A high-energy particle descends from space to Earth's surface, its origin and nature shrouded in mystery. While it might resemble a scene from science fiction, this scenario is an actual scientific occurrence supported by the investigations led by Associate Professor Toshihiro Fujii at the Graduate School of Science and Nambu Yoichiro Institute of Theoretical and Experimental Physics at Osaka Metropolitan University.

Ultra-high-energy cosmic ray captured by the Telescope Array experiment on May 27, 2021, dubbed Amaterasu. The detected cosmic ray had an estimated energy of 244 EeV, comparable to the most energetic cosmic ray ever observed. Image Credit: Osaka Metropolitan University/L-INSIGHT, Kyoto University/Ryuunosuke Takeshige

Cosmic rays, energetic charged particles stemming from galactic and extragalactic origins, encompass an array of energy levels.

Among these, exceedingly high-energy cosmic rays are exceptionally scarce, surpassing 1018 electron volts or one exa-electron volt (EeV). This level of energy stands roughly a million times greater than what even the most potent human-made accelerators have achieved.

Professor Fujii and an international team of scientists have dedicated their efforts to pursuing these space-originating rays through the Telescope Array experiment, which has been ongoing since 2008. This specialized cosmic ray detector comprises 507 scintillator surface stations, collectively spanning a vast detection area of 700 square kilometers in Utah, United States.

A significant breakthrough occurred on May 27, 2021, when the researchers identified a particle boasting an astonishing energy level of 244 exa-electron volts (EeV).

When I first discovered this ultra-high-energy cosmic ray, I thought there must have been a mistake, as it showed an energy level unprecedented in the last 3 decades.

Toshihiro Fujii, Professor, Graduate School of Science and Nambu Yoichiro Institute of Theoretical and Experimental Physics, Osaka Metropolitan University

The most energetic cosmic ray of 320 EeV observed in 1991 was dubbed the Oh-My-God particle.

Among various potential names for the particle, Professor Fujii and his colleagues reached a consensus on naming it "Amaterasu," drawing from the sun goddess central to Shinto beliefs and credited with playing a pivotal role in Japan's creation mythology.

The Amaterasu particle is as enigmatic as the Japanese goddess herself. The questions were raised about the origin and domain of the Amaterasu particle. The Amaterasu particle might illuminate the origins of cosmic rays.

No promising astronomical object matching the direction from which the cosmic ray arrived has been identified, suggesting possibilities of unknown astronomical phenomena and novel physical origins beyond the Standard Model. In the future, we commit to continue operating the Telescope Array experiment, as we embark, through our ongoing upgraded experiment with fourfold sensitivities, dubbed TAx4, and next-generation observatories, on a more detailed investigation into the source of this extremely energetic particle.

Toshihiro Fujii, Professor, Graduate School of Science and Nambu Yoichiro Institute of Theoretical and Experimental Physics, Osaka Metropolitan University

The research was published in the journal Science on November 24th, 2023.

The Telescope Array experiment is supported by the Japan Society for the Promotion of Science (JSPS) through Grants-in-Aid for Priority Area 431, for Specially Promoted Research JP21000002, for Scientific Research (S) JP19104006, for Specially Promoted Research JP15H05693, for Scientific Research (S) JP15H05741, for Science Research (A) JP18H03705, for Young Scientists (A) JPH26707011, and for Fostering Joint International Research (B) JP19KK0074.

It is also supported by the joint research program of the Institute for Cosmic Ray Research (ICRR), The University of Tokyo; and by the Pioneering Program of RIKEN for the Evolution of Matter in the Universe (r-EMU).

The study was funded by the US National Science Foundation awards PHY-1607727, PHY-1712517, PHY-1806797, PHY-2012934, and PHY-2112904; by the National Research Foundation of Korea (2017K1A4A3015188, 2020R1A2C1008230, 2020R1A2C2102800); by the Ministry of Science and Higher Education of the Russian Federation under the contract 075-15-2020-778, IISN project No. 4.4501.18, Belgian Science Policy under IUAP VII/37 (ULB), and Simons Foundation (00001470, NG).

The Telescope Array project receives partial support from grants within the joint research program of the Institute for Space-Earth Environmental Research at Nagoya University and the Inter-University Research Program of the Institute for Cosmic Ray Research at the University of Tokyo. Additionally, funding stems from the Dr Ezekiel R. and Edna Wattis Dumke, Willard L. Eccles, and George S. and Dolores Dore Eccles foundations.

The State of Utah's backing is facilitated through its Economic Development Board, while the University of Utah contributes through the Office of the Vice President for Research.

Source: https://www.omu.ac.jp/en/

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Unraveling the Secrets of the Universe's Most Energetic Cosmic Ray - AZoQuantum

A super-small, highly precise, ultra-cold physics experiment has revealed a brand new quantum state, called the spinaron.

