Science & TechnologyS


Star

Best of the Web: Younger Dryas Cometary Impact AGU Press Conference, Acapulco, Mexico, May 23, 2007


Youtube
Wed, 04 Jul 2007 08:07 UTC
Investigations of a buried layer at sites from California to Belgium reveal materials that include metallic microspherules, carbon spherules, nanodiamonds, fullerenes, charcoal, and soot. The layer's composition may indicate that a massive body, possibly a comet, exploded in the atmosphere over the Laurentide Ice Sheet 12,900 years ago. The timing coincides with a great die-off of mammoths and other North American megafauna and the onset of a period of cooling in Northern Europe and elswhere known as the Younger Dryas Event. The American Clovis culture appears to have been dramatically affected, even terminated, at this same time. Speakers discuss numerous lines of evidence contributing to the impact hypothesis. The nature and frequency of this new kind of impact event could have major implications for our understanding of extinctions and climate change.

Part 1
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Magic Wand

Reciprocal altruism among rats

Jonathan M. Gitlin
ars technica
Wed, 04 Jul 2007 04:02 UTC
Rats in lab exhibit reciprocal altruistic behavior: more prone to help if they themselves received help before.
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Rocket

NASA Gives Two Successful Spacecraft New Assignments


PR Newswire
Wed, 04 Jul 2007 03:48 UTC
WASHINGTON -- Two NASA spacecraft now have new assignments after successfully completing their missions. The duo will make new observations of comets and characterize extrasolar planets. Stardust and Deep Impact will use their flight-proven hardware to perform new, previously unplanned, investigations.
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Magnify

Discovered Dodo DNA Delights!

Ed Harris
Reuters
Tue, 03 Jul 2007 23:18 UTC
Bois Cheri, Mauritius - The remains of a dodo found in a cave beneath bamboo and tea plantations in Mauritius offer the best chance yet to learn about the extinct flightless bird, a scientist said on Friday.

©na
What scientists assume a living Dodo looks like.

Comment: How ironic that scientists will have DNA with which to clone a new Dodo just in time for it to become extinct again.

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Star

Stellar fireworks through Hubble's eyes


ESA
Tue, 03 Jul 2007 14:35 UTC
Nearly 12.5 million light-years away, in the dwarf galaxy NGC 4449, stellar fireworks on display have been captured by the Hubble Space Telescope.

NGC 4449 belongs to a group of galaxies in the constellation Canes Venatici, 'the Hunting Dogs'. Astronomers think that NGC 4449's episode of star formation has been influenced by interactions with several of its neighbours. It is likely that the current widespread starburst was triggered by interaction or merger with a smaller companion.

The NASA/ESA Hubble Space Telescope's Advanced Camera for Surveys observed NGC 4449 in the visible (blue and green), infrared, and hydrogen-alpha regions of the spectrum.

Hundreds of thousands of vibrant blue and red stars are visible in this new image. Hot bluish white clusters of massive stars are scattered throughout the galaxy, interspersed with numerous dustier reddish regions where star formation is taking place. Massive, dark clouds of gas and dust are silhouetted against starlight.
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Coffee

Building found in China tomb


Herald Sun
Mon, 02 Jul 2007 17:09 UTC
The tomb of China's first emperor, guarded for more than 2000 years by 8000 terracotta warriors and horses, has yielded another archaeological secret.

Archaeologists have confirmed that a 30m-high building is buried in the vast mausoleum of Emperor Qinshihuang near the former capital, Xian.
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Magic Wand

Understanding Smooth Eye Pursuit - The Incredible Targeting System of Human Vision


UPENN
Mon, 02 Jul 2007 12:18 UTC
Researchers at the University of Pennsylvania have shed new light on how the brain and eye team up to spot an object in motion and follow it, a classic question of human motor control. The study shows that two distinctly different ways of seeing motion are used - one to catch up to a moving object with our eyes, a second to lock on and examine it.

"Without the ability to lock our eyes onto a moving target, something called smooth pursuit, athletes cannot 'keep their eye on the ball,' and a person walking down the street cannot examine the facial expression or identity of a passerby," said Jeremy Wilmer, postdoctoral fellow in the Department of Psychology in Penn's School of Arts and Sciences and lead author of the study.

Researchers found that volunteers showed a range of capabilities when it came to sensing and following motion, and the careful measurement of such differences produced novel insights into the workings of the smooth pursuit system.
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Network

Flashback Test run? Hackers target Internet's 13 root servers

James Simpson
Earthtimes.org
Wed, 07 Feb 2007 07:19 UTC
Hackers hit the heart of the Internet yesterday when they launched an attack on three of the 13 root servers that are responsible for directing all web traffic. The computers were disabled for 12 hours before resuming routine operations.

The hackers hit the UltraDNS company, which directs traffic to websites containing the .info and.org suffixes. The attacks went unnoticed for several hours because legitimate traffic remained unaffected.

Comment: New methodology? Unusually powerful attacks? No problem, if you have unlimited resources (of a secret intelligence service) at your disposal

;-)

Attack of the Bots - The New Internet Mafia, Latest Threat to the 'Net



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Network

A glitch in the Matrix, or a hungry exploit? Weird internet behaviour. What's going on?

Sûnnet Beskerming
The Register
Sat, 30 Jun 2007 08:29 UTC
Sûnnet Beskerming researchers observed an interesting deviation in global network trafficover the last 24 hours, particularly for South American, Asian, and Australian networks. Normally, global Internet traffic (as observed by the Internet Traffic Report) oscillates around nine per cent packet loss, with global response times of 138 ms, and the internally derived traffic index at around 79.

Sustained over the last 24 hours, the traffic index has dipped almost five per cent, packet loss has climbed to 11 per cent, and the global response time to almost 150 ms.

Normal spikes and dips as observed on the Internet Traffic Report show up as no more than three- or four-hour blocks of odd results before settling back into normalcy. This latest spike and dip has been sustained for at least 18 hours, with a rapid ramp up in the six hours prior to the peaks (and lows) being reached.
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Magic Wand

Saturday's Full Moon Offers Strange Illusion

Robert Roy Britt
Space.com
Fri, 29 Jun 2007 14:37 UTC
This weekend's full moon hangs lower in the sky than any other full moon of 2007, according to NASA, and it's a good time to be fooled.

When low on the horizon, the Moon can appear to be larger than when it's higher in the sky. It's all an illusion, scientists say, and it does not involve any enlarging effects of the atmosphere. Rather, it's all in your mind.

Here's how it works:

Our brains think things on the horizon are farther away than stuff overhead, because we're used to seeing overhead clouds that are close compared to those on the horizon. In the mind's eye, the sky is a flattened dome.

With this dome as a reference, we expect something on the horizon (such as the moon) to be farther, and because it is actually no farther than when overhead, our brains goof and imagine that it is larger.

Skeptical? You can test this from home.
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