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The central principle of superconductivity is that electrons form pairs. But can they also condense into foursomes? Recent findings have suggested they can, and a physicist at KTH Royal Institute of Technology today published the first experimental evidence of this quadrupling effect and the mechanism by which this state of matter occurs. Reporting in Nature Physics, Professor Egor Babaev and collaborators presented evidence of fermion quadrupling in a series of experimental measurements on the iron-based material, Ba1−xKxFe2As2. The results follow nearly 20 years after Babaev first predicted this kind of phenomenon, and eight years after he published a paper predicting...

Gravitational waves—ripples in the fabric of Einstein's spacetime—that cross the universe at the speed of light have all sorts of wavelengths, or frequencies. Scientists have not yet managed to detect gravitational waves at extremely low 'nanohertz' frequencies, but new approaches currently being explored are expected to confirm the first low frequency signals quite soon. The main method uses radio telescopes to detect gravitational waves using pulsars—exotic, dead stars, that send out pulses of radio waves with extraordinary regularity. Researchers at the NANOGrav collaboration, for example, use pulsars to time to exquisite precision the rotation periods of a network, or array,...

Astronomers have used a planet-hunting satellite to see a white dwarf abruptly switching on and off for the first time. The researchers led by Durham University, UK, used NASA's Transiting Exoplanet Survey Satellite (TESS) to observe the unique phenomenon. White dwarfs are what most stars become after they have burned off the hydrogen that fuels them. They are approximately the size of the Earth, but have a mass closer to that of the Sun. The white dwarf observed by the team is known to be accreting, or feeding, from an orbiting companion star. With the new observations astronomers saw it...

Explanation: Most galaxies have a single nucleus -- does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image. The central cloverleaf is rather light emitted from a background quasar. The gravitational field of the visible foreground galaxy breaks light from this distant quasar into four distinct images. The quasar must be properly aligned behind the center of a massive galaxy for a mirage like this to be evident. The general effect is known as gravitational lensing, and this specific case is known as the...

Explanation: Sure, you can see the 2D rectangle of colors, but can you see deeper? Counting color patches in the featured image, you might estimate that the most information that this 2D digital image can hold is about 60 (horizontal) x 50(vertical) x 256 (possible colors) = 768,000 bits. However, the yet-unproven Holographic Principle states that, counter-intuitively, the information in a 2D panel can include all of the information in a 3D room that can be enclosed by the panel. The principle derives from the idea that the Planck length, the length scale where quantum mechanics begins to dominate classical...

Left: what the tunnel would look like; right: what the sky does look like. (Image Credit Below) Mysterious structures in the sky that have puzzled astronomers for decades might finally have an explanation – and it's quite something. The North Polar Spur and the Fan Region, on opposite sides of the sky, may be connected by a vast system of magnetized filaments. These form a structure resembling a tunnel that circles the Solar System, and many nearby stars besides. "If we were to look up in the sky," said astronomer Jennifer West of the University of Toronto in Canada, "we...

Quantum teleportation of an unknown input state from an outside source onto a quantum node is considered one of the key components of long-distance quantum communication protocols. It has already been demonstrated with pure photonic quantum systems as well as atomic and solid-state spin systems linked by photonic channels. Now, a team of researchers from the Netherlands, Brazil and China has demonstrated quantum teleportation of a polarization-encoded optical input state onto the joint state of a pair of nanomechanical resonators. “The use of optomechanical devices is a breakthrough because they can be designed to operate at any optical wavelength, including...

The structure of the material. (Li et al., Nature, 2021) Physicists have taken the first ever image of a Wigner crystal – a strange honeycomb-pattern material inside another material, made entirely out of electrons. Hungarian physicist Eugene Wigner first theorized this crystal in 1934, but it's taken more than eight decades for scientists to finally get a direct look at the "electron ice". The fascinating first image shows electrons squished together into a tight, repeating pattern – like tiny blue butterfly wings, or pressings of an alien clover. The researchers behind the study, published on Sept. 29 in the...

These two galaxies are so tight, the stellar formation encompassing them both actually has a name of its own. Say hello to Arp 91, a pair of spiral galaxies that are situated so close together (in relative terms, space is big) we can actually see their outer arms reaching out and colliding with one another. BFFs on an intergalactic scale. Like a good marriage, these galaxies may share a name but they are their own individuals as well. In the center of the frame is NGC 5953. Just above it and slightly to the right is NGC 5954. They're both...

For one of the first times, topological photons—light—has been combined with lattice vibrations, also known as phonons, to manipulate their propagation in a robust and controllable way. "We coupled helical photons with lattice vibrations in hexagonal boron nitride, creating a new hybrid matter referred to as phonon-polaritons," said Alexander Khanikaev, lead author and physicist with affiliation in CCNY's Grove School of Engineering. "It is half light and half vibrations. Since infrared light and lattice vibrations are associated with heat, we created new channels for propagation of light and heat together. Typically, lattice vibrations are very hard to control, and guiding...

