Friday, February 26, 2010
Because observations of the cosmos has indicated far more mass than can be easily explained by the observed material it has been necessary to plug in an additional value that has been named ‘dark matter’. I have additional concerns regarding the actual correctness of our models, but these do not seem likely to be sufficient to actually eliminate the need for the corrective value.
If we then accept the existence of dark matter, the next important question becomes ‘what exactly is it?’ The obvious candidate is free neutrons.
We presently know that neutrons carry slightly more mass than a proton and that the impressed local curvature is effectively that of gravity itself. This immediately begs the question of the actual nature of the impressed curvature. We actually do not know. We need to find a way to run experiments in which neutrons act on each other and the local curvature can be measured.
My first conjecture is that the force is gravitational in magnitude but repulsive. This has the immediate advantage of explaining why we are not buried in the stuff. In fact it tends to leave gravity wells in general.
However, without been bound to other such particles it cannot form its own gravity wells and simply moves to regions of fairly minimal curvature. Recall the natural short range of gravity itself and its geometric dependence for building such a well.
I want to observe that the close local curvature of the neutron is not neutral at all and is similar to that of a proton. We are dealing with net curvature at a remove where local geometry ceases to be a factor.
We can make the additional conjecture that the present neutron - proton balance is caused by the sorting power of the gravity well itself and for that reason distorts the observed mass balance of the cosmos.
The neutron itself is an assemblage of fundamental particles (note that I have a lot more to say on the subject) maintaining complete geometric symmetry. This has recently been observed with imaging technology. A proton has lost a particle equivalent to an electron and has a disturbed symmetry generating strong curvature effects. (let’s leave it at that for now). The free neutron on its own generates an impressed curvature but the net result is a small negative gravity like effect.
Curiously, this is important. It strongly suggests that the combination of proton and neutron may be necessary to produce positive net gravitational curvature. I had already come across hints of this in some of my theoretical deliberations which clearly provide for the possibility.
I remind my readers that the current theoretical framework fails to properly deal with gravity.
This brings us up to date on the development of the focus fusion technology and progress is been made. They are learning to manage the spin of the plasma sheath which must be a good thing. That is the one variable that looks able to create problems. Here it is been controlled during its passage into the plasmoid stage.
Recall that what is been fused here is one proton to a bismuth atom. When that happens the bismuth isotope so formed immediately fissions into three helium atoms carrying off a huge amount of energy that is then stripped out using electromagnetic means. Astonishingly, no radiation is produced. The nature of the process was a much lower energy threshold for ignition also.
The success of this test is so beneficial to humanity, that all should cheer its quick success.
Besides producing all the electrical power we will ever need, it will also power space craft using ion engines and magnetic exclusion craft in particular.
FEBRUARY 23, 2010
Lawrenceville Plasma Physics (LPP) has obtained the first preliminary evidence that the injection of angular momentum into the DPF considerably increases the efficiency of energy transfer into the plasmoid, the size of the plasmoid and thus the fusion energy yield.
On Feb. 19 and 22, the team fired Focus-Fusion-1 at 24 kV with a pressure of 8 torr of deuterium in the vacuum chamber. In some shots, they connected the angular momentum coil (AMC) to the power supply, so current could flow through it. In other shots, they left the coil circuit open, so no current could flow. The shots with the AMC connected have a neutron yield 8-10 times that of those with the AMC disconnected, so this is a large and very promising effect.
What they believe is happening is that the current in the coil is producing a small magnetic field along the axis of the device. The interaction of the currents with this field induces angular momentum—spin—in the plasma sheath. This in turn diverts the current in the sheath in the same direction as the current in the coils, amplifying the field. The angular momentum, conveyed ultimately to the tiny plasmoid, creates a centrifugal force that balances the compressive magnetic forces. The bigger the centrifugal force, the bigger the magnetic field that can be balanced and the bigger the plasmoid. However, if the centrifugal force is too big, it will prevent the plasmoid from forming at all. Thus only small fields are effective.
The Angular Momentum test was one of Eight Objectives of the Lawrenceville Plasma Physics Focus Fusion Experiments
Lawrenceville Plasma Physics (LPP) a small research and development company part way through a two-year-long experimental project to test the scientific feasibility of Focus Fusion, controlled nuclear fusion using the dense plasma focus (DPF) device and hydrogen-boron fuel. Hydrogen-boron fuel produces almost no neutrons and allows the direct conversion of energy into electricity. Success would mean thousands of times more total energy would be available and the energy would be cleaner and cheaper. LPP believes that with success they can lower the cost of energy up to 50 times.
