Even a ‘Limited’ Nuclear War Could Wreck Earth’s Climate And Trigger Global Famine


Deadly tensions between India and Pakistan are boiling over in Kashmir, a disputed territory at the northern border of each country.

A regional conflict is worrisome enough, but climate scientists warn that if either country launches just a portion of its nuclear weapons, the situation might escalate into a global environmental and humanitarian catastrophe.

On February 14, a suicide bomber killed at least 40 Indian troops in a convoy travelling through Kashmir. A militant group based in Pakistan called Jaish-e-Mohammed claimed responsibility for the attack. India responded by launching airstrikes against its neighbour – the first in roughly 50 years – and Pakistan has said it shot down two Indian fighter jets and captured one of the pilots.

Both countries possess about 140 to 150 nuclear weapons. Though nuclear conflict is unlikely, Pakistani leaders have said their military is preparing for “all eventualities“. The country has also assembled its group responsible for making decisions on nuclear strikes.

“This is the premier nuclear flashpoint in the world,” Ben Rhodes, a political commentator, said on Wednesday’s episode of the “Pod Save the World” podcast.

For that reason, climate scientists have modelled how an exchange of nuclear weapons between the two countries – what is technically called a limited regional nuclear war – might affect the world.

Though the explosions would be local, the ramifications would be global, that research concluded. The ozone layer could be crippled and Earth’s climate may cool for years, triggering crop and fishery losses that would result in what the researchers called a “global nuclear famine”.

“The danger of nuclear winter has been under-understood – poorly understood – by both policymakers and the public,” Michael Mills, a researcher at the US National Center for Atmospheric Research, told Business Insider.

“It has reached a point where we found that nuclear weapons are largely unusable because of the global impacts.”

Why a ‘small’ nuclear war could ravage Earth

When a nuclear weapon explodes, its effects extend beyond the structure-toppling blast wave, blinding fireball, and mushroom cloud. Nuclear detonations close to the ground, for example, can spread radioactive debris called fallout for hundreds of miles.

But the most frightening effect is intense heat that can ignite structures for miles around. Those fires, if they occur in industrial areas or densely populated cities, can lead to a frightening phenomenon called a firestorm.

“These firestorms release many times the energy stored in nuclear weapons themselves,” Mills said. “They basically create their own weather and pull things into them, burning all of it.”

Mills helped model the outcome of an India-Pakistan nuclear war in a 2014 study. In that scenario, each country exchanges 50 weapons, less than half of its arsenal. Each of those weapons is capable of triggering a Hiroshima-size explosion, or about 15 kilotons’ worth of TNT.

The model suggested those explosions would release about 5 million tons of smoke into the air, triggering a decades-long nuclear winter.

The effects of this nuclear conflict would eliminate 20 to 50 percent of the ozone layer over populated areas. Surface temperatures would become colder than they have been for at least 1,000 years.

The bombs in the researchers’ scenario are about as powerful as the Little Boy nuclear weapon dropped on Hiroshima in 1945, enough to devastate a city.

But that’s far weaker than many weapons that exist today. The latest device North Korea tested was estimated to be about 10 times as powerful as Little Boy. The US and Russia each possess weapons 1,000 times as powerful.

Still, the number of weapons used is more important than strength, according to the calculations in this study.

How firestorms would wreck the climate

Most of the smoke in the scenario the researchers considered would come from firestorms that would tear through buildings, vehicles, fuel depots, vegetation, and more.

This smoke would rise through the troposphere (the atmospheric zone closest to the ground), and particles would then be deposited in a higher layer called the stratosphere. From there, tiny black-carbon aerosols could spread around the globe.

“The lifetime of a smoke particle in the stratosphere is about five years. In the troposphere, the lifetime is one week,” Alan Robock, a climate scientist at Rutgers University who worked on the study, told Business Insider.

“So in the stratosphere, the lifetime of smoke particles is much longer, which gives it 250 times the impact.”

The fine soot would cause the stratosphere, normally below freezing, to be dozens of degrees warmer than usual for five years. It would take two decades for conditions to return to normal.

