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The “no-hair theorem” of black holes, which greatly simplifies the way we model them, may not be true if an alternative theory of gravity known as the teleparallel formulation is correct, an unpublished paper argues. This could make the study of black holes considerably more complicated, but it would also allow physicists to understand them in ways many have feared they never will.

According to the “no-hair theorem”, a black hole’s mass, electric charge, and spin can tell us everything there is to know about that hole. Anything else we might measure, such as its magnetic moment, can be derived from these three measures.

Crucially, that means that when matter is swallowed by a black hole’s event horizon, all the information contained within it is lost, once the black hole has emitted any gravitational waves or light associated with its meal. It doesn’t matter what elements went into forming a black hole’s predecessor star, or even if it was made of antimatter rather than matter – under the no-hair theorem, it would appear identical to anyone outside its event horizon. The term “hair” is a metaphor for information streaming out of a black hole beyond the point of no return for incoming objects.

The orbits of 27 stars orbiting closely around the black hole at the center of our Milky Way are so chaotic that researchers cannot predict with confidence where they will be in about 462 years. This finding emerges from simulations by three astronomers based in the Netherlands and the United Kingdom. The researchers have published their findings in two papers in the International Journal of Modern Physics D and in the Monthly Notices of the Royal Astronomical Society.

Simulating 27 stars and their interactions with each other and with the black hole is easier said than done. For centuries, for example, it was impossible to predict the motions of more than two interacting stars, planets, rocks, or other objects. It was only in 2018 that Leiden researchers developed a computer program in which rounding errors no longer play a role in the calculations. With this, they were able to calculate the motions of three imaginary stars. Now the researchers have expanded their program to deal with 27 stars that, by astronomical standards, move close to the black hole at the center of the Milky Way.

The simulations of the 27 and the black hole resulted in a surprise. Although the stars remain in their orbits around the black hole, the interactions between the stars show that the orbits are chaotic. This means that small perturbations caused by the underlying interactions change the orbits of the stars. These changes grow exponentially and, in the long run, make the star orbits unpredictable.

Atomic clocks are the most accurate timekeeping instruments we have. A new study proposes a way to use the instruments’ mind-blowing level of precision to detect the tiniest of energy fluctuations, potentially giving scientists a way to observe some types of dark matter.

Dark matter continues to prove elusive: though we haven’t observed it directly, we can see its effects on the Universe. Frustratingly, there is nothing in our current models of physics to explain what we see.

Here, researchers from the University of Sussex and the National Physical Laboratory in the UK have suggested using atomic clocks to detect certain low-mass particles theorized to potentially make up this mysterious material.

For a few hours after a star smashes into a supermassive black hole, some of the brightest light in the Universe is produced.

The subsequent flash of radio waves were thought to simmer down within weeks or months of a collision. It turns out we might have been a little impatient to turn our gaze elsewhere.

An international team of astrophysicists has witnessed radio waves bursting from material surrounding an assortment of supermassive black holes hundreds of days after they ripped apart a star, suggesting many collisions could be responsible for a serious case of cosmic indigestion.

As the universe evolves, scientists expect large cosmic structures to grow at a certain rate: dense regions such as galaxy clusters would grow denser, while the void of space would grow emptier.

But University of Michigan researchers have discovered that the rate at which these grow is slower than predicted by Einstein’s Theory of General Relativity.

They also showed that as dark energy accelerates the ’s global expansion, the suppression of the cosmic structure growth that the researchers see in their data is even more prominent than what the theory predicts. Their results are published in Physical Review Letters.

The universe is big, as Douglas Adams would say.

The most distant light we can see is the (CMB), which has taken more than 13 billion years to reach us. This marks the edge of the , and while you might think that means the is 26 billion light-years across, thanks to it is now closer to 46 billion light-years across. By any measure, this is pretty darn big. But most cosmologists think the universe is much larger than our observable corner of it. That what we can see is a small part of an unimaginably vast, if not infinite creation. However, a new paper published on the arXiv preprint server argues that the observable universe is mostly all there is.

In other words, on a cosmic scale, the universe is quite small.

Roman Space Telescope team is integrating a complex electrical harness, crucial for the spacecraft’s communication and power. After a detailed two-year construction and a preparatory “bakeout” process, assembly into the spacecraft is ongoing, with future installations planned for power components.

NASA’s Nancy Grace Roman Space Telescope team has begun integrating and testing the spacecraft’s electrical cabling, or harness, which enables different parts of the observatory to communicate with one another. Additionally, the harness provides power and helps the central computer monitor the observatory’s function via an array of sensors. This brings the mission a step closer to surveying billions of cosmic objects and untangling mysteries like dark energy following its launch by May 2027.