Brainy Quote of the Day

Tuesday, September 1, 2015

Squeezing Deuterium...

Figure 1. To squeeze liquid deuterium into its metallic phase, researchers discharged the 2160 capacitors of Sandia National Laboratories’ Z machine and sent a precisely shaped 1-μs current pulse that delivered 2 MJ of energy to a target at the machine’s center. The power transmission cables, as big around as small cars, are submerged in oil or deionized water, which serves as an insulator. Electrical arcs that play over the device during discharge, shown here, make for a dazzling display. (Photo by Randy Montoya/Sandia National Laboratories.)
Citation: Phys. Today 68, 9, 12 (2015); http://dx.doi.org/10.1063/PT.3.2899

Topics: Condensed Matter Physics, Electrical Engineering, Materials Science, Solid State Physics

The world’s strongest pulsed-power source takes a shot at an 80-year-old condensed-matter-physics problem.

Hydrogen is the simplest and most abundant element in the universe. But that simplicity belies its often unpredictable nature. A case in point: Unlike the alkali metals that sit below it on the periodic table, hydrogen, even in its solid phase, remains a molecular insulator down to the lowest temperatures.

In 1935 Eugene Wigner and Hillard Huntington predicted that squeezing solid hydrogen to a sufficiently high pressure could cause it to shed its molecular bonds and transform into an atomic metal. The race to find the insulator-to-metal transition in hydrogen was on, but it’s turned out to be a marathon rather than a sprint.

High-pressure experiments are notoriously difficult, and ones on hydrogen even more so. Diamond-anvil cells, the go-to equipment for static-compression experiments, are hampered by hydrogen’s tendency to penetrate into the diamond and cause cracks. Dynamic experiments using shock compression reach higher pressures, but they heat the sample to high temperatures and only access specific values of pressure and temperature that depend on the system’s initial state. Still, experimentalists have subjected hydrogen to pressures of 320 GPa using static techniques and 500 GPa using dynamic methods but have not found the metallic phase.

Physics Today: Liquid deuterium pressured into becoming metallic, Sung Chang

Monday, August 31, 2015

Graphene Superconductor...

Graphene turns into a superconductor when decorated with lithium atoms. (Courtesy: Shutterstock/Inozemtsev Konstantin)
Topics: Condensed Matter Physics, Graphene, Materials Science, Nanotechnology, Phonons, Semiconductor Technology, Superconductors, Solid State Physics, Quantum Mechanics

THIS changes the game! The application to longer life batteries is the first thought that comes to mind. Within semiconductors, we could supplement the physical limitations we're butting up to at the Moore's Law limit with a neat change in the material chemistry used to build the circuitry. A step before and enhancement of carbon nanotubes when they eventually replace them. Exciting times!

The "wonder material" graphene has another significant quality to add to its impressive list of electrical and mechanical properties: superconductivity. Physicists in Canada and Germany have shown that graphene turns into a superconductor when doped with lithium atoms – a result that could lead to a new generation of superconducting nanoscale devices.

Graphene exhibits a range of remarkable properties, thanks to its special structure – a one-atom-thick hexagonal lattice of carbon atoms. It is far stronger than steel while also flexible, and is an excellent conductor of both electricity and heat. In its pristine form, however, it is not a superconductor.

Neither is pure graphite, but in 2005 physicists showed that graphite could be made to superconduct when chemically treated, so as to create bulk materials consisting of graphene alternated with one-atom-thick layers of another element. The best performing material thus created, calcium graphite (CaC6), has a superconducting transition temperature of 11.5 K. Theorists identified the underlying mechanism for that superconductivity as electron–phonon coupling. Phonons are vibrations in a material's crystal lattice that bind electrons together into "Cooper pairs" that can travel through the lattice without resistance – one of the hallmarks of superconductivity. It was then realized that such electron–phonon coupling might occur not just in bulk graphite compounds but also by depositing atoms of a suitable element on to single layers of graphene.

Physics World: 'Decorated' graphene is a superconductor, Edwin Cartlidge

Saturday, August 29, 2015

Near the Levee (repost)...