This would cause ozone loss “on a scale never observed,” the study said.

That ozone damage would consequently allow harmful amounts of ultraviolet radiation from the sun to reach the ground, hurting crops and humans, harming ocean plankton, and affecting vulnerable species all over the planet.

But it gets worse: Earth’s ecosystems would also be threatened by suddenly colder temperatures.

Screen Shot 2019 03 01 at 3.52.36 pm(Mills et al., Earth’s Future, 2014)

The fine black soot in the stratosphere would prevent some sun from reaching the ground. The researchers calculated that average temperatures around the world would drop by about 1.5 degrees Celsius over the five years following the nuclear blasts.

In populated areas of North America, Europe, Asia, and the Middle East, changes could be more extreme (as illustrated in the graphic above). Winters there would be about 2.5 degrees colder and summers between 1 and 4 degrees colder, reducing critical growing seasons by 10 to 40 days. Expanded sea ice would also prolong the cooling process, since ice reflects sunlight away.

“It’d be cold and dark and dry on the ground, and that would affect plants,” Robock said. “This is something everybody should be concerned about because of the potential global effects.”

The change in ocean temperatures could devastate sea life and fisheries that much of the world relies on for food. Such sudden blows to the food supply and the “ensuing panic” could cause “a global nuclear famine”, according to the study’s authors.

Temperatures wouldn’t return to normal for more than 25 years.

The effects might be much worse than previously thought

Robock is working on new models of nuclear-winter scenarios; his team was awarded a nearly US$3 million grant from the Open Philanthropy Project to do so.

“You’d think the Department of Defence and the Department of Homeland Security and other government agencies would fund this research, but they didn’t and had no interest,” he said.

Since his earlier modelling work, Robock said, the potential effects of a nuclear conflict between India and Pakistan have gotten worse. That’s because India and Pakistan now have more nuclear weapons, and their cities have grown.

“It could be about five times worse than what we’ve previously calculated,” he said.

Because of his intimate knowledge of the potential consequences, Robock advocates the reduction of nuclear arsenals around the world. He said he thinks Russia and the US – which has nearly 7,000 nuclear weapons – are in a unique position to lead the way.

“Why don’t the US and Russia each get down to 200? That’s a first step,” Robock said.

“If President Trump wants the Nobel Peace Prize, he should get rid of land-based missiles, which are on hair-trigger alert, because we don’t need them,” he added.

“That’s how he’ll get a peace prize – not by saying we have more than anyone else.”

A shift in climate


The Intergovernmental Panel on Climate Change has done much to alert politicians to the effects of global warming. But to push climate change up the agenda, it will need to do the same for the public.

Hoesung Lee has laid out a vision for his tenure as the fourth chair of the Intergovernmental Panel on Climate Change (IPCC). The South Korean economist says that he wants to increase coordination between the working groups, work with more scientists from developing countries, boost interaction with the business and financial industries and expand the panel’s influence by making its findings easier to digest. Above all, Lee says that he wants to be remembered as the man who shifted the panel’s focus towards solutions. Those are all worthy goals, but the organization that assesses — and in some senses oversees — the world of climate science is well placed to do a lot more.

The basic science underlying climate change has been firmly established, and we now know much more about not only the threats posed by a rapidly warming world, but also the options humanity has for changing course. Even though the commitments that have been proffered going into the United Nations climate summit in Paris at the end of next month are generally tepid, the governments of the world by and large recognize the problem and know that they need to act. What else can the IPCC do? The answer is plenty, and Lee’s emphasis on solutions is one piece of the puzzle.

Most of the world’s major emitters — rich, poor and in between — have offered commitments and policies to move their countries in the right direction. Without concerted action in the decades to come, however, these commitments will fall well short of what the best science suggests is needed to achieve the formal goal of limiting the rise in global average temperatures to 2 °C. Political leaders are leaving the hard work for later, and could well be committing future generations to more warming than anybody wants to experience.

