New source of hydroxyl radicals found in the clouds

31 July 2014

By:  Caryl Richards    

Original Link:  http://www.rsc.org/chemistryworld/2014/07/new-source-hydroxyl-radicals-found-clouds

© Shutterstock

 

An international collaboration of scientists has discovered a previously unidentified source of tropospheric hydroxyl radicals generated by the interaction of ozone with the surface of clouds. Their simulations predict that the rate of hydroxyl radical production at the clouds’ air–water interface could be four orders of magnitude higher than in the rest of the atmosphere.

‘This is an important finding because the hydroxyl radical is the main “cleaner” of the atmosphere, and all the sources and sinks of this radical, which are gas phase, play a key role in the chemistry of the atmosphere,’ explains team member Josep Anglada, from the Institute of Advanced Chemistry of Catalonia, Spain.

 

While better known as the atmospheric trace gas that protects us from much of the solar UV radiation, ozone is also an important source of hydroxyl radicals in the troposphere owing to photodissociation. Nonetheless, according to Anglada, even though many atmospheric species are adsorbed at the air–water interface, up until now the chemistry at the interface has often been overlooked.

 

Applying quantum mechanics and molecular mechanics method first used to study biochemical reaction pathways, the team simulated the effects of water on the spectroscopic signature and dissociation rate constant of ozone adsorbed at the cloud surface. Crucially, they predicted that ozone exhibits a strong affinity for the air–water interface. ‘Our results suggest that the ozone adsorption process is thermodynamically spontaneous,’ Anglada says. ‘The predicted frequency shifts and enlargements of the spectral bands reveal that the photodissociation of ozone is strongly favoured by its interaction with water.’

 

‘This is exciting work linking together two of the new trends in atmospheric chemistry, multiphase chemistry and quantum calculations,’ says Mathew Evans at the University of York, UK, where he uses models to better predict the composition of the atmosphere. ‘We usually think about clouds as sinks for radicals, whereas this work suggests we should potentially start looking at them as sources.’

 

According to Dwayne Heard, an atmospheric chemist at the University of Leeds, UK, this is important since hydroxyl radicals are the dominant daytime oxidising species of greenhouse gases, such as methane, whose levels are continuing to rise. ‘More hydroxyl radicals means a globally shorter methane lifetime,’ he says, but concedes ‘the impact will depend on whether the radicals can escape the interface region to the gas phase, where it can oxidise trace gases, or remain trapped at the surface’.

 

Evans agrees. ‘These are theoretical calculations and they need to be assessed in both the lab and in the field but they highlight how the chemistry of the atmosphere can still surprise us.’

References

J M Anglada et al, Proc. Natl. Acad. Sci. USA, 2014, DOI: 10.1073/pnas.1411727111

Is our universe a bubble in the multiverse?

Is our universe a bubble in the multiverse?

July 21, 2014

From:  http://www.kurzweilai.net/is-our-universe-a-bubble-in-the-multiverse

Screenshot from a video of Matthew Johnson explaining the multiverse hypothesis (credit: Perimeter Institute)

Researchers at the Perimeter Institute for Theoretical Physics are working to bring the multiverse hypothesis — we are living in one universe of many — into the realm of testable science.
Perimeter Associate Faculty member Matthew Johnson and his team are looking for clues for the existence of multiverses (a.ka. parallel universes) in the cosmic microwave background data, assumed to be left over from the Big Bang.

To do that, “we simulate the whole universe,” he says, but only on the largest scales. “We start with a multiverse that has two bubbles in it, we collide the bubbles on a computer to figure out what happens, and then we stick a virtual observer in various places and ask what that observer would see from there.”

For example, if another universe had collided with ours in the early universe, it would have left evidence in the form of a  “a disk on the sky,” creating a “bruise” in the pattern, he says. That the search for such a disk has so far come up empty makes certain collision-filled models less likely.

Hypothesized disks in the cosmic microwave background (CMB) from the early universe, indicating that another bubble universe had collided with our universe (credit: Perimeter Institute)

Meanwhile, the team is at work figuring out what other kinds of evidence a bubble collision might leave behind. It’s the first time, the team writes in their paper, that anyone has produced a direct quantitative set of predictions for the observable signatures of bubble collisions. And though none of those signatures has so far been found, some of them are possible to look for.

