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Black hole merger challenges our understanding of black hole formation
- thaumasiotes 1y agoWay to headline. The numbers in the article suggest a violation of conservation of mass: > Today, the LIGO Collaboration announced the detection of the most colossal black hole merger known to date, the final product of which appears to be a gigantic black hole more than 225 times the mass of the Sun. > GW231123, first observed on November 23, 2023, seems to be an unprecedented beast of a black hole merger. Two enormous black holes—137 and 103 times the mass of the Sun—managed to keep it together despite their immense combined mass Is the explanation here "225 is a nice round number, and 240 is technically 'more than' that", or "a lot of mass evaporates into other forms of energy when black holes merge", or "during a merge, it becomes possible for matter to escape an event horizon", or what?
- jraines 1y agothe extra mass is converted into energy in the form of gravitational waves (maybe other forms too idk but this is part of it)
- maxbond 1y agoEntire solar masses being lost to gravitational waves, like the voltage drop across a resistor, is a humbling prospect.
- bot403 1y agoI'll underscore your awe by reminding you those solar masses disappeared in only 1 tenth of a second - the length of the gravitational wave signal.
- ikari_pl 1y agobut that's the time that passed here... it sounds like a mind-warpingly different perspective might have been seen there
- IAmBroom 1y agoI think you have it backwards. From the POV of someone near the Event Horizon, other space speeds up. Galaxies begin to spin at noticeable speeds.... But the black holes would appear to be approaching each other at "normal" speeds.
- Bluestein 1y agoDang
- nine_k 1y agoI suppose nothing but gravitational waves can escape the even horizon — or, rather, gravitational waves are born near / around it, because the black holes bend the space enormously. OTOH whatever else may be outside the black holes near the merger and count towards their mass for astronomical purposes, such as accretion discs, should be much lighter weight than what's inside the event horizon.
- ars 1y agoGravitational waves also can not escape. Those waves carry energy, and it's actually energy that can't escape. The waves are actually made just to the outside of the event horizon.
- thaumasiotes 1y ago> The waves are actually made just to the outside of the event horizon. How do we feel about this vis-a-vis action-at-a-distance?
- ars 1y agoGravity does action at a distance. That's its thing. The reason these waves are not generated from inside the black hole is that, to us, time stops there. For example these black hole mergers aren't actually merging, they are getting closer, and then they time dilate out of existence.
- thaumasiotes 1y ago> Gravity does action at a distance. That's its thing. Why does it need to travel in waves at the speed of light? If one mass moves, a distant mass is unaffected until the information reaches it. That's the opposite of action at a distance.
- ars 1y agoYour question is confusing. Action at a distance does not imply going faster than light, it means there is some sort of field connecting the two things.
- david38 1y agoRather confused. 225 solar masses isn’t gigantic by any means
- NooneAtAll3 1y agoit's above what's considered possible to create by usual star collapse means https://en.wikipedia.org/wiki/List_of_most_massive_stars https://en.wikipedia.org/wiki/List_of_most_massive_stars lists only 2 stars more massive than that
- thaumasiotes 1y agoSo if you have two black holes within each other's event horizons, but they're too big to collide, what's supposed to happen instead?
- pfdietz 1y agoThe situation you describe is impossible. "If you have a very large positive number that is less than zero, what happens?"
- thaumasiotes 1y agoWhat's the contradiction in the black hole setup?
- naasking 1y agoI'm not even sure what it would mean for two black holes to be too big to collide, or where that became some kind of constraint.
- dskloet 1y agoI thought it was just thought that it would take too long for them to spiral into each other for it to have happened enough times in our universe
- gnabgib 1y agoTitle needs an edit (maybe the clickbait algo): Astronomers Detect a Black Hole Merger That’s So Massive It Shouldn’t Exist - although, it's not a great title.
- imoverclocked 1y ago“Black hole merger detected that defies theoretical boundaries.”
- abrookewood 1y agoStill not clear to me how this "contradicts known models for stellar evolution".
- tomhow 1y agoThanks – I changed it (earlier today) to: Black hole merger challenges our understanding of black hole formation
- sherdil2022 1y agoOur understanding of this universe constantly changes. We all know those - Earth is flat or it is center of universe, on and on. The black hole is happening. So it exists. So either the observations are wrong or the undeying assumptions are wrong or math / physics we are using to make sense of the event is wrong. Click-bait articles serve no purpose in advancing science.
- gmuslera 1y agoGreg Egan's Diáspora starts with the merger of two neutron stars, and that causes a lot of trouble in this side of the galaxy, don't want to imagine what would it be with 2 massive blackholes for the nearby galaxies.
- ars 1y agoIt wouldn't do anything special actually. A black hole from a distance does nothing a sun can't do. Black holes only become destructive/powerful when you are very close to them. To elaborate: A black hole is mass, a sun is mass. From a distance there's no difference. The only difference is up close - you can get a lot closer to a black hole dramatically increasing the gravitational force. But from a distance? Nothing special.
- adrianN 1y agoExcept black holes can be a lot more massive than the biggest stars.
- atoav 1y agoWhich is true, but also just means you need more distance. And if there is anything in space it is distance.
