Friday, January 3, 2020

U.S. tests ways to sweep space clean of radiation after nuclear attack

The U.S. military thought it had cleared the decks when, on 9 July 1962, it heaved a 1.4-megaton nuclear bomb some 400 kilometers into space: Orbiting satellites were safely out of range of the blast. But in the months that followed the test, called Starfish Prime, satellites began to wink out one by one, including the world’s first communications satellite, Telstar. There was an unexpected aftereffect: High-energy electrons, shed by radioactive debris and trapped by Earth’s magnetic field, were fritzing out the satellites’ electronics and solar panels.

Scientists got a glimpse of a potential solution from NASA’s Van Allen Probes, which launched in 2012 and ducked in and out of Earth’s radiation belts until the mission ended last summer. It offered a deep dive into natural remediation processes, showing how radio waves resonate with high-energy electrons, scattering them down the magnetic field lines and sweeping them out of the belts. “Compared to 10 years ago, we just know so much more about how these wave-particle interactions work,” says Geoff Reeves, a space physicist at Los Alamos National Laboratory. (Full story)

The 20 Coolest Machines of the 2010s

The Plasma Liner Experiment at LANL.

At Los Alamos National Laboratory in New Mexico, a new type of fusion reactor is underway. The Plasma Liner Experiment, as it's being called, will draw on two different confinement methods to enable the prototype: magnetic and inertial confinement. Cooler still, it has 36 plasma guns, surrounding the spherical chamber, that shoot jets of ionized gas into the chamber, itself. That targets, compresses and heats a cloud of fusion fuel inside. The reactor should be finalized sometime this year. (Full story)

Scientists model dynamic feedback loop that fuels the spread of wildfires

Flames spread up a hillside near firefighters at the
Blue Cut Fire on August 18, 2016 near Wrightwood,
California. Courtesy photo.

From a physics and chemistry standpoint, fire is an incredibly complicated phenomenon—so much so that 19th century physicist Michael Faraday built an entire series of six lectures around the flame of a single candle at the Royal Institution in 1848. Fuel, heat, and oxygen, combined under the right conditions, ignite into a sustained chemical reaction: fire. Add in factors like conduction, convection, radiation, and any number of environmental factors, and that fire can rapidly spread out of control.

Scientists have been trying to better delineate how wildfires spread for decades, and understanding the complicated fluid dynamics at work is key to those efforts. Rodman Linn, an atmospheric scientist at Los Alamos National Laboratory, does computational modeling of how fires interact with the surrounding atmosphere to predict how a given fire behaves. It's a challenging phenomenon to model, since it involves the interaction of several different processes. Linn describes the various factors that influence how a wildfire spreads in an article in the November issue of Physics Today. (Full story)

1 big thing: The return of analog?

Illustration: Aïda Amer/Axios.         

Returning to a technology largely discarded since the 1960s, scientists are betting on analog computing to wean AI systems off the monstrous amounts of electricity they currently require.

Why it matters: AI is on track to use up a tenth of the world's electricity by 2025, by one estimate. Cutting back on this consumption has huge climate implications — plus it’s essential for mobile devices and autonomous cars to do complex calculations on the fly.

But an analog computer is built on the physical properties of its components. It can perform multiplication, for example, by utilizing the properties of transistors. “The idea is to let the natural dynamics of the physical system solve the problem,” says Garrett Kenyon of the Los Alamos National Laboratory. (Full story)

Study picks up nearly 2 million tiny, undetected earthquakes in California

Seismologists at Caltech and Los Alamos National Laboratory identified 1.81 million tiny tremors hidden in data from 2008 to 2017-roughly one every three minutes. This newly detected seismic activity will help researchers to better understand how earthquakes start. (Full story)

What did Curiosity find on Mars in 2019? Ancient and extinct oasis but worth it

The Curiosity Rover. Credit NASA/JPL-Caltech/MSSS

The ChemCam camera atop NASA's Mars Curiosity rover that uses laser beams to analyze Martian rocks to analyze their chemical make-up startled researchers with clues into the planet's past habitability of the Red planet that was believed to be once home to shallow, salty ponds.

In a paper published in October this year in Nature Geoscience, the results from the analysis of rocks enriched in mineral salts in Gale Crater, a 100-mile-wide dry lakebed on Mars came to light from NASA's Curiosity rover.

"Mars' climate was habitable once, long ago," said Roger Wiens, key investigator of the ChemCam instrument at Los Alamos National Laboratory and a co-author of the paper. "What these new findings show is that the climate on Mars was not as stable as we thought it was. There were very wet periods and very dry periods--as these sulfate-rich rocks show us." (Full story)

LANL instrument helps in search for life on Mars

If life exists on Mars, it still hasn’t showed itself — but recent evidence from the Red Planet increasingly supports the possibility. Life could have developed there. Most of the conditions are right, and nothing found so far rules out the possibility, either in the distant past or today.

If something is or was alive on the Red Planet, it’s probably tiny. Because microbes make up the vast majority of life on Earth and live in its most inhospitable environments, they are the most likely thing to find somewhere else. It’s not so easy figuring out what “alive” means on another planet — let alone discovering a living microbe. Scientists are still puzzled by life on Earth — struggling to understand how life started, what it requires to survive, what it looked like 4 billion years ago, and how to recognize traces of ancient life today. (Full story)

LANL Employees Gather Hundreds Of Holiday Gifts For Those In Need

Every year, hundreds of Los Alamos National Laboratory employees spread a little holiday cheer by donating gifts to members of our community in need throughout Northern New Mexico.

This year, the Laboratory collected more than 900 individual requests for gifts from 27 nonprofits and social service agencies across Northern New Mexico. The recipients include infants, children, senior citizens and others facing life challenges. (Full story)