Science & TechnologyS


Question

What Can Swiss Cheese Teach Us About Dark Energy?


Science Daily
Sun, 28 Dec 2008 17:54 UTC
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© NASA/Jet Propulsion LaboratoryIs dark energy really real? Is our universe really accelerating? These questions hang around in the mind of Ali Vanderveld, a post-doctoral cosmologist at JPL.
About 10 years ago, scientists reached the astonishing conclusion that our universe is accelerating apart at ever-increasing speeds, stretching space and time itself like melted cheese. The force that's pushing the universe apart is still a mystery, which is precisely why it was dubbed "dark energy."

But is dark energy really real? Is our universe really accelerating? These questions hang around in the mind of Ali Vanderveld, a post-doctoral cosmologist at JPL. Vanderveld and her colleagues recently published a paper in the journal Physical Review looking at how giant holes in our "Swiss-cheese-like" universe might make space look as if it's accelerating when it's really not. They concluded these holes, or voids, are not sufficient to explain away dark energy; nevertheless, Vanderveld says it's important to continue to question fundamental traits of the very space we live in.

"Sometimes we take dark energy for granted," said Vanderveld. "But there are other theories that could explain why the universe appears to be moving apart at faster and faster speeds."
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Bulb

2008 in Science, Medicine and Space

Iddo Genuth
The Future Of Things
Sat, 27 Dec 2008 11:20 UTC
From a possible cure for Aids to a new discovery of quasiparticles, 2008 brought with it important scientific and medical advances as well as great disappointments such as the unexpected malfunction of the Large Hadron Collider, which postponed the multi billion dollar scientific enterprise by several months.

Continuing our annual tradition since 2006, TFOT presents a summary of the passing year's most remarkable discoveries, innovations, research, and applications in science, medicine, and space.
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Info

New Titanium-glass Alloys Are Tough, Cheap And Light-weight


Science Daily
Sun, 28 Dec 2008 02:25 UTC
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© Douglas Hofmann/CaltechSamples of the new titanium-based metallic-glass composites show their toughness and ductility.
Scientists from the California Institute of Technology (Caltech) have created a range of structural metallic-glass composites, based in titanium, that are lighter and less expensive than any the group had previously created, while still maintaining their toughness and ductility--the ability to be deformed without breaking.

Earlier this year, the same Caltech group had published a paper in the journal Nature, describing new strategies for creating the liquid-metal composites. This research resulted in "alloys with unrivaled strength and toughness," notes Douglas Hofmann, visiting scientist and lead author on the PNAS paper that, along with the Nature paper, describes work he did while a graduate student at Caltech. "They are among the toughest engineering materials that currently exist."
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Info

Visual Areas Of Brain Respond More To Valuable Objects, Brain-imaging Shows


Science Daily
Sun, 28 Dec 2008 02:21 UTC
Brain
© John Serences, UC San Diego
Dollar signs for eyes - cartoonists have been drawing them for years, and the artists, while whimsical, may have been onto something. According to new research from UC San Diego, areas of the brain responsible for vision respond more strongly to objects of value.

Led by John Serences, assistant professor of psychology and head of the Perception and Cognition Lab at UC San Diego, the study is published in the Dec. 26 issue of the Cell Press journal Neuron.

Past rewards influence how humans (and other animals) make decisions. We've known about that for a long time, said Serences - through day-to-day experience as well as the numerous experiments of economists and cognitive psychologists. Though more and more research is looking into it, little is known about how rewards affect the way the brain processes incoming sensory information, specifically as it relates to vision. Could it be that we see things differently if they have paid off before?
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Saturn

Saturn's Crazy Christmas Tilt


NASA
Mon, 22 Dec 2008 18:42 UTC
You look through the telescope. Blink. Shake your head and look again. The planet you expected to see in the eyepiece is not the one that's actually there. Too much eggnog?

No, it's just Saturn's crazy Christmas tilt.

All year long, the rings of Saturn have been tilting toward Earth and now they are almost perfectly edge-on. The opening angle is a paper-thin 0.8o. Viewed from the side, the normally wide and bright rings have become a shadowy line bisecting Saturn's two hemispheres--a scene of rare beauty.

