Year 2022 😗
A team of researchers found that a simulated black hole could have multiple masses simultaneously.
Category: cosmology – Page 173
What happens if dark-matter particles are produced inside a jet of Standard-Model particles? This leads to a novel detector signature known as semi-visible jets! The ATLAS Collaboration has come up with the first search for semi-visible jets, looking for them in a general production mode where two protons interact by exchanging an intermediate particle, which is then converted into two jets.
The elusive nature of dark matter remains one of the biggest mysteries in particle physics. Most of the searches have so far looked for events where a “weakly interacting” dark-matter particle is produced alongside a known Standard-Model particle. Since the dark-matter particle cannot be seen by the ATLAS detector, researchers look for an imbalance of transverse momentum (or “missing energy”).
We’ve probably all heard the phrase you can’t make something from nothing. But in reality, the physics of our universe isn’t that cut and dry. In fact, scientists have spent decades trying to force matter from absolutely nothing. And now, they’ve managed to prove that a theory first shared 70 years ago was correct, and we really can create matter out of absolutely nothing.
The universe is made up of several conservation laws. These laws govern energy, charge, momentum, and so on down the list. In the quest to fully understand these laws, scientists have spent decades trying to figure out how to create matter – a feat that is far more complex than it even sounds. We’ve previously turned matter invisible, but creating it out of nothing is another thing altogether.
There are many theories on how to create matter from nothing – especially as quantum physicists have tried to better understand the Big Bang and what could have caused it. We know that colliding two particles in empty space can sometimes cause additional particles to emerge. There are even theories that a strong enough electromagnetic field could create matter and antimatter out of nothing itself.
A new supernova has turned into the most watched phenomenon in the May night sky. The close proximity of the stellar explosion and the vast amount of observations gathered since the discovery promise to advance astronomers’ understanding of stellar evolution and could even lead to major advances in supernova forecasting.
Supernovas are powerful explosions in which very massive stars, at least eight times more massive than our sun, die when they use up all the hydrogen fuel in their cores. The discovery of this latest exploding star, known officially as 2023ifx, was a serendipitous one.
A potential intermediate-mass black hole may be lurking in Messier 4, the nearest globular star cluster to Earth, new Hubble data reveals.
New studies reveal that the universe originated with a Big Bang rather than a bouncing phenomenon, challenging previous theories.
The viability of a bouncing universe, a cosmological theory proposing that our universe formed from the contraction and subsequent expansion of a prior universe, has been questioned in a recent study by two publications published by experts.
The new investigations support the idea that the universe’s expansion and contraction may have occurred only once, contrary to the bouncing universe theories’ assertion that this cycle may have happened.
After three years of upgrading and waiting, due in part to the coronavirus pandemic, the Laser Interferometer Gravitational-wave Observatory has officially resumed its hunt for the signatures of crashing black holes and neutron stars.
“Our LIGO teams have worked through hardship during the past two-plus years to be ready for this moment, and we are indeed ready,” Caltech physicist Albert Lazzarini, the deputy director of the LIGO Laboratory, said in a news release.
Lazzarini said the engineering tests leading up to today’s official start of Observing Run 4, or O4, have already revealed a number of candidate events that have been shared with the astronomical community.
Using various space telescopes, an international team of astronomers have observed a recently detected luminous quasar known as SMSS J114447.77–430859.3, or J1144 for short. Results of the observational campaign, available in the July 2023 edition of Monthly Notices of the Royal Astronomical Society, shed more light on the properties of this source.
Quasars, or quasi-stellar objects (QSOs) are active galactic nuclei (AGN) of very high luminosity, emitting electromagnetic radiation observable in radio, infrared, visible, ultraviolet and X-ray wavelengths. They are among the brightest and most distant objects in the known universe, and serve as fundamental tools for numerous studies in astrophysics as well as cosmology. For instance, quasars have been used to investigate the large-scale structure of the universe and the era of reionization. They also improved our understanding of the dynamics of supermassive black holes and the intergalactic medium.
J1144 was detected in June 2022 at a redshift of 0.83. It has a bolometric luminosity of about 470 quattuordecillion erg/s, which makes it the most luminous quasar over the last 9 billion years of cosmic history. It is also the optically brightest (unbeamed) quasar at a redshift greater than 0.4.
In a distant star system, a sunlike star orbits an invisible object that may be the first example of a ‘boson star’ made of dark matter, new research suggests.
Perspective from a very-educated layman. Er, laywoman.
This is Hello, Computer, a series of interviews carried out in 2023 at a time when artificial intelligence appears to be going everywhere, all at once.
Sabine Hossenfelder is a German theoretical physicist, science communicator, author, musician, and YouTuber. She is the author of Lost in Math: How beauty leads physics astray, which explores the concept of elegance in fundamental physics and cosmology, and of Existential Physics: A scientist’s guide to life’s biggest questions.
Sabine has published more than 80 research papers in the foundations of physics, from cosmology to quantum foundations and particle physics. Her writing has appeared in Scientific American, Nautilus, The New York Times, and The Guardian.
Sabine also works as a freelance popular science writer and runs the YouTube channel Science Without the Gobbledygook, where she talks about recent scientific developments and debunks hype, and a separate YouTube channel for music she writes and records.