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Two supermassive black holes will collide in 10,000 years, warping space and time.

A Cosmic Collision in the Making

In a galaxy 9 billion light-years away, two enormous black holes are locked in a cosmic dance that will eventually end in a massive collision. These supermassive black holes, each hundreds of millions of times the mass of our sun, are currently orbiting one another. In about 10,000 years, they will merge in a violent event, unleashing enough force to distort space and time by creating gravitational waves—ripples in the universe’s fabric.

One proposed way of examining if such a force could exist is by closely monitoring asteroid trajectories, and few near-Earth asteroids are as well observed as Bennu. A new study by an international team of scientists analyzes Bennu to try and placing constraints on a possible fifth fundamental force in the search of ultralight dark matter.

Bennu, one of the most dangerous near-Earth objects, has been meticulously tracked by optical and radar astrometric data since it was discovered in 1999. As the destination for the OSIRIS-REx asteroid retrieval mission, additional X-band radiometric and optical navigation tracking data added even more trajectory precision. The idea is that any deviation in the expected trajectory of the asteroid could be the result of an unknown fifth force at work. The results of the study were published in the journal Nature Communications Physics.

All our science, measured against reality, is primitive and childlike – and yet it is the most precious thing we have. – Albert Einstein (1879−1955)

Astronomers have observed light bending around a black hole, a phenomenon predicted by Einstein’s theory of general relativity. By studying X-rays from a black hole in the Zwicky 1 galaxy, scientists detected unexpected “light echoes” coming from behind the black hole, proving that the black hole’s gravity was curving space-time and allowing light to bend around it.

Although this effect was predicted over a century ago, it’s the first time astronomers have witnessed it. The researchers now aim to investigate how black hole coronas produce intense X-ray flares and continue studying space-time distortion.

A spinning white dwarf drags space-time around it 100 million times more powerfully than Earth.

Astronomers have recently provided compelling evidence of a star dragging space-time, showcasing one of Einstein’s lesser-known predictions. This phenomenon, known as “frame-dragging,” describes how a spinning object distorts the very fabric of space-time around it. While this effect is nearly imperceptible in everyday life, even on a planetary scale, certain cosmic conditions make it much more noticeable. A study published in Science details these observations using a radio telescope to study a rare pair of compact stars.

Frame-Dragging and Einstein’s Predictions Einstein’s theory of general relativity is fundamental to our understanding of gravity. It suggests that massive objects bend space-time, affecting the motion of nearby objects. Additionally, when these massive bodies spin, they twist space-time around them. Detecting frame-dragging on Earth is extremely challenging, requiring highly sensitive instruments like the Gravity Probe B, a satellite that measures minute changes in angular velocity. But in the cosmos, certain celestial objects can serve as natural laboratories to observe this effect with greater clarity.

SCATTERED THROUGHOUT THE UNIVERSE are ravenous black holes that pull gas, dust, light and even other black holes into their maw, never to be seen again. Like a riptide pulling swimmers out to sea, the gravity inside a black hole pulls matter past a point of no return, called the event horizon, and condenses it so tightly that physics as we know it begins to break down, creating a “singularity.” It’s this singularity, in particular, that troubles physicists because it throws their most important theories about the universe into question.

That’s why theoretical physicist Nikodem Poplawski, Ph.D., asked a big question back in 2010: what if black holes don’t contain a singularity at all? Instead, Poplawski’s theory suggests, the center of a black hole could contain a pathway into another universe. Weirder yet, his theory predicts that this may be how our own universe was created.

A paper describing this work, titled “Radial motion into an Einstein–Rosen bridge,” was published 14 years ago in the journal Physics Letters B. While the theory captured attention at the time, this topic is still rather niche among physicists. Many researchers have either moved on, or have never heard of the idea to begin with.