Posts Tagged ‘science’
[LINK] “Fish farming tops beef production in race to the plate”
Aquaculture isn’t of the future, the CBC notes; it’s an increasingly dominant reality.
The human diet appears to have reached an important milestone, as worldwide fish farm production has surpassed beef production for the first time in the modern era.
[. . .]
The UN’s Food and Agriculture Organization estimates that fish farm production has grown by six times over the last 20 years.
[. . .]
Everything from fish to seaweed and shellfish is farmed today. And not surprisingly, China leads the world in aquaculture.
“I think farmed fish will be part of the answer in terms of food supply,” said Janet Larsen, research director with the Earth Policy Institute in the U.S.
Aquaculture is the least energy-intensive means of producing animal protein, but not all fish farms are created equal, says Larsen.
Some threaten ecologically-sensitive areas while farming certain species, such as salmon, causes a drain on wild fish.
“We’re overfishing a lot of our smaller fish stocks like menhaden, herring or sardines so that we could grind them up into fish meal and fish oil to feed to these farmed fish,” she said.
Larsen predicts that, for the first time, more fish and seafood will be produced on farms this year than caught in the wild, meaning the need for sustainable aquaculture is greater than ever.
The website of the Food and Agriculture Organization has more.
[LINK] “Cloaking Device Makes a Cat Disappear”
Wired Science’s Nadia Drake writes about a new cloaking device.
Scientists in Singapore and China have crafted a cloaking device that works in natural light, and they’ve recorded videos of animals disappearing inside it. You wouldn’t want to wear it, though. The cloak is made from thin sheets of glass, and it doesn’t work from all angles.
This new device, described June 7 in a manuscript uploaded to arXiv.org, works by redirecting light waves around objects inside it. But unlike other recently described cloaking devices built from metamaterials — artificial materials with properties not found in nature — it’s made from a type of ordinary glass that bends and disperses light. Scientists reasoned that since human eyes cannot perceive light phase or polarization, it should be possible to achieve a cloaking effect without needing to keep redirected light waves in phase, which has been a challenge for other forms of cloaking.
Instead, ordinary materials arranged in clever ways should do the trick.
First, the team placed six thin pieces of glass inside a hollow, transparent hexagonal chamber. The result is a device with six-fold radial symmetry that will cloak an object from six different directions. To demonstrate its effectiveness, the team submerged the cloak in an aquarium — and watched as a goldfish disappeared as it swam through it while plants in the background remained visible.
Next, the team built a larger version of the device that could hide a cat. Unlike the hexagonal device, this cloak only shields an object from viewers directly in front of or behind it, as evidenced by bits of the curious cat disappearing while inside. Like the fish experiment, the cloak didn’t obscure the background, which in this case was a flowery scene projected onto the wall.
The cloak isn’t ready for prime time yet. In both environments — terrestrial and aquatic — the device itself is still partially visible, owing to the shadows it casts on the projected background and the bits of glue joining the glass with the container.
There are videos at the article.
[LINK] “New Physics Complications Lend Support to Multiverse Hypothesis”
This Scientific American article, by Natalie Wolchover and Simons Science News, makes the interesting case that the universe is just one of a near-infinitude, that our particular universe with its laws and contants is the product of not of inevitable things but of chance events. We’re just lucky enough to be living in one that supports our kind of life. (Others, committed to religious explanations of one type or another, might argue this is proof of some agency’s planning.)
With the discovery of only one particle, the LHC experiments deepened a profound problem in physics that had been brewing for decades. Modern equations seem to capture reality with breathtaking accuracy, correctly predicting the values of many constants of nature and the existence of particles like the Higgs. Yet a few constants — including the mass of the Higgs boson — are exponentially different from what these trusted laws indicate they should be, in ways that would rule out any chance of life, unless the universe is shaped by inexplicable fine-tunings and cancellations.
In peril is the notion of “naturalness,” Albert Einstein’s dream that the laws of nature are sublimely beautiful, inevitable and self-contained. Without it, physicists face the harsh prospect that those laws are just an arbitrary, messy outcome of random fluctuations in the fabric of space and time.
