June 3rd, 2010

[META] Apologies re: "Reflections"

I'd like to apologize for my uncritical link to Robert Silverberg's essay on the shortages of different elements. As any number of commenters at james_nicoll's blog pointed out, and as many commenters here pointed out, it's quite possible to economically extract the different metals Silverberg cites, like gallium, affordably with relatively little effort. All the commenters link to different credible sources, but I'd like to point out this post by Dreamwidth's mishalak for pointing out the basic flaws in Silverberg's assumption about prices and usage.

I'm sorry for not being adequately critical of the essay. Whenever I blog, I try to blog smartly and accurately, describing subjects of interest. All that I can say by way of defense is that I'm sorry this happened, and that I'll not let it happen again.


[LINK] "Unearthed Trash at Jamestown Reveals Tough Times for Settlers"

I've at least two Virginians who may be interested in this Wired Science report, which confirms via material evidence that the inhabitants of the pioneering settlement of Jamestown had it quite, quite rough: a devastating drought ravaged also ravaged their settlement, in addition to disease.

Oyster shells excavated from a well in Jamestown, Virginia, the first permanent British settlement in North America, bolster the notion that the first colonists suffered an unusually deep and long-lasting drought.

The shells reveal that water in the James River near the colony, where many of those oysters were harvested, was much saltier then than along that stretch of the estuary today, says Howard Spero, a geochemist at the University of California, Davis. For the water to have been so brackish, river flow must have been slacker compared to today, a sign that precipitation was dramatically lower when those oysters were growing. Spero and his colleagues report their findings online May 31 in the
Proceedings of the National Academy of Sciences.

Jamestown was established in 1607. The early years weren’t easy: Many accounts of Jamestown’s early settlers, including journal entries and letters home, chronicled the drought. So did the region’s trees, Spero says. Previous studies based on tree rings and original documents revealed that the first colonists’ arrival coincided with the beginning of a drought that included the driest seven-year interval in almost 800 years.

“It was interesting trying to figure out what was happening in the colony at a time when 70 to 80 percent of the colonists were dying,” Spero says. “This was ‘CSI Jamestown’.”

Now, oysters independently confirm the tale from trees and historical accounts, comments William M. Kelso, an archaeologist at Preservation Virginia’s Jamestown Rediscovery project who was not involved in the study. “We’re getting a consistent story from science and the humanities,” he notes. “It’s pretty fantastic.”

[LINK] "Will California Be the First State to Ban the Plastic Shopping Bag?"

Toronto started charging five cents per plastic bag a year ago, and I have coped very well. Then again, I used reusable bags long before then, it didn't mind extra payment. I still use them after I'm done of them to line garbage cans and the like. California going the same route would obviously have a greater impact than mere subprovincial Toronto.

Previously, California’s fight over banning plastic bags at the state level had bogged down into a predictable back-and-forth: Green groups cited the 19 million plastic bags Californians use every year, most of which don’t get recycled, while plastic industry people complained that such a rule is just a tax. The breakthrough, though, came when the California Grocers Association, led by David Heylen, decided it wanted the ban.

Cities such as San Francisco and Oakland already have bans, and 20 other California municipalities are considering similar laws. Heylen said there was a growing concern among grocery chains that a patchwork of laws would be untenable. Another important change was that the bill covered not just supermarkets but convenience stores and smaller markets [San Diego Union-Tribune].

The bill could go to the California Senate this year. Bot one thing that remains to be decided: If grocers charge more than 5 cents for a paper bag, where will the extra money go? It makes sense to offer a financial deterrent if you want people to use less plastic, as only so many people are going to buy reusable bags out of the goodness of their hearts (or to be more eco-conscious than their friends). But the San Diego Union-Tribune says that the money isn’t directed to particular recycling or other environmental programs, and grocers could charge more than the nickel per bag and pocket the difference.

Here in Toronto, the retailers can spend the five cents earned per bag on whatever they want, notwithstanding official encouragement to spend it on green causes.

[LINK] "Snails on Meth Have Sharper Memories"

"Blink," I say, "blink."

During the experiment, Sorg and colleagues put aquatic snails in tanks, some of which contained meth-laced water, and some that that contained regular water. As aquatic creatures, the snails breathe mostly through their skins, but will extend air tubes above the water's surface when oxygen is scarce.

Low-oxygen levels in the water caused the snails to extend their tubes. The researchers poked the tubes with sticks, irritating the animals, thus training them not to extend their tubes.