* Test theory of axial magnetic field
* Test theory of axial magnetic field
The third goal is to test the theory that adding a small axial magnetic field, and thus a small amount of angular momentum, to the plasma will greatly increase the size of the plasmoids and thus the efficiency of energy transfer into the plasmoid.
Good progress is being made to another goal (1 megaAmp at 25 kilovolts), with 0.85 megaAmps at 30 kilovolts with only some of the switches firing. All 12 switches being fired should result in the excess of megaAmp at 25 kilovolts
This is important in that it clearly explains why our present fertilizer protocol is unable to sustain performance. The nitrogen acts to speed consumption of the soils organic content.
The solution is to increase the soil content of elemental carbon. This makes the move to that protocol all the more pressing.
I have already posted at length on biochar and it contribution to soil health. The Amazonian Indians ran two millennia of field tests in soils that could hold no water soluble nutrients. The carbon grabbed the nutrients until the living root arrived and extracted them
We now need to do exactly this on the soils of industrial farms. Nitrogen held by the carbon may not be as easily available to microbes destroying organic material, or if they are, their products will not escape as easily into groundwater. This has been clearly shown by all the work done to date.
I presently think that a carbon content as low as one percent over normal soil thickness will facilitate a large part of soil restoration. There is good reason to think that the process is well optimized at a content level between five and fifteen percent. Also recall the experiments done in a one hundred percent matrix and some nutrients that were very successful.
Yet the stover from a single corn crop is visibly beneficial. Assume ten tons plus per acre in dry stover converting to two tons of powdered carbon per acre. Allow a full year’s growth to fully integrate the carbon in the soil for optimum benefit. Notice that thereafter the benefit does not decline at all.
As I have posted before, the advent of biochar is the greatest revolution in agriculture since the development of commercial fertilizer. It will end fertilizer wastage and also hugely improve the organic content of soils by stimulating superior root growth, or at least that is what we have been observing.
New research: synthetic nitrogen destroys soil carbon, undermines soil health
23 FEB 2010 9:47 AM
BY TOM PHILPOTT
Just precisely what does all of that nitrogen ferilizer do to the soil?
“Fertilizer is good for the father and bad for the sons.”
For all of its ecological baggage, synthetic nitrogen does one good deed for the environment: it helps build carbon in soil. At least, that’s what scientists have assumed for decades.
If that were true, it would count as a major environmental benefit of synthetic N use. At a time of climate chaos and ever-growing global greenhouse gas emissions, anything that helps vast swaths of farmland sponge up carbon would be a stabilizing force. Moreover, carbon-rich soils store nutrients and have the potential to remain fertile over time—a boon for future generations.
The case for synthetic N as a climate stabilizer goes like this. Dousing farm fields with synthetic nitrogen makes plants grow bigger and faster. As plants grow, they pull carbon dioxide from the air. Some of the plant is harvested as crop, but the rest—the residue—stays in the field and ultimately becomes soil. In this way, some of the carbon gobbled up by those N-enhanced plants stays in the ground and out of the atmosphere.
Well, that logic has come under fierce challenge from a team of
researchers led by professors Richard Mulvaney, Saeed Khan, and Tim Ellsworth. In two recent papers (see here and here) the trio argues that the net effect of synthetic nitrogen use is to reduce soil’s organic matter content. Why? Because, they posit, nitrogen fertilizer stimulates soil microbes, which feast on organic matter. Over time, the impact of this enhanced microbial appetite outweighs the benefits of more crop residues. University of Illinois
And their analysis gets more alarming. Synthetic nitrogen use, they argue, creates a kind of treadmill effect. As organic matter dissipates, soil’s ability to store organic nitrogen declines. A large amount of nitrogen then leeches away, fouling ground water in the form of nitrates, and entering the atmosphere as nitrous oxide (N2O), a greenhouse gas with some 300 times the heat-trapping power of carbon dioxide. In turn, with its ability to store organic nitrogen compromised, only one thing can help heavily fertilized farmland keep cranking out monster yields: more additions of synthetic N.