This is partly because of a lack of political leadership and of active opposition by entrenched industrial interests, as environmentalists argue. But it is also evidence of the vastness of the challenge. It is not easy to transform the global economy and industrial base for a large and growing population, much of which is still mired in poverty but wants access to the modern conveniences that so many on the planet take for granted. The world needs a full suite of technologies that are not only cost-effective but also socially and politically viable. Here, the IPCC has a particular part to play.

“The real challenge is to raise public awareness about the risks of inaction.”

The weak commitments going into Paris are also evidence of a disconnect between scientists, who think that the evidence speaks for itself, and citizens and policymakers, who have a lot of other things on their minds. The IPCC is looking at bringing science writers and graphics experts on board in an effort to improve its reports. A linguistics study published earlier this month showed that the IPCC summaries for policymakers score low in terms of readability, and recommends that key panel members receive science-communication training (R. Barkemeyer et al. Nature Clim. Changehttp://doi.org/79f; 2015). All this makes sense, but communicating the science more clearly is just the first, and a relatively minor, step.

The IPCC’s reports are aimed mainly at — and written in coordination with — governments, yet politicians at the very highest levels are already talking about climate change. The unfortunate truth is that taking steps to combat climate change is way down the political agenda, and that makes more aggressive action difficult. The real challenge is to raise public awareness about the risks of inaction — as well as the benefits of action — and to identify policies that can pass the political litmus test.

Here, as Lee himself has said, the IPCC has an important role. The panel must generate and incorporate knowledge about how information filters through society and about the kinds of policies that are most likely to work. This is the domain of sociologists, psychologists, anthropologists and political scientists, and they must be an integral part of the IPCC’s sixth assessment.

The IPCC has had its controversies, including a glitch in its 2007 projection for Himalayan glacier melt and this year’s resignation of former chairman Rajendra Pachauri, who faces — and denies — accusations of sexual harassment. But the challenges that face the panel today are in many ways a result of its success. Much ground has been covered; the challenge now, for both researchers and the IPCC, is to adapt and to identify research that will help policymakers to bridge the gap between what they say they want to do and what they are actually doing.

Researchers find tie between global precipitation and global warming.


The rain in Spain may lie mainly on the plain, but the location and intensity of that rain is changing not only in Spain but around the globe.

A new study by Lawrence Livermore National Laboratory scientists shows that observed changes in global (ocean and land) precipitation are directly affected by human activities and cannot be explained by natural variability alone. The research appears in the Nov. 11 online edition of the Proceedings of the National Academy of Sciences.

Emissions of heat-trapping and ozone-depleting gases affect the distribution of precipitation through two mechanisms. Increasing temperatures are expected to make wet regions wetter and dry regions drier (thermodynamic changes); and changes in will push storm tracks and subtropical dry zones toward the poles.

“Both these changes are occurring simultaneously in global precipitation and this behavior cannot be explained by natural variability alone,” said LLNL’s lead author Kate Marvel. “External influences such as the increase in are responsible for the changes.”

The team compared climate model predications with the Global Precipitation Climatology Project’s global observations, which span from 1979-2012, and found that natural variability (such as El Niños and La Niñas) does not account for the changes in global precipitation patterns. While natural fluctuations in climate can lead to either intensification or poleward shifts in precipitation, it is very rare for the two effects to occur together naturally.

“In combination, manmade increases in greenhouse gases and stratospheric ozone depletion are expected to lead to both an intensification and redistribution of global precipitation,” said Céline Bonfils, the other LLNL author. “The fact that we see both of these effects simultaneously in the observations is strong evidence that humans are affecting global precipitation.”

https://i2.wp.com/cdn.physorg.com/newman/gfx/news/2013/35-researchersf.jpg

Marvel and Bonfils identified a fingerprint pattern that characterizes the simultaneous response of precipitation location and intensity to external forcing.

“Most previous work has focused on either thermodynamic or dynamic changes in isolation. By looking at both, we were able to identify a pattern of precipitation change that fits with what is expected from human-caused climate change,” Marvel said.