The real significance of this work is as a proof of principle: it shows that the multiverse can be testable. In other words, if we are living in a bubble universe, we might actually be able to tell.

Perimeter Institute | Perimeter Associate Faculty member Matthew Johnson explains
the related concepts of inflation, eternal inflation, and the multiverse.

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Abstract of Journal of Cosmology and Astroparticle Physics paper
The theory of eternal inflation in an inflaton potential with multiple vacua predicts that our universe is one of many bubble universes nucleating and growing inside an ever-expanding false vacuum. The collision of our bubble with another could provide an important observational signature to test this scenario. We develop and implement an algorithm for accurately computing the cosmological observables arising from bubble collisions directly from the Lagrangian of a single scalar field. We first simulate the collision spacetime by solving Einstein’s equations, starting from nucleation and ending at reheating. Taking advantage of the collision’s hyperbolic symmetry, the simulations are performed with a 1+1-dimensional fully relativistic code that uses adaptive mesh refinement. We then calculate the comoving curvature perturbation in an open Friedmann-Robertson-Walker universe, which is used to determine the temperature anisotropies of the cosmic microwave background radiation. For a fiducial Lagrangian, the anisotropies are well described by a power law in the cosine of the angular distance from the center of the collision signature. For a given form of the Lagrangian, the resulting observational predictions are inherently statistical due to stochastic elements of the bubble nucleation process. Further uncertainties arise due to our imperfect knowledge about inflationary and pre-recombination physics. We characterize observational predictions by computing the probability distributions over four phenomenological parameters which capture these intrinsic and model uncertainties. This represents the first fully-relativistic set of predictions from an ensemble of scalar field models giving rise to eternal inflation, yielding significant differences from previous non-relativistic approximations. Thus, our results provide a basis for a rigorous confrontation of these theories with cosmological data.

References:

• Carroll L. Wainwright et al., Simulating the universe(s): from cosmic bubble collisions to cosmological observables with numerical relativity, Journal of Cosmology and Astroparticle Physics, 2014, doi:10.1088/1475-7516/2014/03/030

World first: Australian solar plant has generated “supercritical” steam that rivals fossil fuels’

World first: Australian solar plant has generated “supercritical” steam that rivals fossil fuels’

 

ScienceAlert Staff

Original Link:  http://pda.sciencealert.com.au/news/20140506-25618.html 

 

Thursday, 05 June 2014

A CSIRO test plant in Australia has broken a world record and proved solar power could efficiently replace fossil fuels.

Image: CSIRO

 

A solar thermal test plant in Newcastle, Australia, has generated “supercritical” steam at a pressure of 23.5 MPa (3400 psi) and 570°C (1,058°F).

CSIRO is claiming it as a world record, and it’s a HUGE step for solar thermal energy.
"It's like breaking the sound barrier; this step change proves solar has the potential to compete with the peak performance capabilities of fossil fuel sources," Dr Alex Wonhas, CSIRO’s Energy Director, told Colin Jeffrey for Gizmag.

The Energy Centre uses a field of more than 600 mirrors (known as heliostats) which are all directed at two towers housing solar receivers and turbines, Gizmag reports.
This supercritical steam is used to drive the world’s most advanced power plant turbines, but previously it’s only been possible to produce it by burning fossil fuels such as coal or gas.

"Instead of relying on burning fossil fuels to produce supercritical steam, this breakthrough demonstrates that the power plants of the future could instead be using the free, zero emission energy of the sun to achieve the same result,” Dr Wonhas explained.

Image: CSIRO

Currently, commercial solar thermal or concentrating solar power power plants only operate a “subcritical” levels, using less pressurised steam. This means that they’ve never been able to match the output or efficiency of the world’s best fossil fuel power plants - until now.

The commercial development of this technology is still a fair way off, but this is an important first step towards a more sustainable future.

