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Archive for the ‘particle physics’ category: Page 226

Nov 18, 2022

One-unit-cell thick semiconductors with room-temperature magnetism

Posted by in category: particle physics

The discovery of magnetism in two-dimensional (2D) ultrathin crystals opens up opportunities to explore new physics and to develop next-generation spintronic devices. However, 2D magnetic semiconductors with Curie temperatures higher than room temperature have rarely been reported. Researchers now show that high-quality, nonlayered cobalt ferrite nanosheets as thin as a single unit cell can be synthesized via van der Waals epitaxy.

Nov 18, 2022

Wild New Study Reveals Neutron Stars Are Actually Like a Box of Chocolates

Posted by in categories: alien life, particle physics

Life isn’t really like a box of chocolates, but it seems that something out there is. Neutron stars – some of the densest objects in the Universe – can have structures very similar to chocolates, with either gooey or hard centers.

What kinds of particle configurations those centers consist of is still unknown, but new theoretical work revealing this surprising result could put us a step closer to understanding the strange guts of these dead stars, and the wild extremes possible in our Universe.

Neutron stars are pretty incredible. If we consider black holes to be objects of immense (if not infinite) concentrations of matter, neutron stars win second place in the Universe’s Most Dense Award. Once a star with a mass of around 8 to 30 times that of the Sun’s runs out of matter to fuse in its core, it’s no longer supported by heat’s outward pressure, allowing the core to collapse under gravity as its shell of surrounding gases drift off into space.

Nov 16, 2022

Simulations Using a Quantum Computer Show the Technology’s Current Limits

Posted by in categories: computing, particle physics, quantum physics

Quantum circuits still can’t outperform classical ones when simulating molecules.

Quantum computers promise to directly simulate systems governed by quantum principles, such as molecules or materials, since the quantum bits themselves are quantum objects. Recent experiments have demonstrated the power of these devices when performing carefully chosen tasks. But a new study shows that for problems of real-world interest, such as calculating the energy states of a cluster of atoms, quantum simulations are no more accurate than those of classical computers [1]. The results offer a benchmark for judging how close quantum computers are to becoming useful tools for chemists and materials scientists.

Richard Feynman proposed the idea of quantum computers in 1982, suggesting they might be used to calculate the properties of quantum matter. Today, quantum processors are available with several hundred quantum bits (qubits), and some can, in principle, represent quantum states that are impossible to encode in any classical device. The 53-qubit Sycamore processor developed by Google has demonstrated the potential to perform calculations in a few days that would take many millennia on current classical computers [2]. But this “quantum advantage” is achieved only for selected computational tasks that play to these devices’ strengths. How well do such quantum computers fare for the sorts of everyday challenges that researchers studying molecules and materials actually wish to solve?

Nov 16, 2022

Chinese scientists build atom-sized ‘4-stroke’ quantum engine

Posted by in categories: particle physics, quantum physics

Researchers use lasers to increase or suppress an ion’s quantum characteristics and generate power at microscopic level.

Nov 15, 2022

Nuclear fusion experiment just made something very strange happen

Posted by in category: particle physics

In a recent study, charged atoms, also known as ions, have been found to behave strangely during nuclear fusion reactions, in ways that scientists did not expect.

According to a paper published on November 14 in the journal Nature Physics, researchers at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory discovered that when deuterium and tritium ions, which are isotopes of hydrogen with one and two neutrons, respectively—are heated using lasers during laser-fusion experiments, there are more ions with higher energies than expected when a thermonuclear burn starts.

“The process of inertial confinement fusion (ICF) squeezes a small (1mm radius) capsule filled with a layer of frozen deuterium and tritium (isotopes of hydrogen) surrounding a volume of deuterium and tritium gas down to a radius of about 30 micrometers. In the process, these isotopes of hydrogen ionize and a plasma of electrons, deuterium and tritium nuclei [is the result],” Edward Hartouni, a physicist at NIF and a co-author of the paper, told Newsweek.

Nov 15, 2022

Scientists Created a Black Hole in The Lab, And Then It Started to Glow

Posted by in categories: cosmology, mathematics, particle physics, quantum physics

A new kind of black hole analog could tell us a thing or two about an elusive radiation theoretically emitted by the real thing.

Using a chain of atoms in single-file to simulate the event horizon of a black hole, a team of physicists has observed the equivalent of what we call Hawking radiation – particles born from disturbances in the quantum fluctuations caused by the black hole’s break in spacetime.

This, they say, could help resolve the tension between two currently irreconcilable frameworks for describing the Universe: the general theory of relativity, which describes the behavior of gravity as a continuous field known as spacetime; and quantum mechanics, which describes the behavior of discrete particles using the mathematics of probability.

Nov 15, 2022

Boltzmann Brains — Why The Universe is Most Likely a Simulation

Posted by in categories: computing, mathematics, particle physics, space

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Watch Part 2 over on Isaac Arthur’s channel.

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Nov 14, 2022

Powerful linear accelerator begins smashing atoms — 2 scientists on the team explain how it could reveal rare forms of matter

Posted by in category: particle physics

A new particle accelerator has just begun operation. It is the most powerful accelerator of its kind on Earth and will allow physicists to study some of the rarest matter in the universe.

Nov 14, 2022

Recent searches for light fermionic dark matter by the PandaX-4T collaboration

Posted by in categories: cosmology, particle physics

Teams of astrophysicists worldwide are trying to observe different possible types of dark matter (DM), hypothetical matter in the universe that does not emit, absorb or reflect light and would thus be very difficult to detect. Fermionic DM, however, which would be made of fermions, has so far been primarily explored theoretically.

The PandaX Collaboration, a large consortium of researchers in China involved in the PandaX-4T experiment, has recently carried out a study aimed at extending the sensitive window for experiments aimed at directly detecting fermionic DM from above GeV to MeV or even keV ranges.

The team recently published two papers in Physical Review Letters outlining the results of the two searches for the absorption of fermionic DM using data gathered as part of the Panda X-4T experiment, a large-scale research effort aimed at detecting DM using a dual-phase time projection chamber (TPC) in China.

Nov 14, 2022

Is Physical Law an Alien Intelligence?

Posted by in categories: alien life, existential risks, mobile phones, particle physics, singularity

Perhaps Arthur C. Clarke was being uncharacteristically unambitious. He once pointed out that any sufficiently advanced technology is going to be indistinguishable from magic. If you dropped in on a bunch of Paleolithic farmers with your iPhone and a pair of sneakers, you’d undoubtedly seem pretty magical. But the contrast is only middling: The farmers would still recognize you as basically like them, and before long they’d be taking selfies. But what if life has moved so far on that it doesn’t just appear magical, but appears like physics?

After all, if the cosmos holds other life, and if some of that life has evolved beyond our own waypoints of complexity and technology, we should be considering some very extreme possibilities. Today’s futurists and believers in a machine “singularity” predict that life and its technological baggage might end up so beyond our ken that we wouldn’t even realize we were staring at it. That’s quite a claim, yet it would neatly explain why we have yet to see advanced intelligence in the cosmos around us, despite the sheer number of planets it could have arisen on—the so-called Fermi Paradox.

For example, if machines continue to grow exponentially in speed and sophistication, they will one day be able to decode the staggering complexity of the living world, from its atoms and molecules all the way up to entire planetary biomes. Presumably life doesn’t have to be made of atoms and molecules, but could be assembled from any set of building blocks with the requisite complexity. If so, a civilization could then transcribe itself and its entire physical realm into new forms. Indeed, perhaps our universe is one of the new forms into which some other civilization transcribed its world.