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Simulation of a supermassive black hole. (NASA Goddard Space Flight Center; ESA/Gaia/DPAC) _____________________________________________________________________________________ The most energetic light and particles in the Universe represent an enduring mystery: we don't know where they come from. Sure, we can trace some; but there's more gamma radiation and neutrinos streaming through the Universe than we can account for. A lot more. And astronomers have just found an explanation for some of them: nearly dormant black holes. This, they say, can explain the excess of 'soft' gamma rays in the Universe without relying on cold (nonthermal) electrons – which has always been a problematic explanation,...

Given that our first direct detections confirming the existence of black holes only took place in this century, humanity can be forgiven for not knowing a few things about these mysterious cosmic objects. We don't even know everything we don't know – a fact that's been made evident in a new discovery. While running equations for quantum gravity corrections for the entropy of a black hole, a pair of physicists found that black holes exert pressure on the space around them. Not much pressure, to be sure – but it's a finding that's fascinatingly consistent with Stephen Hawking's prediction that...

A wave signal from space validates Hawking’s prediction that the area of an event horizon should never decrease. One of Stephen Hawking’s most important predictions about black holes has finally been observationally confirmed by ripples in the fabric of spacetime, reports a new study. The milestone not only validates the theories of the influential physicist, who died in 2018, it also provides a new means to test some of our most fundamental assumptions about the universe. Black holes are famous for extremely strange behaviors, such as the capacity to trap anything, including light, inside the event horizon that marks their...

Scientists were expecting to find an intermediate-mass black hole at the heart of the globular cluster NGC 6397, but instead they found evidence of a concentration of smaller black holes lurking there. New data from the NASA/ESA Hubble Space Telescope have led to the first measurement of the extent of a collection of black holes in a core-collapsed globular cluster. Globular clusters are extremely dense stellar systems, in which stars are packed closely together. They are also typically very old — the globular cluster that is the focus of this study, NGC 6397, is almost as old as the Universe...

There are supermassive black holes. There are ultramassive black holes. How large can these strange objects grow? Well, there could be something even bigger than ultramassive: stupendously large black holes, according to the latest research. Such hypothetical black holes - larger than 100 billion times the mass of the Sun - have been explored in a new paper which names them SLABs, an acronym that stands for "Stupendously LArge Black holeS". "We already know that black holes exist over a vast range of masses, with a supermassive black hole of 4 million solar masses residing at the centre of our...

The largest black holes in the universe... sit at the centers of almost every galaxy in the cosmos. Even the Milky Way has one, a monster at 4 million solar masses, designated as Sagittarius A*. ...[A]s far as we know, the only way to form black holes is through the deaths of massive stars. When they die, they leave behind a black hole a few times more massive than the sun. To get to supergiant status, they have to merge with other black holes and/or consume as much gas as possible, bulking up all those millions of solar masses... Either...

String theorists are making the case for flipping physics on its head.What if string theorists have been right all along, and black holes are just balls of yarn? These celestial rat kings, scientists say, represent a place where a huge bunch of fundamental strings have tangled together and can’t be extricated. This sounds far out, but we don’t understand a great deal about how black holes work to begin with. Positing a tangled string idea instead doesn’t even require much more of an ideological buy-in. Space.com’s Paul Sutter explains the big mental “tangle” with black holes: “Black holes appear in...

Few sports have seen the explosive growth enjoyed by Cornhole. Millions of players around the globe grab their sacks and fling them at holes in boards. Resembling something like a cross between hopscotch and competitive ax throwing, Cornhole is a game of stamina and speed. Cornhole has become so popular that in some circles, you can hear discussion of it becoming an Olympic event. Earl Flopper, President of the Cornhole Association Of Greenland says that it can’t come soon enough. “It can’t come soon enough.” Where do you stand on this, the most important issue of our time? Should Cornhole...

Roger Penrose’s theoretical work demonstrated the objects could form. Reinhard Genzel and Andrea Ghez independently discovered a supermassive one at the center of the Milky Way. Roger Penrose, Reinhard Genzel, and Andrea Ghez are to be awarded the 2020 Nobel Prize in Physics for their theoretical and observational work on black holes, the Royal Swedish Academy of Sciences announced on Tuesday. Penrose will receive half the 10 million Swedish krona (roughly $1.1 million) prize; Ghez and Genzel will share the other half. Penrose, of the University of Oxford, helped place the previously idealized concept of a black hole on sound...

Spacecraft already navigate our solar system using gravity wells as slingshots. The same basic principles operate in the intense gravity wells around black holes, which bend not only the paths of solid objects, but light itself. If a photon, or a light particle, enters a particular region in the vicinity of a black hole, it will do one partial circuit around the black hole and get flung back in exactly the same direction. Physicists call those regions "gravitational mirrors" and the photons they fling back "boomerang photons." Boomerang photons already move at the speed of light, so they don't pick...

