Tag Archives: radio wave

UT Austin Engineers Build First Nonreciprocal Acoustic Circulator: A One-Way Sound Device

AUSTIN, Texas — A team of researchers at The University of Texas at Austin’s Cockrell School of Engineering has built the first-ever circulator for sound. The team’s experiments successfully prove that the fundamental symmetry with which acoustic waves travel through air between two points in space (“if you can hear, you can also be heard”) can be broken by a compact and simple device.

“Using the proposed concept, we were able to create one-way communication for sound traveling through air,” said Andrea Alù, who led the project and is an associate professor and David & Doris Lybarger Endowed Faculty Fellow in the Cockrell School’s Department of Electrical and Computer Engineering. “Imagine being able to listen without having to worry about being heard in return.” (more…)

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Scientists solve a decades-old mystery in the Earth’s upper atmosphere

New research published in the journal Nature resolves decades of scientific controversy over the origin of the extremely energetic particles known as ultra-relativistic electrons in the Earth’s near-space environment and is likely to influence our understanding of planetary magnetospheres throughout the universe.

Discovering the processes that control the formation and ultimate loss of these electrons in the Van Allen radiation belts — the rings of highly charged particles that encircle the Earth at a range of about 1,000 to 50,000 kilometers above the planet’s surface — is a primary science objective of the recently launched NASA Van Allen Probes mission. Understanding these mechanisms has important practical applications, because the enormous amounts of radiation trapped within the belts can pose a significant hazard to satellites and spacecraft, as well astronauts performing activities outside a craft. (more…)

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Interstellar Travelers of the Future May be Helped by MU Physicist’s Calculations

University of Missouri’s Sergei Kopeikin may have solved the Pioneer anomaly

COLUMBIA, Mo. – Former President Bill Clinton recently expressed his support for interstellar travel at the 100 Year Spaceship Symposium, an international event advocating for human expansion into other star systems. Interstellar travel will depend upon extremely precise measurements of every factor involved in the mission. The knowledge of those factors may be improved by the solution a University of Missouri researcher found to a puzzle that has stumped astrophysicists for decades.

“The Pioneer spacecraft, two probes launched into space in the early 70s, seemed to violate the Newtonian law of gravity by decelerating anomalously as they traveled, but there was nothing in physics to explain why this happened,” said Sergei Kopeikin, professor of physics and astronomy in MU’s College of Arts and Science. “My study suggests that this so-called Pioneer anomaly was not anything strange. The confusion can be explained by the effect of the expansion of the universe on the movement of photons that make up light and radio waves.” (more…)

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Researchers Develop New Amp to Study the Universe

Researchers at NASA’s Jet Propulsion Laboratory and the California Institute of Technology, both in Pasadena, have developed a new type of amplifier for boosting electrical signals. The device can be used for everything from studying stars, galaxies and black holes to exploring the quantum world and developing quantum computers.

“This amplifier will redefine what it is possible to measure,” said Jonas Zmuidzinas, chief technologist at JPL, who is Caltech’s Merle Kingsley Professor of Physics and a member of the research team. (more…)

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Today in the Milky Way: Cloudy Skies

Adam Block of the UA’s Mount Lemmon SkyCenter brings us a rare view of the clouds wafting through our Milky Way in this Astronomy Picture of the Day.

In silhouette against the Milky Way’s faint starlight, its dusty molecular clouds likely contain raw material to form hundreds of thousands of stars, prompting astronomers to eagerly search the clouds for telltale signs of star birth.

This telescopic close-up looks toward the region at a fragmented Aquila dark cloud complex identified as LDN 673, stretching across a field of view slightly wider than the full moon.

For this image selected by NASA as the June 29 Astronomy Picture of the Day, astrophotographer Adam Block of the University of Arizona’s Mount Lemmon SkyCenter remotely operated the 32-inch Schulmann Telescope to peer into the vast chasms of gas and dust wafting through the Milky Way, exposing for about 15 minutes at a time during several nights in April and May. (more…)

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Inspired by Insects

For treatment of vocal fold disorders, UD researchers look to insect protein

A one-inch long grasshopper can leap a distance of about 20 inches. Cicadas can produce sound at about the same frequency as radio waves. Fleas measuring only millimeters can jump an astonishing 100 times their height in microseconds. How do they do it? They make use of a naturally occurring protein called resilin.

Resilin is a protein in the composite structures found in the leg and wing joints, and sound producing organs of insects. Highly elastic, it responds to exceptionally high rates of speed and demonstrates unmatched resilience after being stretched or deformed. (more…)

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Yale Research Offers New Way To See Inside Solids

Researchers at Yale University have developed a new way of seeing inside solid objects, including animal bones and tissues, potentially opening a vast array of dense materials to a new type of detailed internal inspection.

The technique, a novel kind of magnetic resonance imaging (MRI), creates three-dimensional images of hard and soft solids based on signals emitted by their phosphorus content. (more…)

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