Of all the far-out concepts in astronomy, black holes may be the weirdest. A region of space where matter is so tightly packed that nothing, not even light itself, can escape, these dark behemoths present a pretty terrifying prospect, too. With all the normal rules of physics breaking down inside them, it's tempting to dismiss black holes as the stuff of science fiction. Yet there's plenty of evidence both direct and indirect that they really do exist in the universe.
As a theoretical possibility, black holes were predicted in 1916 by Karl Schwarzschild, who found them to be an inevitable consequence of Einstein's theory of general relativity. In other words, if Einstein's theory is correct and all the evidence suggests it is then black holes must exist. They were subsequently put on even firmer ground by Roger Penrose and Stephen Hawking, who showed that any object collapsing down to a black hole will form a singularity where the traditional laws of physics break down, according to the University of Cambridge. This has become so widely accepted that Penrose was awarded a share in the 2020 Nobel prize in physics "for the discovery that black hole formation is a robust prediction of the general theory of relativity."
In the 1930s, Indian astrophysicist Subramanian Chandrasekhar looked at what happens to a star when it has used up all its nuclear fuel, according to NASA. The end result, he found, depends on the star's mass. If that star is really big, say 20 solar masses, then its dense core which may itself be three or more times the mass of the sun collapses all the way down to a black hole, according to NASA. The final core collapse happens incredibly quickly, in a matter of seconds, and it releases a tremendous amount of energy in the form of a gamma-ray burst. This burst can radiate as much energy into space as an ordinary star emits in its entire lifetime. And telescopes on Earth have detected many of these bursts, some of which come from galaxies billions of light-years away; so we can actually see black holes being born.
Black holes don't always exist in isolation sometimes they occur in pairs, orbiting around each other. When they do, the gravitational interaction between them creates ripples in space-time, which propagate outward as gravitational waves another prediction of Einstein's theory of relativity. With observatories like the Laser Interferometer Gravitational-Wave Observatory and Virgo, we now have the ability to detect these waves, Live Science sister site Space.com reported. The first discovery, involving the merger of two black holes, was announced back in 2016, and many more have been made since then. As detector sensitivity improves, other wave-generating events besides black hole mergers are being discovered such as a crash between a black hole and a neutron star, which took place way beyond our own galaxy at a distance of 650 million to 1.5 billion light-years from Earth, Live Science reported.
The short-lived, high-energy events that produce gamma-ray bursts and gravitational waves may be visible halfway across the observable universe, but for most of their lives black holes, by their very nature, will be almost undetectable. The fact that they don't emit any light or other radiation means they could be lurking in our cosmic neighborhood without astronomers being aware of it. There's one sure-fire way to detect the dark beasts, though, and that's through their gravitational effects on other stars. When observing the ordinary-looking binary system, or pair of orbiting stars, known as HR 6819 in 2020, astronomers noticed oddities in the motion of the two visible stars that could be explained only if there was a third, totally invisible, object there. When they worked out its mass at least four times that of the sun the researchers knew there was only one possibility left. It had to be a black hole the closest yet discovered to Earth, a mere thousand light-years away inside our own galaxy, as Live Science reported.
The first observational evidence for a black hole emerged in 1971, and this too came from a binary star system within our own galaxy. Called Cygnus X-1, the system produces some of the universe's brightest X-rays. These don't emanate from the black hole itself, or from its visible companion star which is enormous, at 33 times the mass of our own sun, according to NASA. Rather, matter is constantly being stripped from the giant star and dragged into an accretion disk around the black hole, and it's from this accretion disk, NASA said, that the X-rays are emitted. As they did with HR 6819, astronomers can use observed star motion to estimate the mass of the unseen object in Cygnus X-1. The latest calculations put the dark object at 21 solar masses concentrated into such a small space that it couldn't be anything other than a black hole, Live Science reported.
In addition to black holes created through stellar collapse, evidence suggests that supermassive black holes, each millions or even billions of solar masses, have been lurking in the centers of galaxies since early in the history of the universe, Live Science reported. In the case of so-called active galaxies, the evidence for these heavyweights is spectacular. According to NASA, the central black holes in these galaxies are surrounded by accretion disks that produce intense radiation at all wavelengths of light. We also have evidence that our own galaxy has a black hole at its center. That's because we see the stars in that region whizzing around so fast up to 8% of the speed of light that they must be orbiting something extremely small and massive. Current estimates put the Milky Way's central black hole somewhere around 4 million solar masses.