The light released from around the first massive black holes in the universe is so intense that it is able to reach telescopes across the entire expanse of the universe. Incredibly, the light from the most distant black holes (or quasars) has been traveling to us for more than 13 billion light years. However, we do not know how these monster black holes formed. New research led by researchers from Georgia Institute of Technology, Dublin City University, Michigan State University, the University of California at San Diego, the San Diego Supercomputer Center and IBM provides a new and extremely promising...

Late in 2018, the gravitational wave observatory, LIGO, announced that they had detected the most distant and massive source of ripples of spacetime ever monitored: waves triggered by pairs of black holes colliding in deep space. Only since 2015 have we been able to observe these invisible astronomical bodies, which can be detected only by their gravitational attraction. The history of our hunt for these enigmatic objects traces back to the 18th century, but the crucial phase took place in a suitably dark period of human history – World War II. The concept of a body that would trap light,...

Broderick's work builds on earlier research by two teams that studied the galactic center of the Milky Way in near-infrared. This included the work of Reinhard Genzel, an astronomer from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, as well as researchers Andrea Ghez and Mark Morris of University of California, Los Angeles. At the time, their work revealed that the center of the Milky Way wasn't steady, but instead would drastically brighten about once a day for about 30 or 40 minutes, Broderick said. Researchers think supermassive black holes exist at the center of most, if not...

Scientists at Lawrence Livermore National Laboratory in California suspect that midsize black holes might be just the right size to provide enough gravitational force to reignite a dead white dwarf star — the stellar corpse of a star that's about the mass of the sun and that's used up its nuclear fuel. To test their idea, the team members ran supercomputer simulations of dozens of different close-encounter scenarios between these dead stars and midsize black holes. Every time a white dwarf got close to the Goldilocks black hole, the star reignited. The gravitational force from the black hole would cause the...

Close encounters with medium-size black holes can reanimate dead stars, if only momentarily, a new study suggests. A team of astronomers performed computer simulations to determine what happens when a burned-out stellar corpse known as a white dwarf passes close to an intermediate-mass black hole — one that harbors between 1,000 and 10,000 times the mass of Earth's sun. The researchers determined that the black hole's powerful gravity can stretch and distort the white dwarf's previously inert innards so dramatically that nuclear-fusion processes can reignite for a few seconds, converting helium, carbon and oxygen into heavier elements such as iron....

Sound has negative mass, and all around you it's drifting up, up and away — albeit very slowly. That's the conclusion of a paper submitted on July 23 to the preprint journal arXiv, and it shatters the conventional understanding that researchers have long had of sound waves: as massless ripples that zip through matter, giving molecules a shove but ultimately balancing any forward or upward motion with an equal and opposite downward motion. That's a straightforward model that will explain the behavior of sound in most circumstances, but it's not quite true, the new paper argues. A phonon — a...

The Next Big Discovery in Astronomy? We Probably Found It Years Ago — But Don't Know It Yet By Eileen Meyer, University of Maryland, Baltimore County | June 3, 2018 08:44am ET MORE An artist's illustration of a black hole "eating" a star.Credit: NASA/JPL-Caltech This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights. Earlier this year, astronomers stumbled upon a fascinating finding: Thousands of black holes likely exist near the center of our galaxy. The X-ray images that enabled this discovery weren't from some state-of-the-art new telescope. Nor were...

Nearly 40 years after it was proposed, mathematicians have settled one of the most profound questions in the study of general relativity. In a paper posted online last fall, mathematicians Mihalis Dafermos and Jonathan Luk have proven that the strong cosmic censorship conjecture, which concerns the strange inner workings of black holes, is false.“I personally view this work as a tremendous achievement — a qualitative jump in our understanding of general relativity,” emailed Igor Rodnianski, a mathematician at Princeton University.The strong cosmic censorship conjecture was proposed in 1979 by the influential physicist Roger Penrose. It was meant as a...

Anticipated but never before seen, the existence of tens of thousands of these dark objects at the galactic center could have far-reaching implications for astrophysics An artist's rendering of the Milky Way's core, with a supermassive black hole at its center. Scientists have discovered what appear to be twelve smaller black holes orbiting our galaxy's central giant. Each is thought to actually be a binary system composed of a black hole and a low-mass star. Gas siphoned from the star glows in x-rays as it falls into the black holes, allowing them to be seen. Credit: Columbia University For the...

An immense black hole 100,000 times bigger than the sun has been discovered at the heart of the Milky Way. The enormous void, which lies around 25,000 light years from Earth, could help scientists uncover the how stars, galaxies and even life itself came to be in the universe. ..." According to reports, this newly-discovered black hole could rank as the second largest ever seen in the Milky Way. Despite its immense size, scientists have called it a "mini me" version of its super-massive "cousin" known as Sagittitarius A*.