Science & TechnologyS


Bulb

Cold and Ice, and Heat, Episodically Gripped Tropical Regions 300 Million Years Ago


NSF
Thu, 31 Jul 2008 17:54 UTC


Image
©Gerilyn Soreghan
Unaweep Canyon in the Rocky Mountains is the site of a deep gorge that reveals ancient landscapes and sediments. The inset image is of a "dropstone" from an eons-old glacier.

Geoscientists have long presumed that, like today, the tropics remained warm throughout Earth's last major glaciation 300 million years ago.

New evidence, however, indicates that cold temperatures in fact episodically gripped these equatorial latitudes at that time.

Geologist Gerilyn Soreghan of Oklahoma University found evidence for this conclusion in the preservation of an ancient glacial landscape in the Rocky Mountains of western Colorado. Three hundred million years ago, the region was part of the tropics. The continents then were assembled into the supercontinent Pangaea.

Soreghan and colleagues published their results in the August 2008, issue of the journal Geology.
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Telescope

Universe's Spiral Galaxy Population Evolving

Irene Klotz
Discovery News
Thu, 31 Jul 2008 16:23 UTC


Barred Galaxy NGC 1300
©Unknown
Barred Galaxy NGC 1300

New generations of small spiral galaxies are three times as likely to sport a central bar of stars as their counterparts seven billion years ago, a census of more than 2,000 galaxies shows.

The finding indicates that the galaxies, which are believed to build up over time by merging with other galaxies, are still evolving in form as the universe ages, said Kartik Sheth at the California Institute of Technology in Pasadena.

Spiral galaxies were around in the universe's early days, but only about 20 percent of them had the bar-shaped cores so prevalent in newer galaxies. Sheth's team found that spiral galaxies younger than about seven billion years -- roughly half the age of the universe -- were three times as likely as older generations to have bars.

The structures, which are found in two-thirds of all spiral galaxies including our own Milky Way, form when the orbits of stars in the disk become unstable and drift from circular paths.

"It turns out that stars prefer to be in these bar orbits," Sheth told Discovery News. "It's a lower-energy state."
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Star

Universe's first star born tiny, grew huge

Will Dunham
Reuters
Thu, 31 Jul 2008 16:18 UTC


Image
©REUTERS/Handout/David Aguilar
In this artist's impression, swirling clouds of hydrogen and helium gases are illuminated by the first starlight to shine in the universe after the Big Bang. Japanese and U.S. scientists, writing in the journal Science, present the results of a sophisticated computer simulation of how the first stars in the universe came into being.

The first object to brighten the dark, primordial universe after the Big Bang was the tiny seed of a star that rapidly grew into a behemoth 100 times more massive than the sun, scientists said on Thursday.

This first generation of stars apparently lived hard and died quickly. While our sun may live 5 billion years, this first generation of stars likely lasted only a slim fraction of that -- about 1 million years, the researchers said.

Scientists think the universe was born in a Big Bang explosion 13.7 billion years ago and has been expanding ever since. But they have struggled to understand how the first stars formed in the aftermath of this cataclysm.
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Cloud Lightning

Flashback Lightning Bolts within Cells

Katherine Bourzac
Technology Review
Mon, 10 Dec 2007 08:12 UTC
Using novel voltage-sensitive nanoparticles, researchers have found electric fields inside cells as strong as those produced in lightning bolts. Previously, it has only been possible to measure electric fields across cell membranes, not within the main bulk of cells. It's not clear what causes these strong fields or what they might mean. But now that it's possible to measure them, researchers hope to learn about disease states such as cancer by studying these electric fields.

Electric field in cells
©Raoul Kopelman, University of Michigan
The cell electric: Encapsulated in a polymer shell just 30 nanometers across, voltage-sensitive dyes (red) emit red and green light when illuminated with blue light. These encapsulated dyes make it possible to measure electric fields inside cells.
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Network

With Security at Risk, a Push to Patch the Web

John Markoff
The New York Times
Wed, 30 Jul 2008 23:02 UTC
Since a secret emergency meeting of computer security experts at Microsoft's headquarters in March, Dan Kaminsky has been urging companies around the world to fix a potentially dangerous flaw in the basic plumbing of the Internet.

While Internet service providers are racing to fix the problem, which makes it possible for criminals to divert users to fake Web sites where personal and financial information can be stolen, Mr. Kaminsky worries that they have not moved quickly enough.
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Pharoah

Ancient device yields secrets

Dan Vergano
USA Today
Wed, 30 Jul 2008 22:48 UTC


Olympic Dial
©Tony Freeth, Antikythera Mechanism Research Project
A computer image reconstruction of the Olympiad Dial, showing the four-year cycle of the Panhellenic Games.

Archaeologists had long known the Antikythera Mechanism, a bronze relic pulled from a Roman shipwreck, had been an astronomical calculator used by the ancient Greeks to predict phases of the moon and planets.

Now, a study out Wednesday shows the mechanism, which is at least 2,100 years old, also revealed the timing of the Greek Olympics, kept tabs on the local calendar and was used for eclipse predictions, making the device surprisingly practical.
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Telescope

NASA Moon Probe Launch Delayed for Military Payload

Brian Berger
Space News
Wed, 30 Jul 2008 19:41 UTC
NASA has delayed the launch of its Lunar Reconnaissance Orbiter (LRO) aboard a United Launch Alliance Atlas 5 rocket from late this year until the end of February at the earliest to make way for a military payload slated to fly atop a similar vehicle.
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Question

UK: Part of a rockery - or priceless relic?


Kent Online
Tue, 29 Jul 2008 17:14 UTC


Image
©Unknown
The fossil - alive when T-rex was king of the world

This may seem like a lump of old rock to you, but to one expert it is priceless.

Until a few weeks ago the 80 million-year-old fossilised fish head was part of a garden rockery - until a chance conversation led to it being viewed by Dr Ed Jarzembowski, Maidstone Museum's keeper of natural history.

"I have never seen one of these before. Quite simply it's priceless," he said.

The cod-like creature, which stares eerily from its prison of rock, probably roamed the open ocean at around the same time as Tyrannosaurus Rex still lived on what would become the continent of North America.
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Bulb

Snapshot of past climate reveals no ice in Antarctica millions of years ago


Cardiff University
Mon, 28 Jul 2008 17:08 UTC
A snapshot of New Zealand's climate 40 million years ago reveals a greenhouse Earth, with warmer seas and little or no ice in Antarctica, according to research published this week in the journal Geology.

A snapshot of New Zealand's climate 40 million years ago reveals a greenhouse Earth, with warmer seas and little or no ice in Antarctica, according to research published this week in the journal Geology.

The study suggests that Antarctica at that time was yet to develop extensive ice sheets. Back then, New Zealand was about 1100 km further south, at the same latitude as the southern tip of South America - so was closer to Antarctica - but the researchers found that the water temperature was 23-25°C at the sea surface and 11-13°C at the bottom.
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Meteor

Ex-Astronaut Slams Asteroid Plan


Sky News
Mon, 28 Jul 2008 09:05 UTC


Fireball / Asteroid
©Sky News

A former Nasa astronaut claims plans to blast Earth-bound asteroids out of space with nuclear weapons is not the best way to beat the threat.

Comment: The notion that "we can do something about this" may be an indulgence in more than a little wishful thinking.

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