Science & TechnologyS


Einstein

Physicists Discover 'Doubly Strange' Particle


Science Daily
Thu, 04 Sep 2008 11:44 UTC
Physicists of the DZero experiment at the U.S. Department of Energy's Fermi National Accelerator Laboratory have discovered a new particle made of three quarks, the Omega-sub-b (Ωb).

Image
©DZero collaboration
Once produced, the decay of the Omega-sub-b (Ωb) proceeds like fireworks. The particle travels about a millimeter before it disintegrates into two intermediate particles called J/Psi (J/ψ) and Omega-minus (Ω-). The J/Psi then promptly decays into a pair of muons. The Omega-minus baryon, on the other hand, can travel several centimeters before decaying into yet another unstable particle called a Lambda (Λ) baryon along with a long-lived particle called kaon (K). The Lambda baryon, which has no electric charge, also can travel several centimeters prior to decaying into a proton (p) and a pion (π).

The particle contains two strange quarks and a bottom quark (s-s-b). It is an exotic relative of the much more common proton and weighs about six times the proton mass.

The discovery of the doubly strange particle brings scientists a step closer to understanding exactly how quarks form matter and to completing the "periodic table of baryons." Baryons (derived from the Greek word "barys," meaning "heavy") are particles that contain three quarks, the basic building blocks of matter. The proton comprises two up quarks and a down quark (u-u-d).

Combing through almost 100 trillion collision events produced by the Tevatron particle collider at Fermilab, the DZero collaboration found 18 incidents in which the particles emerging from a proton-antiproton collision revealed the distinctive signature of the Omega-sub-b. Once produced, the Omega-sub-b travels about a millimeter before it disintegrates into lighter particles. Its decay, mediated by the weak force, occurs in about a trillionth of a second.

Theorists predicted the mass of the Omega-sub-b baryon to be in the range of 5.9 to 6.1 GeV/c2. The DZero collaboration measured its mass to be 6.165 ± 0.016 GeV/c2. The particle has the same electric charge as an electron and has spin J=1/2.
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Telescope

Closest Look Ever At Edge Of A Black Hole


Science Daily
Thu, 04 Sep 2008 11:38 UTC
Astronomers have taken the closest look ever at the giant black hole in the center of the Milky Way. By combining telescopes in Hawaii, Arizona, and California, they detected structure at a tiny angular scale of 37 micro-arcseconds - the equivalent of a baseball seen on the surface of the moon, 240,000 miles distant. These observations are among the highest resolution ever done in astronomy.

Image
©NASA
This image is from a computer animation illustrating a spinning black hole. The close-up view here represents the immediate vicinity of the black hole, with the event horizon depicted as a black sphere. The surrounding disk of gas, represented by white and blue rings, whirls around the black hole. The white column over the pole of the black hole represents a jet of gas being ejected from the vicinity of the black hole at nearly the speed of light.

"This technique gives us an unmatched view of the region near the Milky Way's central black hole," said Sheperd Doeleman of MIT, first author of the study that will be published in the Sept. 4 issue of the journal Nature.

"No one has seen such a fine-grained view of the galactic center before," agreed co-author Jonathan Weintroub of the Harvard-Smithsonian Center for Astrophysics (CfA). "We've observed nearly to the scale of the black hole event horizon - the region inside of which nothing, including light, can ever escape."

Using a technique called Very Long Baseline Interferometry (VLBI), a team of astronomers led by Doeleman employed an array of telescopes to study radio waves coming from the object known as Sagittarius A* (A-star). In VLBI, signals from multiple telescopes are combined to create the equivalent of a single giant telescope, as large as the separation between the facilities. As a result, VLBI yields exquisitely sharp resolution.
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Gear

Physicists Rule Out the Production of Dangerous Black Holes at the LHC

Laura Mgrdichian
Physorg.com
Mon, 01 Sep 2008 08:50 UTC
On August 8, the world's largest particle accelerator, the Large Hadron Collider near Geneva, Switzerland, began the process of slowly throttling to full power. When its proton beams are circling at full speed and collisions begin, scientists from around the world will finally be able to start collecting data.

LHC
©Maximilien Brice, CERN

Comment: Once in a while the overwhelming majority of the scientific community happens to be in error. Then a scientific revolution follows - if humanity survives the error. On August 10 R. Plaga submitted a paper "On the potential catastrophic risk from metastable quantum-black holes produced at particle colliders" where he remarked that:
The question of whether the collider production of subnuclear black holes might constitute a catastrophic risk is explored in a model of Casadio & Harms (2002) that treats them as quantum mechanical objects. A plausible scenario in which these black holes accrete ambient matter at the Eddington limit shortly after their production, thereby emitting Hawking radiation that would be harmful to Earth and/or CERN and its surroundings, is described.

Such black holes are shown to remain undetectable in astrophysical observations and thus evade a recent exclusion of risks from subnuclear black holes by Giddings & Mangano (2008). I further question that their risk analysis is complete for the reason that it excludes plausible parameter ranges from safety consideration without giving a sufficient reason. The reasons why Giddings & Mangano drew very different general conclusions are found to be of a methodological rather than scientific nature.
On August 29 Goldings and Magnano submitted "Comments on claimed risk from metastable black holes" where they reassured us that "it was argued that a hypothetical metastable black hole scenario could pose collider risk not excluded by our previous study. We comment on inconsistency of this proposed scenario."

