Selected readings 4/3/10

Interesting reading and news items.

These items are also bookmarked at my Diigo account.

Out There: A Strange Zoo of Other Worlds

More than 400 worlds have been found beyond the reach of our sun, and the tally is rising rapidly. From super-Earths to giants dwarfing Jupiter, our galaxy is a zoo of different kinds of planets. [Space.com, 2/14/10]

Detecting Our Martian Cousins

The iguanas of the Galapagos Islands have evolved many unique characteristics due to their isolation from mainland iguanas. Because they can't swim long distances, biologists believe that the first Galapagos iguanas arrived on natural rafts made from vegetation. The same thing may have happened across the ocean of space. Some researchers speculate that life on Mars - if there is any - may be composed of "island species" that were carried away from Earth on interplanetary meteorites. [Physorg.com, 2/15/10]

The rhythm of our star

When we look at the Sun we cannot penetrate beyond its outer surface, the photosphere, which emits the photons that make up the radiation we can see. So how can we find out what is inside it? [Physorg.com, 2/15/10]

‘X-woman’ challenges out-of-Africa theory

DNA from a female of previously unknown hominid – dubbed the X-woman – lived in southern Siberia some 40,000 years ago and could be a new branch on the human family tree, a finding that would rewrite Homo's exodus from Africa. [Cosmos, 3/25/10]

Is this a new species of human being?

Scientists have extracted DNA from a bone discovered in Siberia that almost certainly belongs to a new kind of human – one that may have lived as recently as 30,000 years ago. Will this transform our views of human evolution? [Guardian, 3/26/10]

Near-threshold computing could enable up to 100x reduction in power consumption

While electronic devices have greatly improved in many regards, such as in storage capacity, graphics, and overall performance, etc., they still have a weight hanging around their neck: they’re huge energy hogs. When it comes to energy efficiency, today’s computers, cell phones, and other gadgets are little better off than those from a decade ago, or more. [Physorg.com, 2/17/10]

Rock climber takes on surfer's theory

The “exceptionally simple theory of everything,” proposed by a surfing physicist in 2007, does not hold water, says Emory mathematician Skip Garibaldi. Garibaldi, a rock climber in his spare time, did the math to disprove the theory, which involves a mysterious structure known as E8. [eScienceCommons, 3/18/10]

Nasa rides 'bucking bronco' to Mars

It weighs almost a tonne, has cost more than $2bn and, in 2013, it will be lowered on to the surface of Mars with a landing system that has never been tried before. The Mars Science Laboratory will "revolutionise investigations in science on other planets", says Doug McCuistion, director of Nasa's Mars exploration programme. [BBC News, 2/17/10]

Primordial giant: The star that time forgot

If the original conditions of the universe were preserved in these dwarf galaxies, there would be no reason why further waves of megastars should not continually form and die within them throughout cosmic time. If it is the absence of metals that determines stellar size, behemoth stars are not restricted to the furthest reaches of the universe: they could be found in any dwarf galaxy with a low enough metal content, including places well within reach of our telescopes. It is a line of reasoning that the identification of SN 2007bi now seems to support in spectacular fashion. [New Scientist, 2/15/10]

Do-It-Yourself Genetic Engineering

The first thing to understand about the new science of synthetic biology is that it’s not really a new science; it’s a brazen call to conduct an existing one much more ambitiously. For almost 40 years, genetic engineers have been decoding DNA and transplanting individual genes from one organism into another. [New York Times, 2/10/10]

The writing on the cave wall

What emerged was startling: 26 signs, all drawn in the same style, appeared again and again at numerous sites (see illustration). Admittedly, some of the symbols are pretty basic, like straight lines, circles and triangles, but the fact that many of the more complex designs also appeared in several places hinted to von Petzinger and Nowell that they were meaningful - perhaps even the seeds of written communication. [New Scientist, 2/17/10]

Comet crash creates potential for life

Striking a glancing blow to a planet could create the perfect conditions in a comet's icy core to create amino acids — molecules that are vital to forming life on Earth. [Nature News, 3/26/10]