The loss of organic matter has other ill effects, the researchers say. Injured soil becomes prone to compaction, which makes it vulnerable to runoff and erosion and limits the growth of stabilizing plant roots. Worse yet, soil has a harder time holding water, making it ever more reliant on irrigation. As water becomes scarcer, this consequence of widespread synthetic N use will become more and more challenging.
In short, “the soil is bleeding,” Mulvaney told me in an interview.
team is correct, synthetic nitrogen’s effect on carbon sequestration swings from being an important ecological advantage to perhaps its gravest liability. Not only would nitrogen fertilizer be contributing to climate change in a way not previously taken into account, but it would also be undermining the long-term productivity of the soil. Illinois
An Old Idea Germinates Anew
While their research bucks decades of received wisdom, the
That idea also appears prominently in The Soil and Health (1947), a founding text of modern organic agriculture. In that book, the British agronomist Sir Albert Howard stated the case clearly:
The use of artificial manure, particularly [synthetic nitrogen] ... does untold harm. The presence of additional combined nitrogen in an easily assimilable form stimulates the growth of fungi and other organisms which, in the search for organic matter needed for energy and for building up microbial tissue, use up first the reserve of soil hummus and then the more resistant organic matter which cements soil particles.
In other words, synthetic nitrogen degrades soil.
That conclusion has been current in organic-farming circles since Sir Albert’s time. In an essay in the important 2002 anthology Fatal Harvest Reader, the
organic farmer Jason McKenney puts it like this: California
Fertilizer application begins the destruction of soil biodiversity by diminishing the role of nitrogen-fixing bacteria and amplifying the role of everything that feeds on nitrogen. These feeders then speed up the decomposition of organic matter and humus. As organic matter decreases, the physical structure of soil changes. With less pore space and less of their sponge-like qualities, soils are less efficient at storing water and air. More irrigation is needed. Water leeches through soils, draining away nutrients that no longer have an effective substrate on which to cling. With less available oxygen the growth of soil microbiology slows, and the intricate ecosystem of biological exchanges breaks down.
Although those ideas flourished in organic-ag circles, they withered to dust among soil scientists at the big research universities. Mulvaney told me that in his academic training—he holds a PhD in soil fertility and chemistry from the
, where he is now a professor in the Department of Natural Resources and Environmental Sciences—he was never exposed to the idea that synthetic nitrogen degrades soil. “It was completely overlooked,” he says. “I had never heard of it, personally, until we dug into the literature.” University of Illinois
What sets the
scientists apart from other critics of synthetic nitrogen is their provenance. Sir Albert’s denouncement sits in a dusty old tome that’s pretty obscure even within the organic-agriculture world; Jason McKenney is an organic farmer who operates near Berkeley—considered la-la land by mainstream soil scientists. Both can be—and, indeed have been—ignored by policymakers and large-scale farmers. By contrast, Mulvaney and his colleagues are living, credentialed scientists working at the premier research university in one of the nation’s most prodigious corn-producing—and nitrogen-consuming—states. Illinois
The Dirt on Nitrogen, Soil, and Carbon
To come to their conclusions, the researchers studied data from the Morrow plots on the
’ Urbana-Champaign campus, which comprise the “the world’s oldest experimental site under continuous corn” cultivation. The Morrow plots were first planted in 1876. University of Illinois
Mulvaney and his collaborators analyzed annual soil-test data in test plots that were planted with three crop rotations: continuous corn, corn-soy, and corn-oats-hay. Some of the plots received moderate amounts of fertilizer application; some received high amounts; and some received no fertilizer at all. The crops in question, particularly corn, generate tremendous amounts of residue. Picture a Midwestern field in high summer, packed with towering corn plants. Only the cobs are harvested; the rest of the plant is left in the field. If synthetic nitrogen use really does promote carbon sequestration, you’d expect these fields to show clear gains in soil organic carbon over time.
Instead, the researchers found, all three systems showed a “net decline occurred in soil [carbon] despite increasingly massive residue [carbon] incorporation.” (They published their findings, “The Myth of Nitrogen Fertilization for Soil Carbon Sequestration,” in the Journal of Environmental Quality in 2007.) In other words, synthetic nitrogen broke down organic matter faster than plant residue could create it.
A particularly stark set of graphs traces soil organic carbon (SOC) in the surface layer of soil in the Morrow plots from 1904 to 2005. SOC rises steadily over the first several decades, when the fields were fertilized with livestock manure. After 1967, when synthetic nitrogen became the fertilizer of choice, SOC steadily drops.