Another piece of evidence for the existence of black holes is spaghettification. What, you might wonder, is spaghettification? It's what happens when you fall into a black hole, and it's pretty self-explanatory. You get stretched out into thin strands by the black hole's extreme gravitational pull. Luckily, that's not likely to happen to you or anyone you know, but it may well be the fate of a star that wanders too close to a supermassive black hole, Live Science reported. In October 2020, astronomers witnessed this shredding or at least, they saw the flash of light from a hapless star as it was ripped apart. Fortunately, the spaghettifying didn't happen anywhere near Earth, but instead in a galaxy 215 million light-years away.
So far we've had plenty of compelling indirect evidence for black holes: bursts of radiation or gravitational waves, or dynamical effects on other bodies, that couldn't have been produced by any other object known to science. But the final clincher came in April 2019, in the form of a direct image of the supermassive black hole at the center of active galaxy Messier 87. This stunning photo was taken by the Event Horizon Telescope a slightly misleading name, because it consists of a large network of telescopes scattered all over the world rather than a single instrument. According to NASA, the more telescopes that can participate, and the more widely spaced they are, the better the final image quality. The result clearly shows the dark shadow of the 6.5 billion-solar-mass black hole against the orange glow of its surrounding accretion disk, as reported by Live Science.
Originally published on Live Science.
The rest is here:
8 ways we know that black holes really do exist - Livescience.com
- Singularity Future Technology Ltd (SGLY) is up 43.55% Tuesday In Premarket Trading - InvestorsObserver - March 18th, 2024 [March 18th, 2024]
- This Week's Awesome Tech Stories From Around the Web (Through March 16) - Singularity Hub - March 18th, 2024 [March 18th, 2024]
- Palia reaches over 3m players in six months thanks to "invaluable" Switch partnership - GamesIndustry.biz - March 18th, 2024 [March 18th, 2024]
- Beyond the Singularity: Exploring the Fusion of AI and Art - Hong Kong Standard - March 18th, 2024 [March 18th, 2024]
- Your Comprehensive Guide to Telos Staking Success | by Pizza Singularity Sapphire | Feb, 2024 - Medium - February 20th, 2024 [February 20th, 2024]
- BTS' Kim Taehyung's 'Singularity' Performance Featured in Harvard Professor's Book - BNN Breaking - February 20th, 2024 [February 20th, 2024]
- Title: Understanding the Singularity: Unveiling the Future of Humanity - Medium - December 12th, 2023 [December 12th, 2023]
- What happens at the center of a black hole? - Astronomy Magazine - December 12th, 2023 [December 12th, 2023]
- IBM Is Planning to Build Its First Fault-Tolerant Quantum Computer by 2029 - Singularity Hub - December 12th, 2023 [December 12th, 2023]
- 22 Laws of Singularity And How You Can Apply Them To Live A Better Life - Medium - December 12th, 2023 [December 12th, 2023]
- Singularity: Here's When Humanity Will Reach It, New Data Shows - March 31st, 2023 [March 31st, 2023]
- sentinelOne expands singularity marketplace with new SOAR, insider threat, training, and prioritization integrations - ZAWYA - March 31st, 2023 [March 31st, 2023]
- Reaching the Singularity May be Humanitys Greatest and Last ... - March 4th, 2023 [March 4th, 2023]
- Singularity: Explain It to Me Like I'm 5-Years-Old - Futurism - March 4th, 2023 [March 4th, 2023]
- SINGULARITY FUTURE TECHNOLOGY LTD. : Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Change in... - March 4th, 2023 [March 4th, 2023]
- Apple co-founder Steve Wozniak on Artificial Intelligence: Not worried about The Singularity, well still be in control - MacDailyNews - February 12th, 2023 [February 12th, 2023]
- Cauchy principal value - Wikipedia - January 4th, 2023 [January 4th, 2023]
- Singularity Future Technology Ltd. (SGLY) Stockholder Notice: Robbins LLP Reminds Investors of the Class Action Against Singularity Future Technology... - December 14th, 2022 [December 14th, 2022]
