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May 2002

The Laboratory
in the News

Commentary by
Jeff Wadsworth

Building a Virtual Telescope

A New Understanding of Soft Materials

At Livermore, Audacious Physics Has Thrived for
50 years

Patents

Awards

 

The Laboratory
in the News

Studying 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 researchers—Chris Fragile and James Wilson—together 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. “We’re 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 space–time around them, acting like tornado funnel clouds. This is a phenomenon called frame-dragging and is predicted by Einstein’s theory of general relativity.
Contact: Chris Fragile (925) 422-2176 (fragile1@llnl.gov).

Outer 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 acids—key building blocks for organic life—could 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 the universe.
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 life’s origin hold that amino acids form in water found on Earth rather than in extraterrestrial ice. Blank’s work is helping to support the extraterrestrial source theory.
Saying, “I’m 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 gun’s 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 (blank4@llnl.gov).

New kind of cool in a radiation detector
One more tool is coming along to counter terrorism. It’s 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 field—for example, at border crossings, into airports—to 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. Cryo3’s 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 ion batteries.
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 package.”
Contact: John Becker (925) 422-9676 (becker3@llnl.gov).


 



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UCRL-52000-02-5 | May 28, 2002