In their other major paper, “Synthetic Nitrogen Fertilizers Deplete Soil Nitrogen: A Global Dilemma for Sustainable Cereal Production” (2009), the authors looked at nitrogen retention in the soil. Given that the test plots received annual lashings of synthetic nitrogen, conventional ag science would predict a buildup of nitrogen. Sure, some nitrogen would be removed with the harvesting of crops, and some would be lost to runoff. But healthy, fertile soil should be capable of storing nitrogen.
In fact, the researchers found just the opposite. “Instead of accumulating,” they wrote, “soil nitrogen declined significantly in every subplot sampled.” The only explanation, they conclude, is that the loss of organic matter depleted the soil’s ability to store nitrogen. The practice of year-after-year fertilization had pushed the Morrow plots onto the chemical treadmill: unable to efficiently store nitrogen, they became reliant on the next fix.
The researchers found similar data from other test plots. “Such evidence is common in the scientific literature but has seldom been acknowledged, perhaps because N fertilizer practices have been predicated largely on short-term economic gain rather than long-term sustainability,” they write, citing some two dozen other studies which mirrored the patterns of the Morrow plots.
The most recent bit of evidence for the Mulvaney team’s nitrogen thesis comes from a team of researchers at
and the USDA. In a 2009 paper (PDF), this group looked at data from two long-term experimental sites in Iowa State University . And they, too, found that soil carbon had declined after decades of synthetic nitrogen applications. They write: “Increases in decay rates with N fertilization apparently offset gains in carbon inputs to the soil in such a way that soil C sequestration was virtually nil in 78% of the systems studied, despite up to 48 years of N additions.” Iowa
Mulvaney and Khan laughed when I asked them what sort of response their work was getting in the soil-science world. “You can bet the fertilizer industry is aware of our work, and they aren’t too pleased,” Mulvaney said. “It’s all about sales, and our conclusions aren’t real good for sales.”
As for the soil-science community, Mulvaney said with a chuckle, “the response is still building.” There has been negative word-of-mouth reaction, he added, but so far, only two responses have been published: a remarkable fact, given that the first paper came out in 2007.
Both published responses fall into the those-data-don’t-say-what-you-say-they category. The first, published as a letter to the editor (PDF) in the Journal of Environmental Quality, came from D. Keith Reid, a soil fertility specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs. Reid writes that the Mulvaney team’s conclusion about synthetic nitrogen and soil carbon is “sensational” and “would be incredibly important if it was true.”
Reid acknowledges the drop in soil organic carbon, but argues that it was caused not by synthetic nitrogen itself, but rather by the difference in composition between manure and synthetic nitrogen. Manure is a mix of slow-release organic nitrogen and organic matter; synthetic nitrogen fertilizer is pure, readily available nitrogen. “It is much more likely that the decline in SOC is due to the change in the form of fertilizer than to the rate of fertilizer applied,” Reid writes.
Then he makes a startling concession:
From the evidence presented in this paper, it would be fair to conclude that modern annual crop management systems are associated with declines in SOC concentrations and that increased residue inputs from high nitrogen applications do not mitigate this decline as much as we might hope. In other words, modern farming—i.e., the kind practiced on nearly all farmland in the
—destroys soil carbon. (The Mulvaney team’s response to Reid’s critique can be found in the above-linked document.) United States
The second second critique (PDF) came from a team led by D.S. Powlson at the Department of Soil Science and Centre for Soils and Ecosystem Function at the Rothamsted Research Station in the United Kingdom. Powlson and colleagues attack the Mulvaney team’s contention that synthetic nitrogen depletes the soil’s ability to store nitrogen.
“We propose that the conclusion drawn by Mulvaney et al. (2009), that inorganic N fertilizer causes a decline in soil organic N concentration, is false and not supported by the data from the Morrow Plots or from numerous studies worldwide,” they write.
Then they, too, make a major concession: “the observation of significant soil C and N declines in subsoil layers is interesting and deserves further consideration.” That is, they don’t challenge Mulvaney team’s contention that synthetic nitrogen destroys organic carbon in the subsoil.
