Does a Black hole burp indicate faster than light travel?

[dimreepr]

http://www.bbc.co.uk/news/science-environment-42655685

[Janus]

No.  The "burp" is created by in-falling matter before it passes the event horizon

[Phi for All]

21 minutes ago, Janus said:

No.  The "burp" is created by in-falling matter before it passes the event horizon

And if I understand it correctly, the release of energy is from the friction of matter from an accretion disk ripping itself apart and bashing into itself as it follows the increasingly limited paths into the event horizon and beyond, correct? So it's not faster than light travel, it's collected matter being forced along a path where gravity is increasing at an unbounded rate, which eventually surpasses the energy light needs to travel out of it. 

More pop-sci references that make people think of black holes as vacuum cleaners, or creatures searching for mass to gobble up and belch out. The reference probably got a lot of folks to read the article, but can they understand it when there's misunderstanding built in?

[beecee]

1 hour ago, dimreepr said:

http://www.bbc.co.uk/news/science-environment-42655685

The crux of the matter is simply once any matter/energy crosses the EH into the BH, it only has one path to follow, and that is towards the center [singularity] Any "burping," any polar jets, all actually emanate from matter/energy before it crosses the EH. Even the concept of Hawking radiation does not entail any particle crossing from inside to outside. That could be said to be the first rule/edict of BHs. 

[dimreepr]

20 hours ago, beecee said:

The crux of the matter is simply once any matter/energy crosses the EH into the BH, it only has one path to follow, and that is towards the center [singularity] 

 

I realise that hence my question.

20 hours ago, beecee said:

Any "burping," any polar jets, all actually emanate from matter/energy before it crosses the EH. 

 

The closer a particle gets to the EH the more energy/speed it will need to escape the gravity well.  

21 hours ago, Phi for All said:

And if I understand it correctly, the release of energy is from the friction of matter from an accretion disk ripping itself apart and bashing into itself as it follows the increasingly limited paths into the event horizon and beyond, correct? So it's not faster than light travel, it's collected matter being forced along a path where gravity is increasing at an unbounded rate, which eventually surpasses the energy light needs to travel out of it. 

 

Now I'm confused???

[Strange]

There is an article on the latest work on how relativistic jets are formed: https://www.universetoday.com/138247/astronomers-figure-black-holes-can-blast-relativistic-jets-material-across-light-years-space/ (not quite the same thing, tough)

 

[Endy0816]

2 hours ago, dimreepr said:

I realise that hence my question.

The closer a particle gets to the EH the more energy/speed it will need to escape the gravity well.  

Now I'm confused???

Before it reaches the event horizon, it still has a chance to escape.

Edited January 13, 2018 by Endy0816

[MigL]

The Event Horizon is a mathematical construct. There is nothing actually there, it is simply a radius defining an ( imaginary ) sphere.
This radius is defined as the distance from the center of the given mass where the escape velocity is equal to the speed of light.
Which is an impossibility for any particle with mass.

 Even though the massive energies involved ( kinetic due to the extreme potential ) make it seem otherwise, anything emanating from a BH's event horizon originates outside it,

[Strange]

1 minute ago, MigL said:

This radius is defined as the distance from the center of the given mass where the escape velocity is equal to the speed of light.
Which is an impossibility for any particle with mass.

Worth saying that, while that is true, it is not the reason that things can't escape a black hole. After all, objects can (temporarily) leave the Earth's surface at less than the escape velocity. You can go arbitrarily far at less than escape velocity.

But you can't leave the event horizon at any speed, because there are no paths that lead out of it.

[MigL]

Agreed, but that's a whole 'nother level of explanation and not so easily grasped.
(

[beecee]

3 hours ago, dimreepr said:

The closer a particle gets to the EH the more energy/speed it will need to escape the gravity well.  

Now I'm confused???

Yes, that's because as any particle approaches the EH, it is continually accelerated to speeds approaching "c" but never quite reaching "c", thereby leaving open the chance of possible escape. With polar jets for example, it is thought that these occur with rotating [Kerr] BHs, where matter possible interacts with magnetic fields near the BH, and creating the jets that we observe.

Edited January 13, 2018 by beecee

[Phi for All]

7 hours ago, dimreepr said:

Now I'm confused???

4 hours ago, Strange said:

Worth saying that, while that is true, it is not the reason that things can't escape a black hole. After all, objects can (temporarily) leave the Earth's surface at less than the escape velocity. You can go arbitrarily far at less than escape velocity.

But you can't leave the event horizon at any speed, because there are no paths that lead out of it.

Strange said it better. Past the event horizon, there are no paths other than the one to the black hole available no matter how fast you go, so the extremely warped gravity essentially puts the black hole in your future.