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Category: physics – Page 143

Astrophysicists scan the galaxy for signs of life

The astrophysicists, from Trinity and the Breakthrough Listen team and Onsala Space Observatory in Sweden, are scanning the universe for “technosignatures” emanating from distant planets that would provide support for the existence of intelligent, alien life.

Using the Irish LOFAR telescope and its counterpart in Onsala, Sweden, the team—led by Professor Evan Keane, Associate Professor of Radio Astronomy in Trinity’s School of Physics, and Head of the Irish LOFAR Telescope—plans to monitor millions of star systems.

Scientists have been searching for extraterrestrial radio signals for well over 60 years. Many of these have been carried out using single observatories which limits the ability to identify signals from the haze of terrestrial interference on Earth. Much of the effort has focused on frequencies above 1 GHz because the single-dish telescopes employed operate at these frequencies.

Adaptive optical neural network connects thousands of artificial neurons

Modern computer models—for example for complex, potent AI applications—push traditional digital computer processes to their limits. New types of computing architecture, which emulate the working principles of biological neural networks, hold the promise of faster, more energy-efficient data processing.

A team of researchers has now developed a so-called event-based architecture, using photonic processors with which data are transported and processed by means of light. In a similar way to the brain, this makes possible the continuous adaptation of the connections within the neural network. This changeable connections are the basis for learning processes.

For the purposes of the study, a team working at Collaborative Research Center 1,459 (Intelligent Matter)—headed by physicists Prof. Wolfram Pernice and Prof. Martin Salinga and computer specialist Prof. Benjamin Risse, all from the University of Münster—joined forces with researchers from the Universities of Exeter and Oxford in the UK. The study has been published in the journal Science Advances.

Do we live in a computer simulation like in The Matrix? Proposed new law of physics backs up the idea

The simulated universe theory implies that our universe, with all its galaxies, planets and life forms, is a meticulously programmed computer simulation. In this scenario, the physical laws governing our reality are simply algorithms. The experiences we have are generated by the computational processes of an immensely advanced system.

While inherently speculative, the simulated theory has gained attention from scientists and philosophers due to its intriguing implications. The idea has made its mark in popular culture, across movies, TV shows and books—including the 1999 film “The Matrix.”

The earliest records of the concept that reality is an illusion are from ancient Greece. There, the question “What is the nature of our reality?” posed by Plato (427 BC) and others, gave birth to idealism. Idealist ancient thinkers such as Plato considered mind and spirit as the abiding reality. Matter, they argued, was just a manifestation or illusion.

Black holes could come in ‘perfect pairs’ in an ever expanding universe

Researchers from the University of Southampton, together with colleagues from the universities of Cambridge and Barcelona, have shown it’s theoretically possible for black holes to exist in perfectly balanced pairs—held in equilibrium by a cosmological force—mimicking a single black hole.

Black holes are massive astronomical objects that have such a strong gravitational pull that nothing, not even light, can escape. They are incredibly dense. A black hole could pack the mass of the Earth into a space the size of a pea.

Conventional theories about , based on Einstein’s theory of General Relativity, typically explain how static or spinning black holes can exist on their own, isolated in space. Black holes in pairs would eventually be thwarted by gravity attracting and colliding them together.

Accelerating waves shed light on major problems in physics

Whenever light interacts with matter, light appears to slow down. This is not a new observation and standard wave mechanics can describe most of these daily phenomena.

For example, when light is incident on an interface, the standard wave equation is satisfied on both sides. To analytically solve such a problem, one would first find what the wave looks like at either side of the interface, and then employ electromagnetic boundary conditions to link the two sides together. This is called a piecewise continuous solution.

However, at the boundary, the must experience an acceleration. So far, this has not been accounted for.

Unbreakable Barrier Broken: New “Superlens” Technique Will Finally Allow Scientists to See the Infinitesimal

Researchers have developed a potentially revolutionary superlens technique that once seemed impossible to see things four times smaller than even the most modern microscopes have seen before. Known as the ‘diffraction limit’ because the diffraction of light waves at the tiniest levels has prevented microscopes from seeing things smaller than those waves, this barrier once seemed unbreakable.

Many have tried to peer below this optical barrier using a technique that researchers in the field term ‘superlensing, including making customized lenses out of novel materials. But all have gathered too much light. Now, a team of physicists from the University of Sydney says they have discovered a viable path that peeks beyond the diffraction limit by a factor of four times, allowing researchers to see things smaller than ever seen before. And the way they did, it is like nothing anyone else has tried.

Breaking the Diffraction Limit by ‘Superlensing’ without a Superlens.

From a five-layer graphene sandwich, a rare electronic state emerges

Despite its waif-like proportions, scientists have found over the years that graphene is exceptionally strong. And when the material is stacked and twisted in specific contortions, it can take on surprising electronic behavior.

Now, MIT physicists have discovered another surprising property in graphene: When stacked in five layers, in a rhombohedral pattern, graphene takes on a very rare, “multiferroic” state, in which the material exhibits both unconventional magnetism and an exotic type of electronic behavior, which the team has coined ferro-valleytricity.

“Pseudogravity” in crystals can bend light like black holes

Scientists in Japan have managed to manipulate light as though it was being influenced by gravity. By carefully distorting a photonic crystal, the team was able to invoke “pseudogravity” to bend a beam of light, which could have useful applications in optics systems.

One of the quirks of Einstein’s theory of general relativity is that light is affected by the fabric of spacetime, which itself is distorted by gravity. That’s why objects with extremely high masses, like black holes or entire galaxies, wreak such havoc on light, bending its path and magnifying distant objects.

In recent studies, it was predicted that it should be possible to replicate this effect in photonic crystals. These structures are used to control light in optics devices and experiments, and they’re generally made by arranging multiple materials into periodic patterns. Distortions in these crystals, it was theorized, could deflect light waves in a way very similar to cosmic-scale gravitational lenses. The phenomenon was dubbed pseudogravity.

Scientists Can Now Make Tiny Black Holes With Pseudogravity

Published 8 seconds ago.

Physicists at the Kyoto Institute of Technology altered a special material called a photonic crystal to change the way light moves, creating pseudogravity, an effect similar to a tiny black hole. The experiment was inspired by Einstein’s theory of relativity and showcased light similar to how it would be if it were passing through a gravitational field. According to Science Alert, this experiment has far-reaching implications for the control and manipulation of light in optics and communications technology.

Mistranslation of Newton’s First Law Discovered after Nearly 300 Years

A subtle mistranslation of Isaac Newton’s first law of motion that flew under the radar for three centuries is giving new insight into what the pioneering natural philosopher was thinking when he laid the foundations of classical mechanics.

The first law of motion is often paraphrased as “objects in motion tend to stay in motion, and objects at rest tend to stay at rest.” But the history of this rather obvious-seeming axiom about inertia is complicated. Writing in Latin in his 17th-century book Philosophiae Naturalis Principia Mathematica, Newton said, “Every body perseveres in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by the forces impressed.”

Throughout the centuries, many philosophers of science have interpreted this phrasing to be about bodies that don’t have any forces acting upon them, says Daniel Hoek, a philosopher at Virginia Tech. For example, in 1965 Newton scholar Brian Ellis paraphrased him as saying, “Every body not subject to the action of forces continues in its state of rest or uniform motion in a straight line.” But that’s a bit puzzling, Hoek says, because there are no bodies in the universe that are free of external forces acting upon them. Why make a law about something that doesn’t exist?

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