It occurs under extremely cold conditions when a cobalt atom on a copper surface is subjected to a strong magnetic field, causing its direction of spin to flip back and forth.

The discovery could trigger a major rethink of assumptions on how low-temperature conductive materials behave, according to physicists from the Julius Maximilian University of Wrzburg (JMU) and the Jlich Research Centre in Germany.

The researchers were able to see the magnetic spin of the cobalt atom in the experimental setup thanks to the combination of the intense magnetic field and an iron tip added to their atomic-scale scanning tunneling microscope.

This spin wasn't rigid, but rather continually switching back and forth, which then excited the electrons of the copper surface. To use an analogy very helpful in high-level physics, the cobalt atom is like a spinning rugby ball.

"When a rugby ball spins continuously in a ball pit, the surrounding balls are displaced in a wave-like manner," says experimental physicist Matthias Bode from JMU.

"That's precisely what we observed the copper electrons started oscillating in response and bonded with the cobalt atom."

The new observations had previously been predicted, and challenge existing thinking on something called the Kondo effect: a curious lower limit to electrical resistance when magnetic impurities are present in cold materials.

In these new experiments, the cobalt atom stays in constant motion, maintaining its magnetism even while interacting with the electrons. Under the rules of the Kondo effect, however, the magnetic moment would be neutralized by the electron interactions.

Since the 1960s, scientists have used the Kondo effect to explain certain types of quantum activity when metals such as cobalt and copper are combined. Now, some of that long-standing thinking might have to be changed and the researchers are looking for other scenarios where spinarons could apply instead of the Kondo effect.

"We suspect that many might actually be describing the spinaron effect," says experimental physicist Artem Odobesko from JMU, adding: "If so, we'll rewrite the history of theoretical quantum physics."

Quantum physics can be difficult to get your head around, but every breakthrough like this leads scientists to a greater understanding of how materials and the forces on them work together at the atomic level.

And the researchers themselves acknowledge the tension between making such an important discovery in highly precise and extreme lab conditions and yet not really having any immediate practical use for it.

"Our discovery is important for understanding the physics of magnetic moments on metal surfaces," says Bode. "While the correlation effect is a watershed moment in fundamental research for understanding the behavior of matter, I can't build an actual switch from it."

The research has been published in Nature Physics.

Originally posted here:

New Quantum Effect Could Mean The Kondo State Isn't What We Thought - ScienceAlert

Quantum mechanics affects the small and tiny usually, but at extremely low temperatures quantum behavior can become macroscopic. This is the case of helium, which can be a superfluid: a liquid that flows without losing any kinetic energy. An interesting consequence of that is that a superfluid in an open container will crawl up its walls and escape it. What would that feel like to touch? In a new paper, a team of researchers tells us how.

Senses are a way we understand the universe, at least up to a point, so it's natural to wonder what it would be like to feel a superfluid. Would it begin to crawl up your hand like touching the mirror in The Matrix? Unfortunately nothing so dramatic, but science guarantees that you will feel something weird.

Touching a superfluid would be like touching a 2D surface. You would not be able to feel the bulk of the fluid you are interacting with. Picture (or go and try it) immersing your finger in water; you will feel the whole liquid as it interacts with your finger. Not a superfluid, a 2D surface would form between your fingers and the superfluid, and your interaction would be only with that. The rest of the fluid is a vacuum, a void, entirely passive to your interaction.

The more we try and picture it, the more curious we are to find a superfluid to try it on. Maybe a big vat to slowly move your hand through although it would feel like you are not even pushing it through air, and yet youd be creating vortices behind it that will stay there indefinitely. Unfortunately for our and your curiosity, there is no known superfluid that we could safely touch, they are all too cold for our hands.

These experimental conditions are extreme and the techniques complicated, but I can now tell you how it would feel if you could put your hand into this quantum system, Dr Samuli Autti, from the University of Lancaster, said in a statement.

Nobody has been able to answer this question during the 100-year history of quantum physics. We now show that, at least in superfluid 3He, this question can be answered.

To understand how it would feel, researchers studied the thermodynamical behavior of having a finger-sized mechanical resonator in the superfluid, and the whole system was kept at one 10,000th of a degree above absolute zero. The heat produced in the stirring did not affect the bulk of the system, it simply propagated along the 2D surface around the finger

The research showed that a superfluid Helium-3 is thermomechanically two-dimensional even though it is in 3D.

This also redefines our understanding of superfluid 3He. For the scientist, that may be even more influential than hands-in quantum physics, Dr Autti explained.

Superfluid helium-3 is an extremely versatile macroscopic quantum system. Research on it influences a lot of other fields not directly related, such as the study of theHiggs mechanism, cosmological ideas, and the always peculiar time crystals.

The study is published in the journal Nature Communication.