In their response (PDF), Mulvaney and his colleagues mount a vigorous defense of their methodology. And then they conclude:
In the modern era of intensified agriculture, soils are generally managed as a commodity to maximize short-term economic gain. Unfortunately, this concept entirely ignores the consequences for a vast array of biotic and abiotic soil processes that aff ect air and water quality and most important, the soil itself.
So who’s right? For now, we know that the Illinois team has presented a robust cache of evidence that turns 50 years of conventional soil science on its head—and an analysis that conventional soil scientists acknowledge is “sensational” and “incredibly important” if true. We also know that their analysis is consistent with the founding principles of organic agriculture: that properly applied manure and nitrogen-fixing cover crops, not synthetic nitrogen, are key to long-term soil health and fertility.
The subject demands more study and fierce debate. But if Mulvaney and his team are correct, the future health of our farmland hinges on a dramatic shift away from reliance on synthetic nitrogen fertilizer.
It looks like the hobbit has kicked over the edifice of ancient human linage which is just as well. I really get annoyed with the creation of theoretical castles in the air based on a couple of data points and effectively arguments that lack of other evidence is in fact evidence of lack. A data point allows conjecture only.
In my manuscript, I argue for global distribution of the human linage in the tropical old world as early as plausible. The hobbit shows us that such took place millions of years before and that this happened in the tropical environments. I argued as much in my manuscript.
I also argued that the best place for modern humanity to have evolved in the first instance was the Indonesian archipelago. Once modern man so evolved around 100.000 years ago or more, it was no big trick to penetrate all other ecological niches. Critical to his evolution was the richness of the intertidal zone on the millions of miles of coastline. This supported enlarged social structures that became villages with large brained humanity. It also supported the breeding of aquatically adapted humanity at the same time.
My only restraint was an outright lack of early human migration from
Africa in the limited fossil record. The advent of the hobbit ends that need. In fact there is now no need whatsoever to restrict human evolution to Africa. (It is not the best place for it anyway)
Also recall that the Ice Age limited activity to the tropics mostly and the sea level was a hundred meters lower. For other reasons the crust itself was thirty degrees further south. This all made the tropical life zone much larger in this region.
How a hobbit is rewriting the history of the human race
The discovery of the bones of tiny primitive people on an Indonesian island six years ago stunned scientists. Now, further research suggests that the little apemen, not Homo erectus, were the first to leave
Africa and colonise other parts of the world, reports Robin McKie
It remains one of the greatest human fossil discoveries of all time. The bones of a race of tiny primitive people, who used stone tools to hunt pony-sized elephants and battle huge Komodo dragons, were discovered on the Indonesian
in 2004. island of Flores
The team of Australian researchers had been working in a vast limestone cavern, called Liang Bua, in one of the island's remotest areas, when one scientist ran his trowel against a piece of bone. Carefully the group began scraping away the brown clay in which pieces of a tiny skull, and a little lower jaw, were embedded.
This was not any old skull, they quickly realised. Although small, it had special characteristics. In particular, it had adult teeth. "This was no child, but a tiny adult; in fact, one of the smallest adult hominids ever found in the fossil record," says Mike Morwood, of Australia's University of Wollongong and a leader of the original Flores expedition team.
The pieces of bone were carefully wrapped in newspaper, packed in cardboard boxes and then cradled on the laps of scientists on their journey, by ferry and plane, back to
. Then the pieces of skull, as well as bones from other skeletons found in Liang Bua, were put together. Jakarta
The end result caused consternation. These remains came from a species that turned out to be only three feet tall and had the brain the size of an orange. Yet it used quite sophisticated stone tools. And that was a real puzzle. How on earth could such individuals have made complex implements and survived for aeons on this remote part of the
Some simply dismissed the bones as the remains of deformed modern humans with diseases that had caused them to shrink: to them, they were just pathological oddities, it was alleged. Most researchers disagreed, however. The hobbits were the descendants of a race of far larger, ancient humans who had thrived around a million years ago. These people, known as Homo erectus, had become stranded on the island and then had shrunk in an evolutionary response to the island's limited resources.
That is odd enough. However, new evidence suggests the little folk of
Flores may be even stranger in origin. According to a growing number of scientists, Homo floresiensis is probably a direct descendant of some of the first apemen to evolve on the African savannah three million years ago. These primitive hominids somehow travelled half a world from their probable birthplace in the Rift Valley to make their homes among the orangutans, giant turtles and rare birds of Indonesia before eventually reaching Flores.
