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Archive for the ‘physics’ category: Page 130

Sep 2, 2022

Physicists Broke The Speed of Light With Pulses Inside Hot Plasma

Posted by in categories: law, physics

Most of us grow up familiar with the prevailing law that limits how quickly information can travel through empty space: the speed of light, which tops out at 300,000 kilometers (186,000 miles) per second.

While photons themselves are unlikely to ever break this speed limit, there are features of light which don’t play by the same rules.

Manipulating them won’t hasten our ability to travel to the stars, but they could help us clear the way to a whole new class of laser technology.

Sep 1, 2022

Dark Matter: The Situation has Changed

Posted by in categories: cosmology, physics

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Today I tell you how my opinion about dark matter has changed an why. Is modified gravity better or worse? What evidence speaks for one side or the other, and is the case really as clear-cut as many astrophysicists claim?

Continue reading “Dark Matter: The Situation has Changed” »

Sep 1, 2022

Using magnetic and electric fields to emulate black hole and stellar accretion disks

Posted by in categories: computing, cosmology, mathematics, physics

A team of researchers at the Sorbonne University of Paris reports a new way to emulate black hole and stellar accretion disks. In their paper published in the journal Physical Review Letters, the group describes using magnetic and electric fields to create a rotating disk made of liquid metal to emulate the behavior of material surrounding black holes and stars, which leads to the development of accretion disks.

Prior research has shown that massive objects have a gravitational reach that pulls in gas, dust and other material. And since such massive objects tend to spin, the material they pull in tends to swirl around the object as it moves closer. When that happens, gravity exerted by materials in the swirling mass tends to coalesce, resulting in an . Astrophysicists have been studying the dynamics of accretion disks for many years but have not been able to figure out how angular momentum is transferred from the inner parts of a given accretion disk to its outer parts as material in the disk moves ever closer to the central object.

Methods used to study accretion disks have involved the development of math formulas, and real-world models using liquids that swirl like eddies. None of the approaches has proven suitable, however, which has led researchers to look for new models. In this new effort, the researchers developed a method to generate an accretion disk made of bits spinning in the air.

Aug 30, 2022

Philip Goff — “Did the Universe Design Itself?”

Posted by in categories: alien life, physics

There are a number of constants in the basic laws of physics and initial conditions of the universe that are such that, for life to be possible, the values of those constants needed to fall in an exceedingly narrow range. Many scientists and philosophers think there must be an explanation of why, of all the values they might have had, these constants have precisely the values needed in order for life to be possible. There are deep difficulties with both of the standard explanations of this ‘fine-tuning’ of the laws of nature: theism and the multiverse hypothesis. I will argue that if one adopts a certain form of panpsychism, one can explain the fine-tuning in terms of the mental capacities of the universe, and that this constitutes a significantly less problematic and significantly more parsimonious explanation of the fine-tuning.

Philip Goff is Associate Professor in philosophy at the Central European University in Budapest (a unique and wonderful institution). His main research interest is consciousness, although he also has a sideline in political philosophy (taxation, globalisation, social justice). He recently finished his first book, Consciousness and Fundamental Reality (published with Oxford University Press August 2017), which argues against materialism and defends panpsychism. He is now working on a book on these themes aimed at a general audience. He has written for The Guardian and Philosophy Now, and writes a blog at www.conscienceandconsciousness.com. www.philipgoffphilosophy.com @philip_goff

Aug 30, 2022

Astronomers have detected one of the biggest black hole jets in the sky

Posted by in categories: cosmology, physics

Luke barnes, lecturer in physics, western sydney university miroslav filipovic, professor, western sydney university ray norris, professor, school of science, western sydney university velibor velović, phd candidate, western sydney university.

Astronomers at Western Sydney University have discovered one of the biggest black hole jets in the sky.

Spanning more than a million light years from end to end, the jet shoots away from a black hole with enormous energy, and at almost the speed of light. But in the vast expanses of space between galaxies, it doesn’t always get its own way.

