Keyword: darkmatter
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The fabric of the cosmos, as we currently understand it, comprises three primary components: 'normal matter,' 'dark energy,' and 'dark matter.' However, new research is turning this established model on its head. A recent study conducted by the University of Ottawa presents compelling evidence that challenges the traditional model of the universe, suggesting that there may not be a place for dark matter within it. Dark matter, a term used in cosmology, refers to the elusive substance that does not interact with light or electromagnetic fields and is only identifiable through its gravitational effects. Despite its mysterious nature, dark matter...
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I got a lot of questions last week about an article in Quanta Magazine about Dark Dimensions. it's about an idea motivated by string theory that combines large extra dimensions with dark matter. I had a look at the paper.The paper is here: https://arxiv.org/abs/2311.05318The article in quanta magazine is here: https://www.quantamagazine.org/...String theory nonsense makes comeback | 8:12Sabine Hossenfelder | 1.13M subscribers | 147,734 views | February 7, 2024
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The James Webb Space Telescope peered 13.4 billion years into the past and found a black hole-sized conundrum. The oldest supermassive black hole astronomers have ever seen is gorging messily on the heart of its host galaxy, which may ultimately doom the black hole along with its prey. In the process, this ancient black hole — or at least as it looked 13.4 billion years ago — may offer important clues about how the universe’s first supermassive black holes formed and grew. University of Cambridge astrophysicist Roberto Maiolino and his colleagues recently used the James Webb Space Telescope (JWST) instruments...
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Today, supermassive black holes and their host galaxies tell a specific story in terms of mass. But JWST reveals a different story early on. primordial black holes The overdense regions that the Universe was born with grow and grow over time, but are limited in their growth by both the initial small sizes of the overdensities and also by the presence of radiation that's still energetic, which prevents structure from growing any faster. It takes tens-to-hundreds of millions of years to form the first stars; clumps of matter exist long before that, however, and some may directly collapse to form...
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"Stars could be there, we just can't see them." Hydrogen gas in the primordial galaxy J0613+52 with red indicating regions turning away from Earth and blue showing regions turning toward us (Image credit: STScI POSS-II with additional illustration by NSF/GBO/P.Vosteen.) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Astronomers have accidentally discovered a dark galaxy filled with primordial gas untouched that appears to have no visible stars. The researchers behind the discovery say this galaxy, designated J0613+52, could be "the faintest galaxy found to date." Interestingly, scientists using the Green Bank Telescope (GBT) discovered the "dark" galaxy through a complete error. "The GBT was accidentally pointed to...
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India's space agency has successfully launched a rocket that is carrying an observatory which will study astronomical objects like black holes. It was launched from Sriharikota spaceport at 09:10 local time (03:40GMT) on Monday. This is only the second mission in the world of this nature after Nasa launched one in 2021. The space agency said it wanted to help scientists improve their "knowledge of black holes". "We will have an exciting time ahead," Indian Space Research Organisation (Isro) chairperson S Somanath said after the launch.
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Illustration of how a failed supernova can become a black hole. (P. Jeffries/STScI/NASA/ESA) In 2009 a giant star 25 times more massive than the Sun simply…vanished. Okay, it wasn't quite that simple. It underwent a period of brightening, increasing in luminosity to a million Suns, just as if it was ready to explode into a supernova. But then it faded rather than exploding. And when astronomers tried to see the star, using the Large Binocular Telescope (LBT), Hubble, and the Spitzer space telescope, they couldn't see anything. The star, known as N6946-BH1, is now considered a failed supernova. The BH1...
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Five Theories About the Universe to Blow Your Mind | 15:02Sideprojects | 733K subscribers | 1,568,801 views | November 8, 2022
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Concept Black Hole Illustration A team of researchers has affirmed Stephen Hawking’s prediction about the evaporation of black holes via Hawking radiation, though they’ve provided a crucial modification. According to their research, the event horizon (the boundary beyond which nothing can escape a black hole’s gravitational pull) is not as important as previously believed in producing Hawking radiation. Instead, gravity and the curvature of spacetime play significant roles in this process. This insight extends the scope of Hawking radiation to all large objects in the universe, implying that, over a sufficiently long period, everything in the universe could evaporate. Research...
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Einstein's general theory of relativity predicts the existence of black holes, formed when giant stars collapse. But that same theory predicts that their centers are singularities, which are points of infinite density. Since we know that infinite densities cannot actually happen in the universe, we take this as a sign that Einstein's theory is incomplete. But after nearly a century of searching for extensions, we have not yet confirmed a better theory of gravity.But we do have candidates, including string theory. In string theory all the particles of the universe are actually microscopic vibrating loops of string. In order to...
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ESA / Hubble & NASA Physicists believe most of the matter in the universe is made up of an invisible substance that we only know about by its indirect effects on the stars and galaxies we can see. We’re not crazy! Without this “dark matter”, the universe as we see it would make no sense. But the nature of dark matter is a longstanding puzzle. However, a new study by Alfred Amruth at the University of Hong Kong and colleagues, published in Nature Astronomy, uses the gravitational bending of light to bring us a step closer to understanding. Invisible but...
