Blackholes and mass reduction

[paulsutton]

Hi

Just been watching a video on PBS space time (you tube channel) on black holes (well building modelsi a lab which is also interesting) this is really interesting with Hawking radiation being apparently responsible for black hole, mass loss .  This got me thinking if white holes are the opposite to black holes as they emit energy rather than pull it in, and a white hole is possible at the other end of a black hole, are these also perhaps responsible for mass loss.

I think the two being linked is some sort of theory or idea anyway,  but  would it need a model where we take a black hole and a corresponding white hole would emit mass = to that taken in by the black hole, minus the hawking radiation escaping from the black hole and minus any energy created as IIRC energy and mass are interchangeable.

I am not a theoretical physicist so just interested in these topics.  I do understand a little about matter conservation,  so just interested to work out where does all this matter go inside a black hole ?

I have shared the video on my blog post so sharing the post here,  to help answer this included my thoughts on if white holes are possibly responsible for mass reduction.

https://personaljournal.ca/paulsutton/building-black-holes-in-a-lab

Sharing my blog is in not meant to be self promotion, it is a place to put my thoughts so to help me share on forums such as this and a place to add extra resources relating to the question. .

Thanks

 

Paul

[Markus Hanke]

23 hours ago, paulsutton said:

I think the two being linked is some sort of theory or idea anyway

White holes are (in principle at least) a part of maximally extended Schwarzschild spacetime; this type of spacetime is static and stationary, so both black hole and white hole would have constant mass.

Evaporating black holes belong to a different type of spacetime geometry, called Vaidya spacetime. I am not actually sure what the global topology of this kind of spacetime is like, but to the best of my knowledge (someone correct me if wrong) there is no white hole region here.

[Charles 3781]

What would happen, do you think, if a black hole came into close contact with a white hole. 

Would they mutually annihilate, without any outward release of energy.  Each hole internally cancelling the other one out.

Or would there be a stupendous outward burst of of energy.  Perhaps released in the form of "dark matter"?

[MigL]

Theory aside, we have observational evidence for Black Holes ( photographs even ); we have none for 'white' holes.

[Charles 3781]

Do you think the "photograph" of the "Black Hole " is real?  

[Dord]

2 hours ago, MigL said:

Theory aside, we have observational evidence for Black Holes ( photographs even ); we have none for 'white' holes.

I've never heard of a white hole so had to Google it and found this...

Quote

GRB 060614 was a gamma-ray burst detected by the Neil Gehrels Swift Observatory on June 14, 2006, with peculiar properties. It challenged a previously-held scientific consensus on gamma-ray burst progenitors and black holes

[...]

GRB 060614 was subsequently classified as a "hybrid gamma-ray burst", defined as a long burst without accompanying supernova, and was hypothesized to have been an observation of a white hole.

https://en.m.wikipedia.org/wiki/GRB_060614

No photographs, I'm afraid, just 102 seconds of Hulk-creating gamma rays.

Edited August 19, 2020 by Dord

[Endy0816]

1 hour ago, Charles 3781 said:

Do you think the "photograph" of the "Black Hole " is real?  

 

We can observe the accretion discs that form around them, the impact their gravity has on other masses in their vicinity, gravitational waves. That sort of thing.

Similar story to dark matter. All we have been able to 'see' is the shadow cast by hydrogen attracted to it, but we knew it was there already by the impact it has on galaxy rotation.

[Charles 3781]

Thanks Endy.  Do you think the photograph of the supposed "Black Hole" id very convincing.  It  looks like a blurred  image of a distant  planetary nebula.

As for "Dark Matter",  is there really such a thing.  There's no evidence for it.

Except  to account for apparent anomalies in galactic rotation.

But might these anomalies be explained, more normally, by  the presence of meteorites within, and outside the galaxies.  

 

 

[Curious layman]

1 hour ago, Charles 3781 said:

As for "Dark Matter",  is there really such a thing.  There's no evidence for it.

Quote

Dark matter and normal matter have been wrenched apart by the tremendous collision of two large clusters of galaxies. The discovery, using NASA's Chandra X-ray Observatory and other telescopes, gives direct evidence for the existence of dark matter.

https://www.nasa.gov/home/hqnews/2006/aug/HQ_06297_CHANDRA_Dark_Matter.html

 

[Endy0816]

2 hours ago, Charles 3781 said:

Thanks Endy.  Do you think the photograph of the supposed "Black Hole" id very convincing.  It  looks like a blurred  image of a distant  planetary nebula.

