in the News
a Virtual Telescope
New Understanding of Soft Materials
Livermore, Audacious Physics Has Thrived for
in the News
the mysteries of black holes
Black holes have fascinated
astronomers and the general public alike. Now, with detailed simulations
made on massively parallel supercomputers and advances in x-ray
astronomy, knowledge about black holes is growing.
At the January meeting of
the American Astronomical Society, two Laboratory researchersChris
Fragile and James Wilsontogether with Grant Mathews of the
University of Notre Dame, presented findings of what happens when
gas flows into rapidly rotating black holes. The findings centered
on computer simulations and relied on previous research indicating
that gas falling into a black hole orbits the black hole in a disklike
pattern. The simulations are a first attempt to model the complicated
disk dynamics. Said Fragile, Simulations such as ours are
critical since these environments are too complicated to study by
any other means.
The research is of interest
to organizations such as the National Aeronautics and Space Administration
(NASA) because it may help explain unusual periodic timing properties
seen in x rays being emitted near many suspected black holes. Much
of what the NASA Observers [satellites] look for are x rays, and
the black holes produce a lot of that, said Fragile. Were
hoping to simulate a system similar to what a NASA Observer might
see when it looks at a black hole.
The researchers work
is based on how rapidly rotating black holes would drag spacetime
around them, acting like tornado funnel clouds. This is a phenomenon
called frame-dragging and is predicted by Einsteins theory
of general relativity.
Contact: Chris Fragile (925) 422-2176 (email@example.com).
space yields building blocks of life
Geochemist Jennifer Blank
and a group of scientists from around the world are shedding light
on how life might have begun. In two independent laboratory experiments,
published in the March 28, 2002, issue of Nature, the researchers
suggest that amino acidskey building blocks for organic lifecould
have come from extraterrestrial sources. Performing experiments
at low temperatures and pressures, they produced amino acids in
environments that simulated the icy conditions of interstellar space.
The results suggest that amino acids could have formed in space
and hitched rides on comets and asteroids to planets throughout
To further support this theory,
the researchers had to see if amino acids borne on a comet could
survive the heat and pressure of an impact with Earth. Other theories
about lifes origin hold that amino acids form in water found
on Earth rather than in extraterrestrial ice. Blanks work
is helping to support the extraterrestrial source theory.
Saying, Im thrilled
about this work, Blank has been simulating a high-speed comet
collision into Earth. She used a 6-meter-long gas gun to blast canisters
of amino acids. The guns impact generates temperatures and
pressures comparable to those of a comet collision. Her results
indicate that amino acids can survive the impact.
Blank says that showing that
chemical reactions in interstellar clouds can form amino acids is
a first big step in explaining where they can originate and
how they might arrive on Earth.
Contact: Jennifer Blank (925) 423-8566 (firstname.lastname@example.org).
New kind of
cool in a radiation detector
One more tool is coming along
to counter terrorism. Its a radiation detector developed by
scientists at the Livermore and Berkeley laboratories. Handheld,
mobile, and able to distinguish between different forms of radiation,
Cryo3, as the new device is called, has clear applications for homeland
security. It can be taken into the fieldfor example, at border
crossings, into airportsto do its work unobtrusively and reach
into areas that big detectors cannot get to.
The Cryo3 is a germanium
radiation spectrometer. The use of germanium crystals allows Cryo3
to detect and measure various types of radiation and distinguish
between, for example, plutonium in nuclear weapons and barium in
medical diagnostics. To work, germanium spectrometers must be kept
very cold and are usually chilled using liquid nitrogen. That need
typically confines their work to the laboratory. Cryo3s developers
eliminated the need for liquid nitrogen by refining an off-the-shelf
cooling engine that is as small as a fist, which they then inserted
in the detector and powered with a pair of rechargeable lithium
Their result: a shoe-box-size
device weighing just 4.5 kilograms that can operate up to 8 hours
on its batteries. Says Livermore physicist John Becker, one of the
developers, Cryo3 couples the high-energy resolution and efficiency
of a laboratory-size germanium detector with a low-power, lightweight,
long-lived microcooler for the first time, enabling a mobile, handheld
Contact: John Becker (925) 422-9676 (email@example.com).
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May 28, 2002