By focusing on the underlying mechanisms that drive changes in global precipitation and by restricting the analysis to the large scales where there is confidence in the models’ ability to reproduce the current climate, “we have shown that the changes observed in the satellite era are externally forced and likely to be from man,” Bonfils said.

Robotic tractor to deliver precision planting.


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A robotic tractor and seeding machine with unprecedented planting accuracy will improve agricultural productivity for farmers and enable cropping on 20% more land, UNSW inventors say.

Broad acre farming currently requires an operator to be present in the cabin of large tractors, but this is often perceived as being unproductive, says Associate Professor Jay Katupitiya from the School of Mechanical and Manufacturing Engineering at UNSW.

Furthermore, large tractors are expensive and compact the soil as they move, creating crop lines. Crop lines render roughly 20% of land on large paddocks unusable and means cropping must happen in the same direction every year, which degrades soil health.

To solve this problem, Katupitiya has partnered with the Grains Research and Development Corporation (GRDC) to develop a lighter, more affordable agricultural machine that can accurately follow and plant seeds along a predefined path without a human operator.

“This system has the ability to lay seeds within one to two centimetres of lateral accuracy on rough agricultural terrain, which is an unprecedented level of precision for an autonomous machine,” says Katupitiya.

Achieving this precision with existing technology has been challenging because the forces generated by a plough digging into soil often cause seeding implements to veer off course. However, advanced control systems and sensors, and an optimised design, enable the UNSW invention to automatically correct against these deviations.

“Our unique design and technology allows farmers to know exactly where their crop is,” says Katupitiya. “It means the same machine can be used repeatedly throughout the cropping season to carry out all other subsequent tasks, such as weeding, fertilising and growth monitoring.”

The UNSW-developed machine, which measures just three-metres wide, is a more affordable and lightweight option for farmers, says Katupitiya, which doesn’t create crop lines.

“The flexibility of being able to access more land and plant crops in different directions has advantages for crop growth through better uptake of remnant nutrients, and a better yield,” says Katupitiya.

The research team behind the invention were finalists in the 2012 Eureka Prize for Innovative Use of Technology. They are now working with the GRDC to pursue further development and commercial production.

 

 

Quiet Climate Milestones.


 “All we are not stares back at what we are.” —“The Sea and the MirrorW.H. Auden

Throughout my life, there have been poets and poems I’ve carried with me everywhere, like a briefcase that’s always packed and sitting by the front door. And while it might sound strange, I’ve found myself coming back to Auden in the past few weeks after two things happened in the climate world. First, it was the European Union effectively giving up on its emission trading scheme (ETS) for regulating carbon pollution. Then it was the news that atmospheric carbon levels had reached a new record concentration of 400 parts per million (ppm).

As global milestones go, this was a quiet one. Life went on much as it had when we stood at 399.9 ppm, and few will remember exactly where they were when they heard the news. What it means, though, is that the atmosphere now has more of the heat-trapping gases driving climate change than ever before, taking us further away from the 350 ppm level scientists agree we can safely handle. With the effective collapse of the ETS, our challenge in responding becomes even greater.

Which brings me back to Auden. I can’t help thinking about this line because I can’t help thinking these two events show that we’re simply not rising to meet our potential. When it comes climate change, we’re avoiding the tough decisions instead of stepping up to the challenge, pure and simple. Seeing us cross the 400 ppm threshold or reading another climate denier distort the facts in the papers, I know we are better than this. Because what we are not, as Auden would have it, is extraordinary.

As we celebrate Memorial Day, think back to the generations that came before us and the existential challenges they faced. The ones, for example, who came together selflessly to defeat Nazi tyranny, whether they were daily risking death on the front lines or working hard on the home front. They took on this challenge because there were people and places in their lives they loved deeply and utterly, and there was nothing they wouldn’t do to protect them. And in part because of that love, they won.

