Black Hole at Heart of Our Galaxy Is on Crash Course, Space-Time Ripples Reveal (wsj.com) 53
Supermassive black holes all over the universe are merging, a fate that will eventually come for the black hole at the center of our galaxy. From a report: These mysterious cosmic structures at the heart of nearly every galaxy consume light and matter and are impossible to glimpse with traditional telescopes. But now, for the first time, astrophysicists have gathered knowledge directly from these titans, in the form of gravitational waves that ripple through space and time. What they learned suggests that the population of massive black hole pairs that are merging numbers in the hundreds of thousands -- perhaps even millions.
The gravitational waves from these mergers are all contributing to an underlying background hum of the universe that researchers can detect from Earth. The findings, from a collaboration of more than 100 scientists, help confirm what will one day happen to the supermassive black hole at our galaxy's center, known as Sagittarius A*, as it crashes into the black hole at the heart of the Andromeda galaxy. "The Milky Way galaxy is on a collision course with the Andromeda galaxy, and in about 4.5 billion years, the two galaxies are set to merge," said Joseph Simon, a University of Colorado, Boulder, astrophysicist and a member of the North American Nanohertz Observatory for Gravitational Waves, or Nanograv, which helped lead the new work with support from the National Science Foundation.
That merger, he said, will eventually result in the black hole at the center of Andromeda and Sagittarius A* sinking into the center of the newly combined galaxy and forming what is known as a binary system. The results were announced in a series of papers published Wednesday in the Astrophysical Journal Letters. "Before now, we didn't even know if supermassive black holes merged, and now we have evidence that hundreds of thousands of them are merging," said Chiara Mingarelli, a Yale University astrophysicist and a member of Nanograv. The new work could answer questions such as how these black holes grow, and how often their host galaxies merge, the researchers said. Further reading: The Cosmos Is Thrumming With Gravitational Waves, Astronomers Find.
The gravitational waves from these mergers are all contributing to an underlying background hum of the universe that researchers can detect from Earth. The findings, from a collaboration of more than 100 scientists, help confirm what will one day happen to the supermassive black hole at our galaxy's center, known as Sagittarius A*, as it crashes into the black hole at the heart of the Andromeda galaxy. "The Milky Way galaxy is on a collision course with the Andromeda galaxy, and in about 4.5 billion years, the two galaxies are set to merge," said Joseph Simon, a University of Colorado, Boulder, astrophysicist and a member of the North American Nanohertz Observatory for Gravitational Waves, or Nanograv, which helped lead the new work with support from the National Science Foundation.
That merger, he said, will eventually result in the black hole at the center of Andromeda and Sagittarius A* sinking into the center of the newly combined galaxy and forming what is known as a binary system. The results were announced in a series of papers published Wednesday in the Astrophysical Journal Letters. "Before now, we didn't even know if supermassive black holes merged, and now we have evidence that hundreds of thousands of them are merging," said Chiara Mingarelli, a Yale University astrophysicist and a member of Nanograv. The new work could answer questions such as how these black holes grow, and how often their host galaxies merge, the researchers said. Further reading: The Cosmos Is Thrumming With Gravitational Waves, Astronomers Find.
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Everything i've ever heard about this suggests the galactic merger will be a non-event out here in our spiral arm. The stars are far apart and it's not like the center of Andromeda is going to aim for us. Maybe more of an event in the central bulges of the spiral galaxies. Would love to watch that with time sped up.
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What I have heard is that there will be an orgy of star formation as gas clouds hit gas clouds creating shock waves triggering star formation. Star formation produces a lot of radiation, young stars put out radiation, some will be huge blue stars, which burn up in a few million years of producing a lot of radiation before exploding, which really produces radiation.
How it will affect the solar system really depends on luck, like where in its orbit it is but much of the galaxy will become uninhabitable with s
Paywalls are the web's (Score:1)
...blackholes
The end is nigh! (Score:2)
Repent ye sins. You only have 4.5 billion years left.
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Yeah, where are the contingency plans for that?
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Yeah, where are the contingency plans for that?
Heh. But you know, we'll definitely need the technology to move our planet by then. Moving asteroids will be Phase 1 of the project.
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Most models of stellar evolution show we'll need to move the Earth within a billion years as the Sun gets a higher percentage of helium and therefore denser and hotter. Once the oceans boil, not much life will survive.
Need to start moving soon as it will be hard to move the Earth by more then a few inches a year, at least by flying asteroids close by.
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Most models of stellar evolution show we'll need to move the Earth within a billion years
A billion years is more than long enough to have another giant rock smash into us again and kill everything, maybe even fracture the planet into several smaller pieces. So don't worry, we won't need to plan for the next 4 billion years. Stupid hominids always put off until tomorrow; look at their history. Turns out they are right.
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Well, it has been 4.5 billion years since a big enough rock hit to fracture the planet, so not a frequent occurrence.
Lots of other ways for us to die off in the relative near future though, I'm sure we'll find one.
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I've seen mention of models that put it at 500 million years, models seem all over the place, which makes sense as all we have are observations rather then experiments to go on. Any which way, it is so far in the future that we can't even begin to comprehend the time scales.
