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L-r: A non-rotating black hole; a rotating black hole; a boson star as they'd appear to the EHT. (Olivares et al., MNRAS, 2020 ===================================================================================== Last year, the astronomical community achieved an absolute wonder. For the very first time, the world collectively laid eyes on an actual image of the shadow of a black hole. It was the culmination of years of work, a magnificent achievement in both human collaboration and technical ingenuity. And, like the best scientific breakthroughs, it opened a whole new world of enquiry. For a team led by astrophysicist Hector Olivares from Radboud University in the Netherlands...

Explanation: SS 433 is one of the most exotic star systems known. Its unremarkable name stems from its inclusion in a catalog of Milky Way stars which emit radiation characteristic of atomic hydrogen. Its remarkable behavior stems from a compact object, a black hole or neutron star, which has produced an accretion disk with jets. Because the disk and jets from SS 433 resemble those surrounding supermassive black holes in the centers of distant galaxies, SS 433 is considered a micro-quasar. As illustrated in the animated featured video based on observational data, a massive, hot, normal star is locked in...

The information locked inside black holes could be detected by feeling their 'hair,' new research suggests. As far as we understand them (which, admittedly, is not very much), black holes are suspiciously simple objects. Regardless of what falls in... black holes can be described by three and only three simple numbers: charge, mass and spin. The reason this is suspicious is that something had to happen to all that juicy information that fell into those two black holes. The simplest solution is the theorem, first coined by the American physicist John Wheeler, that "black holes have no hair" — they...

NASA scientists have spotted what they are calling a “halo” around Andromeda. The halo, which is more like a huge bloom of plasma, stretches 1.3 million light-years into space. That’s roughly halfway to our own galaxy, which is an impressive feat. We often think of galaxies as self-contained collections of stars, planets, and gasses, but that’s simply not the case. The effects of a galaxy extend far beyond their outer edge. In fact, the line between the edge of a galaxy and empty space is so blurred that there’s hardly a real “edge” at all. In the case of Andromeda,...

Toroidal, or doughnut-shaped, tokamaks are prone to intense bursts of heat and particles, called edge localized modes (ELMs). These ELMs can damage the reactor walls and must be controlled to develop reliable fusion power. Fortunately, scientists have learned to tame these ELMs by applying spiraling rippled magnetic fields to the surface of the plasma that fuels fusion reactions. However, the taming of ELMs requires very specific conditions that limit the operational flexibility of tokamak reactors. Now, researchers at PPPL and GA have developed a model that... accurately reproduces the conditions for ELM suppression in the DIII-D National Fusion Facility that...

The so-called Fast Radio Burst repeats every 157 days with the power of millions of suns and its latest barrage arrived right on time last week. Known as FRB 121102, scientists hope that studying the strange blinkering signal could unlock the secret to what FRBs are and where they come from. Fast Radio Bursts are intense pulses of radio waves that last no longer than the blink of an eye and come from far beyond our Milky Way galaxy. Their origins are unknown. . The group’s findings, to The Astronomer’s Telegram, suggest the burst is currently in its active phase...

Stephen Hawking won accolades from his peers for having one of the most brilliant minds in science, but he never got a Nobel Prize because no one has yet proven his ideas. The Nobel committee looks for proof, not big ideas. Hawking was a deep thinker — a theorist — and his musings about black holes and cosmology have yet to get the lockdown evidence that accompanies the physics prizes, his fellow scientists said.

Exotic subatomic particles, sterile neutrinos, are no-shows in experiments, increasing doubts about their existence. University of Cincinnati physicists, as part of an international research team, are raising doubts about the existence of an exotic subatomic particle that failed to show up in twin experiments. UC College of Arts and Sciences associate professor Alexandre Sousa and assistant professor Adam Aurisano took part in an experiment at the Fermi National Accelerator Laboratory in search of sterile neutrinos, a suspected fourth "flavor" of neutrino that would join the ranks of muon, tau, and electron neutrinos as elementary particles that make up the known...

Wigner sharpened the paradox by imagining a (human) friend of his shut in a lab, measuring a quantum system. He argued it was absurd to say his friend exists in a superposition of having seen and not seen a decay unless and until Wigner opens the lab door. [Nora] Tischler and her colleagues have carried out a version of the Wigner’s friend test. By combining the classic thought experiment with another quantum head-scratcher called entanglement—a phenomenon that links particles across vast distances—they have also derived a new theorem, which they claim puts the strongest constraints yet on the fundamental nature...

University of Chicago's Pritzker School of Molecular Engineering announced the discovery of a simple modification that allows quantum systems to stay operational—or "coherent"—10,000 times longer than before. Though the scientists tested their technique on a particular class of quantum systems called solid-state qubits, they think it should be applicable to many other kinds of quantum systems and could thus revolutionize quantum communication, computing and sensing. Quantum states need an extremely quiet, stable space to operate, as they are easily disturbed by background noise coming from vibrations, temperature changes or stray electromagnetic fields. Thus, scientists try to find ways to keep...