Originally posted here:

How Does A Quantum Superfluid Feel Like To The Touch? - IFLScience

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The rise of Big Science after World War II was pushed by massive Cold War and Space Race spending. There was, however, one fundamental area of physics that didnt see federal dollars, at least at first. This was research into gravity and general relativity.

Observations of light bending around the sun in 1919 confirmed Albert Einsteins elegant theory of gravitation, as historians of science David Kaiser and Dean Rickles call this aspect of the general theory of relativity. After that confirmation, though, gravitational physics cooled down. Nuclear and quantum physics became where the action was. (The Nazis crushing displacement of worlds most active centers for gravitational research didnt help.)

In the late 1940s, there wasnt a physics department in the US that required their graduate students to study gravitation/relativity. Yet starting in the mid 1960s, there was what has been called a renaissance in relativity, culminating in the work of Stephen Hawking and Roger Penrose on black holes.

As Kaiser and Rickles show, that renaissance was seeded by money from private patrons. Businessmen Robert Ward Babson (18751967) and Agnew Hunter Bahnson (19151964) funded the burgeoning of gravitational physics when no one else would. But since plutocrats usually want a say in where their money is going, that funding was somewhat eccentric: both men were absolutely obsessed by anti-gravity.

Roger Babson was famous for predicting the 1929 stock market crash. In 1948, with something of a personal grudge against Gravity: Our Enemy Number One, he set up the Gravity Research Foundation sixty miles from Boston. The location was chosen because it was supposed to outside the blast radius of an atomic bomb over Boston.

Babson blamed Gravity (he capitalized it) for the deaths of both his sister and a grandson, both of whom drowned inseparateswimming accidents. What Babson most wanted from his gravity researchers was a partial insulator, reflector, or absorber of gravitysomething, anything, that would stop or dampen the damn stuff.

His interest in slaying what he called that dragon Gravity led into fantasies about perpetual motion machines and free and limitless electrical power. He also marketed patent medicine gravity pills, which he sold for sore legs. He even built the Thomas Edison Bird Museum, with 5,000 specimens. This was named after his inventor friend: Edison had once suggested birds could fly because they had the secret of anti-gravity.

Along with block grants to colleges and universities, Babsons foundation also contributed actual blocks of stone to thirteen institutions. The foundations monument at the Tufts Institute of Cosmology is inscribed to remind students of the blessings forthcoming when a semi-insulator is discovered in order to harness gravity as a free power and reduce airplane accidents.

In 1952, the poplar science writer Martin Gardner parodied Babson and his foundation in a book on pseudoscience. But Babsons money was certainly real enough and hard to say no to. The foundations essay competitions first prize was $1,000 in the early 1950s, equal to a graduate student stipend. (Stephen Hawking won six awards from the foundation in the 1960s and 1970s.) Turning away from trying to control gravity to understanding it, the foundation fought its way to respectability. Their first conference on gravitation in 1951 saw twenty-two attendees. By 1958, 280 people were attending.

Agnew Bahnson, meanwhile, was rather younger than Babson but just as fascinated with anti-gravity. A Gravity Research Foundation trustee, Bahnson worked with Bryce DeWitt, the 1953 winner of the foundations essay contest, and Ccile Morette DeWitt, a renewed physicist in her own right, to set up the Institute of Field Physics at the University of North Carolina, Chapel Hill (1956). He was a tireless fundraiser, even though the institutes physicists and administrators made a point of saying that they had no connection with anti-gravity research. (Anti-gravity being impossible under general relativity.)

Bahnson signed off on that official statement but continued his own dabbling in would-be anti-gravity machines. His 1959 novel The Stars Are Too High features a gravity-defying flying saucer helping to ease Cold War tensions. (Gravity claimed Bahnson at the age of forty-eight when his private plane crashed.)

The renaissance of relatively may be an apt term in more ways than one. Babson and Bahnson were like the patrons of the Renaissance, only instead of funding artists, they funded gravitational physicsand physicists. But were the Medici ever so eccentric?

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By: DAVID KAISER and DEAN RICKLES

Historical Studies in the Natural Sciences, Vol. 48, No. 3 (JUNE 2018), pp. 338379

University of California Press

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When Gravity Sucked, According to the Plutocrats - JSTOR Daily

Imagine being able to measure tiny changes in the flow of time caused by Earths gravity with atomic clocks atop one of Colorados iconic peaks above 14,000 feet.

That could soon be a reality thanks to a $1.9 million grant from the National Science Foundation that will advance geodesy the study of accurately measuring Earths geometric shape, orientation in space and gravity field through the use of quantum sensors, some of the most precise in the world.

