Archive for the ‘particle physics’ category: Page 7

Sep 30, 2020

Comet 67P/Churyumov-Gerasimenko Has A Tiny Moon

Posted by in categories: particle physics, space

Comet 67P/C-G is a dusty object. As it neared its closest approach to the Sun in late July and August 2015, instruments on Rosetta recorded a huge amount of dust enshrouding the comet.

This is tied to the comet’s proximity to our parent star, its heat causing the comet’s nucleus to release gases into space, lifting the dust along. Spectacular jets were also observed, blasting more dust away from the comet. This disturbed, ejected material forms the ‘coma’, the gaseous envelope encasing the comet’s nucleus, and can create a beautiful and distinctive tail.

A single image from Rosetta’s OSIRIS instrument can contain hundreds of dust particles and grains surrounding the 4 km-wide comet nucleus. Sometimes, even larger chunks of material left the surface of 67P/C-G — as shown here.

Continue reading “Comet 67P/Churyumov-Gerasimenko Has A Tiny Moon” »

Sep 29, 2020

Quantum entanglement realized between distant large objects

Posted by in categories: particle physics, quantum physics

A team of researchers at the Niels Bohr Institute, University of Copenhagen, have succeeded in entangling two very different quantum objects. The result has several potential applications in ultra-precise sensing and quantum communication and is now published in Nature Physics.

Entanglement is the basis for and quantum sensing. It can be understood as a quantum link between two objects which makes them behave as a single quantum object.

Researchers succeeded in making entanglement between a mechanical oscillator—a vibrating dielectric membrane—and a cloud of atoms, each acting as a tiny magnet, or what physicists call “spin.” These very different entities were possible to entangle by connecting them with photons, particles of light. Atoms can be useful in processing quantum information and the membrane—or mechanical quantum systems in general—can be useful for storage of quantum information.

Sep 28, 2020

Scientists precisely measure total amount of matter in the universe

Posted by in categories: cosmology, particle physics

A top goal in cosmology is to precisely measure the total amount of matter in the universe, a daunting exercise for even the most mathematically proficient. A team led by scientists at the University of California, Riverside, has now done just that.

Reporting in the Astrophysical Journal, the team determined that matter makes up 31% of the total amount of matter and energy in the , with the remainder consisting of dark energy.

“To put that amount of matter in context, if all the matter in the universe were spread out evenly across space, it would correspond to an average mass density equal to only about six per cubic meter,” said first author Mohamed Abdullah, a graduate student in the UCR Department of Physics and Astronomy. “However, since we know 80% of matter is actually , in reality, most of this matter consists not of hydrogen atoms but rather of a type of matter which cosmologists don’t yet understand.”

Sep 28, 2020

Identical Quantum Particles Pass Practicality Test

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

A new study proves that far from being mere mathematical artifacts, particles that are indistinguishable from one another can be a potent resource in real-world experiments.

Sep 27, 2020

Astrophysicists Prove That Water Ice Is Trapped in Star Dust

Posted by in categories: chemistry, particle physics, space travel

Astrophysicists at the University of Jena (Germany) prove that dust particles in space are mixed with ice.

The matter between the stars in a galaxy – called the interstellar medium – consists not only of gas, but also of a great deal of dust. At some point in time, stars and planets originated in such an environment, because the dust particles can clump together and merge into celestial bodies. Important chemical processes also take place on these particles, from which complex organic – possibly even prebiotic – molecules emerge. However, for these processes to be possible, there has to be water. In particularly cold cosmic environments, water occurs in the form of ice. Until now, however, the connection between ice and dust in these regions of space was unclear. A research team from Friedrich Schiller University Jena and the Max Planck Institute for Astronomy has now proven that the dust particles and the ice are mixed. They report their findings in the current issue of the research journal Nature Astronomy.

Better modelling of physico-chemical processes in space.

Sep 27, 2020

Meet the quantum fridge — at three atoms in size, it’s much smaller than a minibar

Posted by in categories: particle physics, quantum physics

Researchers in Singapore have built a refrigerator that’s just three atoms big.

This quantum fridge won’t keep your drinks cold, but it’s cool proof of physics operating at the smallest scales. The work is described in a paper published in Nature Communications (“Quantum absorption refrigerator with trapped ions”).

Researchers have built tiny ‘heat engines’ before, but quantum fridges existed only as proposals until the team at the Centre for Quantum Technologies at the National University of Singapore chilled with their atoms.

Sep 25, 2020

The exotic ‘atom’ positronium surprises scientists

Posted by in category: particle physics


New measurements of a weird but simple atom, one without a nucleus, suggest it may have unexpected properties. Scientists find this troubling.

Sep 24, 2020

Scientists achieve higher precision weak force measurement between protons, neutrons

Posted by in category: particle physics


Through a one-of-a-kind experiment at the Department of Energy’s Oak Ridge National Laboratory, nuclear physicists have precisely measured the weak interaction between protons and neutrons. The result quantifies the weak force theory as predicted by the Standard Model of Particle Physics.

The team’s weak observation, detailed in Physical Review Letters, was measured through a precision experiment called n3He, or n-helium-3, that ran at ORNL’s Spallation Neutron Source, or SNS. Their finding yielded the smallest uncertainty of any comparable weak force measurement in the nucleus of an atom to date, which establishes an important benchmark.

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Sep 23, 2020

Nanostructures with a unique property

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

Nanoscale vortices known as skyrmions can be created in many magnetic materials. For the first time, researchers at PSI have managed to create and identify antiferromagnetic skyrmions with a unique property: critical elements inside them are arranged in opposing directions. Scientists have succeeded in visualizing this phenomenon using neutron scattering. Their discovery is a major step towards developing potential new applications, such as more efficient computers. The results of the research are published today in the journal Nature.

Whether a material is magnetic depends on the spins of its atoms. The best way to think of spins is as minute bar magnets. In a where the atoms have fixed positions in a lattice, these spins can be arranged in criss-cross fashion or aligned all in parallel like the spears of a Roman legion, depending on the individual material and its state.

Under certain conditions it is possible to generate tiny vortices within the corps of spins. These are known as skyrmions. Scientists are particularly interested in skyrmions as a key component in future technologies, such as more efficient data storage and transfer. For example, they could be used as memory bits: a could represent the digital one, and its absence a digital zero. As skyrmions are significantly smaller than the bits used in conventional storage media, data density is much higher and potentially also more energy efficient, while read and write operations would be faster as well. Skyrmions could therefore be useful both in classical data processing and in cutting-edge quantum computing.

Sep 22, 2020

Rosetta spacecraft detects unexpected ultraviolet aurora at a comet

Posted by in categories: particle physics, space

Data from Southwest Research Institute-led instruments aboard ESA’s Rosetta spacecraft have helped reveal auroral emissions in the far ultraviolet around a comet for the first time.

At Earth, auroras are formed when charged particles from the Sun follow our planet’s to the north and south poles. There, solar particles strike atoms and molecules in Earth’s atmosphere, creating shimmering curtains of colorful light in high-latitude skies. Similar phenomena have been seen at various planets and moons in our and even around a distant star. SwRI’s instruments, the Alice far-ultraviolet (FUV) spectrograph and the Ion and Electron Sensor (IES), aided in detecting these novel phenomena at 67P/Churyumov-Gerasimenko (67P/C-G).

“Charged particles from the Sun streaming towards the comet in the solar wind interact with the gas surrounding the comet’s icy, dusty nucleus and create the auroras,” said SwRI Vice President Dr. Jim Burch who leads IES. “The IES instrument detected the electrons that caused the aurora.”

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