Amateur astronomer Efrain Morales Rivera of Aguadilla, Puerto Rico, has been monitoring Saturn and he created this composite image to show how the geometry has changed:
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Star

Speculations On Christmas Star Mystery Continue

Andrew Fazekas
National Geographic News
Wed, 24 Dec 2008 12:52 UTC
In the Bible, a celestial beacon now known as the Star of Bethlehem led the Magi, or wise men, to Jesus's manger.

Astronomers have been debating for centuries whether the star existed and, if so, what it might have been. Comets, meteor showers, and supernovae have all been proposed, but in recent years two main theories have come to dominate the discussion.

The first relates to a singular planetary gathering, or conjunction, of the bright planets Venus and Jupiter. A particularly striking conjunction occurred in June 17, 2 B.C.

It makes for a probable Christmas star, some astronomers say, because the two bright planets appeared so close in the evening sky that they would have seemed to merge.
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Telescope

Orbiter finds evidence of water vapor on far-off planet

David Perlman
San Francisco Chronicle
Thu, 11 Dec 2008 01:47 UTC
A high-flying telescope has detected the strongest evidence yet that water - the essential ingredient for any life we know - exists on a giant gassy planet orbiting a far-away star.

It's highly unlikely that such a huge and massive object - a planet larger even than Jupiter - could be home for anything alive, but it does increase astronomers' confidence that life is just waiting to be detected on smaller, rocky planets in what are called habitable zones around distant suns like ours.

A report on the new discovery is published today in the journal Nature by scientists who monitor images and data sent to Earth from NASA's Spitzer Space Telescope, which has been in orbit around the sun for the past five years.
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Telescope

Reading ripples in the cosmic microwave background

Ron Cowen
Science News
Wed, 10 Dec 2008 01:08 UTC
Hidden in the peaks and valleys imprinted on the cosmic microwave background - the radiation leftover from the Big Bang - is a wealth of information not only about the early universe but the distribution of matter throughout the cosmos.

On December 8, researchers at the Texas Symposium on Relativistic Astrophysics in Vancouver reported reading some of these imprints to identify three previously unknown galaxy clusters. The find bolsters using the cosmic microwave background as a tool for understanding how the universe's galaxy composition has changed over time. This understanding is critical for analyzing the fingerprints of dark energy, the mysterious force that is revving up the rate at which the universe expands.
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Magnify

Study: Climate change during ice age did not happen at once


Sindh Today
Wed, 10 Dec 2008 23:44 UTC
Major climatic events during past global ice ages did not occur at once or with the same intensity everywhere, according to new data.

The research by Australian Nuclear Science and Technology Organisation's (ANSTO), which used sophisticated nuclear dating techniques on rocks from Mongolian glaciers, could impact future climate change forecasts.

The research shows that Mongolian glacier advances during the last ice age were not synchronised with alpine glaciers in Europe and North America, suggesting that climate varied significantly between continents.
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Telescope

Sparkling Spray Of Stars Seen


Science Daily
Thu, 25 Dec 2008 23:36 UTC
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© ESOThis colour image of the region known as NGC 2264 — an area of sky that includes the sparkling blue baubles of the Christmas Tree star cluster — was created from data taken through four different filters (B, V, R and H-alpha) with the Wide Field Imager at ESO's La Silla Observatory, 2400 m high in the Atacama Desert of Chile in the foothills of the Andes. The image shows a region of space about 30 light-years across.
NGC 2264 lies about 2600 light-years from Earth in the obscure constellation of Monoceros, the Unicorn, not far from the more familiar figure of Orion, the Hunter. The image shows a region of space about 30 light-years across.

William Herschel discovered this fascinating object during his great sky surveys in the late 18th century. He first noticed the bright cluster in January 1784 and the brightest part of the visually more elusive smudge of the glowing gas clouds at Christmas nearly two years later. The cluster is very bright and can easily be seen with binoculars. With a small telescope (whose lenses will turn the view upside down) the stars resemble the glittering lights on a Christmas tree. The dazzling star at the top is even bright enough to be seen with the unaided eye. It is a massive multiple star system that only emerged from the dust and gas a few million years ago.
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