We don’t have to face bullets, but we do have to face reality and make real choices about climate change. Those of us who’ve been working in the movement for decades are used to being called merchants of doom and gloom (and sometimes much worse). These names miss the point entirely. What gets me out of bed isn’t dread, but love for the faces that appear in my picture frames and around my breakfast table. Given a choice between giving up my arms or something happening to my family or friends, I’d offer you my legs too. Just like any mother, I want my children to have the freedom to make the lives they want. I also want to be able to run in the mountains and savor a cup of Moka Java in the morning. I could go on and everyone will have their own list, but in every case, this means taking care of what we love on this exquisite planet.

This is the challenge of our time, the one that will define us to our grandchildren and beyond. The good news is that the solution starts with a simple step: putting a price on carbon. With a price on carbon, we curb the carbon pollution accelerating climate change and ultimately take care of what we love. It will not be easy, but it’s a challenge we can solve together. It’s past time to step up, to be worthy of the generations before us and faithful to the ones who’ll come after.

Source: Source: http://climaterealityproject.org

 

 

Side effects of fluorescent light.


Admit it, you don’t like the cold, lifeless light that emits from these bulbs, but what you don’t know may hurt you!

Better to vie for the warm welcoming glow of old school incandescent bulbs then to roll the dice with these bulbs that, if you dare break one, spew toxic matter all over the place.

-Headaches

-Migraines

-Eye discomfort

-Eye strain

-Enhanced tumor formation

-Contributes to agoraphobia

-Endocrine disruption

-Increased stress

At the end of the day, natural sunlight is the best option because it brings a full spectrum of light frequencies.  The unbalanced light emitted from fluorescent bulbs has been studied thoroughly and it is a wonder why many government officials are pushing for regulations requiring their use over incandescent bulbs.  In fact, incandescent bulbs emit a more balanced spectrum light that is more similar to sunlight then fluorescent bulbs.  It is no surprise that many people are willing to pay more in electric bills and replacement in order to avoid the cold, lifeless glow of these mercury laden lights.

Scientists Officially Link Processed Foods To Autoimmune Disease.


Scientists Officially Link Processed Foods To Autoimmune Disease

 

The modern diet of processed foods, takeaways and microwave meals could be to blame for a sharp increase in autoimmune diseases such as multiple sclerosis, including alopecia, asthma and eczema.
A team of scientists from Yale University in the U.S and the University of Erlangen-Nuremberg, in Germany, say junk food diets could be partly to blame.

‘This study is the first to indicate that excess refined and processed salt may be one of the environmental factors driving the increased incidence of autoimmune diseases,’ they said.

Junk foods at fast food restaurants as well as processed foods at grocery retailers represent the largest sources of sodium intake from refined salts.

The Canadian Medical Association Journal sent out an international team of researchers to compare the salt content of 2,124 items from fast food establishments such as Burger King, Domino’s Pizza, Kentucky Fried Chicken, McDonald’s, Pizza Hut and Subway. They found that the average salt content varied between companies and between the same products sold in different countries.

U.S. fast foods are often more than twice as salt-laden as those of other countries. While government-led public health campaigns and legislation efforts have reduced refined salt levels in many countries, the U.S. government has been reluctant to press the issue. That’s left fast-food companies free to go salt crazy, says Norm Campbell, M.D., one of the study authors and a blood-pressure specialist at the University of Calgary.

Many low-fat foods rely on salt–and lots of it–for their flavor. One packet of KFC’s Marzetti Light Italian Dressing might only have 15 calories and 0.5 grams fat, but it also has 510 mg sodium–about 1.5 times as much as one Original Recipe chicken drumstick. (Feel like you’re having too much of a good thing? You probably are.

Bread is the No. 1 source of refined salt consumption in the American diet, according to the Centers for Disease Control and Prevention. Just one 6-inch Roasted Garlic loaf from Subway–just the bread, no meat, no cheeses, no nothing–has 1,260 mg sodium, about as much as 14 strips of bacon.

How Refined Salt Causes Autoimmune Disease

The team from Yale University studied the role of T helper cells in the body. These activate and ‘help’ other cells to fight dangerous pathogens such as bacteria or viruses and battle infections.