It sounds improbable but the basic physical similarity between the two species is striking. Consider Lucy, the 3.2 million-year-old member ofAustralopithecus afarensis. She had a very small brain, primitive wrists, feet and teeth and was only one metre tall, but was still declared "the grandmother of humanity" after her discovery in
in 1974. Crucially, analysis of Lucy's skeleton shows it has great similarities with the bones of H. floresiensis, although her species died out millions of years ago while the hobbits hung on in Flores until about 17,000 years ago. This latter figure is staggeringly close in terms of recent humanevolution and indicates that long after the Neanderthals, our closest evolutionary relatives, had disappeared from the face of the Earth around 35,000 years ago, these tiny, distant relatives of Homo sapienswere still living on remote Ethiopia Flores.
The crucial point about this interpretation is that it explains why the
Flores people had such minuscule proportions. They didn't shrink but were small from the start – because they came from a very ancient lineage of little apemen. They acquired no diseased deformities, nor did they evolve a smaller stature over time. They were, in essence, an anthropological relic and Flores was an evolutionary time capsule. In research that provides further support for this idea, scientists have recently dated some stone tools on Flores as being around 1.1 million years old, far older than had been previously supposed.
The possibility that a very primitive member of the genus Homo left Africa, roughly two million years ago, and that a descendant population persisted until only several thousand years ago, is one of the more provocative hypotheses to have emerged in anthropology during the past few years," David Strait of the University of Albany told Scientific American recently. This view is backed by Professor Chris Stringer of the
Natural History Museum, . "We are still grappling with what this discovery has done for our thinking and our conventional scenarios." London
In addition, Mike Morwood says he has now uncovered stone tools on nearby
Sulawesi. These could be almost two million years old, he believes, which suggests the whole region was populated by very ancient humans for a startlingly long part of human prehistory. "This is going to put the cat among the pigeons," Morwood says.
However, it is the hobbits' similarity to ancient African apemen that provides the most compelling evidence for their ancient origins. In theJournal of Human Evolution, a team led by Debbie Argue of the
Australian National University, recently reported that analysis of H. floresiensis shows they most closely resemble apelike human ancestors that first appeared around 2.3 million years ago in Africa. In other words, their stock may be not quite as old as Lucy's but probably comes from a hominid, known as Homo habilis, that appeared on the evolutionary scene not long after Lucy's species disappeared. Homo habilis's features now seem to match, most closely, those of H. floresiensis.
Consider those hobbit feet, for example. The skeleton unearthed on
Flores had a foot that was 20cm in length. This produces a ratio of 70 per cent when compared with the length of the hobbit's thigh bone. By contrast, men and women today have foot-to-thigh bone ratios of 55 per cent. The little folk of Flores had singularly short legs and long, flapper feet, very similar to those of African apemen, even though limbs like these would have made their long march from Africa to Flores a painful business.
Similarly, the hands of H. floresiensis were more like apes than those of evolved humans, their wrists possessing trapezoid bones that would have made the delicate art of stone tool-making very difficult. Their teeth show primitive traits while their brains were little bigger than those of chimpanzees, though CT scans of skull interiors suggest they may have had cognitive skills not possessed by apes.
Nevertheless, this little apeman, with poor physique, a chimp-sized brain and only a limited ability to make tools, now appears to have left Africa, travelled thousands of miles and somehow colonised part, if not all, of south-east
Asia two million years ago.
Scientists had previously assumed only a far more advanced human ancestor, such as Homo erectus, was capable of undertaking that task and only managed to do so about a million years ago when our predecessors had evolved powerful physiques, a good gait and the beginnings of intellect. Without these, we would have got nowhere, it was implied.
Then along came little H. floresiensis which, quite simply, has "no business being there," says Morwood. And you can see what he means. Apart from the sheer improbability of a jumped-up ape travelling from Africa to
Indonesia, there is the particular puzzle of how it got to Flores.
Primitive hominids were almost certainly incapable of sailing. So how did it arrive on the island in the first place? It is a puzzle, although Stringer believes the region's intense tectonic activity is significant. "After the
Indian Ocean tsunami in 2004, people were found far out at sea clinging to rafts of vegetation. Things like that could have happened regularly in the past and people could have been swept out to sea and washed ashore on Flores. Alternatively, there could have been short-lived connections between now separate islands."
