
Most images of black holes are illustrations. Here’s what our telescopes capture - shawndumas
https://www.vox.com/science-and-health/2018/1/8/16822272/black-hole-looks-like-what
======
oevi
Black holes are an excellent example for so called "cognitive metaphors".

Because we found no better analogy, we named them "holes" despite the fact
that they are basically the opposite: an object with enormous mass.

This influences our thinking and our language when we discuss problems
concerning black holes. We talk about "inside the black hole", "light cannot
escape the black hole" or "spitting things out of the black hole".

I think it is really interesting how these cognitive metaphors can sometime
limit our ability to think about a problem, because they often restrict the
properties of the described thing to the properties of the analogy.

~~~
blackrock
I would prefer if black holes were called "Dark Stars".

Because that really is what they are. A weird star that is so massive, its
gravitational field distorted the fabric of its local space, that not even
light can escape it.

It is theoretically possible that the black hole is still performing fusion,
and emitting light and heat, like a regular star. But its gravitational field
is so intense, that even light cannot escape it. So, from the outside, the
black hole appears dark. Hence, a dark star.

Perhaps if you are inside the Event Horizon of the black hole, then you can
still see the light from the fusion of the star. But if you are outside of the
Event Horizon, then you will only see the star as pitch black, since light
can't even escape it.

~~~
akvadrako
_> It is theoretically possible that the black hole is still performing
fusion, and emitting light and heat, like a regular star._

I don't think that's a useful picture. It's closer to the truth to say that
from the outside perspective, all the information and energy sits on the
border and there is not even an inside to speak about. In other words, it's
the edge of the universe and what's past the event horizon is another
universe. Not like a star at all.

~~~
blackrock
To me, the concept that there is another universe, beyond the Event Horizon,
is a little silly.

However, for fun, I once thought of a science fiction scenario for a novel.

I thought a Black Hole, can be used as the instrument for a wormhole in space.
An Einstein-Rosen Bridge, that connects our universe to another universe, in
the multiverse.

But there are a lot of plot holes in this idea. If light cannot escape the
black hole, then you somehow need to go faster than light, to traverse the
wormhole, and to escape it, when you cross over to the other side. So, once
you exit the black hole, then you land at the other side, and there is a whole
other universe there, with its own set of stars.

But, this will also allow other people from another universe, to cross into
our universe, via this black hole.

Then how does such a black hole form?

It starts with a very massive star, more massive than a Neutron Star, that
roams around our universe. Then, in an adjacent universe, another very massive
star is wandering around also. Think of our universe as a bubble, and the
adjacent universe is another bubble. These two massive stars, will distort the
fabric of their bubbles, at the edges. The two stars will gravitationally
attract each other, and they will basically punch a hole through each bubble.
And when they collide, the mass from each star will form the structure of the
wormhole. They won't explode on contact, but instead, it will now form a
bridge between two universes.

For millions of years, they will dance around each other, until they finally
find a stable orbit, where both are spinning around each other.

Think of this as a binary star system, where the two stars are rotating around
each other, so fast, that it forms this virtual wall. This virtual wall, is
the structure of the Einstein-Rosen bridge. And in the middle, it is
gravitationally neutral.

And this wormhole structure, will now allow regular spacecraft, that can
travel faster than light, to traverse the wormhole, and emerge on the other
side.

Next, I just have to add the other parts of the story, like the bad guy, the
love story and love triangle, and some good guy that is searching for himself.
And with that, I'll have a blockbuster novel that I can turn into a live
action movie.

~~~
wruza
Ah, that story when realistic physics happened and she loves him. First
question, lasers or blasters? Second, is good guy’s dad bad guy?

Third, probably least interesting, how does one get into BH travelling FTL, if
that makes you go back in time?

------
ars
Keep in mind as well that no observation has yet distinguished between a
neutron star and a black hole.

i.e. all those photos of super massive objects could be neutron stars, and we
would not be able to tell the difference.

They are assumed to be black holes because of the mass, but if there is
something in the law of physics that prevents black holes from forming we
would not know.

We do not have a theory on quark degenerative pressure for example, which
could possibly exert enough pressure to prevent black holes from forming (you
would get quark stars instead, with no event horizon).

There are also time dilation issues that might make black holes impossible.

~~~
podiki
I'll take your comment in good faith, but there are very good reasons to
believe black holes exist and that, for instance, the center of our galaxy
contains a very massive black hole and not a neutron star. This is basic
general relativity, which only has (physical and theoretical) evidence in
support of it. While quantum gravity is still very much uncertain, that would
(most likely) only have to do with understanding the possible singularity
inside black hole. Otherwise, defining a black hole as "a thing with an event
horizon" is purely a general relativity prediction, consistent with all of the
other predictions and observations.

(Disclaimer: theoretical physicist)

~~~
wallace_f
OP's claim is that black holes infinite amount of time to form, because matter
would take an infinite amount of time to fall into it.

