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Archive for the ‘particle physics’ category: Page 202

Feb 8, 2023

Breaking: Researchers at CERN break “The Speed of Light”

Posted by in category: particle physics

Scientists said on Thursday they recorded particles travelling faster than light – a finding that could overturn one of Einstein’s fundamental laws of the universe. Antonio Ereditato, spokesman for the international group of researchers, saidthat measurements taken over three years showed neutrinos pumped from CERN near Geneva to Gran Sasso in Italy had arrived 60 nanoseconds quicker than light would have done.

“We have high confidence in our results. We have checked and rechecked for anything that could have distorted our measurements but we found nothing,” he said. “We now want colleagues to check them independently.”

If confirmed, the discovery would undermine Albert Einstein’s 1905 theory of special relativity, which says that the speed of light is a “cosmic constant” and that nothing in the universe can travel faster. That assertion, which has withstood over a century of testing, is one of the key elements of the so-called Standard Model of physics, which attempts to describe the way the universe and everything in it works. The totally unexpected finding emerged from research by a physicists working on an experiment dubbed OPERA run jointly by the CERN particle research center near Geneva and the Gran Sasso Laboratory in central Italy.

Feb 8, 2023

Supercooled Drops Have Rocket-Like Propulsion

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

Claudiu Stan of Rutgers University—Newark, New Jersey, and his colleagues were watching moving drops of supercooled water spontaneously freeze when they noticed something unexpected: drops kept suddenly disappearing. Initially they thought that the lost drops had shattered as they froze. But, on closer inspection, they found that the icy drops were still there, they had just moved out of view. The team has now developed a quantitative model for this behavior, attributing it to a rocket-like propulsion mechanism induced by the freezing process [1]. Stan says that the finding could inspire scientists to design self-propelled systems powered by such phase transitions.

The team’s results add to a growing body of work on self-propelled drops. The mechanisms behind such motion vary wildly, but Stan notes that they all involve symmetry breaking. For the freezing drops, this symmetry breaking arises when the ice nucleation starts off-center. When ice nucleates, the change in structure releases latent heat, causing the local evaporation rate to suddenly increase, and if the nucleation is off-center, this enhanced evaporation occurs unevenly over the drop’s surface. Like a rocket ejecting a propellant heated by a chemical reaction, this asymmetrical evaporation increases the drop’s momentum, with the team’s model predicting peak velocities of nearly 1 m/s.

Stan says that this propulsion mechanism has a unique feature that could make it attractive for applications: unlike most self-propelled particles, it requires no surfaces and no surrounding fluid (the experiments were done under vacuum). But, for him, the findings have another bonus: “I am a fan of space exploration, so it was exciting to realize that [we could] draw an analogy between these tiny droplets and rockets,” he says.

Feb 8, 2023

How Sea Spray Might Disperse Large Particles

Posted by in category: particle physics

Experiments reveal new details of the process by which contaminants in the ocean could reach the atmosphere through the bursting of bubbles in foam.

The bursting bubbles in ocean foam produce a mist of droplets that can contain enhanced concentrations of ocean pollutant particles. In single-bubble lab experiments, researchers have now shown that the inclusion of a particular particle in an airborne droplet depends on some details of the fluid motion that occurs when the droplet forms [1]. The researchers measured the efficiency with which particles are transferred to droplets and also ran simulations of the fluid motion. Their model predicts that the airborne droplets should contain more large particles, such as microplastics, and fewer smaller particles, such as viruses, than expected based on previous theories.

The droplets produced by bursting air bubbles in ocean foam provide the atmosphere’s main source of ocean-originated particles, including pollutants and bacteria, and environmental scientists want to understand this ocean-to-atmosphere transfer process in detail. Experiments in the 1970s showed that bursting bubbles transport pathogens into the environment and also that the droplets produced contain these particles at high concentrations.

Feb 7, 2023

New horizons for organoboron and organosilicon chemistry with triple elementalization

Posted by in categories: chemistry, particle physics

In recent years, organic chemicals containing boron (B) and silicon (Si) have found applications in various fields, including optoelectronics and pharmaceuticals. Moreover, they can also serve as building blocks for complex organic chemicals. As a result, scientists are actively looking for new ways to leverage these versatile chemical tools as well as produce more kinds of organosilicon and organoboron compounds.

One limitation of the synthesis methods currently available for these chemicals is that we cannot introduce multiple B-and Si-containing groups in aromatic heterocycles, i.e., carbon rings in which one of the is replaced by a nitrogen atom. If we could produce and freely transform such molecules, it would unlock the synthesis of several compounds relevant in medicinal chemistry.

Fortunately, a research team including Assistant Professor Yuki Nagashima from Tokyo Institute of Technology (Tokyo Tech), Japan has found a straightforward way around this limitation. As explained in their most recent study published in Nature Communications, the team has developed a method that allows them to modify quinolines, small organic molecules with an aromatic nitrogen heterocycle, with B-, Si-, and carbon-containing groups simultaneously.

