101–110 of 186 posts
Maybe I’m a bit naive here, but I thought finding of many supermassive back holes in the very early universe should be expected, and not a surprise. My chain of thoughts is following: - Blackholes are collapsed masses. In our phase of the universe, they are normally the results of supernovae but only because today stars are the only source of dense masses. - Because the total mass of the universe is constant and the…
Maybe I’m a bit naive here, but I thought finding of many supermassive back holes in the very early universe should be expected, and not a surprise. My chain of thoughts is following: - Blackholes are collapsed masses. In our phase of the universe, they are normally the results of supernovae but only because today stars are the only source of dense masses. - Because the total mass of the universe is constant and the…
Lets say the number of actual black holes is even more - several orders more than what is even mentioned here. Would it be enough to account for the "Dark Matter" conundrum ?
> Over the course of a year, Chandra stared at the cosmic lens for two weeks — one of its longest observation campaigns yet — and collected 19 X-ray photons coming from a galaxy called UHZ1, at a redshift of 10.1. Those 19 high-octane photons most likely came from a growing black hole that existed fewer than half a billion years after the Big Bang, making it by far the most distant X-ray source ever detected. This bl…
Digital TVs just don’t have that 2.73 degrees above absolute zero sound to them.
Earlier quoted context omitted.
Sometimes I despair for humanity [see advertising/social media/politics], but then I see something like this and think, we're doing pretty well for self-taught primates.
and then we see all of the belief systems to mock, punish, or worse people that are trying to expand human knowledge. looking back at history, you have to wonder where we might be now if there wasn't this attempts at mass eradication of learning. there are times i wonder if we're heading in that direction again. this time, rather than burning the Library of Alexandria or locking everything in catacombs, if we're not…
So this is one of them "shower thoughts", you know, those stupid things you think about while working on something else.That is, purely science fiction. Can an analog be drawn between galaxies and solar system creation theories, with several orders of magnitudes in time required for formation due to scale difference. That is, the galaxies we see with their billions of stars are actually young proto accretion disks. w…
It is worth considering that a black hole's hold on its galaxy is not as strong as a sun-like star's on its accretion disk. Our Sun is 99% of the mass of the solar system, our Sagittarius A* is ~4 million solar masses, while our Milky Way is 800 billion solar masses. On top of that, black hole growth rate slows to nearly a stop at ~270 billion solar masses, so even if a black hole manages to meet the rare conditions…
Can someone who really knows this stuff clarify my understanding? I've been given to understand that black holes remain a physics theory that has not been directly observed or proven. I thought that we had a fair amount of observational evidence that suggests their existence, but no "smoking gun" proof of it, and that these types of "observed a black hole" articles are a little misleading - that in reality, what was…
The theoretical prediction of black holes dates back to 1916, when Karl Schwarzschild proposed a solution to Einstein's field equations that were part of his general theory of relativity. General relativity is arguably the most robust theory in physics - that being said, general relativity introduces some tension with the other most robust theory in physics, namely quantum mechanics and the Standard Model. These two…
This article [1] seems to affirm my understanding that this is still all indirect evidence until LISA becomes operational.
[1] https://www.science.org/content/article/after-decades-effort...
Can someone who really knows this stuff clarify my understanding? I've been given to understand that black holes remain a physics theory that has not been directly observed or proven. I thought that we had a fair amount of observational evidence that suggests their existence, but no "smoking gun" proof of it, and that these types of "observed a black hole" articles are a little misleading - that in reality, what was…
I’ve read something like: there are bunch of observations of extremely dense masses in various suroundings. Talented people can find explanations other than black holes in each case. But that feels adhoc, and black hole fits quite nicely for whole class of observations. Current consensus is that b holes exist.
I don't think it works like that?
My read from looking at the literature is that the feeling is more like "black holes are a mathematical theory that have not been falsified by observational evidence, and for which we have some compelling, but inconclusive data, reconstructed from intensely noisy and poor resolution sources. Seems likely, but more data needed."
Earlier quoted context omitted.
It is worth considering that a black hole's hold on its galaxy is not as strong as a sun-like star's on its accretion disk. Our Sun is 99% of the mass of the solar system, our Sagittarius A* is ~4 million solar masses, while our Milky Way is 800 billion solar masses. On top of that, black hole growth rate slows to nearly a stop at ~270 billion solar masses, so even if a black hole manages to meet the rare conditions…
Is the upper limit due to hawking radiation?
Can someone who really knows this stuff clarify my understanding? I've been given to understand that black holes remain a physics theory that has not been directly observed or proven. I thought that we had a fair amount of observational evidence that suggests their existence, but no "smoking gun" proof of it, and that these types of "observed a black hole" articles are a little misleading - that in reality, what was…
Scientist recently got a good picture of one
The "photo" you're referring to was constructed by a super computer massaging enormous amounts of data to fit a model and constructing an image from weighted averages of thousands of data images across the spectrum from an enormously complex array of detectors in an unfathomably noisy environment [1].
It was presented by the media as a "photo", but it seems to me like it's more similar to the "image" we get from reconstruction of wifi signals in a room to determine interior object's shape.
Or maybe a better example would be the "photos" of atoms, which are not photos at all but a reconstruction of miniscule electromagnetic resistance readings from a STM whisker driven by a piezoelectric crystal.
I think we're supposed to get the ability to have better "photos" with the activation of LISA in 2037 [2] but until then, claiming that we have photos of black holes seems a bit misleading (not by you, I mean the science reporting).
[1] https://eventhorizontelescope.org/blog/astronomers-reveal-fi...
[2] https://en.m.wikipedia.org/wiki/Laser_Interferometer_Space_A...
Maybe I’m a bit naive here, but I thought finding of many supermassive back holes in the very early universe should be expected, and not a surprise. My chain of thoughts is following: - Blackholes are collapsed masses. In our phase of the universe, they are normally the results of supernovae but only because today stars are the only source of dense masses. - Because the total mass of the universe is constant and the…
https://en.m.wikipedia.org/wiki/Cosmic_microwave_background#...
A naive view would be that a turbulent Big Bang has turbulence all the way down, with many fine-grain clumps and vortices, giving rise to early black holes.
Inflation is invoked to create a homogeneous CMB, but that begs the question, and cannot be used to rule out small-scale inhomogeneities.