Shedding light on black holes

Shedding light on black holes
Black Hole Image from Event Horizon Telescope Collaboration - 2019

"Black holes" is one of the most highly searched terms about our universe. There's a fascination with the idea of a region of space having a gravitational pull so strong, nothing can escape its deadly grasp, not even a sliver of light. Well, not quite. In fact, much of what we think we know about black holes turn out to be myths.

Myth 1

All are black. As the photograph below from the Event Horizon telescope demonstrated, light can be detected near a black hole's event horizon. This is the boundary between normal space and the space affected by the black hole's gravity, from which no escape is possible. Part of this light comes from the black hole's accretion disk, a flat, pancake like structure composed of dust, gas and other debris. Friction constantly moves the disk's material inward toward the event horizon. Light also comes from jet streams which propel matter outward along the disk's north and south poles.

Myth 2

All black holes are about the same size. Black holes actually come in several different sizes which are defined by their mass. Small black holes are usually the result of a relatively short and violent collapse of a star. Recent work suggests that Intermediate black holes are found in the nuclei of some active galaxies. Super massive black holes on the other hand, are found at the center of nearly every galaxy.

Dr. Dan Evans, an Astrophysicist at NASA Headquarters says, "There's a between the beginning of super and the beginning of their corresponding galaxy. This strongly suggests the two were born about the same time and slowly grew in size together over billions of years."

Myth 3

If you get within a few thousand miles of a black hole, its super gravity will pull you into its center. It turns out you can get surprisingly close to a black hole. If you approached a black hole with mass equal to our Sun's for example, you could get as close as tens of miles. So imagine if we replaced our sun with a black hole of the same mass. All of the planets would continue to revolve around it, at exactly the same speed and distance as they do now.

Myth 4

Once inside a black hole, nothing ever comes out. Nope. It turns out that radiation can escape from a black hole. One of Stephen Hawking's contributions was a theory that a black hole is not so dense in a quantum mechanical sense. The slow leak of what's now known as Hawking radiation would, over time, cause the black hole to simply evaporate.

The image from the Event Horizon telescope confirmed what Albert Einstein's general theory of relativity predicted over 100 years ago—that a black hole's form is that of a perfect circle. And as scientists learn even more about the properties of this gigantic cosmic mystery we call a black hole, they'll be able to puncture even more myths.


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Aug 14, 2019
In fact, much of what we think we know about black holes turn out to be myths.

Without a doubt!

Aug 14, 2019
Those are not myths as much as pop science and science ("myth 3") ideas that we have found to be wrong. With the exception of "myth 4" since Hawking radiation follows from consistency but has only been observed in analogous lab systems and not from black holes.

Aug 14, 2019
In fact, much of what we think we know about black holes turn out to be myths.

Without a doubt!


As opposed to your belief system which is totally based on myth!
The event horizon is real. The mass calculations are correct. Orbital parameters follow prediction. Gravitational redshift follows prediction. Et boring cetera. On the other hand, you have some numpties claiming it is a plasmoid (lol), who offer no explanation for those observations.

Aug 14, 2019
Myth four is a myth ~ Hawking radiation requires antiparticles to travel back in time to just before the Black Hole formed...how likely is that?

Hawking had a stab in the dark and there has been no evidence whatsoever to support his conjecture, a Black Hole model using sound can not be taken seriously on any level, for instance there is no time dilation or other relativistic effects...not even wrong...

Aug 14, 2019
okay, the issues i had with this article as published have been accurately addressed

catthink just can't think
never has, never will

if any commentators of the sane variety of professional sciences
has a contact to Dr. Dan Evans, an Astrophysicist at NASA?

they night ask if he had read this article before it was posted to public incredulity?

however, this is an excellent example of clickbait writing & ignorant editing
at least the advertisers will be happy!

finally, a myth we can all appreciate!

Aug 15, 2019
These are either things not disputed by anyone sufficiently to earn the the claim of 'myth' ("It's a myth that pigs can fly"), or not myths at all.
Myth 1. The black-hole of calcutta wasn't actually black. Circles of black paper aren't black. Etc.
Myth 2. BH's are all the same size. 'scuse, but who (erroneously) claims that?
Myth 3. Get within a few thousand miles... Nope. No layperson says that. Everyone understands some kind of 'point of NO return'; they don't specify any arbitrary 'dangerous distance'. The more sophisticated might cite that point as 'the event horizon', or 'the Schwartzschild radius', but nobody attaches some mileage to those features.
Myth 4 isn't a myth. Hawking radiation is a BH's method of of shedding mass/energy. Hawking radiation isn't some something that comes   o u t   of a BH. The mass/energy isn't something that is inside the BH; mass/energy; and (if any) charge and angular momentum are all that a BH   i s .

Aug 16, 2019
Talking of black holes - hot off the press;

LIGO and Virgo probably spotted the first black hole swallowing up a neutron star
https://www.scien...r?tgt=nr

See also;

https://www.scien...ron-star

Aug 16, 2019
Talking of black holes - hot off the press;

LIGO and Virgo probably spotted the first black hole swallowing up a neutron star
https://www.scien...r?tgt=nr

LOL! Can you say confirmation bias?
From jonesdumb's article;
"Something has occurred out there in the sky,"
ROTFLMFAO!
It was something....