- ikari_pl 1y agothen there are the jets the black holes may form, and I wouldn't like to pass through one
- ars 1y agoNo, those jets look amazing from a distance, where you are looking at a galaxy sized object. But up close they are very thin and you probably would not notice passing through one unless you were checking carefully.
- ErigmolCt 1y agoWe often imagine them as space vacuums sucking everything in, but they're really just compact mass: spooky only if you get way too close
- Stevemiller07 1y agoIt’s impressive how LIGO and Virgo keep pushing the limits of what we thought was possible. Each new event seems to open more questions than it answers.
- misja111 1y agoI don't get it. There are black holes that have millions of sun masses. The current theory is that these were formed by many consecutive mergers. What then makes this 225 sun mass merger so large that it shouldn't exist?
- berkes 1y agoJust guessing, but maybe the common situation is that one ever growing black hole absorbes small ones? But that two of these large ones merging "should not happen"?
- daedrdev 1y agoThere are no medium sized bkack holes. As far as we look back in time with james webb,the largest are already there.
- DrBazza 1y agoLarge mass stars are very, very few in number, and have short lifetimes, so collapse into black holes (if it happens), and then mergers are vanishingly small. 225 solar masses black holes are in the realms of unlikely if only had that information. https://en.wikipedia.org/wiki/List_of_most_massive_stars https://en.wikipedia.org/wiki/List_of_most_massive_stars Then again, the universe is really big and to paraphrase Pratchett, million-to-one chances happen nine times out of ten. https://en.wikipedia.org/wiki/Phoenix_Cluster#Supermassive_black_hole https://en.wikipedia.org/wiki/Phoenix_Cluster#Supermassive_b... "Such a high mass may place it into a proposed category of stupendously large black holes (SLABs), black holes that may have been seeded by primordial black holes with masses that may reach 100 billion M or more, larger than the upper maximum limit for at least luminous accreting black holes hosted by disc galaxies of about 50 billion M[12]" (which comes from a paper from one of my old lecturers). If we accept that primordial black holes do indeed exist (the evidence against, is, I believe that they should be evaporating about now, but are as yet unobserved), there must therefore be a weight distribution of those, which means there are probably other 'solar mass' 'seeded' black holes lurking, that were never created by stellar collapse.
- GoblinSlayer 1y ago
- ErigmolCt 1y ago225 solar masses… that's just wild. We keep building these models that tell us mergers like this shouldn't happen, and the universe keeps dunking on them
- exe34 1y agoThe models are constrained by what is known at the time they are built - those that clash with existing observations are discarded while those that don't, get published.
- debugnik 1y agoThe article fails to explain why this event challenges our understanding of black holes. Did we expect such big masses to spiral for much longer or something? Why was this collision supposed to stay unstable?
- MattPalmer1086 1y agoThere just isn't a way to make black holes that big from the collapse of stars when they go supernova. So maybe both of these black holes formed from earlier mergers of smaller black holes. Or maybe there are other ways to make larger black holes we don't know about. They are in a range of mass we don't really expect to see theoretically.
- Roark66 1y agoCan someone explain how is it possible for black holes to even collide? Wasn't the usual expanation that time goes faster (for you, slower for outside observer) as you approach the black hole singularity and that it stops exactly as you "get there"? If this is true the black holes never actually collide. They just endlessly spin closer and closer. For the outside observer it taking infinite time before they actually "touch"? Or do we just call it a collision if they simply get as close to each other as to be within the event horizon of the other? If the former and we see these true collisions, how is it not a proof the age of the universe is infinite ? If we see events that are supposed to take infinitely long to occur?
- x-yl 1y agoAn observer falling into the black hole would not observe any distortion in time. They would simply fall in, under the influence of gravity. From the perspective of a far-away observer it would look as if time is slowing down as the photons would take increasingly longer to escape. At the event horizon the photons would effectively be held in place. Eventually though, the last photon will have escaped and you will just observe a slightly larger black hole. So the merger definitely happens from the point of view of the black holes. We might observe odd artifacts but they would eventually fade away.
- magicalhippo 1y ago> From the perspective of a far-away observer it would look as if time is slowing down as the photons would take increasingly longer to escape. Photons travel at the speed of light always, that's what Einstein told us. So rather, the observed energy (frequency) of the photons decreases, and it takes longer between each photon. At least that's my understanding.
- exe34 1y agoThey can merge event horizons on a finite timescale from the outside and still take an infinite amount of time to merge singularities or whatever it is that singularities do when they meet up in the privacy of an event horizon.
- ReptileMan 1y agoAll you really need to know for the moment is that the universe is a lot more complicated than you might think, even if you start from a position of thinking it’s pretty damn complicated in the first place.
- VagabundoP 1y agoSo this article confused me. After digging around, the masses of these Black Holes are in the forbidden zone, where there shouldn't really be Black Holes of that size because of how they are formed. They are usually either bigger or smaller depending on their origin. They could be second or third generation Black Holes, which would be unlikely due to the probability of them forming in close neighborhood. So what their reason for existing there are questions that should lead to some interesting answers if we ever get to the bottom of it.