Watch the video to see the plant in action.
https://www.youtube.com/watch?feature=player_embedded&v=RAqd1MuoLo8

A new feathered dinosaur suggests that most dinosaurs had feathers

 

Jul 28, 2014

Original link:  https://richarddawkins.net/2014/07/a-new-feathered-dinosaur-suggests-that-most-dinosaurs-had-feathers/              

 

By Why Evolution Is True

What better evidence that birds arose from dinosaurian reptiles than the discovery of a fossil with both scales and feathers? Further, the fossil comes from the right time period: after reptiles had already evolved but before we see modern flying birds with fully-developed feathers.

 

Of course, we already knew that birds are the only living descendants of dinosaurs—some biologists classify them as dinosaurs—but as we go earlier and earlier back into the evolution of dinos, we’re beginning to find that many, perhaps most, had feather-like structures. That is what we call a “preadaptation”—a feature that could be co-opted later for a different useful function: in the case of birds, gliding and then flight. (“Preadaptations,” of course, didn’t evolve because they’d be useful in the future, for natural selection doesn’t anticipate future needs; it produces features that enhance reproduction in the here and now. But those features can be hijacked for other things later, like penguins’ vestigial wings that became modified for swimming.)

 

The earliest feathers, as we’ll see on the specimen I’ll show shortly, are small, filamentous structures that occur along with scales. They were of no possible use for flying or gliding, but they wouldn’t evolve unless they enhanced the animal’s reproduction (or its proxy, survival). What were they for? The authors of the paper we’re discussing today suggest this (my emphasis):

Here we report a new ornithischian dinosaur, Kulindadromeus zabaikalicus, with diverse epidermal appendages, including grouped filaments that we interpret as avianlike feathers. This suggests that all Dinosauria could have had feathers and that feathers arose for purposes of insulation and signaling and were only later co-opted for flight.

So what is the finding? The researchers found a 150 million-year-old fossil of an ornithischian dinosaur in Siberia. The beast was about 1.5 meters long (4.5 feet), so it wasn’t large. The important thing is that it was an ornithischian dinosaur rather than a theropod dinosaur, and (I’m going from memory here) all of the decently-preserved feathered dinosaurs that were found previously were theropods. Although there were earlier suggestions that some ornithischians had feather-like structures, the preservation was not nearly as good as that in the new fossil.

 

The finding is important because ornithischians are in a completely different evolutionary group from theropods, which were saurischians. The former were herbivores and had hips like birds. “Ornithischian” means “bird-hipped,” even though, confusingly, modern birds descended from the othergroup, the theropods, a carnivorous subgroup of the saurischians. (“Saurishian” means “lizard-hipped.”)

 

Here’s the dinosaur family tree showing the two different groups and their difference in skeletal morphology. Note that birds (“Aves”) are descended from theropods:

Now if both sauriscians and ornithschians were feathered, that means either that both groups evolved feathers independently, or that they inherited feathers (probably rudimentary filaments that later evolved into full plumage) from their common ancestor. The latter possibility is more likely given the probable developmental complexity of feathers. But even if feather evolution was independent in the two groups, it still suggests thatmost dinosaurs, not just the theropods whose descendants became birds, had feathers. T. rex (a theropod) could have been covered in down!

But let’s back up and see the details. The new report in Science by Pascal Godefroit et al. (reference and link below, no free download) reports the finding of feather and scale impressions on an ornithischian dinosaur they named Kulindadromeus zabaikalicus (there were actually six skulls and many bones).  The source of the name and conditions of preservation are given by the lead author in a “news and views”-type piece in National Geographic:

The dinosaur’s name essentially means “Kulinda River running dinosaur.” Zabaikalsky Krai is the region of Siberia where it was discovered (which explains its species name,zabaikalicus).

“There were lakes and there were volcanoes there, lots of volcanoes,” Godefroit says. The plant-eating dinosaurs likely died and fell to the lake bottom, where eruptions soon after covered them with a fine ash. That is what preserved the feather imprints with the fossil bones.

“We don’t know how big this fossil bed is, and it is likely we will find more when we go back,” Godefroit says.