The unexpected discovery of the double-charm tetraquark has given physicists a new tool with which to hone their understanding of the strongest of nature’s fundamental forces ------------------------------------------------------------------------------------ A simple model can explain groupings of two or three quarks, but it fails to explain tetraquarks. ---------------------------------------------------------------------------- This spring, at a meeting of Syracuse University’s quark physics group, Ivan Polyakov announced that he had uncovered the fingerprints of a semi-mythical particle. “We said, ‘This is impossible. What mistake are you making?’” recalled Sheldon Stone, the group’s leader. Polyakov went away and double-checked his analysis of data from the Large Hadron Collider beauty...

Dark energy, a mysterious force believed to be causing the universe to expand at an accelerated rate, may have been detected by scientists for the first time. In a new study, published Wednesday in the journal Physical Review D, the authors suggest certain unexplained results from an experiment designed to detect dark matter could have been caused by dark energy. "Despite both components being invisible, we know a lot more about dark matter, since its existence was suggested as early as the 1920s, while dark energy wasn’t discovered until 1998," Sunny Vagnozzi, of the University of Cambridge’s Kavli Institute for...

Simulation of a supermassive black hole. (NASA Goddard Space Flight Center; ESA/Gaia/DPAC) _____________________________________________________________________________________ The most energetic light and particles in the Universe represent an enduring mystery: we don't know where they come from. Sure, we can trace some; but there's more gamma radiation and neutrinos streaming through the Universe than we can account for. A lot more. And astronomers have just found an explanation for some of them: nearly dormant black holes. This, they say, can explain the excess of 'soft' gamma rays in the Universe without relying on cold (nonthermal) electrons – which has always been a problematic explanation,...

The Molten Ring. (Saurabh Jha/Rutgers, The State University of New Jersey) One of the most spectacular Einstein rings ever seen in space is enabling us to see what's happening in a galaxy almost at the dawn of time. The smears of light called the Molten Ring, stretched out and warped by gravitational fields, are magnifications and duplications of a galaxy whose light has traveled a whopping 9.4 billion light-years. This magnification has given us a rare insight into the stellar 'baby boom' when the Universe was still in its infancy. The early evolution of the Universe is a difficult time...

A team of physicists at CU Boulder has solved the mystery behind a perplexing phenomenon in the nano realm: why some ultra-small heat sources cool down faster if you pack them closer together. The findings, which will publish this week in the journal Proceedings of the National Academy of Sciences (PNAS), could one day help the tech industry design speedier electronic devices that overheat less. “Often heat is a challenging consideration in designing electronics. You build a device then discover that it’s heating up faster than desired,” said study co-author Joshua Knobloch, postdoctoral research associate at JILA, a joint research...

A tabletop gravitational wave detector based around a piece of ringing quartz has recorded two mysterious signals in its first 153 days of operation. It's unclear exactly what these signals are; they could be from a number of phenomena. But one of those phenomena is exactly what the detector is designed to pick up – high-frequency gravitational waves, which have never been recorded before. It's way too soon to come to any conclusions, but the next iteration of the detector will be able to narrow down what caused the quartz to resonate. "It's exciting that this event has shown that...

Accelerators like RHIC and LHC routinely turn energy into matter by accelerating pieces of atoms near the speed of light and smashing them into one another. The 2012 discovery of the Higgs particle at the LHC is a notable example. At the time, the Higgs was the final unobserved particle in the Standard Model, a theory that describes the fundamental forces and building blocks of atoms. Impressive as it is, physicists know the Standard Model explains only about 4% of the matter and energy in the universe. The ions are nuclei of massive elements like gold or lead, and ion...

J2150. (Optical: NASA/ESA/Hubble/STScI; X-ray: NASA/CXC/UNH/D. Lin et al.) _______________________________________________________________________________ The mess created by an encounter between a black hole and an unlucky star has yielded a rare and incredible treasure. By measuring the X-radiation as the star was torn apart by gravity, astronomers have determined that the black hole is an incredibly elusive beast: an intermediate-mass middleweight black hole, sitting between the stellar-mass lightweights and the supermassive heavyweights. Scientists think intermediate mass black holes (IMBHs) could be incredibly common, but for some reason, they have proven adept at evading detection, so this discovery is a real prize - one that...

Quantum mechanicsResearch updateWave–particle duality quantified for the first time 01 Sep 2021 Complementarity A new twist on the double-slit experiment. (Courtesy: Shutterstock/Andrey VP) One of the most counterintuitive concepts in physics – the idea that quantum objects are complementary, behaving like waves in some situations and like particles in others – just got a new and more quantitative foundation. In a twist on the classic double-slit experiment, scientists at Korea’s Institute for Basic Sciences (IBS) used precisely controlled photon sources to measure a photon’s degree of wave-ness and particle-ness. Their results, published in Science Advances, show that the properties of...

Warp Drive remained in the world of fiction until 1994 when Mexican Mathematician Miguel Alcubierre presented a mathematical model under which a human-piloted craft could theoretically exceed the speed of light. A decade passed, but quietly in the background, NASA brought in scientist Dr. Harold G. “Sonny” White in the mid-2000s to continue developing the Warp Drive. White made refinements to the original model, and in 2003 and 2011, significant leaps were made in Warp Drive theory, seemingly making the impossible a little more possible. Even more revisions have been, and today, the leading model for faster-than-light travel is dubbed...