Black Holes

[Shrek]

Hawking radiation is born just above the Horizon.

 

[lexluthermiester]

Hawking radiation is born just above the Horizon.

Hawking Radiation is only a theory and one that a part of a larger work that was never finished, much like Einstein's Black Hole work. There is simple reason for this.

 

[Bones]

Hubble Sees Possible Runaway Black Hole Creating a Trail of Stars | NASA

 

[Shrek]

black hole expert Dr. Becky: I finally got around to watching this day in the life video of what its like to be a black hole expert... honestly kind of glad I didn't major in this stuff, the sheer amount of hours in this video where she is just looking at data sets and command prompts would melt my eyes... I have a lot more respect for astrophysicists like her now. not that I didn't before, but that is just really draining work imo

I am starting out on her book 'A brief History of Black Holes' but feel she has misunderstood retrograde motion.

 

[lexluthermiester]

I am starting out on her book 'A brief History of Black Holes' but feel she has misunderstood retrograde motion.

I stopped following her works years ago. She gets some things right. But sadly she's also one of those people who has painted herself into a corner with her own work. Like many who have come before her, she prays at the alter of G&SR. G&SR does not and can not be used to determine the functionality of objects such as a Black Hole, among many other things. I imagine that in that book, she tried to explain what she doesn't understand herself.

 

[Shrek]

Where (in your opinion) does GR fail with black holes?

Here to learn, not argue.

 

[webbdiscoveries]

Webb Telescope Gets a Closer Look at the Massive Black Hole Enigmatic UHZ-1​

​

​

Read more about this discovery here. Credit: NASA​

 

[TumbleGeorge]

Webb Telescope Gets a Closer Look at the Massive Black Hole Enigmatic UHZ-1​

​

View attachment 311302​

​

Read more about this discovery here. Credit: NASA​

But there in article aren't any pictures taken with the telescope, just a computer generated drawing?

 

[webbdiscoveries]

But there in article aren't any pictures taken with the telescope, just a computer generated drawing?

Check this paper for actual images from this observation - https://arxiv.org/pdf/2308.02750v1.pdf

 

[lexluthermiester]

Where (in your opinion) does GR fail with black holes?

Here to learn, not argue.

G&SR does not and can not explain what a Black Hole is. To be more detailed, it can not explain what matter becomes after a matter-collapse-event is triggered and a Black Hole is created. In a related situation, G&SR does not explain how and why the Big Bang was triggered. The Universe was, before the Big Bang, a immensely massive Black Hole. Nothing is supposed to escape a Black Hole, especially one of such great mass, so how did all the mass in the Universe escape it?

G&SR does not and can not explain those conditions. So it is either flawed or outright incorrect. Which it is has yet to be determined, but it is one of those.

 

[Shrek]

The Universe was, before the Big Bang, a immensely massive Black Hole.

Is there any evidence for this conjecture? recalling that there is nothing outside the Universe, but there is something outside a black hole.

 

[lexluthermiester]

recalling that there is nothing outside the Universe

That is an assumption, VERY likely incorrect.

but there is something outside a black hole.

Yeah. Let that sink in for a moment...
(not trying to offend, just suggesting that you think about that dynamic)

Don't quite get what you are getting at, but I am trying.

Ok, where are WE in relation to SagA(the Black Hole at the center of the MilkyWay Galaxy)? Where does SagA get it's mass(along with every other Black Hole)? Continuing that train of thought...

Is there any evidence for this conjecture?

Othe than the fact that when we reverse the progress of time and move everything we can observe back along the path it's on, everything in the Universe converges on a single point in space(that just happens to be outside our observable range.

So do we think all the mass in the Universe spang out of nowhere and nothingness? Or did all the "stuff" we can observe come from somewhere outside our Universe? Logic and observation are the only tools we need to understand this dynamic.

These points are part of a paper/theory that has yet to be published.

 

[Shrek]

Othe than the fact that when we reverse the progress of time and move everything we can observe back along the path it's on, everything in the Universe converges on a single point in space(that just happens to be outside our observable range.