Previous research suggests that a subset of these cells – known as Th17 cells – also play an important role in the development of autoimmune diseases. In the latest study, scientists discovered that exposing these cells in a lab to a table salt solution made them act more ‘aggressively.’

They found that mice fed a diet high in refined salts saw a dramatic increase in the number of Th17 cells in their nervous systems that promoted inflammation. They were also more likely to develop a severe form of a disease associated with multiple sclerosis in humans.

The scientists then conducted a closer examination of these effects at a molecular level. Laboratory tests revealed that salt exposure increased the levels of cytokines released by Th17 cells 10 times more than usual. Cytokines are proteins used to pass messages between cells.

Study co-author Ralf Linker, from the University of Erlangen-Nuremberg, said: ‘These findings are an important contribution to the understanding of multiple sclerosis and may offer new targets for a better treatment of the disease, for which at present there is no cure.’ It develops when the immune system mistakes the myelin that surrounds the nerve fibres in the brain and spinal cord for a foreign body.

It strips the myelin off the nerves fibres, which disrupts messages passed between the brain and body causing problems with speech, vision and balance.

Another of the study’s authors, Professor David Hafler, from Yale University, said that nature had clearly not intended for the immune system to attack its host body, so he expected that an external factor was playing a part.

He said: ‘These are not diseases of bad genes alone or diseases caused by the environment, but diseases of a bad interaction between genes and the environment.

Humans were genetically selected for conditions in sub-Saharan Africa, where there was no salt. It’s one of the reasons that having a particular gene may make African Americans much more sensitive to salt.

‘Today, Western diets all have high salt content and that has led to increase in hypertension and perhaps autoimmune disease as well.’

The team next plan to study the role that Th17 cells play in autoimmune conditions that affect the skin.

‘It would be interesting to find out if patients with psoriasis can alleviate their symptoms by reducing their salt intake,’ they said.

‘However, the development of autoimmune diseases is a very complex process which depends on many genetic and environmental factors.’

Stick to Good Salts

Refined, processed and bleached salts are the problem. Salt is critical to our health and is the most readily available nonmetallic mineral in the world. Our bodies are not designed to processed refined sodium chloride since it has no nutritional value. However, when a salt is filled with dozens of minerals such as in rose-coloured crystals of Himalayan rock salt or the grey texture of Celtic salt, our bodies benefit tremendously for their incorporation into our diet.

“These mineral salts are identical to the elements of which our bodies have been built and were originally found in the primal ocean from where life originated,” argues Dr Barbara Hendel, researcher and co-author of Water & Salt, The Essence of Life. “We have salty tears and salty perspiration. The chemical and mineral composition of our blood and body fluids are similar to sea water. From the beginning of life, as unborn babies, we are encased in a sack of salty fluid.”

“In water, salt dissolves into mineral ions,” explains Dr Hendel. “These conduct electrical nerve impulses that drive muscle movement and thought processes. Just the simple act of drinking a glass of water requires millions of instructions that come from mineral ions. They’re also needed to balance PH levels in the body.”

Mineral salts, she says, are healthy because they give your body the variety of mineral ions needed to balance its functions, remain healthy and heal. These healing properties have long been recognised in central Europe. At Wieliczka in Poland, a hospital has been carved in a salt mountain. Asthmatics and patients with lung disease and allergies find that breathing air in the saline underground chambers helps improve symptoms in 90 per cent of cases.

Dr Hendel believes too few minerals, rather than too much salt, may be to blame for health problems. It’s a view that is echoed by other academics such as David McCarron, of Oregon Health Sciences University in the US. He says salt has always been part of the human diet, but what has changed is the mineral content of our food. Instead of eating food high in minerals, such as nuts, fruit and vegetables, people are filling themselves up with “mineral empty” processed food and fizzy drinks.

