An artistic impression of the quasar P172+18, which contains a black hole 300 times more massive than the sun.
If you're fascinated by the idea of looking back in time, just look up at the sky. If you stare at the moon, you're seeing the orb as it was around 1.3 seconds ago. Pointing your telescope at Mars? You're seeing it as it was around 20 minutes ago. That's how long it takes for light to travel those vast distances across the solar system. With a big-enough telescope, you can see light from the earliest moments of the universe, some 13 billion years ago.
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Establishing the origin of solar-mass black holes and the connection to dark matter
Surprisingly, LIGO has recently observed a 2.6 solar-mass black hole candidate (event GW190814, reported in Astrophysical Journal Letters 896 (2020) 2, L44). Assuming this is a black hole, and not an unusually massive neutron star, where does it come from?
Solar-mass black holes are particularly intriguing, since they are not expected from conventional stellar evolution astrophysics. Such black holes might arise in the early Universe ( primordial black holes ) or be "transmuted" from existing neutron stars. Some black holes could have formed in the early universe long before the stars and galaxies formed. Such primordial black holes could make up some part or all of dark matter.
A Scientist Made An Artificial Black Hole In The Lab, And You Won’t Believe What Happened
As it turns out, the truth is both less and more than meets the eye. The article above was eventually edited to better reflect the truth that, alas, we have not yet found a way to create objects so massive that even light cannot escape them. Instead, physicist [Jeff Steinhauer] and colleagues at the Technion-Israel Institute of Technology have developed an acoustic model of black holes, which is what was used to observe the equivalent of Hawking radiation for the first time.
That’s where [Steinhauer]’s sonic black holes come in. In these experiments, phonons, packets of mechanical vibrations that stand in for photons, are trapped in a fast-moving stream of fluid. The point in the stream where its speed straddles the local speed of sound is the equivalent to a real black hole’s event horizon; phonons inside that boundary can never escape.
How the Milky Way–Andromeda black hole merger may play out | Science News
The supermassive black holes at the centers of the Milky Way and Andromeda galaxies are doomed to engulf each other in an ill-fated cosmological dance.
Astronomers have long known that Andromeda is on a collision course with our galaxy ( SN: 5/31/12 ). But not much has been known about what will happen to the gargantuan black holes each galaxy harbors at its core. New simulations reveal their ultimate fate.
The galaxies will coalesce into one giant elliptical galaxy — dubbed "Milkomeda" — in about 10 billion years. Then, the central black holes will begin orbiting one another and finally collide less than 17 million years later , researchers propose February 22 at arXiv.org and in an earlier paper published in Astronomy & Astrophysics . Just before the black holes smash into each other, they'll radiate gravitational waves with the power of 10 quintillion suns ( SN: 2/11/16 ).
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Study shows that the GW190521 event could be explained by primordial black holes
"Our paper originated from the observation by the LIGO/Virgo collaboration of the so-called GW190521 event, the merger of two black holes," Antonio Riotto, one of the researchers who carried out the study, told Phys.org. "The more massive black hole turns out to be in the so-called mass gap, that is, in a range of masses where astrophysical arguments are deficient in explaining the astrophysical nature of such a black hole.
To examine the possibility that a signal is associated with the so-called primordial black hole scenario, one can compute the rate at which two black holes of primordial origin merge (i.e., their merger rate) to produce a gravitational wave signal. Subsequently, researchers must compare this prediction to the merger rate that would be needed to explain the signal observed.
Scientists create a sonic black hole in the lab, confirm Stephen Hawking's theory
Physicists in Israel have devised a black hole analogue — only, rather than being a gravitational fortex that doesn’t allow light to escape, this particular object is a sonic black hole that doesn’t allow sound waves to escape. In the process, the researchers measured the long-theorized Hawking radiation, with important consequences for physics.
A black hole is a region of spacetime where gravity pulls so strongly that even light cannot get out once it crosses a point of no return, known as the event horizon — but you probably knew that already. What may be new to you is that almost 50 years ago, Stephen Hawking proposed a more nuanced view whereby black holes can also generate light.
Americans Admit to Having 'Cleaning Black Hole' | PEOPLE.com
Almost 90% of survey respondents said they also have at least one "junk drawer" full of knick-knacks, the messiest of which can typically be found in the kitchen
Eight in 10 Americans admit to having at least one "cleaning black hole" — an area that seems impossible to keep clean or organized on a consistent basis — in their home.
Moreover, new data suggests the average American can identify about three different "cleaning black holes" that currently exist in their home.
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