The authors of the paper were working in four countries—Russia, Ireland, Belgium, and the UK—showing once again the international character of science. Since I’d like the readers to be able to read at least parts of scientific papers, I’ll put the paper’s abstract below, which is not too technical:

Abstract:

Middle Jurassic to Early Cretaceous [JAC: the Cretaceous went from 145 million years ago to 66 million years ago] deposits from northeastern China have yielded varied theropod dinosaurs bearing feathers. Filamentous integumentary structures have also been described in ornithischian dinosaurs, but whether these filaments can be regarded as part of the evolutionary lineage toward feathers remains controversial. Here we describe a new basal neornithischian dinosaur from the Jurassic of Siberia [JAC: the Jurassic was earlier, from about 201 to 145 million years ago] with small scales around the distal hindlimb, larger imbricated scales around the tail, monofilaments around the head and the thorax, and more complex featherlike structures around the humerus, the femur, and the tibia.The discovery of these branched integumentary structures outside theropods suggests that featherlike structures coexisted with scales and were potentially widespread among the entire dinosaur clade; feathers may thus have been present in the earliest dinosaurs.

Green Groups Go To War On Scientific Reform In Europe

By Trevor Butterworth

Original Link:  http://www.forbes.com/sites/trevorbutterworth/2014/07/30/green-groups-go-to-war-on-scientific-reform-in-europe/

 

It is, perhaps, not the best of times for Greenpeace. Many of its supporters are angered at the revelation that a senior executive has been commuting some 500 miles roundtrip to work by plane, which makes a mockery of the group’s campaign to reduce our collective carbon footprint; and there is now revolt inside the organization with over 40 staff signing a letter calling on Pascal Husting, the executive in question, to resign. “If you keep your position… we cannot repair our loss of credibility,” said the letter, published in the Dutch paper Volkskrant. “If Greenpeace does not walk the talk, why should others do so?”

It’s a fair point. “Do as I say, but not as I do” is the most visceral of all hypocrisies, while commuting to work by plane is such an unambiguous excess it can jolt even those weary of climate change and its discontents. Nor did it matter that one might be able to forgive Husting his predicament: a new job but no easy way to get there until he could move his family; once the detail emerged in a story about financial mismanagement in the Guardian newspaper (millions lost in currency trading), Greenpeace’s critics had a symbol and a cudgel.

But all of this is a distraction from a much more unpleasant and significant hypocrisy, which Greenpeace has signed onto, along with eight other environmental groups: a campaign to abolish the position of Chief Scientific Advisor to the President of the European Commission.

The position was created in 2011, and filled by Anne Glover, Chair in Molecular and Cell Biology at the University of Aberdeen, and former chief scientific advisor to Scotland. Glover told a recent meeting in Europe (as reported by the news site EurActive) that she only agreed to accept the position if she was given complete independence from political concerns in order to focus on the evidence, which was agreed.

But in assessing how scientific evidence drives European policy making in general, she found that it was often subordinated to the political imperative—find me the evidence to support my great policy idea!—and, as a consequence, became prey to confirmation bias. You found or commissioned the science to support your position, not the other way around. As Glover saw it, there was little incentive to report back to a politician that the best available scientific evidence does not support your idea, your reasoning, your policy.

Left – Anne Glover, Chief Scientific Adviser to President Barroso; Giles Merritt, SDA Director. (Photo credit: Security & Defence Agenda)

 

So Glover proposed a reform plan that would have the Commission create a new system that would disconnect scientific research on questions of policy from the political imperative, while making the process completely transparent for everyone involved. The position of chief scientific advisor would evolve into an agency with the resources and protection to give evidence without fear or favor. If politicians still wanted to reject the advice, so be it; but they won’t be able to blame it on partial evidence—in both senses of the word. In a “painstaking” demonstration of walking the talk, Glover established a pan-European network of science advisors, which met for the first time in June.

What could be so wrong with this that environmental groups want to trash Glover and have her office abolished? She is “intransparent” (sic) in her advice to the President, their letter says. Well, that’s the way the job was set up, but now that she’s figured out how the whole system of scientific advice isn’t working in Europe, she appears to have a solution that places transparency at the center of evidence-based policy advice. Why not support that?

Glover’s position “concentrates too much influence in one person, and undermines in-depth scientific research and assessments carried out by or for the Commission directorates in the course of policy elaboration,” the petition continues. But she has identified a signal weakness in this process, while laying out a process that will expand the role of science. Glover is, in effect, arguing for the devolution of whatever power she has into an independent institution that can give much greater voice to the scientific consensus.