Snails not exposed to meth seemed to retain long-term memories of the "training" for only a few hours, at which point they would start raising their tubes again.

But snails exposed to meth recalled the poking more than 24 hours later and kept their tubes closed.

It isn't a total surprise that such "meth memories" persist, said Sorg, whose research appeared May 28 in the
Journal of Experimental Biology.

"Amphetamines are given to humans for the purpose of focusing attention," she explained. "Ritalin, for example, is an amphetamine derivative given for treatment of ADHD."

Sorg goes on to suggestion that this research, depending on snail brains though it might, could help provide useful information on treating addictions among human beings.

[LINK] "iPad to help humans speak with dolphins"

When I visited Toronto's Carbon Computing this afternoon with talktooloose, I saw my first iPad. I'm not a particular fan of Apple: apart from its restrictive, manipulative treatment of intellectual property, my Windows-based computer works just fine, thank you very much. Still, I was impressed by the iPad's elegant aesthetics and its power; I can see why some people would find it quite useful, and enjoyable. Ours isn't the only species that can find it useful.

Dolphin researcher Jack Kassewitz is using an iPad loaded with apps, some custom-built, to interact with a 2-year-old dolphin named Merlin — the first steps toward creating what Kassewitz calls a symbolic language, one that will not only allow humans and dolphins to interact more easily but also potentially lead to a universal translator for humans.

“For several years, we’ve recognized that part of the problem in creating an artificial language between humans and dolphins has been the speed of acquisition of the human brain; it’s just not up to competing (with that of the dolphin),” said Kassewitz, president of Global Heart, a non-profit firm heading up the dolphin research.

The dolphin’s “acoustic range is so broad and ours is so limited, and our speed to react to their sound is so slow, I think we were just plain boring,” Kassewitz said.

Kassewitz turned to computer hardware, which can process information much faster than the human brain, special software for recording real-time data, and underwater microphones.

[. . .]

Kassewitz chose the iPad because it’s lightweight and touch sensitive. The other key advantage: The iPad is fast, thanks to Apple’s A4 CPU, and has lots of apps — including SignalScope, which turns the iPad into a high-tech oscilloscope for capturing recorded sound.

To make it dolphin-friendly, the iPad was encased in a waterproof bag called the Waterwear, a transparent, plastic casing made by Tokyo-based Tunewear, and given a yellow border, which Merlin seems to like.

[LINK] "What is Consuming Hydrogen and Acetylene on Titan?"

It's probably not life, but it could be.

[Scientist Darrell] Strobel found a disparity in the hydrogen densities that lead to a flow down to the surface at a rate of about 10,000 trillion trillion hydrogen molecules per second. This is about the same rate at which the molecules escape out of the upper atmosphere.

"It's as if you have a hose and you're squirting hydrogen onto the ground, but it's disappearing," Strobel said. "I didn't expect this result, because molecular hydrogen is extremely chemically inert in the atmosphere, very light and buoyant. It should 'float' to the top of the atmosphere and escape."

Strobel said it is not likely that hydrogen is being stored in a cave or underground space on Titan. The Titan surface is also so cold that a chemical process that involved a catalyst would be needed to convert hydrogen molecules and acetylene back to methane, even though overall there would be a net release of energy. The energy barrier could be overcome if there were an unknown mineral acting as the catalyst on Titan's surface.

The hydrocarbon mapping research, led by Roger Clark, a Cassini team scientist based at the U.S. Geological Survey in Denver, examines data from Cassini's visual and infrared mapping spectrometer. Scientists had expected the sun's interactions with chemicals in the atmosphere to produce acetylene that falls down to coat the Titan surface. But Cassini detected no acetylene on the surface.

In addition Cassini's spectrometer detected an absence of water ice on the Titan surface, but loads of benzene and another material, which appears to be an organic compound that scientists have not yet been able to identify. The findings lead scientists to believe that the organic compounds are shellacking over the water ice that makes up Titan's bedrock with a film of hydrocarbons at least a few millimeters to centimeters thick, but possibly much deeper in some places. The ice remains covered up even as liquid methane and ethane flow all over Titan's surface and fill up lakes and seas much as liquid water does on Earth.

"Titan's atmospheric chemistry is cranking out organic compounds that rain down on the surface so fast that even as streams of liquid methane and ethane at the surface wash the organics off, the ice gets quickly covered again," Clark said. "All that implies Titan is a dynamic place where organic chemistry is happening now."

This organic chemistry is likely not life, but it could be, and regardless of what's there the chemistry of Titan is certainly interesting.