Thus, ancient African apemen travelled half the world, made homes across Indonesia and, in one case, were washed out to sea to end up colonising a remote island that was already populated with pygmy elephants, called stegadons, and giant Komodo dragons, which are still found on the island. It is a truly fantastic tale, worthy of Rider Haggard, and it has turned the study of human evolution on its head.
And then there is the report that dates the stone tools found on
Flores as being 1.1 million years old. "That is utterly remarkable on its own," adds Morwood. "Until we found these dates, the longest period of island isolation that we knew about occurred on Tasmania where the aboriginal people were cut off from mainland 11,000 years ago. We thought that was an amazing length of time. But now we have found an island where early humans were cut off from the rest of evolution for more than a million years." In addition, there are those completed digs carried out by Morwood which suggest that some type of human being was making stone implements up to two million years ago. Australia
A crucial aspect to this remarkable story is the region's geography, Morwood believes. The ocean currents and the remoteness of
Flores make the island difficult to get to, so once a species does get there, it will remain well protected on it, he argues. " Flores seems to protect species that are long past their use-by dates. There were those pygmy elephants, and the Komodo dragon, for example. And now we haveHomo floresiensis. It may be that only a few animals get there but when they do arrive they tend to survive for a long time, which has been science's good fortune."
That is putting it mildly. Had not the original Australian team, led by Morwood, uncovered those hobbit remains in 2004, the story of humanity's African exodus would have been considered a fairly simple affair.
According to this version of events, Homo erectus evolved from apemen predecessors, such as Australopithecus africanus, in Africa and then headed off around the
Old World more than a million years ago, armed with a great physique and a modest intellect. These allowed it to settle across Africa, Asia and Europe. This diaspora was then followed by a second wave of humans – our own species, Homo sapiens – which emerged from Africa 100,000 years ago and took over the planet, replacing all pockets of its predecessors it encountered.
Now a far more complex picture is emerging. Ancient apemen, who might have been thought to lack the nous for global conquest, appear to have done the trick almost a million years earlier. One of the major tenets of human evolution, the story of our world conquest, is now urgently in need of revision.
As to the fate of H. floresiensis, that is unclear. The species disappears abruptly from the archaeological record 17,000 years ago. But why? They had apparently survived quite happily on the island for more than a million years. So what did for them in the end?
There are two competing answers. The first suggests that the species, after all the good fortune that had helped it endure the vicissitudes of life in the
Malay Archipelago, ran out of luck. "There is a thick layer of ash in the Liang Bua cave above the most recent hobbit remains," says Stringer. "We now know this was caused by a major volcanic eruption which occurred about 17,000 years ago. So it may be that they were just unlucky with the local geology." According to this vision, the little folk of Flores were wiped out by choking plumes of volcanic ash or died of starvation on an island denuded of vegetation.
It would have been a pretty terrible way to go. Yet neither Stringer nor Morwood is convinced that was what happened, despite the tight link between dates of eruptions on the island and the disappearance of the species from the fossil record. Instead, they suspect a very different agent: the bloody hand of modern humans. "Look at our track record," says Morwood. When Homo sapiens entered Europe 40,000 years ago, on its route out of
Africa, they would have encountered the continent's original inhabitants, the Neanderthals. Within a few millenniums, the Neanderthals had been rendered extinct.
Stringer agrees. Homo sapiens left Africa about 100,000 years ago and by the time hobbits became extinct on Flores, modern humans were all over south-east
Asia. "I cannot see Homo floresiensis keeping modern humans off the island. There must have been encounters between them and us. It is wonderful to speculate what might have happened when they met up, but I suspect that those moderns used up the resources that the hobbit needed to survive."
Robin McKie is the science editor of the Observer
Thursday, February 25, 2010
This is a strongly suggestive finding. These sea ice arches which gave way in 2007 effectively block losses of multiyear ice jammed up against the arctic islands.
I think that the ongoing deteriation of the sea ice is most likely caused by an increase in the inflow of warm surface waters into the
Arctic some years ago and that this is ongoing. I will go even further. This process will be sustained for centuries and it will also mean warmer north Atlantic waters. These waters were two degrees warmer during the Bronze Age so it is not impossible at all.
What is very important is that we have in the
a critical choke point that if cleared annually will impact hugely on any sustained ice build up. Nares Strait
Conjecture: clearing the strait every spring will accelerate and maintain sea ice removal until the bulk is gone and can also prevent any possible multi season recovery. In short, if we want a lever to manage sea ice, this is it.
