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The researchers applied the higher resonant radio frequency, which prompted any normal, “hot” fermions in the liquid to ring in response. The researchers then could zero in on the resonating fermions and track them over time to create “movies” that revealed heat’s pure motion — a sloshing back and forth, similar to sound waves.

“For the first time, we can take pictures of this substance as we cool it through the critical temperature of superfluidity, and directly see how it transitions from being a normal fluid, where heat equilibrates boringly, to a superfluid where heat sloshes back and forth,” Zwierlein says.

The experiments mark the first time scientists have been able to image second sound directly and the pure motion of heat in a superfluid quantum gas. The researchers plan to extend their work to map heat’s behavior more precisely in other ultracold gases. Then, they say their findings can be scaled up to predict how heat flows in other strongly interacting materials, such as high-temperature superconductors and neutron stars.

Black holes have two fundamental properties: their mass (how much they weigh) and their spin (how quickly they rotate). Determining either of these two values tells scientists a great deal about any black hole and how it behaves. In the past, astronomers made several other estimates of Sgr A*’s rotation speed using different techniques, with results ranging from Sgr A* not spinning at all to it spinning at almost the maximum rate.

The new study suggests that Sgr A* is, in fact, spinning very rapidly, which causes the spacetime around it to be squashed down. The illustration shows a cross-section of Sgr A* and material swirling around it in a disk. The black sphere in the center represents the so-called event horizon of the black hole, the point of no return from which nothing, not even light, can escape.

Looking at the spinning black hole from the side, as depicted in this illustration, the surrounding spacetime is shaped like a football. The faster the spin the flatter the football.

Even if they were dozens of light-years away, two colliding neutron stars could create a powerful enough explosion to wipe out life on Earth.

At least, that’s according to a recent paper published in The Astrophysical Journal, in which a team of researchers concluded that a kilonova could pose a major threat to Earth-like planets, even at formidable interstellar distances.

A kilonova is usually the result of a collision involving two neutron stars within a binary system, or when a neutron star and a black hole merge. These collisions release brain-melting amounts of electromagnetic radiation in the form of gamma-ray bursts.