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Archive for the ‘physics’ category: Page 204

Jul 19, 2020

Magnetic Wormhole Created in Lab

Posted by in categories: cosmology, physics, robotics/AI

Ripped from the pages of a sci-fi novel, physicists have crafted a wormhole that tunnels a magnetic field through space.

“This device can transmit the magnetic field from one point in space to another point, through a path that is magnetically invisible,” said study co-author Jordi Prat-Camps, a doctoral candidate in physics at the Autonomous University of Barcelona in Spain. “From a magnetic point of view, this device acts like a wormhole, as if the magnetic field was transferred through an extra special dimension.”

The idea of a wormhole comes from Albert Einstein’s theories. In 1935, Einstein and colleague Nathan Rosen realized that the general theory of relativity allowed for the existence of bridges that could link two different points in space-time. Theoretically these Einstein-Rosen bridges, or wormholes, could allow something to tunnel instantly between great distances (though the tunnels in this theory are extremely tiny, so ordinarily wouldn’t fit a space traveler). So far, no one has found evidence that space-time wormholes actually exist. [Science Fact or Fiction? The Plausibility of 10 Sci-Fi Concepts].

Jul 18, 2020

Oldest surviving light reveals the universe’s true age

Posted by in category: physics

One of the most important controversies in physics remains unresolved after a major new study. But at least we have a new precise number for the universe’s age.

Jul 17, 2020

Scientists achieve major breakthrough in preserving integrity of sound waves

Posted by in categories: energy, engineering, physics

In a breakthrough for physics and engineering, researchers from the Photonics Initiative at the Advanced Science Research Center at The Graduate Center, CUNY (CUNY ASRC) and from Georgia Tech have presented the first demonstration of topological order based on time modulations. This advancement allows the researchers to propagate sound waves along the boundaries of topological metamaterials without the risk of waves traveling backwards or being thwarted by material defects.

The new findings, which appear in the journal Science Advances, will pave the way for cheaper, lighter devices that use less battery power, and which can function in harsh or hazardous environments. Andrea Alù, founding director of the CUNY ASRC Photonics Initiative and Professor of Physics at The Graduate Center, CUNY, and postdoctoral research associate Xiang Ni were authors on the paper, together with Amir Ardabi and Michael Leamy from Georgia Tech.

The field of topology examines properties of an object that are not affected by continuous deformations. In a topological insulator, electrical currents can flow along the object’s boundaries, and this flow is resistant to being interrupted by the object’s imperfections. Recent progress in the field of metamaterials has extended these features to control the propagation of sound and light following similar principles.

Jul 17, 2020

What if the speed of light were that of a cyclist?

Posted by in category: physics

A new paper revives a hero from physics’s past.

Science & technology Jul 18th 2020 edition.

Jul 14, 2020

“Blinding Whole Galaxies, Destroying Millions of Worlds” –Rare Short Gamma Ray Burst Detected

Posted by in categories: cosmology, physics

A short gamma ray burst left the most-distant optical afterglow ever detected –incredibly faint and fast signals sometimes lasting mere hours–some 10 billion light years away, 3.8 billion years after the Big Bang. Astronomers suspect that up to one-third of all short gamma ray bursts come from merging neutron stars in globular clusters of old stars blinding whole galaxies with light and destroying millions of worlds. Known as SGRB181123B, it is the second most-distant well-established SGRB ever detected and the most distant event with an optical afterglow.

The appearance of an SGRB at such an early time, report astronomers at the Keck Observatory and Northwestern University could alter theories about their origins, particularly the length of time it takes two neutron stars to merge and produce these powerful explosions, as well as the rate of neutron star mergers in the young universe.

“This was a very exciting object to study,” said Kerry Paterson, a postdoctoral associate at Northwestern University’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and lead author of the study. “Our research now suggests neutron star mergers could occur surprisingly quickly for some systems — with neutron star binaries spiraling together in less than a billion years to create an SGRB.”

Jul 13, 2020

Elon Musk on How to Travel Faster than Light Speed “Space travels faster than the speed of light”

Posted by in categories: cosmology, Elon Musk, physics, space travel

“There is conceivably a way to do warp drive.” Elon Musk discusses warping space within the known laws of physics, the expansion of the universe being faster than the speed of light (which allow us to see back in time when looking into space) and dark matter.