Study Source:

This is the result of a study conducted by Dr. Markus Kleinewietfeld, Prof. David Hafler (both Yale University, New Haven and the Broad Institute of the Massachusetts Institute of Technology, MIT, and Harvard University, USA), PD Dr. Ralf Linker (Dept. of Neurology, University Hospital Erlangen), Professor Jens Titze (Vanderbilt University and Friedrich-Alexander-Universitat Erlangen-Nurnberg, FAU, University of Erlangen-Nuremberg) and Professor Dominik N. Muller (Experimental and Clinical Research Center, ECRC, a joint cooperation between the Max-Delbruck Center for Molecular Medicine, MDC, Berlin, and the Charite — Universitatsmedizin Berlin and FAU) (Nature, doi: http://dx.doi.org/10.1038/nature11868)*. In autoimmune diseases, the immune system attacks healthy tissue instead of fighting pathogens.

Source: Prevent Disease

 

 

 

Nanoscale Printing Has Big Implications for Science and Technology.


nano

 

IBM researchers arrange 60-nanometer gold particles to re-create a work of Renaissance art

By Larry Greenemeier

 

Researchers from IBM‘s Zurich Research Lab and Switzerland’s ETH Zurich science and technology university today announced the development of a dramatic new printing process that can manipulate nanosize particles to create larger images. The new technology promises to allow scientists, medical professionals and technologists to for the first time place particles smaller than 100 nanometers precisely where they are needed.

The process, which likely will not be commercially available for several years, is expected to have the most dramatic impact in the fields of biomedicine, electronics andinformation technology. It will help advance the development of nanoscale biosensors and ultratiny lenses that can bend light inside future optical chips as well as the fabrication of nanowires that could be used to build more advanced computer chips, researchers report in Nature Nanotechnology.

“This process is more reliable than any process before it at depositing particles,” says Heiko Wolf, a researcher in nanopatterning at IBM’s Zurich Research Lab who worked on this project with five other IBM and ETH Zurich colleagues.

The researchers are the first to print particles as tiny as 60 nanometers, more than 33,000 times smaller than a pinhead. In “dots per inch,” the measurement used to indicate the number of individual spots of ink printed on a certain area, the nanoprinting method yields a resolution of 100,000 dots of print, or dpi, compared with the 1,500 dpi of common offset printing.

The research utilizes the principles behind printing technology to more efficiently place nanoparticles onto a surface. Scientists demonstrated the efficiency and versatility of their method by using it to print a copy of 17th-century mystic philosopher Robert Fludd‘s image of the sun (the alchemist’s symbol for gold) using about 20,000 gold particles, each of them 60 nanometers in diameter. The printing method placed one particle per dot to create the tiniest piece of artwork ever printed from single pigment particles.

Still just a conceptual construct, the nanoprinting process could be applied to biomedicine to help screen for diseases by graphically illustrating the locations of, say,cancer cells or heart attack markers in a patient’s body.

In the information technology world, nanoprinting could be used to achieve the controlled placement of catalytic seed particles for growing semiconducting nanowires. Such nanowires are promising candidates for future transistors in microchips. “We were looking to find some technique to grow a nanowire,” Wolf says, “where you want one to grow.”

Researchers at the Georgia Institute of Technology are also experimenting with a form of nanoscale printing called nanolithography, which may lead to the production of nanopatterned structures, including nanocircuits, that may be useful in a variety of fields, including electronics, nanofluidics and medicine. Once perfected, nanolithography could be used to draw nanocircuits for the electronics industry, create nanochannels for nanofluidics devices or be adapted for drug delivery or biosensing technologies.

Source: Scientific American

 

Global Average Temperatures Are Close to 11,000-Year Peak.


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Global average temperatures are now higher than they have been for about 75% of the past 11,300 years, a study suggests. And if climate models are any indication, by the end of this century they will be the highest ever since the end of the most recent ice age.

Instrumental records of climate extend back to only the late nineteenth century. Beyond that, scientists depend on analyses of natural chronicles such as tree rings and isotope ratios in cave formations.