 

In short, this attack makes no sense—why would Greenpeace and the other environmental groups want to destroy someone who is proposing one of the most significant reform agendas in Europe, one that could liberate policy decisions from imperfect evidence and bias? Don’t they want science to be protected from political meddling and behind-the-scenes lobbying? In a rambling, appearance on BBC radio’s flagship news show, Today, Greenpeace UK’s Chief Scientist hedged, arguing for more transparency through a return to a pre-Scientific Advisor era, when there was less. We should, in other words, promote scientific transparency by destroying an office that has provided Europe with the best chance of getting it.

After such arguments, it is hard not to conclude that political self-interest is really at work here, given that the NGO petition ends with an attack on Glover for arguing that Genetically Modified Organisms (GMOs) are no more of a threat than conventionally bred plants. In that she is simply reflecting the position of numerous scientific academies, the American Association for the Advancement of Science, and the World Health Organization, one can only assume that Greenpeace assumes an independent scientific agency would do the same, and so make  environmental organizations’ lobbying on the issue that much more difficult. One can only wonder what would have happened had a coalition of pro-business groups demanded Glover’s head on the grounds that she believed climate change to be threat. Would Greenpeace concur on the same principles it now advances?

All of this underscores why, to the politician and lobbyist, science is often no more than an ally when convenient, and disposable when not. Evidence is simply a figure of speech rather than something that emerges from the scientific method. And this is why there has an impassioned response to Greenpeace’s letter from scientific organizations, scientists, teachers and students across Europe. As the counter petition from the British charity Sense About Science puts it “Policy makers or lobbyists who seek to remove scientists because they don’t like their findings or advice do so at the peril of their citizens.”

This is not just a European issue simply because policy decisions taken there have ramifications here and elsewhere; the complex problems we all face demand more evidence based policy analysis, not less. We all need more independent scientific advisors, not fewer—and certainly not zero. We all need more transparency—we need to know how the research was done, how it should be understood, and why it should command our reasoned consideration. Professor Glover is speaking to politicians and citizens everywhere; her voice needs to defended and amplified; her role expanded, not strangled.

Trevor Butterworth is in the process of launching Sense About Science USA

Is the Universe Unnatural?

July 19, 2014 Astrophysics
Original Link:  http://www.fromquarkstoquasars.com/is-the-universe-unnatural/
      

There is a question that is beginning to haunt the world of science; it’s been rearing its ugly head for the last several decades. The question is simply, “is the universe unnatural?”

As most of you are aware, particle physicists at the Large Hadron Collider (LHC) announced in July of 2012 that they had finally discovered the elusive Higgs boson – that discovery has since been confirmed. The confirmation of the Higgs’ existence was one of the greatest triumphs of science in 2012, confirming the nearly 50-year-old theory that aims to explain how elementary particles have mass. Arkani-Hamed from the Institute for Advanced Study explained, “the fact that it was seen more or less where we expected to find it is a triumph for the experiment, it’s a triumph for the theory, and it’s an indication that physics works.”

This discovery, however, was a double edged sword.

The Higgs has gotten all of the media attention; however, quantum theories also suggest that scientists should have found a host of other particles along with the Higgs in order to really show that the whole theory makes sense. Thus far, these particles haven’t been found. That might not sound like a big deal, but without these accompanying particles, using our current understandings of quantum theory, the Higgs’ mass in reality is exponentially different than what is predicted by the modified theories.

Image Credit: ATA Wolerian Walawski

Of course, something somewhere is wrong. It could be that we are missing a piece of the puzzle that allows a Higgs boson with a mass 126 giga-electron-volts to exist (in contrast to 10,000,000,000,000,000,000 giga-electron-volt Higgs our math currently says should exist due to its interactions with other particles), or it could be that somewhere our math is fundamentally wrong, or the universe could simply be unnatural.

“Naturalness” is a term coined by Albert Einstein, and it is used to describe the elegantly intricate laws of nature. In a natural universe, absolutely everything can be explained with the aid of mathematics. All of the constants of nature are refined by the physical laws of nature and the entire puzzle makes perfect sense. In a unnatural universe, the horrible idea that some of the fundamental laws of nature are an arbitrary byproducts of the random fluctuations in the fabric of spacetime becomes a reality.