Aug 16, 2019
Talking of black holes - hot off the press;

LIGO and Virgo probably spotted the first black hole swallowing up a neutron star
https://www.scien...r?tgt=nr

LOL! Can you say confirmation bias?
From jonesdumb's article;
"Something has occurred out there in the sky,"
ROTFLMFAO!
It was something....


Yes, and the technical data is referenced. Care to tell us what it is woo boy?
You should quit commenting on science stories, as you are out of your depth in that area. Stick to mythology.

Aug 16, 2019
Talking of black holes - hot off the press;

LIGO and Virgo probably spotted the first black hole swallowing up a neutron star
https://www.scien...r?tgt=nr

LOL! Can you say confirmation bias?
From jonesdumb's article;
"Something has occurred out there in the sky,"
ROTFLMFAO!
It was something....


Yes, and the technical data is referenced. Care to tell us what it is woo boy?
You should quit commenting on science stories, as you are out of your depth in that area. Stick to mythology.

Yeah, like the "scientist" in the article mentioned, it was something out in the sky....

Aug 16, 2019

Yeah, like the "scientist" in the article mentioned, it was something out in the sky....


Oh dear, woo boy is still trying to understand science via press release! What a silly little dumbo. Like I said - stick to mythology. No science nor maths required. Perfect for you.

Aug 16, 2019
Oh dear, woo boy is still trying to understand science via press release!

These "scientists" should not say things that make themselves look stupid, or honest as this person did.

Aug 16, 2019
Oh dear, woo boy is still trying to understand science via press release!

These "scientists" should not say things that make themselves look stupid, or honest as this person did.


Lol. You are welcome to check the data, and reply to the paper if and when it is published. All he is saying is that something occurred involving GWs, and the signature is unlike ones we have seen previously. There are a limited number of things it can be. BH-NS looks a likely candidate. What it won't be is a plasmoid swallowing Saturn.

Aug 16, 2019
danR, it is my sorrowful duty to report to you
that another myth has bit the dust

observing video of the bogus potus trump, shamble off & on Air Force One?
is positive evidence that swine bores can fly!

"... These "scientists" should not say things that make themselves look stupid, or honest as this person did. ..."

but cant, can't you recognize that the writer of this article is as fallible as you?
stupid & "dis"honest are your cant

Aug 16, 2019
but cant, can't you recognize that the writer of this article is as fallible as you?

And you can't recognize the scientists are in the same boat as the rest of us, not to be placed on the pedestal of infallibility.

Aug 16, 2019
but cant, can't you recognize that the writer of this article is as fallible as you?

And you can't recognize the scientists are in the same boat as the rest of us, not to be placed on the pedestal of infallibility.


Nobody is saying they are infallible. That is just your own strawman. What real scientists will do, is to observe, check, model, check, check again, consult, write a paper, heed the peer-reviewers, publish, and give everybody the chance to reply to their findings.
As opposed to Velikovskian loons making sh!t up, and having their scientifically challenged followers fall for it hook, line and sinker, without any questioning or checks on what they claim. What you have got there is a religion.

Aug 16, 2019
Myth 6: Black Holes are black. I predict that massive ones will turn out to be a bit grey.

Aug 16, 2019
so tux
are you contending that that {some unknown?} grey illumination is emitting from inside the Black Hole & it's Event Horizon?

or, do you mean that there is a sphere of dust obscuring our view of the BH/EH?

cause i would opinionate that the second scenario is a lot more a realistic phenomena

Aug 18, 2019
Just that the Black Hole myth is just that, a irresistibly sexy myth. And that it never reaches infinite density, becoming only nearly so. As such, surface gravity then is sufficient to divert most light into orbit, unless it projects radially. Thus, it might appear rather dim.

And as the new Sag A observation shows, that radial light is likely gravity red-shifted into the near infrared. (See my comment under that story.)

LaViolette's SQK theory maintains that as core density increase, so does the production of new energy (and matter) at perhaps an even faster rate. Thus, a stable condition must be eventually reached where the outward pressure from new energy halts the collapse. And as a result, we see periodic instabilities where newly formed matter is also ejected from the core star, seeding the galaxy with raw material. Hence, galactic core stars and their galaxies are directly related. And nearly every major galaxy starts with the core star.

Aug 18, 2019
^^^^^^Sounds like bollocks to me. How is light (which cannot escape the event horizon) getting gravitationally redshifted? The observed GR comes from the star S0-2 orbiting Sgr A*. By definition, it is not within the EH.

Aug 18, 2019
JFTR, Hawking radiation is not a torrent, it's a trickle. Even a small (stellar mass) black hole will take tens billions of years to evaporate from it, and I may even be off (and low) by an order of magnitude. The accretion rate in our relatively matter-rich universe is far higher.

Aug 18, 2019
Looked it up on Wikipedia, and I'm low by many orders of magnitude; a stellar mass black hole would take 10⁶⁴ years to evaporate by Hawking radiation; that's about 10⁵⁵ times the age of the universe, or a 1 followed by 64 zeroes. To stack up billions, that's about a billion billion billion billion billion billion billion times the age of the universe. It ain't happening any time soon, nor will we detect it anytime soon unless we can get to one, which ain't happening in a hundred generations.

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