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Scientists capture first image of a black hole!!
- Thread starter Romulan_spy
- Start date
there is also the doppler beaming effect.
The disc is rotating clockwise from our perspective.
The bits moving toward us appear brighter, the bits moving away appear darker.
The disc is rotating clockwise from our perspective.
The bits moving toward us appear brighter, the bits moving away appear darker.
Moved, so as not to double-post the same thing:
https://www.trekbbs.com/threads/data-the-kinder-gentler-a-i.299231/#post-12897976
https://www.trekbbs.com/threads/data-the-kinder-gentler-a-i.299231/#post-12897976
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Yeah I'm in awe of this young lady. She's pretty amazing.
C
Captain pl1ngpl0ng
Guest
science are so incredible... Einstein... wow
She reminds me of Felicia Day's character on Eureka. I'm always amazed when people come up with such clever ideas. It also makes me feel dumb.
The principles of very long baseline interferometry (VLBI) are nothing particularly new although it was smart to recognise that combining results from several millimetre wavelength observatories allowed a resolution suitably small to image this object. Beyond the wrangling, correlation, and analysis of quite a few petabytes of data, obtaining funding for the research to the tune of $20+ million was probably the hardest part. It was not a skill that was taught on science courses back in my day. It seems more akin to performing well on Dragon's Den or Shark Tank. Of course, the funders aren't expecting a percentage of a business -- their criteria are different.
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C
Captain pl1ngpl0ng
Guest
A great article in QuantaMagazine:
https://www.quantamagazine.org/what...ole-means-to-a-black-hole-physicist-20190410/
it's a 1hour video of the press conference at the National Press Club in this article
from when they revealed the image for the first time. Q and A at the end.
https://www.quantamagazine.org/what...ole-means-to-a-black-hole-physicist-20190410/
it's a 1hour video of the press conference at the National Press Club in this article
from when they revealed the image for the first time. Q and A at the end.
Scientifically incorrect. Black holes are full.
Photographically empty.
C
Captain pl1ngpl0ng
Guest
you both get 8 Karma-Points each =)
If it's still spinning around to generate enough gravity that is so strong light cannot escape from it, or if it's slowed down... or - indeed, what it must look and even be like today... it's mind-blowing.
Its gravity is mostly due to the instrinsic mass of the original collapsed stellar core and any matter that it has swallowed subsequent to its formation. The gravity is not due to its rotation apart from the small contribution of the mass equivalence of its rotational energy. Once rotating, its rotation won't slow (conservation of angular momentum) unless it consumes mass with an oppositely directed angular momentum vector (or an alien civilisation is harvesting rotational energy from it).
Now that would be a freaky way to find extraterrestrial civilizations - those using black holes as power plants. Make a great book.
I believe all black holes and their accretion disk rotate and are "connected" together via gravity as a joined system. As mass falls into the black hole, the mass redistribution from the outer portions of the "wheel" to its "hub" should cause the system to speed up.
Question: If light (photons) cannot escape a black hole, then how does gravity escape a black hole?
Question: If light (photons) cannot escape a black hole, then how does gravity escape a black hole?
The mass of the black hole is effectively encoded in the curvature of space-time outside the event horizon. In General Relativity, it is the curvature of space-time that gives rise to what we observe and call gravity. Various space-time metrics can be used to describe the curvature, depending on the mass, angular momentum, and nett electric charge of the black hole.
I don't have a quantum field explanation because there is no self-consistent theory of quantum gravity as a quantised field (unrenormalisable infinities arise in second quantisation when trying to derive the properties of graviton bosons). There might be an alternative explanation in loop quantum gravity but I'm getting out of my depth here.
ETA: Actually, I think I can grasp the loop quantum gravity explanation somewhat. It posits that space-time is quantised, probably at the Planck scale: 1.6x10^-35 metres and 5.4x10^-44 seconds.
In the theory, space-time is represented as a quantum superposition of either spin foams or spin networks, which represent space-time's fundamental nature. So, as in General Relativity, the effect of the presence of mass is encoded in space-time itself.
I don't have a quantum field explanation because there is no self-consistent theory of quantum gravity as a quantised field (unrenormalisable infinities arise in second quantisation when trying to derive the properties of graviton bosons). There might be an alternative explanation in loop quantum gravity but I'm getting out of my depth here.
ETA: Actually, I think I can grasp the loop quantum gravity explanation somewhat. It posits that space-time is quantised, probably at the Planck scale: 1.6x10^-35 metres and 5.4x10^-44 seconds.
In the theory, space-time is represented as a quantum superposition of either spin foams or spin networks, which represent space-time's fundamental nature. So, as in General Relativity, the effect of the presence of mass is encoded in space-time itself.
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