The next question is how? I posted two years ago on the topic of nuclear ice breakers. These are huge craft as large as aircraft carriers able to operate on an aircushion between twin hulls. Nuclear power is a necessity.
The craft passes over the ice pack and in the process, forces air under the ice causing it to lift up and break leaving a trail of easily flushed out crushed ice. There is no doubt that the arches can be removed in this manner fairly easily at the beginning of the season and will allow a steady removal of heavy ice all summer.
No one has ever imagined that we could manage the sea ice. Now it appears to be at least a possibility.
Missing 'Ice Arches' Contributed to 2007 Arctic Ice Loss
Large, thick floes of ice can be seen breaking off of the Arctic sea ice cover before entering the
in this Dec. 23, 2007 radar image from the European Space Agency's Envisat satellite. Nares Strait
PASADENA, Calif. – In 2007, the Arctic lost a massive amount of thick, multiyear sea ice, contributing to that year's record-low extent of Arctic sea ice. A new NASA-led study has found that the record loss that year was due in part to the absence of "ice arches," naturally-forming, curved ice structures that span the openings between two land points. These arches block sea ice from being pushed by winds or currents through narrow passages and out of the Arctic basin.
Beginning each fall, sea ice spreads across the surface of the
Arctic Ocean until it becomes confined by surrounding continents. Only a few passages -- including the Fram Strait and -- allow sea ice to escape. Nares Strait
"There are a couple of ways to lose Arctic ice: when it flows out and when it melts," said lead study researcher Ron Kwok of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We are trying to quantify how much we're losing by outflow versus melt."
Kwok and colleagues found that ice arches were missing in 2007 from the Nares Strait, a relatively narrow 30- to 40-kilometer-wide (19- to 25-mile-wide) passage west of
Greenland. Without the arches, ice exited freely from the Arctic. The Fram Strait, east of Greenland, is about 400 kilometers (249 miles) wide and is the passage through which most sea ice usually exits the Arctic.
Despite Nares' narrow width, the team reports that in 2007, ice loss through Nares equaled more than 10 percent of the amount emptied on average each year through the wider
. Fram Strait
"Until recently, we didn't think the small straits were important for ice loss," Kwok said. The findings were published this month in Geophysical Research Letters.
"One of our most important goals is developing predictive models of Arctic sea ice cover," said Tom Wagner, cryosphere program manager at NASA Headquarters in
. "Such models are important not only to understanding changes in the Washington Arctic, but also changes in global and North American climate. Figuring out how ice is lost through the Fram and Nares straits is critical to developing those models."
To find out more about the ice motion in
, the scientists examined a 13-year record of high-resolution radar images from the Canadian RADARSAT and European Envisat satellites. They found that 2007 was a unique year – the only one on record when arches failed to form, allowing ice to flow unobstructed through winter and spring. Nares Strait
The arches usually form at southern and northern points within
when big blocks of sea ice try to flow through the strait's restricted confines, become stuck and are compressed by other ice. This grinds the flow of sea ice to a halt. Nares Strait
"We don't completely understand the conditions conducive to the formation of these arches," Kwok said. "We do know that they are temperature-dependent because they only form in winter. So there's concern that if climate warms, the arches could stop forming."
To quantify the impact of ice arches on
Arctic Ocean ice cover, the team tracked ice motion evident in the 13-year span of satellite radar images. They calculated the area of ice passing through an imaginary line, or "gate," at the entrance to . Then they incorporated ice thickness data from NASA's ICESat to estimate the volume lost through Nares. Nares Strait
They found that in 2007,
Nares Strait drained the Arctic Ocean of 88,060 square kilometers (34,000 square miles) of sea ice, or a volume of 60 cubic miles. The amount was more than twice the average amount lost through Nares each year between 1997 and 2009.
The ice lost through
Nares Strait was some of the thickest and oldest in the Arctic Ocean.
"If indeed these arches are less likely to form in the future, we have to account for the annual ice loss through this narrow passage. Potentially, this could lead to an even more rapid decline in the summer ice extent of the
Arctic Ocean," Kwok said.
For more information about NASA and agency programs, visit: http://www.nasa.gov .
JPL is managed for NASA by the California Institute of Technology in
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