Aug 30, 2022

Spectroscopy That Doesn’t Scratch the Surface

Posted by in categories: energy, physics

Researchers have demonstrated a way of measuring the electronic states of a material’s surface while avoiding signal contaminations from deeper layers.

The electronic states of a material’s surface might only be 2D, but they offer a depth of interesting physics. Such states, which are distinct from those of the material’s bulk, dominate many phenomena, such as electrical conduction, magnetism, and catalysis, and they are responsible for nontrivial surface effects found in topological materials and systems with strong spin-orbit interaction. Surface electronic states also control the properties of so-called 2D materials, such as graphene. To understand surface phenomena and harness them in practical devices, researchers chiefly rely on photoemission spectroscopy, which measures the energy and momentum of electrons emitted when photons hit the material. The high resolution with which electron energy and momentum can be characterized allows physicists to measure both the band structure and the density of states (DOS) in the few surface layers where escaping photoelectrons originate.

Aug 30, 2022

Physicists uncover new dynamical framework for turbulence

Posted by in categories: climatology, engineering, information science, physics

Turbulence plays a key role in our daily lives, making for bumpy plane rides, affecting weather and climate, limiting the fuel efficiency of the cars we drive, and impacting clean energy technologies. Yet, scientists and engineers have puzzled at ways to predict and alter turbulent fluid flows, and it has long remained one of the most challenging problems in science and engineering.

Now, physicists from the Georgia Institute of Technology have demonstrated—numerically and experimentally—that turbulence can be understood and quantified with the help of a relatively small set of special solutions to the governing equations of fluid dynamics that can be precomputed for a particular geometry, once and for all.

“For nearly a century, turbulence has been described statistically as a random process,” said Roman Grigoriev. “Our results provide the first experimental illustration that, on suitably short time scales, the dynamics of turbulence is deterministic—and connects it to the underlying deterministic governing equations.”

Aug 30, 2022

X-shaped radio galaxies might form more simply than expected

Posted by in categories: cosmology, physics

When astronomers use radio telescopes to gaze into the night sky, they typically see elliptical-shaped galaxies, with twin jets blasting from either side of their central supermassive black hole. But every once in a while—less than 10% of the time—astronomers might spot something special and rare: An X-shaped radio galaxy, with four jets extending far into space.

Although these mysterious X-shaped radio galaxies have confounded astrophysicists for two decades, a new Northwestern University study sheds new insight into how they form—and its surprisingly simple. The study also found that X-shaped radio galaxies might be more common than previously thought.

Continue reading “X-shaped radio galaxies might form more simply than expected” »

Aug 29, 2022

NTT unveils what it calls the ‘first edge and private 5G’ service

Posted by in categories: internet, physics

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In today’s enterprise, even just a split second in latency can impact performance and access to data — and, thus, the ability to manage and immediately act on it.

But the physics and costs of multicloud and hybrid cloud environments make near-instantaneous response times all but impossible.

Aug 28, 2022

How the Physics of Nothing Underlies Everything

Posted by in categories: cosmology, physics

Then a mere scientist pulled it off. Otto von Guericke invented a pump to suck the air from within a hollow copper sphere, establishing perhaps the first high-quality vacuum on Earth. In a theatrical demonstration in 1,654, he showed that not even two teams of horses straining to rip apart the watermelon-size ball could overcome the suction of nothing.

Since then, the vacuum has become a bedrock concept in physics, the foundation of any theory of something. Von Guericke’s vacuum was an absence of air. The electromagnetic vacuum is the absence of a medium that can slow down light. And a gravitational vacuum lacks any matter or energy capable of bending space. In each case the specific variety of nothing depends on what sort of something physicists intend to describe. “Sometimes, it’s the way we define a theory,” said Patrick Draper, a theoretical physicist at the University of Illinois.

As modern physicists have grappled with more sophisticated candidates for the ultimate theory of nature, they have encountered a growing multitude of types of nothing. Each has its own behavior, as if it’s a different phase of a substance. Increasingly, it seems that the key to understanding the origin and fate of the universe may be a careful accounting of these proliferating varieties of absence.