The LHC has been nothing short of a revolutionary force in advancing our understanding of the cosmos. Many times, revolutionary understandings present uncomfortable truths; because the LHC did not find the particular zoo of particles scientists were looking for, it’s forcing a large number of physicists to grapple with the idea of an unnatural universe. Hope is not lost for a natural order though. The LHC will start smashing protons together again in 2015 in a final search for answers and naturalness. If the search turns up empty handed, what will happen then?

Image Credit: XKCD

Firstly, it’s very probable that the multiverse theory will take center stage as one of the most plausible models explaining our universe. If the universe is unnatural, and contains arbitrary constants that allow for conditions in our universe perfect for life to arise, physicists reason that, in order to balance out the improbability of such a universe, there must be other universes with differing laws of physics. One such hypothesis containing a multiverse construct, string theory, theorizes about 10^500 multiverses exist. With so many universes, it is extremely likely that this random chance would eventually produce a life-favoring universe, and the rest is history.

String theory is an extremely polarizing hypothesis. You either love it or hate it. Edward Witten, also a physicist at the Institute of Advanced Study, said, “I would be personally happy if the multiverse interpretation is not correct, in part because it potentially limits our ability to understand the laws of physics.”

All of the weight of what happens next rests with the scientists at the LHC. Whatever they find (or, don’t find) in the next decade will fundamentally shape our understanding of absolutely everything.
Scientists will probe the very heart of physics in an attempt to determine whether we live in an overly complicated standalone universe or if we simply exist in a very friendly bubble in a larger multiverse.
In case the doors of unnaturalness and naturalness both seem unfavorable, some physicists have envisioned a third door for a modified naturalness. The main proponents of this model are Joe Lykken of the Fermi National Accelerator Laboratory in Batavia, Illinois and Alessandro Strumia of the University of Pisa in Italy. The basic premise of this hypothesis suggests that scientists are misjudging the affects of other particles on the mass of the Higgs boson. Their idea is far from airtight, when additional particles are thrown in, such as dark matter, the model falters.

Image source

Strumia has said that he isn’t an advocate of the modified naturalness hypothesis, but he wants to open a discussion for the consequences of such a theory. Even though it has problems now, the same line of thinking could help to resolve some of the problems of seemingly arbitrary constants. Modified naturalness, and naturalness for that matter, has a much larger problem standing in the way.
Neither can adequately explain why the universe didn’t annihilate itself in the big bang.
Is the universe natural, unnatural, or does it have a modified naturalness? The most exciting thing about that question is that we are on the brink of having an answer. Whether the answer is comfortable or uncomfortable, pleasant or unpleasant, desirable or undesirable, we are poised to head into a new era of scientific understanding.

Breakthrough Material Could Cut the Cost of Solar Energy in Half

by Orion D. Jones

July 30, 2014, 2:46 PM

What's the Latest?

Renewable energy startup Glint Photonics has created a new material that, when used to cover photovoltaic cells on solar panels, can capture more energy with less infrastructure, greatly reducing the total cost of harvesting the sun's power. By changing its reflectivity in response to heat from concentrated sunlight, the material can gather in light that comes in from different angles throughout the day. Currently, directing sunlight onto the most absorbent part of solar cells requires lenses or mirrors supported by concrete and steel "which must be moved precisely as the sun advances across the sky to ensure that concentrated sunlight remains focused on the cells." That added infrastructure quickly runs up the costs for renewable energy plants.

What's the Big Idea?

Here's how Glint's device works using two essential parts: "The first is an array of thin, inexpensive lenses that concentrate sunlight. The second is a sheet of glass that serves to concentrate that light more—up to 500 times—as light gathered over its surface is concentrated at its edges." As the day goes on, the angle of the incoming light shifts and the material adapts, allowing light in only at the most direct angle, trapping the light beneath the edges of the material until it can be absorbed. The company says its material could produce electricity at four cents per kilowatt-hour, compared to eight cents for the best conventional solar panels.

Read more at Technology Review

Photo credit: Shutterstock

by Orion D. Jones