Science and Reason: Selected reading 12/2/09

Interesting reading and news items.

These items are also bookmarked at my Diigo account.

In the Brain, Seven Is A Magic Number: Countless psychological experiments have shown that, on average, the longest sequence a normal person can recall on the fly contains about seven items. This limit, which psychologists dubbed the "magical number seven" when they discovered it in the 1950s, is the typical capacity of what's called the brain's working memory. Now physicists have come up with a model of brain activity that seems to explain the reason behind the magical memory number. [Inside Science News Service, 11/23/09]
Computers Faster Only for 75 More Years? Physicists determine nature's limit to making faster processors: A pair of physicists has shown that computers have a speed limit as unbreakable as the speed of light. If processors continue to accelerate as they have in the past, we'll hit the wall of faster processing in less than a century. [Physorg.com, 10/14/09]
Black Hole Caught Zapping Galaxy into Existence?: Which come first, the supermassive black holes that frantically devour matter or the enormous galaxies where they reside? A brand new scenario has emerged from a recent set of outstanding observations of a black hole without a home: black holes may be “building” their own host galaxy. This could be the long-sought missing link to understanding why the masses of black holes are larger in galaxies that contain more stars. [European Southern Observatory, 11/30/09]
Cosmic "Dig" Reveals Vestiges of the Milky Way's Building Blocks: A team of astronomers has unveiled an unusual mix of stars in the stellar grouping known as Terzan 5. Never observed anywhere in the bulge before, this peculiar "cocktail" of stars suggests that Terzan 5 is in fact one of the bulge's primordial building blocks, most likely the relic of a proto-galaxy that merged with the Milky Way during its very early days. [European Southern Observatory, 11/25/09]
Watching a Cannibal Galaxy Dine: A new technique using near-infrared images, obtained with ESO’s 3.58-metre New Technology Telescope (NTT), allows astronomers to see through the opaque dust lanes of the giant cannibal galaxy Centaurus A, unveiling its “last meal” in unprecedented detail — a smaller spiral galaxy, currently twisted and warped. [European Southern Observatory, 11/20/09]
Ticking Stellar Time Bomb Identified: Astronomers have made the first time-lapse movie of a rather unusual shell ejected by a “vampire star”, which in November 2000 underwent an outburst after gulping down part of its companion’s matter. This enabled astronomers to determine the distance and intrinsic brightness of the outbursting object. It appears that this double star system is a prime candidate to be one of the long-sought progenitors of the exploding stars known as Type Ia supernovae, critical for studies of dark energy. [European Southern Observatory, 11/17/09]
Astronomers seek to explore the cosmic Dark Ages: Astronomers call it the Dark Ages, and now they're building huge new radio telescopes with thousands of detectors that they hope will let them peer back into the period, when the first stars and galaxies began turning on their lights. [Physorg.com, 10/15/09]
Intergalactic Controversy: New observations of galactic clusters have revealed a controversial phenomenon called “dark flow,” which could be a sign of parallel universes. [Seed Magazine, 12/2/09]