and trash. Five fat green pipes angle down into the pool, sucking out water for nearby banana and avocado fields. A little water slips out through a submerged conduit, emerging as a trickle on the other side of the berm. Into that trickle from another pipe gushes a feculent, gray-green stream of sewage. Signs in English, Hebrew and Arabic warn: “Danger! Don’t enter or drink the water!” It flows away downstream, where it is augmented by more sewage, agricultural runoff and fish pond refuse — the whole mess reconstituted as the sacred waters of the Jordan River.
About 120 kilometers to the south is the spot where Jesus was purportedly baptized. Thousands of devout tourists come to this tranquil patch of reed-lined riverbank every year to follow his example. On a hot day in spring, a black-cassocked Greek Orthodox priest holds the hand of Kristin Londal, a 40-year-old Bible studies teacher from
, as she steps down from a wooden platform into the sluggish green-brown water. She’s dressed in a plain white robe. Holding her nose shut, Londal submerges herself three times. Bronxville, N.Y.
“Yes, I know the river is polluted. Jesus will keep me clean!” she tells me afterward, standing on the platform dripping and radiant. “But,” she adds, “I will take a shower tonight.” As we talk, a water-rat the size of a small dog pops its head up and swims calmly past.
The most obvious way to get more water is desalination, a technology in which
leads the world. But desalinating enough water from the Mediterranean to take care of the towns and farms that rely on the Israel would be tremendously expensive, and would also require large amounts of greenhouse-gas producing energy. There has also been talk of somehow bringing in water from Jordan , another major undertaking. Turkey
Bromberg, however, maintains that at least a third of the
’s flow can be restored by using existing water resources more wisely. For starters, if both Jordan Jordan and reduced their subsidies to agriculture, they could wean themselves off the unsustainable habit of farming water-intensive export crops in the desert, he says. That’s already starting to happen, but only to an extent. “We’ve had to destroy a lot of trees in the last few years because of the lack of water,” says Yuval Malka, a spokesperson for Kibbutz Kinneret, an agricultural settlement near the Israel Sea of Galilee. “We plant fewer bananas, avocados and mangos.” But he balks at the notion of getting rid of them altogether. “Bananas pay good,” Malka says. “We made nearly a million dollars from them last year.”
Other decidedly unsexy proposals for reducing the amount of water drawn from the
Jordan and Sea of Galilee include replacing water toilets with composting ones. “It’s a lot of tiny fixes,” Bromberg says. “That’s the problem; no one’s going to get rich from restoring the . Politicians are more attracted to grand projects that will leave a mark on history — and make their friends a lot of money.” Jordan
Jordan, FoEME is pressing to reduce the water used by the massive mineral-extraction works at the southern end of the Dead Sea. On both sides of the border, these companies channel Dead Sea water through a system of broad, winding canals into a 150-square-kilometer expanse of shallow evaporating pools. There, potash, bromides, magnesium and salt are extracted by floating harvesting machines.
The minerals are then taken to a vast industrial park just south of where the story of
Sodom and supposedly took place. There’s nothing biblical about the landscape now, though. The desert is buried under a massive sprawl of multistory steel scaffolds, conveyor belts, chutes, pipes and power lines. Gray smoke billows skyward from towering chimneys while roaring trucks and toploaders shuffle between mountainous heaps of raw white potash. Gomorrah
This industry is responsible for some 40 percent of the
Dead Sea’s water losses, according to the World Bank. Bromberg says they could cut that substantially if they extracted minerals by pushing the sea’s water through membranes, rather than by evaporating it. That would save water — but would be more expensive.
In any case, even if the river were restored and the mineral industry reined in,
would still need more water. The conduit offers the best fix for that and the Jordan Dead Sea, its supporters argue. “The environmentalists want to let the water all flow back, but this is utopian. In my opinion, the conduit is the only valid solution,” says Elias Salameh, a Jordan University of Jordan hydrologist who has studied the Dead Sea problem extensively. “Of course, it will have bad environmental impacts. We should study and try to minimize them. But the benefits will be far greater.”
If the conduit could also significantly improve relations between
Israel, and the Palestinians, as supporters like Salameh argue, it might even be worth a certain amount of environmental damage. Jordan Israel’s peace with is reasonably sturdy but could use reinforcing. Israel’s relations with the Palestinians, on the other hand, fluctuate between bad and appalling. Resolving their conflict would be a boon to the whole world. Israeli and Palestinian politicians and even French President Nicolas Sarkozy claim the conduit will help. Jordan
“This project brings hope to the region,” Attili says. “Despite all the crisis and conflict, we are talking to each other and working together.”
But the World Bank’s most recent assessment of the project’s potential political implications, released in May, is only guardedly optimistic on this score.
