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A type of aurora briefly tore a 400 km wide hole in Earth’s ozone layer.

An international team of researchers showed that a certain type of aurora called the “Isolated proton aurora” depletes our atmosphere’s ozone layer. They discovered a nearly 250-mile-wide (400 kilometers) hole in the ozone layer right above where an aurora occurred. Before now, the influence of these particles was only vaguely known. The study is published in Scientific reports.

What causes the auroras?

Solar storms on the sun’s surface give out huge clouds of electrically charged particles. These particles can travel millions of miles, and some may eventually collide with the Earth. Most of these particles are deflected away, but some become captured in the Earth’s magnetic field. When they are entrapped, their charge ionizes the atmosphere and produces nitrogen oxides and hydrogen oxides. Both compounds contribute to ozone loss.

Astronomers have discovered a mysterious neutron star that’s far lighter than previously thought possible, undermining our understanding of the physics and evolution of stars. And fascinatingly, it may be composed largely of quarks.

As detailed in a new paper published in the journal Nature Astronomy this week, the neutron star has a radius of just 6.2 miles and only the mass of 77 percent of the Sun.

That makes it much lighter than other previously studied neutron stars, which usually have a mass of 1.4 times the mass of the Sun at the same radius.

The engineering of so-called Floquet states leads to almost-perfect atom-optics elements for matter-wave interferometers—which could boost these devices’ ability to probe new physics.

Since Michelson and Morley’s famous experiment to detect the “luminiferous aether,” optical interferometry has offered valuable tools for studying fundamental physics. Nowadays, cutting-edge applications of the technique include its use as a high-precision ruler for detecting gravitational waves (see Focus: The Moon as a Gravitational-Wave Detector) and as a platform for quantum computing (see Viewpoint: Quantum Leap for Quantum Primacy). But as methods for cooling and controlling atoms have advanced, a new kind of interferometer has become available, in which light waves are replaced by matter waves [1]. Such devices can measure inertial forces with a sensitivity even greater than that of optical interferometers [2] and could reveal new physics beyond the standard model.

A multiwavelength laser source known as a frequency comb provides a new technique for atom interferometry, potentially leading to new tests of fundamental physics.

In atom interferometry, researchers use the interference of quantum waves of matter, often for high-precision experiments testing fundamental physics principles. A research team has now demonstrated a new way to produce matter-wave interference by using a frequency-comb laser—a comb-like set of spectral lines at regularly spaced frequencies [1]. The comb allowed the team to generate interference in a cloud of cold atoms. The method might ultimately be used to investigate differences between matter and antimatter.

According to the weak equivalence principle, gravity must cause both matter and antimatter to fall at the same rate (see the graphical explanation, The Equivalence Principle under a MICROSCOPE). Deviations from this principle could point to explanations for the hitherto mysterious imbalance in the amounts of matter and antimatter in the Universe. Atom interferometry could provide a test of weak equivalence through precise measurements of the free fall of antihydrogen. So far, light-based control of atom interferometry has used continuous-wave (cw) lasers [2], which can’t easily be extended to the short wavelengths in the extreme ultraviolet (XUV) that are needed for such studies of antihydrogen.

Just in time for Halloween’s spooky season, a quantum sensor now has double the spookiness by combining entanglement between atoms and delocalization of atoms.

Future quantum sensors will be able to provide more precise navigation, explore for needed natural resources, more precisely determine fundamental constants, look more precisely for dark matter, or maybe someday discover gravitational waves thanks to a team of researchers led by Fellow James K. Thompson from the Joint Institute for Laboratory Astrophysics (JILA) and the National Institute of Standards and Technology (NIST).

Thompson and his team have for the first time successfully combined two of the “spookiest” features of quantum mechanics: entanglement between atoms and delocalization of atoms. By doubling down on these “spooky” features, better quantum sensors can be made.

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What are these ‘spooky’ features?

Put horror movies and games aside for a few minutes to listen to something truly unsettling this Halloween season. The has released audio of what our planet’s magnetic field sounds like. While it protects us from cosmic radiation and charged particles from solar winds, it turns out that the magnetic field has an unnerving rumble.

You can’t exactly point a microphone at the sky and hear the magnetic field (nor can we see it). Scientists from the Technical University of Denmark collected by the ESA’s three Swarm satellites into sound, representing both the magnetic field and a solar storm.

The ethereal audio reminds me of wooden wind chimes rattling as a mass of land shifts, perhaps during an earthquake. It brings to mind the cracking sounds of a moving glacier as well. You might get something different out of the five-minute clip.

Quarks all the way down.


Astronomers recently discovered that this neutron star left behind by the collapse and explosion of a supergiant is now roughly 77 percent the mass of our Sun, packed into a sphere about 10 kilometers wide. That’s a mind-bogglingly dense ball of matter — it’s squished together so tightly that it doesn’t even have room to be atoms, just neutrons. But as neutron stars go, it’s weirdly lightweight. Figuring out why that’s the case could reveal fascinating new details about exactly what happens when massive stars collapse and explode.

What’s New — When a massive star collapses, it triggers an explosion that blasts most of the star’s outer layers out into space, where they form an ever-widening cloud of hot, glowing gas. The heart of the star, however, gets squashed together in the final pressure of that collapse and becomes a neutron star. Normally, what’s left behind is something between 1.17 and 2.35 times as massive as the Sun, crammed into a ball a few dozen kilometers wide.