Personally, as a layman on the subject of black holes, what I understand is
that mass does take infinite amount of time to fall into an event horizon. But
I don't know about the formation process of how/when that event horizon is
formed.

Perhaps you can help me, and him, understand why his claim is false--that it
would happen in finite time?

~~~
Santosh83
Signals take an infinte amount of time to reach a distant observer from just
outside the event horizon. Which means we cannot see the event horizon or what
is beyond, and we cannot also 'see' the event horizon being formed, or any
matter crossing the event horizon. When the star collapses, light takes
progressively longer to reach an outside observer, and eventually becomes too
dim to detect. The same thing happens with an object falling into a black
hole. But since the gravitational effect can still be felt, we cannot also say
that the black hole never formed. At all events, a region of spacetime that
emits no discernable signals _has_ formed. You can call it a black hole or
speculate further about what it is, but the phenomenon is still right there.

~~~
wallace_f
>we cannot also 'see' the event horizon being formed

I think what you're saying here is the confusing part.

If no observer in the universe can ever witness a black hole being formed, it
stands to reason they cannot exist (within the reference frame of observers
outside it).

Now I'm not asserting this as true or not, because I wouldn't assert such
contrarian conclusions on a subject I have not properly studied; rather I am
just highlighting what appears to be the confusing bit here.

~~~
Santosh83
What is meant when we say we expect to see a black hole, or event horizon,
forming? If we mean that we can no longer detect any signal from particular
region, then to that extent, we can assert that what we call as a black hole
exists there. We're defining it by its negatives, but I can't see how one can
say that even those negatives don't exist.

Also its gravitational effects can be detected, so that is another reason why
merely claiming a black hole doesn't exist, or never forms, seems to rather
miss the mark.

------
Pigo
Every time I read articles like this I feel bad about my career choice. How
could anything I do compare to the fascination of space exploration? The
universe we live in is nothing short of mind-boggling.

I'm thankful that I can at least marvel at nebula pictures taken by Hubble.
However, I wish they'd switch goals from getting a few people to another
planet to getting imaging equipment there that is capable of forming a VR
experience we all could share.

~~~
wickawic
But then who would deliver the ads?? /s

I completely agree, but with the arts as my object of fixation. I could never
live the swanky life I lead without my current job, but damn I would have been
a good potter. Luckily, there is still time...

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onion-soup
It bugs me how almost never in astronomy-related animated gifs authors never
tell explicitly how long is 1 frame.

In that blue x-ray burst image, am I looking at 1000 years per frame, 1
second? 1 minute?

Really frustrating

~~~
RileyJames
I found this gif particularly amazing because it did. And the others a little
underwhelming.

[https://cdn.vox-
cdn.com/uploads/chorus_asset/file/9984865/st...](https://cdn.vox-
cdn.com/uploads/chorus_asset/file/9984865/stars_orbit.gif)

------
dumbfounder
When I first loaded the article all of the images were black, and I thought it
was just a joke. Then after about 30 seconds they started filling in with
actual pictures...

------
corysama
Source for the ring of fire image at the bottom of the page:
[http://eventhorizontelescope.org/simulations-
gallery](http://eventhorizontelescope.org/simulations-gallery) under ">
Accretion Disk"

------
matte_black
If the speed of light of this universe was raised significantly, is there some
point where black holes would be impossible to form?

I assume if the speed of light were lowered black holes would become far more
common?

~~~
clarkmoody
In the _Death 's End_ by Cixin Liu, there is a speed of light weapon that
_lowers_ the local speed of light to almost nothing, effectively taking an
enemy out of the game until the end of the universe.

~~~
AnimalMuppet
In _Redshift Rendesvous_ (don't recall the author), there was an environment
where the speed of light was just above running speed - maybe 15 m/s. You
observed relativistic effects just walking around.

~~~
matte_black
There was a game like this, I wonder if such a universe can be simulated in
VR? Perhaps it would allow for a better understanding of relativity?

------
orf
Reminds me of one of my favorite moments[1] in Red Dwarf:

> Well, the thing about a black hole - its main distinguishing feature - is
> it's black. And the thing about space, the colour of space, your basic space
> colour, is black. So how are you supposed to see them?

1\. [https://www.quotes.net/show-quote/66989](https://www.quotes.net/show-
quote/66989)

------
booleandilemma
If nothing can escape black holes how is it they “spew” things?

~~~
podiki
They also (are believed to, based on famous calculations by Hawking) radiate
like a black body with a temperature related to their mass. And this leads to
them losing mass over time, eventually evaporating. (Leaving what is a subject
of much debate.)