- ROSEN, A LEADING LAW FIRM, Encourages Singularity Future Technology Ltd. f/k/a Sino-Global Shipping America Ltd. Investors to Secure Counsel Before... - December 12th, 2022 [December 12th, 2022]
- Singularity (mathematics) - Wikipedia - November 23rd, 2022 [November 23rd, 2022]
- GitHub: Where the world builds software GitHub - November 21st, 2022 [November 21st, 2022]
- Review: The Singularities, by John Banville - The New York Times - October 25th, 2022 [October 25th, 2022]
- We need to manage AI better as we are approaching the Creative Singularity - RedShark News - October 15th, 2022 [October 15th, 2022]
- This Week's Awesome Tech Stories From Around the Web (Through October 15) - Singularity Hub - October 15th, 2022 [October 15th, 2022]
- Ferguson: A second helping of QB play from Thanksgiving weekend - CFL.ca - October 15th, 2022 [October 15th, 2022]
- Kanimozhi slams Union govt over conducting CGL exams in only Hindi and English - The News Minute - October 15th, 2022 [October 15th, 2022]
- New Bayonetta 3 Trailer Reveals An In-Universe Singularity, And Lots Of Witches - Gameranx - October 13th, 2022 [October 13th, 2022]
- Singularity Future Technology Announces Receipt of Nasdaq Notice of Delisting and Intention to Request Hearing - Yahoo Finance - October 13th, 2022 [October 13th, 2022]
- Six Recent Discoveries That Have Changed How We Think About Human Origins - Singularity Hub - October 13th, 2022 [October 13th, 2022]
- This AI Uses a Scan of Your Retina to Predict Your Risk of Heart Disease - Singularity Hub - October 13th, 2022 [October 13th, 2022]
- The Moon May Have Formed Just Hours After Earth Collided With a Protoplanet - Singularity Hub - October 13th, 2022 [October 13th, 2022]
- UK HealthCare hosting 2 nationally esteemed guests for 60th anniversary symposium - UKNow - October 13th, 2022 [October 13th, 2022]
- Why Transcend Fund believes the opportunity for game investments is only getting bigger - VentureBeat - October 13th, 2022 [October 13th, 2022]
- Austin Powers References in This Fool, Ramy, Bros - Vulture - October 13th, 2022 [October 13th, 2022]
- Bayonetta 3 Everything You Need to Know About this Bewitching Beat em Up - Wccftech - October 8th, 2022 [October 8th, 2022]
- Longtermism: The Future Is VastWhat Does This Mean for Our Own Life? - Singularity Hub - October 8th, 2022 [October 8th, 2022]
- Ohio creates elections integrity office while voter fraud is already 'exceedingly rare' - ideastream - October 8th, 2022 [October 8th, 2022]
- Elon Musk Warns of World War III - TheStreet - October 8th, 2022 [October 8th, 2022]
- Durga reminds us of our collective obligations - Daily Pioneer - October 8th, 2022 [October 8th, 2022]
- Glitch in the algorithm - The Bucknellian - October 8th, 2022 [October 8th, 2022]
- As the Robot Fry Cook Takes Over the Kitchen - Walter Bradley Center for Natural and Artificial Intelligence - October 8th, 2022 [October 8th, 2022]
- The Singularity Image Format (SIF) Selected as a Finalist in the HPCwire Readers' Choice Awards - PR Web - October 6th, 2022 [October 6th, 2022]
- The Singularity Image Format (SIF) Selected as a Finalist in the HPCwire Readers' Choice Awards - Benzinga - October 6th, 2022 [October 6th, 2022]
- The Singularity of the Dual Mandate - Federal Reserve Bank of San Francisco - October 6th, 2022 [October 6th, 2022]
- What Is the Quirk Singularity Doomsday Theory in My Hero Academia? Explained - Twinfinite - October 6th, 2022 [October 6th, 2022]
- Introduction to week 4 of Tekedia Mini-MBA: Exponential Technologies and Singularity - Tekedia - October 6th, 2022 [October 6th, 2022]
- A $500 Million International Project Will Create the Most Detailed Map of the Brain Ever - Singularity Hub - October 6th, 2022 [October 6th, 2022]
- There Are Cheaper, More Sustainable Ways Than Desalination to Meet Our Water Needs - Singularity Hub - October 6th, 2022 [October 6th, 2022]
- #3DStartup: Unlimited Tomorrow and its 3D Printed Bionic Prosthetic Arm - 3Dnatives - October 6th, 2022 [October 6th, 2022]