Scott Diddams, professor in CU Boulders Department of Electrical, Computer and Energy Engineering(ECEE), is collaborating on this four-year, multi-agency effort with physicists from the National Institute of Standards and Technology (NIST) and the National Oceanic and Atmospheric Administration (NOAA). To further get students involved, Diddams aims to bring undergraduate and graduate researchers in on the endeavor.

Our vision is to take the best quantum science from the lab and translate it out to the world, said Diddams. Its going to be an important activity for the university and field to show how optical clocks can impact the field of geodesy.

Albert Einsteins theory of general relativity states that time evolves more slowly under the influence of gravity known as the gravitational redshift. Essentially, a clock at higher elevations will tick at a faster rate than ones closer to the Earth.

Diddams and the research group are developing a portable hyper-accurate optical atomic clock, which will be the most advanced quantum sensor of time to operate at such a high elevation.

Andrew Ludlow, an adjoint professor with ECEE and the NIST physicist building the ytterbium optical clocks used in the project, noted, if you can measure time extremely well with these atomic clocks, you can look for tiny signals that are signatures of interesting new phenomena in physics.

We're also constantly improving our time standards to support the measurement of evolving technologies in industry and science, he added.

While there have been other efforts around the world to replicate similar aspects of this project, this one will take place at one of the most elevated locations in the United States - an exciting feat for the research community.

Mount Blue Sky, nestled in the Rocky Mountains of Colorado,is home to the highest paved road in North Americapeaking at 14,264 feet. This will allow the team to transport an optical atomic clock up the summit to measure geopotential differences corresponding to one centimeter changes in elevation.

If successful, these measurements could open up new realms of how we use quantum and atomic physics for areas in hydrology, seismology, coastal mapping and geodetic surveying.

The research team will first test these clocks at lower elevations before taking them ultimately up 14,000 feet in summer 2025.

We sat down with Professor Scott Diddams for a deep dive into the ambitious project.

What does your project entail with this new NSF grant?

Our project is really focused on using the best optical clocks the most precise measurement tools ever made to measure gravity. We think of the Earth as being just a sphere, but theres actually significant variation in the Earths shape on large and small scales. Our plan is to use our clocks to measure those gravitational changes very precisely due to those features at different elevations.

How will you achieve this?

We're going to take one clock to the top of Mount Blue Sky and compare it to a local atomic clock in Boulder, Colo. This will be done via a laser link that transmits the clocks rate over a laser beam through the air from Mount Blue Sky down to the Denver metro area. A challenge is that you dont have a clear light of sight to Boulder, so well have to go to a location about 10 miles away near the Broomfield area for that. Well use an optical fiber to connect from that location back to the reference clock at NIST.

This perspective provides how the mobile optical clock atop Mt. Blue Sky will communicate with the transfer node in Broomfield, Colo. and connect with a reference optical clock in Boulder.

What do you hope these atomic optical clocks will prove?

When we compare their rates with the two clocks, we should see the one on the top of Mount Blue Sky ticking faster. By measuring the difference in the tick rates, we hope to make the most accurate test Einstein's predictions of general relativity.

How can we relate this to everyday life?

One thing that absolutely knows gravity is water, and water will flow to the lowest gravitational potential. And so in large coastal areas, determining elevation and the flow of water at the centimeter or a few centimeters level is quite important, particularly with climate change and rising sea levels. So our project will build a connection from very fundamental quantum science to a whole new area in geodesy and surveying as we know it. This is not a topic that you would initially think is connected to quantum physics.

What makes Colorados Rocky Mountains uniquely fitting for this project?

We have this tremendous difference in elevation or relief, in topographic terms over a relatively short distance. There is around 9,000 feet of relief from Denver to Mount Blue Sky over a span of less than 50 miles, which we can use as leverage in the relative precision of our measurement. If we can measure the effect of that difference at the centimeter level, we stand to make the most precise measurement of the gravitational redshift. So that's pretty unique to Colorado.

What excites you about the collaboration with NIST & NOAA?

This is a very unique team, and even more so that we are all here in Boulder. We have world experts in all the areas that are needed to make the project successful like being able to develop portable atomic optical clocks (Andrew Ludlow) and synchronize these clocks from the top of mountains down to the city (Laura Sinclair). Well also have a leading expert in geodesy (Derek van Westrum) who has actually already surveyed benchmarks in our labswith millimeter-level precision.

Would you say this will be the highest altitude experiment youve ever conducted so far?

This probably will be the highest altitude experiment of its kind in the world. I have done short-term experiments with frequency combs on Mauna Kea in Hawaii, but that's 13,800 feet above sea level. I've never had an experiment at 14,000 feet yet, which makes this pretty unique. We're going to have to learn to efficiently work and operate the clock over extended periods in that high-altitude environment, as well.

Atomic Optical Clock Image Credit: Jesse Petersen

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Researchers to test Einstein's predictions of general relativity atop ... - University of Colorado Boulder