Architecture About.com: What is a Levee?
Topics: #BlackLivesMatter, African Americans, Architectural Engineering, Civil Engineering, Civil Rights, Climate Change, Global Warming, History, Politics

© 21 September 2005, The Griot Poet
Inspired by the article from Dr. Cornel West: “Exiles from a city and from a nation,” 11 September 2005.

Note: I corrected the spelling of levee in the title and text (it was originally "levy" as a double entendre). On reflection of the carnival barking political times we're in and to avoid the appearance of xenophobia, a preposition and country name were both exchanged from their original versions. The piece still hits powerfully, and clarifies instead of stereotypes, origin of the demand for drugs in this country is this country in total, and no one group in particular.

Dedicated to my cousin from New Orleans, John (Gus) Holmes, Jr., his beautiful family, and the survivors of Hurricane Katrina (note: they're all fine, and relocated to another state).

**********

“When you live so close to death”
You create songs in the French Quarter on Slave Sundays that follow no pattern.
Rhythm set by clap and tambourine; washboard and kettle drum,

Old people hum in accompaniment to a Constantine Christian jubilee celebration of no cotton bailed; no backbreaking labor toiled.
The one suit you own is spoiled from overuse, and your children’s children carry on the tradition of “dress up” to anesthetize their pain.

“When you live so close to death”
The Mississippi delta builds a sediment foundation for your tragicomic pain:
“Laughing to keep from crying” births the blues!

“When you live so close to death”
People of your hue fought and escaped the French back in the day, and each day are turned away each year as they try to escape the death-hole now known as… Haiti.

“When you live so close to death, you live (life a little) more intensely,”
You create order out of chaos, from Massa raping your sisters and mothers to slaves tipping with another man’s lover: “hey baby, can we JAZZ around a little bit”?

Fighting fiercely in mock duels modeled after “southern gentlemen,” feeling disrespected, passing it down from Jazz procreation to your Hip Hop great-grandchildren’s generation as being “dissed”: with the same deadly consequences.

“When you live so close to death”
What are scraps from Massa’s table become culinary creations:
- Craw dads;
- Jambalaya;
- Gumbo;
- Shrimp Creole
- And Etoufée!

“When you live so close to death”
Lead and pollutants they allowed for your kind to warp your minds & drive the I.Q.s of your babies down scarred your psychology

BEFORE the levees broke;
BEFORE the drug flights to America!

“When you live so close to death”
You are not counted; clouded – an invisible majority under the all-mighty shadow of insignificance: exiles in your own country, resembling from years of neglect more “third world” than ninth ward or US citizenry

Hence, their news media in their quest for a ratings spree mislabeled you “refugees.”

Now, suddenly they are on our side, “shocked and awed” back to the reality of their sacred duty to inform the citizenry of a democracy… neglected for five years.

Shocked by the sight of dead bodies marred by dogs and crocodiles, piled in stairwells like logs… floating downstream! It seems perceptions change once you’re beyond a sheltered, suburban political haze, and find YOURSELF for many days
Breathing the stench,
Your own eyes seeing,
Your own ears hearing the gunshots and screams… in this country,
You cannot believe you could stay reasonably SANE…

Living so close to death!

Friday, August 28, 2015

NextSTEP...

This diagram details how the VASIMR plasma rocket works.
Credit: Ad Astra Rocket Company © all rights reserved
Topics: Diversity, Diversity in Science, Hispanic Americans, Latino Americans, Mars, NASA, Space Exploration, Spaceflight

Note to a certain presidential candidate: Isn't it ironic our journey to Mars will have been engineered by a Hispanic/Latino immigrant (see #P4TC link below)?

A potential advancement in the United States' electric propulsion capability for the future of spaceflight is being underscored by a new NASA contract to support work on the VASIMR project – short for the Variable Specific Impulse Magnetoplasma Rocket.

VASIMR works with plasma, an electrically charged gas that can be heated to extreme temperatures by radio waves and controlled and guided by strong magnetic fields.

Ad Astra Rocket Company announced today that it has completed contract negotiations with NASA on the group's Next Space Technology Exploration Partnerships (NextSTEP) award and are now entering the execution phase of the project. [How to Launch Superfast Trips to Mars]

Space.com: Plasma Rocket Technology Receives NASA Funding Boost, Leonard David
#P4TC: Dr. Franklin Ramón Chang Díaz...