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A factor of 4 difference (500Myr to 2 Gyr) is pretty close to agreement. I'm a geologist, and I don't cringe at it. I doubt most biologists would really be upset at such results. Social scientists would be ecstatic, and economists would be convinced the modelling is wrong, the results not being dismal enough.
Physics and maths may enjoy in precision, but down here where measurement is uncertain and sample sizes are in the
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"Social scientists would be ecstatic, and economists would be convinced the modelling is wrong, the results not being dismal enough. "
FLOTD (First Laugh of the Day)
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Good point about it only being a factor of 4.
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That don't confront me... (Score:5, Funny)
Long as I get my money next Friday!
The "Big Crunch"? (Score:2)
it's possible (Score:2)
That outcome would mean that a lot of matter that is invisible to us, as it is beyond the edge of the visible universe, would have to reconcentrate. Another thing that would be fun to watch. Well sort of, as black holes it wouldn't be very visible. Maybe watch in simulation.
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Well yeah at real life speed, but how about at trillion to one speed?
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Does all the material that fall into a black hole get converted into "universe starter fuel" automatically? Or does it retain some of it's post-creation properties?
Starting to think more mystery is assigned to black holes than there should be. There's things we don't understand still sure, but I'm pretty sure there's no hidden universes or gateway's to other dimensions in there too. No lizard people in the earth either. Sorry!
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Apparently the equations suggested that 'white holes' should exist also. None have been seen yet. They are supposed to have the reverse properties of black holes.
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Forgot about those. At a glance, it sounds like mathematical fantasy. I didn't see any theory as to how something like that would form. A black hole is more understandable. You pack stuff so tightly that it exceeds the limits of gravity, to the point where it's unable to correct itself, except for small radiation.
I just don't see how people think about the interior of a black hole as containing some sort of magical pixie dust that's somehow different than whatever matter was dumped into it. It's just a ball
singularity (Score:2)
Meaning, it's a place where you can't expect the existing theories we have to govern the activity.
Also, it's got an event horizon, preventing us from seeing what is going on in there. Maybe it's a big party in there.
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Consider that in a black hole, light gets sucked in if it gets too close and time slows down relative to the rest of the universe the closer you get. Not magical pixie dust, but pretty weird.
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Re: The "Big Crunch"? (Score:2)
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All the matter in universe will be consumed by black holes and the black holes will merge into one, a singularity and when that explodes will create a new universe,
I came here to post this same thing. Maybe it is just a cycle of expanding and contracting over and over. Maybe each time it gets a little weaker until the last big bang is just a little pop and then its all over.
Re:The "Big Crunch"? (Score:5, Informative)
All the matter in universe will be consumed by black holes and the black holes will merge into one
That seems very unlikely given that, due to the accelerating expansion of the universe, the fraction of the universe that we are causally connected to is shrinking. This will make it impossible for the black holes in one part of the universe to meet and merge with those in another no matter how much time you give them.
In addition, BHs only have a limited lifespan since they evaporate due to Hawking radiation. While the lifetimes are insanely long with supermassive BHs having the longest on the order of 10^100 years even if mass does end up concentrated in BHs it will eventually be emitted again. The long-term fate of the universe may well be a "big rip" depending on what happens with the causally connected distance shrinks towards the planck length as the expansion of space continues to accelerate into the incredibly distant future.
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We should introduce a tax to address the supermassive black hole merge issue. I'm sure politician will fix the problem with more money.
The EU can fix or stop anything with regulations.
And if regulations don't work, then they will tax it out of existence.
And if all those regulations and taxes don't work...they will declare it is the work of Brexit supporters and turn the politicians & bureaucrats loose on it.
The Pierson's Puppeteers are already fleeing (Score:2)
But not too fast.
We don't know (Score:2)
Paraphrasing Marx and Engels... (Score:2)
Are there any binary galaxies already? (Score:2)
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There are. A famous example is the Mice Galaxies https://duckduckgo.com/?t=ffab... [duckduckgo.com]
Considering the state of humanity (Score:1)
Larry Niven's Known Universe (Score:2)
Is this what the Puppeteers were running away from?
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No, a chain reaction of novas and/or supernovas in the densely packed core. In that case it was something like 20,000, or 40,000 years before the radiation got here, forget the exact figure.
Is the summary cleverly designed to confuse? (Score:2)
The title and summary confused me and made me want to read the article, breaking the Slashdot tradition. Is the discovery that black holes are merging generally, per how the summary starts off "now we have evidence that hundreds of thousands of them are merging". Or is it that black hole pairs are merging, and the summary says shortly thereafter "the population of massive black hole pairs that are merging"?
Or is it that the way that the general merging is happening is one pair at a time, such as with Sagitt
Typical Slashdot - bullshit journalism, no papers. (Score:2)
The NANOGrav 15 yr Data Set: Detector Characterization and Noise Budget Link [iop.org]
Focus on NANOGrav's 15 yr Data Set and the Gravitational Wave Background Link [iop.org]
The observations and timing methodologies (Agazie et al. 2023a [iop.org])
the modeling used to describe the various noise processes that affect PTA data Link [iop.org]