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The concept of universal physics is intriguing, as it enables researchers to relate physical phenomena in a variety of systems, irrespective of their varying characteristics and complexities. Ultracold atomic systems are often perceived as ideal platforms for exploring universal physics, owing to the precise control of experimental parameters (such as the interaction strength, temperature, density, quantum states, dimensionality, and the trapping potential) that might be harder to tune in more conventional systems. In fact, ultracold atomic systems have been used to better understand a myriad of complex physical behavior, including those topics in cosmology, particle, nuclear, molecular physics, and most notably, in condensed matter physics, where the complexities of many-body quantum phenomena are more difficult to investigate using more traditional approaches.

Understanding the applicability and the robustness of universal physics is thus of great interest. Researchers at the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder have carried out a study, recently featured in Physical Review Letters, aimed at testing the limits to universality in an ultracold system.

“Unlike in other physical systems, the beauty of ultracold systems is that at times we are able to scrap the importance of the periodic table and demonstrate the similar phenomenon with any chosen atomic species (be it potassium, rubidium, lithium, strontium, etc.),” Roman Chapurin, one of the researchers who carried out the study, told Phys.org. “Universal behavior is independent of the microscopic details. Understanding the limitations of universal phenomenon is of great interest.”

Astronomers from UCLA’s Galactic Center Orbits Initiative have discovered a new class of bizarre objects at the center of our galaxy, not far from the supermassive black hole called Sagittarius A*. They published their research today in the journal Nature.

“These objects look like gas and behave like stars,” said co-author Andrea Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics and director of the UCLA Galactic Center Group.

The new objects look compact most of the time and stretch out when their orbits bring them closest to the black hole. Their orbits range from about 100 to 1,000 years, said lead author Anna Ciurlo, a UCLA postdoctoral researcher.

Objects raise hopes of scientists managing to track ‘blobs’ being swallowed by black hole.

The collision might have produced hundreds of Earths’ worth of gold and platinum. But some signs indicate the metals disappeared into a black hole.

It would be really, really exciting if a single observation could completely overturn astrophysicists’ current understanding of the universe. But that hasn’t happened yet, at least with regards to dark energy.

This week, a press release proclaimed that “new evidence shows that the key assumption made in the discovery of dark energy is in error,” garnering some attention from astronomers and riling up science skeptics. But scientists have already identified some issues with the paper’s claims.

When David Poses As Goliath

Stellar black holes form when massive stars end their life in a dramatic collapse. Observations have shown that stellar black holes typically have masses of about ten times that of the Sun, in accordance with the theory of stellar evolution. Recently, a Chinese team of astronomers claimed to have discovered a black hole as massive as 70 solar masses, which, if confirmed, would severely challenge the current view of stellar evolution. The publication immediately triggered theoretical investigations as well as additional observations by other astrophysicists.

Among those to take a closer look at the object was a team of astronomers from the Universities of Erlangen-Nürnberg and Potsdam. They discovered that it may not necessarily be a black hole at all, but possibly a massive neutron star or even an ‘ordinary’ star. Their results have now been published as a highlight-paper in the renowned journal Astronomy & Astrophysics.

And how many potentially exploding stars are located within the unsafe distance?

Scientists believe that mysterious dark matter is key to forming galaxies in the cosmos. Now, a recent series of bizarre findings threatens to undermine everything we think we know.

The image, and resulting data, has helped astronomers learn more about black holes in general, and this one in particular, making that two-year wait more than worthwhile. Part of the reason for the delay was simply the logistics of gathering so many observations. Each observatory collects data over a narrow range of wavelengths, resulting in massive amounts of information — the equivalent of up to 5,000 years of mp3 music files. That’s too much to just email someone. Researchers instead had to find ways to physically move that data around. For instance, to transport the information out of the South Pole Telescope in Antarctica, scientists had to wait until spring, when planes finally started flying out again.

Only then could researchers begin the complicated process of stitching together data from the eight observatories, a technique known as interferometry. The team had their work cut out for them: Raw files from each of the observing sites came in with different angles on the sky, in different wavelengths and at different observation times.

“The calibrating and working with it took many months,” Özel says. “And at the end we synthesize it into a single image.” But that’s still not the end of the work, she says. “[You] spend another six months worrying about all the things you might have done wrong, and ask yourself more and more questions, until finally you can be certain that what you have is real.”

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