Thursday, August 27, 2015

Fire Fountains of the Moon...

This NASA image shows the moon coalescing from debris created when a Mars-size object slammed into the early Earth. Carbon found in lunar samples suggests that the moon's surface composition was very similar to Earth's.
Credit: NASA/Goddard Space Flight
Topics: Moon, Planetary Science, NASA

The ancient lunar surface once erupted with geysers of lava — and now, scientists think they know what caused those fiery fountains.

Current research suggests that the moon formed when a Mars-size object barreled into Earth in the early solar system, and for a long time, its surface was much different from the staid, unmoving landscape present today. Rather, the moon's surface was hot and active, and magma often bubbled up from below and broke the surface in fiery fountains — like a molten-hot version of Old Faithful. Until recently, researchers were unsure of the driving force behind those explosions, which could reveal more about conditions on the early moon.

But now, scientists may have found a possible culprit for the molten explosions: carbon monoxide. [Watch: How the Moon Was Made]

"The carbon is the one that is producing the large spectacle," said Alberto Saal, a geologist at Brown University in Providence and co-author of the new study. "With a little bit of water, with a little bit of sulfur — but the main driver is carbon."

This finding suggests the early moon's makeup was very close to early Earth's, Saal told Space.com. "All these volatile elements … are in concentrations that are very similar to the lava that formed the ocean floor of the Earth," he said.

Space.com: Fire Fountains of the Ancient Moon Explained, Sarah Levin

Wednesday, August 26, 2015

Alibaba and 30 Qubits...

Image Source: Alibaba group's offices in Hangzhou, China. (Courtesy: Alibaba group)
Topics: Computer Science, Research, STEM, Quantum Computer

The global effort to develop practical quantum computers got a boost this month with the inauguration of a dedicated laboratory in Shanghai, China. The new lab – a joint venture between the Chinese Academy of Sciences (CAS) and the Chinese online retail giant Alibaba – aims to develop a general-purpose prototype quantum computer by 2030.

The new CAS–Alibaba Quantum Computing Laboratory's interim goals include the coherent manipulation of 30 quantum bits (qubits) by 2020, and quantum simulation with calculation speeds equivalent to those achieved by today's fastest supercomputers by 2025. This ambitious series of five-year plans will be supported by an annual injection of $5m from Alibaba's cloud-computing subsidiary, Aliyun, over the next 15 years.

Physics World: Joint quantum-computing venture is a first for China
Xin Ling is a science writer based in Beijing

Tuesday, August 25, 2015

Accretion of Dark Matter...

Image Source (and sound): Dark Matter Sound System - Band Camp
Topics: Black Holes, Dark Matter, General Relativity, Heliophysics, Humor, Quantum Cosmology

First of all, from the astrophysics classes I've taken, accretion is attributed to stars diffusing material around it, usually to create things like planets. This is a novel way to look at the pursuit of dark matter and I found the paper intriguing.

What teachers will hate me for: since everyone knows what a black hole looks like, and it really didn't coincide with the paper (abstract below), I did find a techno metal group that has a whole unique take on combining the two subjects (link below above image). As always, I get no gratuities for sharing this, but hopefully like me, it makes you grin for many of you, the first day of school (at least in Texas). Think of it as your "hook," but don't dwell on it very long...the students will catch on you're enjoying it too much.

Abstract
Searches for dark matter imprints are one of the most active areas of current research. We focus here on light fields with mass mB, such as axions and axion-like candidates. Using perturbative techniques and full-blown nonlinear Numerical Relativity methods, we show that (i) dark matter can pile up in the center of stars, leading to configurations and geometries oscillating with frequency which is a multiple of f=2.51014 mBc2/eV Hz. These configurations are stable throughout most of the parameter space, and arise out of credible mechanisms for dark-matter capture. Stars with bosonic cores may also develop in other theories with effective mass couplings, such as (massless) scalar-tensor theories. We also show that (ii) collapse of the host star to a black hole is avoided by efficient gravitational cooling mechanisms.

Physics arXiv: Accretion of dark matter by stars
Richard Brito, Vitor Cardoso, Hirotada Okawa