The observational evidence (Hubble expansion) says that things are expanding out from each and every point; which speaks against a single point.

So do we think all the mass in the Universe spang out of nowhere and nothingness?

One might ask where did all the energy of the Universe come from, but when measured it sums to zero (gravitational energy is negative).

 

[damric]

Do any of you play around with Universe Sandbox?

I made a black hole experiment this morning:

Steam Workshop::Earth Orbiting Black Hole by Luke G.

steamcommunity.com

 

[lexluthermiester]

The observational evidence (Hubble expansion) says that things are expanding out from each and every point; which speaks against a single point.

There's some debate about it, I subscribe to the central point conclusion because that is what the actual evidence strongly points to.

One might ask where did all the energy of the Universe come from, but when measured it sums to zero (gravitational energy is negative).

That is the same line of thinking as the infinite universe(not to be confused with an infinite Cosmos) theory.

 

[authorized]

Is there any evidence for this conjecture? recalling that there is nothing outside the Universe, but there is something outside a black hole.

No, but whether there exists anything outside our universe or not, there's no evidence one way or another either.

 

[lexluthermiester]

there's no evidence one way or another either.

But we do have plausible insight that has very solid merit. Again, where are we in relation to the Black Hole at the center of our galaxy?

 

[Shrek]

I subscribe to the central point conclusion because that is what the actual evidence strongly points to.

I am not aware of any such evidence, could you point me in the right direction?

 

[lexluthermiester]

I am not aware of any such evidence, could you point me in the right direction?

Really? Ok. The following are good places to start.

A Science Odyssey: People and Discoveries: Hubble finds proof that the universe is expanding

Hubble's diagram and cosmic expansion - PMC

Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so ...

www.ncbi.nlm.nih.gov

Don't have too much fun..

 

[Shrek]

Didn't you see my post #688

"The observational evidence (Hubble expansion) says that things are expanding out from each and every point; which speaks against a single point."

I put some emphasis on 'every point is special, and so no point is special'

 

[lexluthermiester]

Didn't you see my
"The observational evidence (Hubble expansion) says that things are expanding out from each and every point; which speaks against a single point."

Yup, I saw, understood and disagreed with it.

 

[Shrek]

Then I should take it further:

Let's take a point where things rush away in proportion to distance (Hubble's law)

<-- <- -> -->
A B C D E

We see that C is special (everything runs away from C); but the proportionality in Hubble's law is very important for if we now look at things from the point of view of B

<- -> --> --->
A B C D E

we see that B is also special (everything runs away from B); this only works for Hubble's law.

So yes, there are very special points, namely all points.

 

[lexluthermiester]

Then I shoul take it further:

Let's take a point where things rush away in proportion to distance (Hubble's law)

<-- <- -> -->
A B C D E

We see that C is special (everything runs away from C); but the proportionality in Hubble's law is very important;
let's look at things from the point of view of of B

<- -> --> --->
A B C D E

Suddenly we see that B is special (everything runs away from B). This only works for Hubble's law.

So yes, there are very special points, namely all points.

Issac Asimov was very pleased to present this 1D argument, except I can't get the formatting right...

But none of that takes into account the fact that everything we observe is moving away from a point beyond our observational range. The central point of the Universe in not inside our observation range. We are expanding out from a point no longer in sight. However, what is in sight seems to be moving in a direction that moves away not just from each other, but also from a central point. This is consistent with what we understand about conventional explosions. When we account for enormous expanse of the Universe and the limits of the speed of light and expand beyond that limit, the expansion of the Universe is easy to explain and visualize.

 

[Shrek]

The speed of light limit is local (Special relativity); Galaxies far enough apart can seperate at faster than light speed since it is the space itself that is expanding (General relativity).

What I have written so far is common understanding and can be found in most any recent cosmology text.

 

[Jacky_BEL]

This might be interesting to watch:

Sky Scholar on black holes