~~~
saagarjha
I believe the "spew" that booleandilemma was referring to were the twin
perpendicular "jets" that black holes often seem to eject, for which the
explanation is probably some sort of angular momentum/near miss close to the
event horizon sort of thing.

------
pbhjpbhj
No mention of gravitational lensing (except in a dead comment here)? 20 years
ago those images were in all the pop-sci media as evidence of black holes.
They seem as strong evidence as x-ray sources.

------
acobster
My favorite video about observing black holes:
[https://youtu.be/iphcyNWFD10](https://youtu.be/iphcyNWFD10)

Enjoy :)

------
sandworm101
Saying we have not "seen" a BH is like saying we haven't seen the core of any
other star. We haven't, we cannot and never will. Such things are hidden
behind the massively bright regions they power (corona, acretion disks ect).
We must calculate the interior of a BH as we calculate the interior of
jupiter. That doesnt make thier existance any less real or profound.

------
NopeLupe
Where could I get that last image 1600x900. Wanna use it as my background
picture because this looks incredible!!

------
OscarTheGrinch
If nothing can escape a black hole how can it have massive jets?

~~~
ahmedalsudani
1\. Energy does actually escape black holes

2\. The jets are not matter originating inside the black hole. They are are
matter that is accelerated by the black hole then slung away. It’s a similar
mechanism to how we accelerate some of our spacecraft (by flying them close to
the mooon or Jupiter) but with much higher energy levels!

------
asah
serious question: the accretion disk lies flat in the same plane as the
earth... so how do we get an image showing the black hole "top-down" ? do they
take a guess at what the far side must look like, then rotate the perspective
?

either way, how is this new imagery any less synthesized than the old imagery
?

------
oldandtired
Thank you all for the various comments made here, both for and against "black
holes".

For those who assume that General Relativity is "fact", there is an extension
of classical mechanics that gives the same predictions without the space-time
curvature aspects. Came out a number of years ago.

For those who believe gravity (and relative density) are the causes of the
theoretical entity "black hole", a question to think about in relation to
fields, what happens as you move towards the centre of any mass? A second
question is related to electromagnetic fields strength and approaching atomic
nuclei? The same question applies to "neutron stars".

For those who see want a change of reference between the external universe and
the reference point of approaching the "event horizon", what does the observer
see of the external universe when falling towards an "event horizon"?

The term "dark star" long predates the GR model and is an entity that is quite
different to the "black hole" entity of Einstein's GR theory.

Due to inconsistencies between Einstein's SR theory and his GR theory, which
model is more correct, if either are correct?

All of our models and theories are simplifications of the explanation of how
our universe works and as such will be subject to change. They all have limits
of applicability.

Too often, it is assumed that certain things happen in a specific way because
a theory or model has some applicability in explaining observations. What a
lot of intelligent people forget is that if you cannot observe some feature of
the universe then the explanation of what is going on in that feature is only
speculation and belief not "fact", irrespective of how "good" your theory is,
including any predictions it makes.

At any time, there are competing theories about specific subjects and each
will have it proponents and opponents. Which of them is more correct is not
the question, the question is are they useful models to help in understanding
the universe around us?

There is nothing wrong with pushing that a specific model or theory is more
applicable than another. What we must be careful of is believing that the
theories and models we push and believe in are "truth". When we do this,
observations that disagree with or theories and models will (due to human
nature) be discarded as irrelevant or faulty.

It is interesting to note that there are many observations that have been made
that are no longer reported because they do not match the predicted outcomes
of the consensus theories and models. This is a shame as we then lose our
ability to expand our understanding of the universe about.

It is useful to remember that mathematics is a useful tool to help in building
our explanations of what we observe, but every field of mathematics has
specific premises, axioms etc that are simplifications or generalisations that
are not actually matched by the universe around us.

------
IntronExon
Magnificent. I’ve been totally entranced by black holes since I first read A
Brief History of Time as a kid. Years and years of trying to wrap my head
around them, and they’re still just about the closest thing I get to a
spiritual moment.

This is a fantastic piece, and even though some images are more visually
striking, for me the ones that gives me the most chills are the time-lapse of
stellar motion around Sagittarius A _. Those are_ stars* being whipped around
like toys. Stars. Over 97% of the mass of the solar system is just Sol, and
these stars are more massive, and look at them move!

Chills.

------
blackrock
I love black holes

Between two pillars they lie

Dark and mysterious

It pulls me in

Its gravity is so strong

And out comes

A new born star.