“The magnitude of the [conduit project] is such that regular and close coordination will be necessary. … This will bind the parties together in mutual dependency, which can only promote better understanding and ties,” the report says. However, it continues, “the relationships between
and the Palestinian Authority are dominated by political realities. … Implementation of the [project]… will not, of itself, affect these issues.” The report projects only “minor to moderate positive impacts” on the political front. Israel
With all this in mind, the World Bank recently launched another study, this one examining alternatives to a Red-to-Dead canal or pipeline, including a restoration of some flow to the Jordan River and a water conveyance from the Mediterranean. The whole suite of World Bank studies is scheduled to be completed in June 2011.
In the meantime, however,
Jordan plans to start its own, separate project, which would pump Red Sea water to desalination plants near Aqaba and channel the leftover brine to the Dead Sea.
Alex McPhail, the World Bank’s study program manager for the Red-Dead conduit, claims the bank is not concerned about Jordan going ahead with this project before the bank’s studies have been completed. “We’re talking about 2 billion cubic meters of water in our project,” McPhail says. “They’re talking about a fraction of that amount. And the Jordanians have assured us our studies will be done long before they turn the first shovel on their project.”
Whether it will save the
Dead Sea or damage it further, however, neither project will have any impact at all for a long time. Each will take an estimated 20 years to complete. In the meantime, the sinkholes devouring the fields of Ghawr al Hadithah and Kibbutz Ein Gedi will keep multiplying. The mud flats in front of the tourist hotels will keep growing. And the Dead Sea will keep slipping further and further away from us all.
This places stone arrow making technology around 64,000 years ago in the key locale fro the rise of modern humanity. Perhaps a little too coincidental but we have rich marine environment to act as an incubator that was not obviously too dangerous. Recall sea levels were then three hundred feet lower providing broad marine plains in an ice age climate that was most likely temperate in nature here at this time.
Arrow making is as advanced as stone age technology pretty well got. Thus we have the likelihood of a full stone age tool kit emerging here first. That tool kit was then spread out throughout the world. Remember my comment that a given tool kit can be distributed globally in around ten millennia and actually be ubiquitous within a few millennia thereafter to allow its appearance in the archeological record.
Thus the establishment of this tool kit likely began 75,000 years ago and was globally common by fifty thousand years ago. This could even include the
and there is some evidence of all that but scant. Americas
Yet wooden arrows came much sooner and certainly preceded the stone arrow. In fact observation of such tribesmen suggests that this weapon form arose possibly simultaneously with modern humanity. It was just too obvious an invention needing only the ability to shape wood and to twist fiber to make something useful.
Stalking easily brought the hunter into a short bow range while at a difficult throwing range. It was too powerful an assist to not be used quickly. The question is whether it was used by earlier forms of humanity who did have the spear.
Oldest evidence of arrows found
By Victoria GillScience reporter, BBC News
26 August 2010
** The stone points are approximately 64,000 years old
have revealed the earliest direct evidence of human-made arrows. South Africa
The scientists unearthed 64,000 year-old "stone points", which they say were probably arrow heads.
Closer inspection of the ancient weapons revealed remnants of blood and bone that provided clues about how they were used.
The team reports its findings in the journal Antiquity.
The arrow heads were excavated from layers of ancient sediment in
Sibudu Cave in . During the excavation, led by Professor Lyn Wadley from the University of the South Africa Witwatersrand, the team dug through layers deposited up to 100,000 years ago.
Marlize Lombard from the university based in
led the examination of the findings. She described her study as "stone age forensics". Johannesburg
"We took the [points] directly from the site, in little [plastic] baggies, to the lab," she told BBC News.
"Then I started the tedious work of analysing them [under the microscope], looking at the distribution patterns of blood and bone residues."
Because of the shape of these "little geometric pieces", Dr Lombard was able to see exactly where they had been impacted and damaged. This showed that they were very likely to have been the tips of projectiles - rather than sharp points on the end of hand-held spears.
** Closer inspection revealed remnants of blood (left) and bone fragments (right)
The arrow heads also contained traces of glue - plant-based resin that the scientists think was used to fasten them on to a wooden shaft.
"The presence of glue implies that people were able to produce composite tools - tools where different elements produced from different materials are glued together to make a single artefact," said Dr Lombard.
"This is an indicator of a cognitively demanding behaviour."
The discovery pushes back the development of "bow and arrow technology" by at least 20,000 years.
Researchers are interested in early evidence of bows and arrows, as this type of weapons engineering shows the cognitive abilities of humans living at that time.
** The arrows were excavated from
Sibudu Cave in South Africa
The researchers wrote in their paper: "Hunting with a bow and arrow requires intricate multi-staged planning, material collection and tool preparation and implies a range of innovative social and communication skills."
Dr Lombard explained that her ultimate aim was to answer the "big question": When did we start to think in the same way that we do now?
"We can now start being more and more confident that 60-70,000 years ago, in
Southern Africa, people were behaving, on a cognitive level, very similarly to us," she told BBC News.