The LHC will resume smashing protons in 2015 in a last-ditch search for answers. But in papers, talks and interviews, Arkani-Hamed and many other top physicists are already confronting the possibility that the universe might be unnatural. (There is wide disagreement, however, about what it would take to prove it.)
“Ten or 20 years ago, I was a firm believer in naturalness,” said Nathan Seiberg, a theoretical physicist at the Institute, where Einstein taught from 1933 until his death in 1955. “Now I’m not so sure. My hope is there’s still something we haven’t thought about, some other mechanism that would explain all these things. But I don’t see what it could be.”
Physicists reason that if the universe is unnatural, with extremely unlikely fundamental constants that make life possible, then an enormous number of universes must exist for our improbable case to have been realized. Otherwise, why should we be so lucky? Unnaturalness would give a huge lift to the multiverse hypothesis, which holds that our universe is one bubble in an infinite and inaccessible foam. According to a popular but polarizing framework called string theory, the number of possible types of universes that can bubble up in a multiverse is around 10^500. In a few of them, chance cancellations would produce the strange constants we observe.
[LINK] “Haida group dumps man behind ocean fertilization”
The Globe and Mail‘s Mark Hume notes that the Haida organization involved in a recent controversial effort at geoengineering, dumping iron sulfate into the Pacific Ocean off the British Columbia coast in the aim of promoting plankton growth and thus absorbing carbon dioxide from the atmosphere, has fired Russ George, the man responsible for the decision. ((The Vancouver Sun has more, noting that apparently George disputes his firing.)
In a statement released on Thursday, Haida Salmon Restoration Corp. (HSRC) said it has “removed” Mr. George as a director of the company. “In addition, the HSRC has terminated Mr. George’s employment as an officer of the corporation,” it states.
Mr. George could not be reached for comment. The California businessman is a proponent of the theory that global warming can be blunted and ocean acidification stopped by fertilizing the ocean with iron.
The Haida organization made international headlines several months ago, when it dumped more than 100 tonnes of an iron substance into the ocean off Haida Gwaii in an attempt to stimulate plankton growth.
The HSRC hoped to recover its investment through increased salmon harvests and through selling carbon credits by demonstrating that the iron grew massive clouds of plankton that sucked CO2 out of the atmosphere.
But the experiment, which was not sanctioned by any official body and lacked the involvement of recognized ocean scientists, was widely condemned by researchers, the federal government and the United Nations.
[LINK] “World’s oldest water bubbling into Northern Ontario mine”
Postmedia’s Margaret Munro has a fascinating article recounting life-supporting veins of water buried for billions of years beneath the Canadian Shield that’s only now surfacing. The implications for geology, for the study of life on our planet and on others, are fascinating.
An international research team reported Wednesday that miners near Timmins are tapping into an ancient underground oasis that may harbour prehistoric microbes. The water flowing out of fractures and bore holes in one mine near Timmins dates back more than a billion years, perhaps 2.6 billion, making it the oldest water known to exist on Earth, says the team that details the discovery in the journal Nature.
“This is the oldest (water) anybody has been able to pull out, and quite frankly, it changes the playing field,” says geologist Barbara Sherwood Lollar, at the University of Toronto, who co-led the team.
[. . .]
Analyses of isotopes of the compounds and gases in the samples revealed the salty water, which sparkles as ancient gas bubbles out of it, has been trapped in the rocks between 1.5 and 2.64 billion years. The water also contains plenty of hydrogen, comparable to rates found on hydrothermal vents in the deep ocean, which can fuel microbial life.
The rocks in the mines near Timmins were created by a massive hydrothermal vent system on an ancient seafloor 2.7 billion years ago. Volcanic lava and sea sediments are stacked up in the rocks like a “layer cake,” says Sherwood Lollar. “When you go down in the mines you can see some of the pillow lavas structures still preserved in the rock.”