Scientists have produced the firmest evidence yet of so-called sterile neutrinos, mysterious particles that pass through matter without interacting with it at all. The first hints these elusive particles turned up decades ago. But after years of dedicated searches, scientists have been unable to find any other evidence for them, with many experiments contradicting those old results. These new results now leave scientists with two robust experiments that seem to demonstrate the existence of sterile neutrinos, even as other experiments continue to suggest sterile neutrinos don't exist at all. That means there's something strange happening in the universe that is...

Ron Cowen 3-22-2016 In tunnels deep inside a granite mountain at Daya Bay, a nuclear reactor facility some 55 kilometers from Hong Kong, sensitive detectors are hinting at the existence of a new form of neutrino, one of nature’s most ghostly and abundant elementary particles.Neutrinos, electrically neutral particles that sense only gravity and the weak nuclear force, interact so feebly with matter that 100 trillion zip unimpeded through your body every second. They come in three known types: electron, muon and tau. The Daya Bay results suggest the possibility that a fourth, even more ghostly type of neutrino exists —...

In the fall of 2019, Betelgeuse began dimming significantly, losing about two-thirds of its brightness by February. This dramatic dip spurred speculation that the star's demise may have been imminent — perhaps just weeks away. But the dramatic sky show didn't happen: Betelgeuse powered through the dimming episode and returned to its normal brightness by May of this year. The recovery sparked a new round of speculation, this time about the dimming's cause. Some scientists attributed the doldrums to a light-blocking dust cloud, for example, whereas others said big starspots on Betelgeuse's surface were likely to blame. A new study...

Most FRBs originate hundreds of millions of light-years away. This one came from inside the Milky Way. Thirty thousand years ago, a dead star on the other side of the Milky Way belched out a powerful mixture of radio and X-ray energy. On April 28, 2020, that belch swept over Earth, triggering alarms at observatories around the world. The signal was there and gone in half a second, but that's all scientists needed to confirm they had detected something remarkable: the first ever "fast radio burst" (FRB) to emanate from a known star within the Milky Way, according to a...

Metrology is the science of estimations and measurements. We are used to dealing with probabilities that range from 0% (never happens) to 100% (always happens). To explain results from the quantum world however, the concept of probability needs to be expanded to include a so-called quasi-probability, which can be negative. This quasi-probability allows quantum concepts such as Einstein's 'spooky action at a distance' and wave-particle duality to be explained in an intuitive mathematical language. An experiment whose explanation requires negative probabilities is said to possess 'quantum negativity.' In state-of-the-art metrology however, the probes are quantum particles, which can be controlled...

Last year, scientists detected the most energetic gamma ray burst we've ever seen. A distant galaxy spat out a colossal flare in the range of a trillion electron volts (TeV), providing invaluable new insight into the physics of these incredibly energetic events. That was pretty amazing on its own - but now astrophysicists have used the burst to perform a new, precise test of the theory of general relativity. And - quelle surprise! - this test found that the speed of light is constant in a vacuum. Relativity, once again, has passed with flying colours. The test hinges on a...

Artist's conception. Image: Caltech/R. Hurt (IPAC) Astronomers from Caltech have reported that they’ve observed a collision between two black holes. Normally such an event is invisible, but this time a more massive black hole sitting nearby helped illuminate the other two as they collided. If confirmed, the findings, published in Physical Review Letters, would be the first optical observations ever made of a black hole merger. What happened: First detected in May 2019 and dubbed S190521g, the merger happened about 4 billion light-years away, within the vicinity of a supermassive black hole called J1249+3449. This object is 100 million times...

A small team of researchers at Purdue University has found the strongest evidence yet of the existence of abelian anyons. They have written a paper describing experiments they conducted designed to reveal the existence of the quasiparticles and have uploaded it to the arXiv preprint server while they await peer review. Anyons are neither bosons nor fermions—in fact, they are not elementary particles at all. Instead, they are classified as quasiparticles that exist in two dimensions. They can be observed, theoretically speaking, when they appear as disturbances in two-dimensional sheets of materials. Theoretical physicists have suggested their existence since the...

All tetraquarks and pentaquarks that have been discovered so far contain two charm quarks, which are relatively heavy, and two or three light quarks – up, down or strange. This particular configuration is indeed the easiest to discover in experiments. But the latest tetraquark discovered by LHCb, which has been dubbed X(6900), is composed of four charm quarks. Produced in high-energy proton collisions at the Large Hadron Collider, the new tetraquark was observed via its decay into pairs of well-known particles called J/psi mesons, each made of a charm quark and a charm antiquark. This makes it particularly interesting as...

There's something unusual lurking out in the depths of space: Astronomers have discovered four faint objects that at radio wavelengths are highly circular and brighter along their edges. And they're unlike any class of astronomical object ever seen before. The objects, which look like distant ring-shaped islands, have been dubbed odd radio circles, or ORCs, for their shape and overall peculiarity. Astronomers don't yet know exactly how far away these ORCs are, but they could be linked to distant galaxies. All objects were found away from the Milky Way's galactic plane and are around 1 arcminute across (for comparison, the...