This reminds us of past history when the majority of the scientific community assured us that the Earth is flat and that the scenario of Earth being round is inconsistent for the simple reason that people on the other side would be falling down.

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Robot

'Autonomous' Helicopters Teach Themselves To Fly


Science Daily
Wed, 03 Sep 2008 14:17 UTC
Stanford computer scientists have developed an artificial intelligence system that enables robotic helicopters to teach themselves to fly difficult stunts by watching other helicopters perform the same maneuvers.

autonomous helicopters
©Stanford University
Computer Science Professor Andrew Ng (center) and his graduate students Pieter Abbeel (left) and Adam Coates.


The result is an autonomous helicopter than can perform a complete airshow of complex tricks on its own.

The stunts are "by far the most difficult aerobatic maneuvers flown by any computer controlled helicopter," said Andrew Ng, the professor directing the research of graduate students Pieter Abbeel, Adam Coates, Timothy Hunter and Morgan Quigley.

The dazzling airshow is an important demonstration of "apprenticeship learning," in which robots learn by observing an expert, rather than by having software engineers peck away at their keyboards in an attempt to write instructions from scratch.
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Info

Oldest Gecko Fossil Ever Found, Entombed In Amber


Science Daily
Wed, 03 Sep 2008 14:14 UTC
Scientists from Oregon State University and the Natural History Museum in London have announced the discovery of the oldest known fossil of a gecko, with body parts that are forever preserved in life-like form after 100 million years of being entombed in amber.

amber fossil
©OSU
Digital images of the amber fossil discovered by OSU researchers, containing the foot and partial tail.

Due to the remarkable preservative power of being embalmed in amber, the tiny foot of this ancient lizard still shows the tiny "lamellae," or sticky toe hairs, that to this day give modern geckos their unusual ability to cling to surfaces or run across a ceiling. Research programs around the world have tried to mimic this bizarre adhesive capability, with limited success.

This gecko's running days are over, however, as only the foot, toes and part of a tail are left in the stone. The rest might have become lunch for a small dinosaur or other predator during an ancient fight in the tropical forests of Myanmar during the Lower Cretaceous Period, from 97 million to 110 million years ago.
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Sherlock

Researchers to examine gas trapped in Lake Baikal's depths


RIA Novosti
Tue, 02 Sep 2008 13:01 UTC
Researchers studying Siberia's Lake Baikal have said they plan to use the lake to test the potential use of methane clathrates as an energy source, but that the lake itself would not be tapped for the fuel.

Methane clathrates, which look like ice and are found mainly in Antarctic ice cores and ocean beds, are composed of crystallized water molecules trapping methane and other gases. Baikal, the world's deepest lake, holds large volumes of clathrates in its sediment.
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Magic Hat

Does Memory Reside Outside the Brain?

Leonardo Vintiñi
Epoch Times
Fri, 29 Aug 2008 10:11 UTC


brain
©Photos.com
While many believe that memory resides inside the brain, evidence suggests that our minds might actually exist within a morphogenic field.

After decades of investigation, scientists are still unable to explain why no part of the brain seems responsible for storing memories.

Most people assume that our memories must exist somewhere inside our heads. But try as they might, medical investigators have been unable to determine which cerebral region actually stores what we remember. Could it be that our memories actually dwell in a space outside our physical structure?

Biologist, author, and investigator Dr. Rupert Sheldrake notes that the search for the mind has gone in two opposite directions. While a majority of scientists have been searching inside the skull, he looks outside.
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Pharoah

Tutankhamen fathered twins


Physorg.com
Mon, 01 Sep 2008 08:56 UTC
Two foetuses found in the tomb of Tutankhamen may have been twins and were very likely to have been the children of the teenage Pharaoh, according to the anatomist who first studied the mummified remains of the young King in the 1960s.
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Snowman

Ice Age Ivory Carving Discovered in Germany

Silke Jeklic
The Epoch Times
Mon, 18 Aug 2008 23:02 UTC


Ivory Mastodon
©Joself Jelkic/The Epoch Times
The mastodon was found immediately outside the cave during a 2006 dig. The dig continues into 2009; who knows what other treasures might be unearthed.

It was a cool afternoon. A small gathering of people assembled at the Swabian village Stetten ob Lontal, in Germany. They waited for a guided trip to Vogelherd Cave.

It cannot be called a real cave, like one that allows you to descend deeply into the earth and that might feature artfully dripping stalactite and stalagmite sculptures, perhaps like the Charlotte Cave and other natural caves found in the Swabian Alps.

Excursion leader Brigitta Roeck led the group in stages up a soft, rain-soaked footpath. Ms. Roeck gave out snippets of information about climate and vegetation in the Aurignacia of 30,000 years ago.

What were people's days like back then? What did they eat? What thoughts did they have? We have only partial answers to our questions. Our limited knowledge is based on archeological discoveries. Aided by modern carbon-dating techniques, we may arrive at new interpretations.
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Telescope

Amateur Astronomers See Perseids Hit the Moon


NASA
Tue, 02 Sep 2008 19:12 UTC
There's more than one way to watch a meteor shower.

One, the old-fashioned way: Find a dark place with starry skies and count the meteors streaking overhead. Two, the new way: Find a dark place with starry skies and then completely ignore the meteors. Instead, watch the Moon. That's where the explosions are.
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