But even these archives have their limits: many detailed reconstructions of climate, particularly of temperature, apply to only limited regions or extend back at most a couple of millennia, says Shaun Marcott, a climate scientist at Oregon State University in Corvallis.

Marcott and his colleagues set about reconstructing global climate trends all the way back to 11,300 years ago, when the Northern Hemisphere was emerging from the most recent ice age. To do so, they collected and analyzed data gathered by other teams. The 73 overlapping climate records that they considered included sediment cores drilled from lake bottoms and sea floors around the world, along with a handful of ice cores collected in Antarctica and Greenland.

Each of these chronicles spanned at least 6,500 years, and each included a millennium-long baseline period beginning in the middle of the post-ice-age period at 3550 BC.

For some records, the researchers inferred past temperatures from the ratio of magnesium and calcium ions in the shells of microscopic creatures that had died and dropped to the ocean floor; for others, they measured the lengths of long-chain organic molecules called alkenones that were trapped in the sediments.

After the ice age, they found, global average temperatures rose until they reached a plateau between 7550 and 3550 BC. Then a long-term cooling trend set in, reaching its lowest temperature extreme between ad 1450 and 1850.

Since then, temperatures have been increasing at a dramatic clip: from the first decade of the twentieth century to now, global average temperatures rose from near their coldest point since the ice age to nearly their warmest, Marcott and his team report today in Science.

Climate context
The temperature trends that the team identified for the past 2,000 years are statistically indistinguishable from results obtained by other researchers in a previous study, says Marcott. “That gives us confidence that the rest of our record is right too,” he adds.

Marcott and his colleagues “have put together a pretty impressive set of climate proxies”, says Gavin Schmidt, a climate scientist at the NASA Goddard Institute for Space Studies in New York. “The overall climate picture has been clear for a long time, mostly from the Northern Hemisphere, but this compilation really puts the rest of the world in context,” he adds.

“Prior to this study, researchers could only guess whether global temperatures had exceeded the warmest part of the present interglacial period,” says Darrell Kaufman, a geologist at Northern Arizona University in Flagstaff. The latest findings show that the recent high temperatures are not necessarily the warmest, but they are unusually high, he notes.

The temperature trends during most of the post-ice-age period match those expected from natural factors such as the long-term variation in the tilt of Earth’s axis, says Marcott. But in the past century and a half, industrial emissions of the greenhouse gas carbon dioxide have increased — which helps to explain why global temperatures have risen so quickly in recent decades, he suggests.

Climate models from the Intergovernmental Panel on Climate Change suggest that by the end of this century, regardless of future carbon dioxide emissions, temperatures will be at their highest since the end of the most recent ice age, the researchers say.

Source: Scientific American.

‘Pac-Man’ in Saturn moon Tethys is a repeat performance.


SUNAstronomers have seen that the temperature of Saturn’s moon Tethys has hotter regions uncannily like the 1980s arcade game character Pac-Man.

A similar feature was spotted in 2010 on Mimas, another Saturnian moon.

A report in Icarus suggests the effect is due to high-energy electrons bombarding the sides of the moons that face their direction of orbital travel.

That compacts the surfaces to a hard, icy texture that does not heat or cool as rapidly as the unaffected surface.

Thermal images of both moons were obtained by the Cassini-Huygens mission, launched in 1997 to study the Saturn system in detail.

The temperatures seen by the spacecraft are distinctly chilly – the warmest parts of Tethys were at – 183C, but inside the “mouth” of the Pac-Man shape it was 15C cooler still.

At the time of the finding of the first Pac-Man shape on Mimas, scientists were unsure what might be the cause, theorising that differing surface textures probably played a role.

The existence of another such shape nearby has cemented the idea that fast-moving electrons are responsible.

“Finding a second Pac-Man in the Saturn system tells us that the processes creating these ‘Pac-Men’ are more widespread than previously thought,” said Carly Howett, of the Southwest Research Institute in Texas and lead author of the study.

“The Saturn system – and even the Jupiter system – could turn out to be a veritable arcade of these characters,” she said.

Source:BBC

 

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