# QuestionHow dense are black holes?

#### Curiosity_George

I just read an article suggesting that black holes emit radiation and heat, and exert pressure on the surrounding space. One statement got me thinking... "If you consider black holes within only general relativity, one can show that they have a singularity in their centres where the laws of physics as we know them must break down."

With the density of a black hole compressing everything that is unfortunate enough to get drawn in,... Does this mean that the space between atoms and their electrons get crushed together? Also, would there be atomic explosions/reactions that occur, and then be sucked in?

Here's a link to the article..

#### Catastrophe

##### "There never was a good war, or a bad peace."
""If you consider black holes within only general relativity, one can show that they have a singularity in their centres where the laws of physics as we know them must break down." "

How do you show that black holes have a singularity in their centres if you are using physics which is not valid ("has broken down") because of division by zero?

Quote
"If you consider black holes within only general relativity, one can show that they have a singularity in their centres where the laws of physics as we know them must break down.
"It is hoped that when quantum field theory is incorporated into general relativity, we might be able to find a new description of black holes."
Quote

Cat

vincenzosassone

#### vincenzosassone

""If you consider black holes within only general relativity, one can show that they have a singularity in their centres where the laws of physics as we know them must break down." "

How do you show that black holes have a singularity in their centres if you are using physics which is not valid ("has broken down") because of division by zero?

Quote
"If you consider black holes within only general relativity, one can show that they have a singularity in their centres where the laws of physics as we know them must break down.
"It is hoped that when quantum field theory is incorporated into general relativity, we might be able to find a new description of black holes."
Quote

Cat
To sum up, we don't know it yet, but that's a question of time.
Anyway, I don't feel comfortable to state that a Black Hole has an infinite dense core (singularity) cause it's impossible to think about this concept in physics.

Catastrophe

#### Catastrophe

##### "There never was a good war, or a bad peace."
Here, again, we have division by zero, which necessarily means departure from science and entry into speculation. As has been pointed elsewhere, density is mass divided by volume, so to achieve the "infinite" density of a singularity you must have "infinite" mass and/or "zero" volume. These are both, of course, impossible for a black hole fed with matter.

No one knows the density of a black hole since the contents are unknown and immeasurable.
Singularities do not exist, since they require division by zero, and "infinite" properties which are not possible.
If a singularity had infinite mass, then it would have to contain the whole Universe, which they do not,

Cat

vincenzosassone

#### vincenzosassone

Nothing left to say, I totally agree with you.

Catastrophe

#### Malcolm

Black holes don't exist.

#### vincenzosassone

Black holes don't exist.
What does it mean? We also have a clear picture of it...

Catastrophe

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What does it mean? We also have a clear picture of it...
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#### Atlan0101

I had not really wanted to enter this particular fray but I do have a view on it and an opinion. It's early morning here and I am sleepless.

The greatest density and heaviest gravity of a blackhole is never in its singularity but in its ring-rim event horizon. It is the direct opposite, the simultaneous opposite, of our own Sol and every other kind of star anywhere and everywhere but it or its kind.

A blackhole models a universe where the greatest density is not in any center point, which is every foreground local point of it, but always in and to the background non-local infinity of event horizon! In other words, we, and most particularly our sun 'Sol', happen to be a where and when of a singularity; our macro-verse come micro-verse universe singularity (come quantum fluctuation).

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