Scientists supersize quantum mechanics

A team of scientists has succeeded in putting an object large enough to be visible to the naked eye into a mixed quantum state of moving and not moving. [Nature News, 3/17/10]

Everything you ever wanted to know about particle smashers (but were afraid to ask)

On March 30th, humanity is scheduled to start running the biggest, baddest particle collider ever constructed, the one that makes its closest competitor, Fermi's Tevatron, so out-of-date that the current plan is simply to shut the Tevatron down. But Brookhaven's RHIC, which can't even reach the Tevatron's energies, will be kept running indefinitely. [Nobel Intent, 3/28/10]

Evolution: Revenge of the hopeful monster

Experiments have revealed how single mutations can have huge effects that drive evolution. But small steps pave the way. [Nature News, 2/17/10]

Astronomy: The decadal dinner club

As hundreds of US astronomers draft their latest decadal wish list of new projects, Nature took a short-cut by convening a small survey around a dinner table. [Nature News, 2/17/10]

What Is Time? One Physicist Hunts for the Ultimate Theory

One way to get noticed as a scientist is to tackle a really difficult problem. Physicist Sean Carroll has become a bit of a rock star in geek circles by attempting to answer an age-old question no scientist has been able to fully explain: What is time? [Wired, 2/26/10]

Physicists look for the arrow of time, biologists find it

Carroll set up the problem by noting that, based on thermodynamics alone, we shouldn't expect that the Universe should be anything more than a momentary dip from maximum entropy. Unfortunately, that means that anything outside of the room we're in, and all of past history, is likely to be unreliable, an illusion of our specific entropy dip. We avoid this thermodynamic awkwardness because the big bang provides us with a low entropy boundary state. [Nobel Intent, 3/1/10]

Earth science: The climate machine

A new generation of sophisticated Earth models is gearing up for its first major test. But added complexity may lead to greater uncertainty about the future climate. [Nature News, 2/24/10]

Life beyond our universe: Physicists explore the possibility of life in universes with laws different from our own

Whether life exists elsewhere in our universe is a longstanding mystery. But for some scientists, there?s another interesting question: could there be life in a universe significantly different from our own? A definitive answer is impossible, since we have no way of directly studying other universes. But cosmologists speculate that a multitude of other universes exist, each with its own laws of physics. Recently physicists at MIT have shown that in theory, alternate universes could be quite congenial to life, even if their physical laws are very different from our own. [Physorg.com, 2/22/10]

Dopamine and Obesity: The D2 Receptor

Dopamine is a signaling molecule known as a neurotransmitter, which is released from one neuron and binds to receptors on another neuron to produce effects. There are two major classes of receptors which bind dopamine (called dopamine receptors, obviously), the D1 like and the D2 like. Both types of dopamine receptors are very important in addiction related stuff. [Neurotopia, 4/1/10]

Cognition Without Control

In "Cognition Without Control: When a Little Frontal Lobe Goes a Long Way," neuroscientist Sharon Thompson-Schill argues that kids' inability to filter out distractions is a good thing. In fact, she argues, it's precisely what makes them such prodigious learners of language. Written with a scientist from Stanford and a postdoc from her lab and published in Current Directions in Psychological Science, the paper looks at how immature, driven-to-distraction brain structures make possible the learning of complex social and linguistic conventions. [Physorg.com, 2/24/10]

On the hunt of what makes all of us recoil

The pungent sting of wasabi, the searing pain of tear gas, and the watery eyes we get from chopping an onion are all triggered by an ancient chemical sensor that is found in everything from humans to mollusks and may hold the key to developing new kinds of insect repellents and pain medications. Research by Brandeis University scientists finds that the ability to detect noxious compounds comes from a biological pathway older than our sense of smell, emerging far in the evolutionary past, about half a billion years ago. ... The sensor’s ubiquity and stability suggested it does something essential for the survival of animals, but what? [Boston.com, 3/29/10]

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