Jul 12, 2020

What’s the most amazing thing about the universe?

Posted by in categories: information science, physics, space

A few scant equations can explain a variety of phenomena in our universe, over vast gulfs of space and time. Here’s a taste of just how powerful modern physics can be.

Jul 9, 2020

New study detects ringing of the global atmosphere

Posted by in categories: media & arts, physics

A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound. A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawai’i at Mānoa, shows that the Earth’s entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.

In the case of the , the “music” comes not as a sound we could hear, but in the form of large-scale waves of spanning the globe and traveling around the equator, some moving east-to-west and others west-to-east. Each of these waves is a resonant vibration of the global atmosphere, analogous to one of the resonant pitches of a bell. The basic understanding of these atmospheric resonances began with seminal insights at the beginning of the 19th century by one of history’s greatest scientists, the French physicist and mathematician Pierre-Simon Laplace. Research by physicists over the subsequent two centuries refined the theory and led to detailed predictions of the wave frequencies that should be present in the atmosphere. However, the actual detection of such waves in the has lagged behind the theory.

Now in a new study by Takatoshi Sakazaki, an assistant professor at the Kyoto University Graduate School of Science, and Kevin Hamilton, an Emeritus Professor in the Department of Atmospheric Sciences and the International Pacific Research Center at the University of Hawai?i at Mānoa, the authors present a detailed analysis of observed atmospheric pressure over the globe every hour for 38 years. The results clearly revealed the presence of dozens of the predicted wave modes.

Jul 8, 2020

Contest between superconductivity and insulating states in ‘magic angle’ graphene

Posted by in categories: materials, physics

If you stack two layers of graphene one on top of the other, and rotate them at an angle of 1.1º (no more and no less) from each other—the so-called ‘magic-angle,’ experiments have proven that the material can behave like an insulator, where no electrical current can flow, and at the same can also behave like a superconductor, where electrical currents can flow without resistance.

This major finding took place in 2018. Last year, in 2019, while ICFO researchers were improving the quality of the device used to replicate such breakthroughs, they stumbled upon something even bigger and totally unexpected. They were able to observe a zoo of previously unobserved superconducting and correlated states, in addition to an entirely new set of magnetic and topological states, opening a completely new realm of richer physics.

So far, there is no theory that has been able to explain superconductivity in magic angle graphene at the microscopic level. However, this finding has triggered many studies, which are trying to understand and unveil the physics behind all these phenomena that occur in this material. In particular, scientists drew analogies to unconventional high temperature superconductors—the cuprates, which hold the record highest superconducting temperatures, only 2 times lower than . Their microscopic mechanism of the superconducting phase is still not understood, 30 years after its discovery. However, similarly to magic angle twisted bi-layer graphene (MATBG), it is believed that an insulating phase is responsible for the superconducting phase in proximity to it. Understanding the relationship between the superconducting and insulating phases is at the center of researcher’s interest, and could lead to a big breakthrough in superconductivity research.

Jul 8, 2020

Mysterious spinning neutron star detected in the Milky Way proves to be an extremely rare discovery

Posted by in categories: physics, space

On March 12th 2020 a space telescope called Swift detected a burst of radiation from halfway across the Milky Way. Within a week, the newly discovered X-ray source, named Swift J1818.0–1607, was found to be a magnetar, a rare type of slowly rotating neutron star with one of the most powerful magnetic fields in the universe.

Spinning once every 1.4 seconds, it’s the fastest spinning known, and possibly one of the youngest in the Milky Way. It also emits pulses like those seen from pulsars—another type of rotating neutron star. At the time of this detection, only four other radio-pulse-emitting magnetars were known, making Swift J1818.0–1607 an extremely rare discovery.

In a recently published study led by a team of scientists from the ARC Center of Excellence for Gravitational Wave Discovery (OzGrav), it was found that the pulses from the magnetar become significantly fainter when going from low to high : It has a steep radio spectrum. Its radio emission is not only steeper than the four other radio magnetars, but also steeper than ~90% of all pulsars. Additionally, they found the magnetar had become over 10 times brighter in only two weeks.