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Astronomers have discovered a chaotic scene unlike any witnessed before in a cosmic "train wrecK" between giant galaxy clusters. NASA's Chandra X-ray Observatory and optical telescopes revealed a dark matter core that was mostly devoid of galaxies, which may pose problems for current theories of dark matter behavior. Astronomers have discovered a chaotic scene unlike any witnessed before in a cosmic “train wreck” between giant galaxy clusters. NASA’s Chandra X-ray Observatory and optical telescopes revealed a dark matter core that was mostly devoid of galaxies, which may pose problems for current theories of dark matter behavior. "These results challenge our...
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When the Swift Gamma Burst Mission spacecraft first detected the flash within the constellation Draco, astronomers thought it was a gamma-ray burst from a collapsing star. On March 31, however, UC Berkeley's Joshua Bloom sent out an email circular suggesting that it wasn't a typical gamma-ray burst at all, but a high-energy jet produced as a star about the size of our sun was shredded by a black hole a million times more massive. Careful analysis of the Swift data and subsequent observations by the Hubble Space Telescope and the Chandra X-ray Observatory confirmed Bloom's initial insight. The details are...
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Scientists have seen the afterglow of a gamma-ray burst just nine minutes after the explosion, a result of precision coordination and fast slewing of ground-based telescopes upon detection of the burst by NASA's High-Energy Transient Explorer (HETE) satellite. The quick turnaround has so far allowed scientists to determine a minimum distance to the explosion, which likely marks the creation of a black hole. Results continue to pour in, as nearly 100 telescopes in 11 countries have tracked the burst. The burst was detected on Friday, Oct. 4, at 8:06 a.m. EDT. NASA's Hubble Space Telescope and Chandra X-ray Observatory observed...
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Astronomers have published a major finding: A black hole has been "burping" out energy from a small star it was observed shredding in 2018, after two years in which it didn't eject any such material. How unusual is this? "Super unusual," Yvette Cendes, an astronomer at the Center for Astrophysics, Harvard and Smithsonian and lead author of the paper, tells NPR. "We've never really seen this before to this degree." Researchers made the discovery when they used a powerful radio telescope facility — the Very Large Array in New Mexico – to check in on some two dozen black holes...
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Periodically, these gravitational behemoths will devoir stars and other objects in their vicinity, releasing tremendous amounts of light and radiation. In October 2018, astronomers witnessed one such event when observing a black hole in a galaxy located 665 million light-years from Earth....another team from the Harvard & Smithsonian Center for Astrophysics noticed something unprecedented when they examined the same black hole three years later. As they explained in a recent study, the black hole was shining very brightly because it was ejecting...leftover material from the star at half the speed of light. [T]he team observed the outburst while revisiting data...
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1.) How did the Universe begin? What “type” of inflation occurred? What preceded and/or caused inflation? 2.) What explains neutrino mass? Are neutrinos Dirac or Majorana particles? Are there heavy, sterile neutrino species? 3.) Why is our Universe matter-dominated? More matter than antimatter permeates the Universe. 4.) What is dark matter? Its effects are understood, not its underlying cause. 5.) What is dark energy? Its properties indicate a constant, positive spatial energy density.
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Nasa With the recent release of fascinating images coming out of the James Webb Telescope, there’s been a renewed public interest in deep space. In a new post, NASA Exoplanet, the branch responsible for searching for potential life-bearing worlds beyond our solar system, released the “actual sound” of a black hole. “The misconception that there is no sound in space originates because most space is a vacuum, providing no way for sound waves to travel,” NASA Exoplanets writes in the tweet. “A galaxy cluster has so much gas that we’ve picked up actual sound. Here it’s amplified, and mixed with...
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Newton’s Theory of Gravity explains most large-scale events fairly well. ... However, the theory is not foolproof. Einstein’s theories of general and special relativity, for example, explained data that Newton’s theory couldn’t. Scientists still use Newton’s theory because it works in the overwhelming majority of cases and has much simpler equations. Dark matter was proposed as a way to reconcile Newtonian physics with the data. But what if, instead of reconciliation, a modified theory is needed.... Mordehai Milgrom...developed a theory of gravity (called Modified Newtonian Dynamics or “Mond” for short) in 1982 that postulates gravity functions differently when it becomes...
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I first wrote about the topic of "Dark Matter" back in 2009, but it was scrubbed from the files of the Chico Enterprise Record Newspaper I wrote for and lost to history, after I was unceremoniously let me go. Well, I just found it in a file I was going through which someone sent me a few years ago. I lost the email address of the person, since I changed internet companies, even at that the person who sent not to me preferred to remain anonymous. Anyway, I updated this article with some new information and this is what I...
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