Feb 7, 2023

Watch nuclear fusion reactor form plasma: “You can’t take your eyes off it”

Posted by in categories: nuclear energy, particle physics, space travel

What does the inside of a nuclear fusion reactor look like?

“It looks like the future,” Stuart White, head of communications at Tokamak Energy, told Newsweek. “A spaceship. It’s extremely striking, powerful and exciting. You can’t take your eyes off it.”

Nuclear fusion is a technology that creates energy in the same way as the sun: it occurs when two atoms are thrust together with such force that they combine into a single, larger atom and release huge amounts of energy in the process.

Feb 7, 2023

Underdog technologies gain ground in quantum-computing race

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

Individual atoms trapped by optical ‘tweezers’ are emerging as a promising computational platform.

Feb 7, 2023

Rabi oscillations in a stretching molecule

Posted by in categories: particle physics, quantum physics

Over eighty years ago, Rabi oscillations were proposed to describe the strong coupling and population transfer in a two-level quantum system exposed to an oscillatory driving field. As compared to atoms, molecules have an extra degree of vibration, which adds an additional knob to the Rabi oscillations in light-molecule interactions. However, how such a laser-driven Rabi oscillation during the stretching of molecular bonds determines the kinetic energy release (KER) spectrum of dissociative fragments is still an open question.

In a new article published in Light: Science & Applications, a joint team of scientists, led by Professor Feng He from Shanghai Jiao Tong University and Professor Jian Wu from East China Normal University has investigated Rabi oscillations in a stretching molecule and discovered the strong-field-induced dissociation dynamics beyond the well-accepted resonant one-photon dissociation scenario. During the dissociation of the simplest molecular ion of H2+, coupled with the laser field, the electron hops between the 1sσg and 2pσu states, forming the Rabi oscillations.

The ionization-created nuclear wave packet (NWP) may propagate alternatively along the two potential energy curves towards a larger internuclear distance monotonically, termed as the rolling process, or may propagate outwards along the 2pσu curve followed by the inward propagation in the 1sσg curve and then be relaunched to 2pσu state again followed by subsequent dissociation, termed as the looping process. The rolling and looping dissociation pathways lead to different KERs of the ejected dissociative fragments, which have been verified by comparing experimental measurements with quantum simulation results.

Feb 6, 2023

Time Projection Chamber Installed at sPHENIX

Posted by in categories: cosmology, particle physics

Experts assembling sPHENIX, a state-of-the-art particle detector at the U.S. Department of Energy’s Brookhaven National Laboratory, successfully installed a major tracking component on Jan. 19. The Time Projection Chamber, or TPC, is one of the final pieces to move into place before sPHENIX begins tracking particle smash-ups at the Relativistic Heavy Ion Collider (RHIC) this spring.

The TPC is a gas-filled detector that, combined with the detector’s strong magnetic field, allows nuclear physicists to measure the momentum of charged particles streaming from RHIC collisions. It is one of many detector components that nuclear physicists will use to glean more information about the quark-gluon plasma (QGP)—a primordial soup made up of matter’s fundamental building blocks, quarks and gluons.

“QGP existed at the dawn of the universe some 14 billion years ago, about a millionth of a second after the Big Bang,” said Thomas Hemmick, a physicist at Stony Brook University (SBU) and a collaborator on RHIC research “RHIC’s collisions and sPHENIX’s ability to capture snapshots of particles traversing the QGP will help scientists understand how quarks and gluons cooled and coalesced to form the protons and neutrons that make up the atomic nuclei of all visible matter in the universe today.”

Feb 6, 2023

Free Will and Determinism from a Physicist’s Perspective (Sabine Hossenfelder)

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

The michael shermer show # 294

What is time? Does the past still exist? How did the universe begin and how will it end? Do particles think? Was the universe made for us? Why doesn’t anyone ever get younger? Has physics ruled out free will? Will we ever have a theory of everything? According to Sabine Hossenfelder, it is not a coincidence that quantum entanglement and vacuum energy have become the go-to explanations of alternative healers, or that people believe their deceased grandmother is still alive because of quantum mechanics. Science and religion have the same roots, and they still tackle some of the same questions: Where do we come from? Where do we go to? How much can we know? The area of science that is closest to answering these questions is physics. Over the last century, physicists have learned a lot about which spiritual ideas are still compatible with the laws of nature. Not always, though, have they stayed on the scientific side of the debate.

Continue reading “Free Will and Determinism from a Physicist’s Perspective (Sabine Hossenfelder)” »

Feb 4, 2023

Rolls-Royce’s new micro-reactor design could send humans to Mars

Posted by in categories: engineering, nuclear energy, particle physics, space travel

It is “designed to use an inherently safe and extremely robust fuel form.”

The future of deep space exploration is near. Rolls-Royce revealed a new image of a micro-reactor for space that it says is “designed to use an inherently safe and extremely robust fuel form.”

The iconic engineering firm recently tweeted the image alongside a caption. It is designing the nuclear fission system as part of an agreement it penned with the UK Space Agency in 2021.

Continue reading “Rolls-Royce’s new micro-reactor design could send humans to Mars” »