- First As Parody, Then As Free Speech: The Onion Goes To The Supreme Court. It's About As Awesome As You'd Suspect. - Above the Law - October 6th, 2022 [October 6th, 2022]
- 10 Hot Cyber Threat Intelligence Tools And Services In 2022 - CRN - October 6th, 2022 [October 6th, 2022]
- Nintendo comes out strong with its offering of upcoming titles - The UML Connector - October 6th, 2022 [October 6th, 2022]
- The metaverses evolutionary roots could aid its success | Mint - Mint - October 6th, 2022 [October 6th, 2022]
- The Tech That Will Push VR to the Limits of the Human Eye - Singularity Hub - September 27th, 2022 [September 27th, 2022]
- Super-Earths Are Bigger and More Habitable Than Earth, and Astronomers Are Discovering More of the Billions They Think Are Out There - Singularity Hub - September 27th, 2022 [September 27th, 2022]
- Scientists Have Long Dreamed of a Memory Prosthesis. The First Human Trials Look Promising - Singularity Hub - September 27th, 2022 [September 27th, 2022]
- NASA's DART Spacecraft Will Smack an Asteroid at 14,000 MPH Todayand You Can Watch - Singularity Hub - September 27th, 2022 [September 27th, 2022]
- Why You Should Read This: 'The Gold Coast' - Alta Magazine - September 27th, 2022 [September 27th, 2022]
- The Multitude of Stromae - Mail and Guardian - September 27th, 2022 [September 27th, 2022]
- Warhammer 40,000: Space Marine is Getting a Location-based VR Experience Next Year - Road to VR - September 27th, 2022 [September 27th, 2022]
- What the pandemic taught us about teaching (On the Other Hand) - Montclair Local - September 27th, 2022 [September 27th, 2022]
- Where to get the Boom Sniper in Fortnite Chapter 3 Season 4 - The Nerd Stash - September 27th, 2022 [September 27th, 2022]
- Machine learning has predicted the winners of the Worlds - CyclingTips - September 27th, 2022 [September 27th, 2022]
- Vaonis Vespera Review: Easy To Use But with Underwhelming Results - PetaPixel - September 27th, 2022 [September 27th, 2022]
- The biggest problem with gravity and quantum physics - Big Think - September 27th, 2022 [September 27th, 2022]
- V gets inked on his butt cheek? BTS star spills the details about his friendship tattoo - Zoom TV - September 27th, 2022 [September 27th, 2022]
- Robots & Humans: Are we heading towards Singularity? - INDIAai - September 20th, 2022 [September 20th, 2022]
- This Week's Awesome Tech Stories From Around the Web (Through September 17) - Singularity Hub - September 20th, 2022 [September 20th, 2022]
- A Swedish Company Wants to Transform Offshore Wind With Vertical-Axis Turbines - Singularity Hub - September 20th, 2022 [September 20th, 2022]
- Decarbonizing the Energy Sector by 2050 Could Save the World $12 Trillion - Singularity Hub - September 20th, 2022 [September 20th, 2022]
- This Sleek Solar Car Goes 600 Miles on a Charge and Is Gearing Up for Production - Singularity Hub - September 20th, 2022 [September 20th, 2022]
- Meta Built an AI That Can Guess the Words You're Hearing by Decoding Your Brainwaves - Singularity Hub - September 20th, 2022 [September 20th, 2022]
- Gory Throwback FPS 'Prodeus' Exits Early Access This Thursday, Launching for PC and Consoles [Trailer] - Bloody Disgusting - September 20th, 2022 [September 20th, 2022]
- Meet the New Vespera Telescope From Vaonis - Universe Today - September 20th, 2022 [September 20th, 2022]
- Of God and Machines - The Atlantic - September 20th, 2022 [September 20th, 2022]
- Humans Destroyed Forests for Thousands of Years. We Can Become the First Generation to Expand Them - Singularity Hub - September 20th, 2022 [September 20th, 2022]
- Intel Core i9-13900K beats the 12900K by +10% in CPU-bound games - KitGuru - September 20th, 2022 [September 20th, 2022]
- INVESTIGATION ALERT: The Schall Law Firm Encourages Investors in Singularity Future Technology Ltd. with Losses of $100000 to Contact the Firm -... - August 15th, 2022 [August 15th, 2022]
- How To Open Singularity Rock in Tower of Fantasy - Attack of the Fanboy - August 15th, 2022 [August 15th, 2022]
- Intel i9-13900K Tested in Ashes Of The Singularity, Offers Neglible Increments in Performance - Appuals - August 15th, 2022 [August 15th, 2022]