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Archive for the ‘physics’ category: Page 66

Oct 27, 2023

350-Year-Old Theorem Reveals ‘Profound’ Connection Between Properties of Light

Posted by in category: physics

Dutch-born Christiaan Huygens is probably one of the most famous physicists you’ve never heard of. His work in the late 17th century straddled both the intangible and tangible realms of our Universe: the nature of light, and the mechanics of moving objects.

Among his many contributions, Huygens proposed a wave theory of light that would give rise to physical optics, which deals with the interference, diffraction, and polarization of light. He also invented the first pendulum clock; the most accurate timekeeper for almost 300 years, right through the Industrial Revolution.

Little has been made of the connections between these two seemingly disparate fields of optics and classical mechanics – until now.

Oct 27, 2023

New research sheds light on early galaxy formation

Posted by in categories: computing, physics, space

Researchers have developed a new computer simulation of the early universe that closely aligns with observations made by the James Webb Space Telescope (JWST).

Initial JWST observations hinted that something may be amiss in our understanding of early galaxy formation. The first galaxies studied by JWST appeared to be brighter and more massive than theoretical expectations.

The findings, published in The Open Journal of Astrophysics, by researchers at Maynooth University, Ireland, with collaborators from US-based Georgia Institute of Technology, show that observations made by JWST do not contradict theoretical expectations. The so-called “Renaissance simulations” used by the team are a series of highly sophisticated computer simulations of galaxy formation in the early universe.

Oct 25, 2023

Astrophysicists scan the galaxy for signs of life

Posted by in categories: alien life, physics

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.

Oct 23, 2023

Adaptive optical neural network connects thousands of artificial neurons

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

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.

Oct 22, 2023

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

Posted by in categories: alien life, computing, information science, physics

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.

Oct 22, 2023

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

Posted by in categories: cosmology, physics

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.

Oct 21, 2023

Accelerating waves shed light on major problems in physics

Posted by in categories: information science, 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.

Oct 20, 2023

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

Posted by in categories: materials, physics

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.

Oct 20, 2023

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

Posted by in categories: materials, physics

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.

Oct 20, 2023

“Pseudogravity” in crystals can bend light like black holes

Posted by in categories: cosmology, physics

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.

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