Professor Chris Stringer from the
Natural History Museum in London said the work added to the view that modern humans in Africa 60,000 years ago had begun to hunt in a "new way".
Neanderthals and other early humans, he explained, were likely to have been "ambush predators", who needed to get close to their prey in order to dispatch them.
Professor Stringer said: "This work further extends the advanced behaviours inferred for early modern people in
"But the long gaps in the subsequent record of bows and arrows may mean that regular use of these weapons did not come until much later.
"Indeed, the concept of bows and arrows may even have had to be reinvented many millennia [later]."
The graphene story continues to get better. Now we are learning to produce perfect edges and monolayers perfectly separated.
Essentially graphene is shaping up to exceed the capabilities of all other materials in terms of fabrication ease and flexibility.
Now we need some smart strategy to use graphene to store a lot of electrical energy.
Graphene fabrication gets a boost
R. Colin Johnson
8/25/2010 8:06 PM EDT
PORTLAND, Ore. -- Graphene, which promises to solve many problems as silicon design rules approach the atomic scale, performs better when these pure carbon devices are made smaller. The catch is that at the nanoscale level, features must have atomic accuracy, including near perfect edges and monolayers.
The Energy Department's
Researchers reported last year on a method called Joule heating, that uses an electric current to trim graphene edges to perfection, albeit at the expense of creating structural loops that make connections between monolayers. Using quantum molecular dynamics in their supercomputer simulations, an intermediate step in the edge-formation process was discovered. The researchers harnessed that step to perfect the fabrication method.
The group now reports that using electron irradiation during the edge formation process prevents loops between layers from forming.
This is always welcome news. We are refining our knowledge of the time and place of the Egyptian dynasties and individual rulers.
All very nice, but we are sorely lacking actual accounts. Then of course we do not have artifacts for many vast cultures even. Yet when we compare our scant knowledge of this history to contemporaneous information from the Bible we also know how much has been lost.
This narrows ranges nicely and should allow a rather good chronology now. It had been getting pretty good and much of this work is independent confirmation.
Constraining the Reign of Ancient
: Radiocarbon Dating Helps to Nail Down the Chronology of Kings, Researchers Say Egypt
ScienceDaily (June 18, 2010) — For several thousands of years, ancient Egypt dominated the Mediterranean world -- and scholars across the globe have spent more than a century trying to document the reigns of the various rulers of Egypt's Old, Middle and New Kingdoms. Now, a detailed radiocarbon analysis of short-lived plant remains from the region is providing scientists with a long and accurate chronology of ancient Egyptian dynasties that agrees with most previous estimates but also imposes some historic revisions.
Although previous chronologies have been precise in relative ways, assigning absolute dates to specific events in ancient Egyptian history has been an extremely contentious undertaking. This new study tightly constrains those previous predictions, especially for the
Old Kingdom, which was determined to be slightly older than some scholars had believed. The study will also allow for more accurate historical comparisons to surrounding areas, like Libya and , which have been subject to many radiocarbon dating techniques in the past. Sudan
Christopher Bronk Ramsey and colleagues from the Universities of Oxford and Cranfield in England, along with a team of researchers from France, Austria and Israel, collected radiocarbon measurements from 211 various plants -- obtained from museum collections in the form of seeds, baskets, textiles, plant stems and fruits -- that were directly associated with particular reigns of ancient Egyptian kings. They then combined their radiocarbon data with historical information about the order and length of each king's reign to make a complete chronology of ancient Egyptian dynasties.
Their research is published in the June 18 issue of Science, the peer-reviewed journal published by AAAS, the nonprofit science society.
"My colleague, Joanne Rowland, went to a lot of museums, explaining what we were doing and asking for their participation," Bronk Ramsey said. "The museums were all very helpful in providing material we were interested in -- especially important since export of samples from
is currently prohibited. Fortunately, we only needed samples that were about the same size as a grain of wheat." Egypt
The researchers' new chronology does indicate that a few events occurred earlier than previously predicted. It suggests, for example, that the reign of Djoser in the Old Kingdom actually started between 2691 and 2625 B.C. and that the
New Kingdom began between 1570 and 1544 B.C.
Bronk Ramsey and his colleagues also found some discrepancies in the radiocarbon levels of the Nile Valley, but they suggest that these are due to ancient Egypt's unusual growing season, which is concentrated in the winter months.
For the most part, the new chronology simply narrows down the various historical scenarios that researchers have been considering for ancient
"For the first time, radiocarbon dating has become precise enough to constrain the history of ancient
to very specific dates," said Bronk Ramsey. "I think scholars and scientists will be glad to hear that our small team of researchers has independently corroborated a century of scholarship in just three years." Egypt
This report by Bronk Ramsey et al. was funded by the Leverhulme Trust with additional financial support from the German-Israeli Foundation for Scientific Research and Development, NERC, CNRS, CEA, IRSN, IRD, and Ministère de La Culture.