As for "Dark Matter",  is there really such a thing.  There's no evidence for it.

Except  to account for apparent anomalies in galactic rotation.

But might these anomalies be explained, more normally, by  the presence of meteorites within, and outside the galaxies.  

 

 

 

They are crazy dense, but not big relative to their accretion disc. If you could get close to one, would look more interesting. Conservation of angular momentum is the underlying mechanism so will look the same a a planetary nebula or even our own solar system, spiraling around a central point as they do.

 

Yes, dark matter is real. Doesn't interact with light though.

https://ysjournal.com/cosmic-web-seen-for-the-very-first-time/

x-posted

 

 

 

Edited August 20, 2020 by Endy0816

[MigL]

3 hours ago, Charles 3781 said:

might these anomalies be explained, more normally

Do you think that's air you're breathing ?
Or just 'anomalies' in the way moving wings stay aloft, or balloons get inflated ?
I've never seen a photograph of air either, but I can take photos of the effect it has on things.

I may not be able to photograph a BH directly, as there are no photons from it to be captured by the CCD ( or CMOS ) in my camera, but perhaps you know of something else that can bend light at the extreme angles ( you can see the accretion disk behind the BH ) displayed in those photographs.

White Holes were first proposed by I Novikov in the 60s, as a possible solution to the EFEs for the maximally extended ( no edges ) Shwarzschild metric, along with 'eternal' BHs, with no charge or rotation, such that every BH has a white hole in its past. So GR does allow for them.
However, you will note that this does not realistically describe BHs.
All are thought to be rotating, and none are eternal, since we know the mechanism for their formation ( gravitational collapse ).
Incidentally, there is no known mechanism for forming a white hole.

[paulsutton]

14 hours ago, Charles 3781 said:

What would happen, do you think, if a black hole came into close contact with a white hole. 

Would they mutually annihilate, without any outward release of energy.  Each hole internally cancelling the other one out.

Or would there be a stupendous outward burst of of energy.  Perhaps released in the form of "dark matter"?

Good point,  maybe we would see any energy / matter ejected from the white hole being drawn towards the black hole but interesting idea,  there would certainly probably be a lot of energy involved,  it depends on what is meant by  close, esp in terms of space distances. 

6 hours ago, MigL said:

Do you think that's air you're breathing ?
Or just 'anomalies' in the way moving wings stay aloft, or balloons get inflated ?
I've never seen a photograph of air either, but I can take photos of the effect it has on things.

I may not be able to photograph a BH directly, as there are no photons from it to be captured by the CCD ( or CMOS ) in my camera, but perhaps you know of something else that can bend light at the extreme angles ( you can see the accretion disk behind the BH ) displayed in those photographs.

White Holes were first proposed by I Novikov in the 60s, as a possible solution to the EFEs for the maximally extended ( no edges ) Shwarzschild metric, along with 'eternal' BHs, with no charge or rotation, such that every BH has a white hole in its past. So GR does allow for them.
However, you will note that this does not realistically describe BHs.
All are thought to be rotating, and none are eternal, since we know the mechanism for their formation ( gravitational collapse ).
Incidentally, there is no known mechanism for forming a white hole.

Incidentally, there is no known mechanism for forming a white hole.

Yeah as we know the mechanism for a BH is a collapsed star,    a supernova is a exploding star,  so a white hole would have to be some other process,  which as you said we don't know yet.

Fascinating to think about really,  even if complex.

[paulsutton]

On 8/20/2020 at 12:06 AM, Charles 3781 said:

Do you think the "photograph" of the "Black Hole " is real?  

As in this?

https://edition.cnn.com/2019/04/10/world/black-hole-photo-scn/index.html

If the article says this was taken with 8 telescopes.  I guess it is not a photo in the traditional sense, and definition (as with a camera) as radio telescopes work with radio waves rather than light and this is a combination of different instruments with data combined.  Still cool, even though all the memes were of donuts, which I think is the analogy  model for a blackhole anyway (well sort of).  if you look at the curve of a donut (the sort with the hole in).

Edited August 21, 2020 by paulsutton