Do Magnetic Fields Around Black Holes Overpower Gravitational Pull?

Click For Summary

Discussion Overview

The discussion centers around the relationship between magnetic fields and gravitational forces in the context of black holes, specifically addressing whether magnetic fields can overpower the gravitational pull of black holes and the nature of jets emitted from them. The scope includes theoretical and conceptual aspects of astrophysics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that magnetic fields play a significant role in the formation of jets from black holes, suggesting a potential competition with gravitational forces.
  • One participant clarifies that the magnetic fields are anchored in the accretion disk, which orbits outside the event horizon, indicating that it is not the gravity within the black hole that is being overpowered.
  • Another participant argues that while magnetic fields are important for collimating jets, the energy for ejection primarily comes from the conditions during the accretion process, including high densities and shock phenomena.
  • There is a question raised about whether the matter in the jets eventually falls into the black hole or can escape entirely.
  • One participant asserts that the matter in the jets can escape completely, often at relativistic speeds, and confirms that these jets are visible to distant observers.

Areas of Agreement / Disagreement

Participants express differing views on the extent to which magnetic fields can counteract gravitational pull, with some suggesting a significant role for magnetic fields while others emphasize the importance of the accretion process. The discussion remains unresolved regarding the balance of these forces.

Contextual Notes

There are limitations in the discussion regarding the definitions of terms like "accretion disk" and the conditions under which jets are formed, as well as the specifics of gravitational influence at different distances from the black hole.

abhiroop_k
Messages
42
Reaction score
0
recently i came to know that the jets of gases from black holes are due to magnetic fields...so in effect does this field overpower the effect of the gravitational pull of the BH?
 
Astronomy news on Phys.org
In a way yes, but remember that the fields are anchored in the accretion disk, not the event horizon, so it's not the "one-way" gravity inside the black hole that is being overpowered, but more mundane (yet strong) gravity. The accretion disk is the matter that has not yet fallen across the event horizon, because it had too much angular momentum so is orbiting outside the event horizon. It is called an "accretion" disk because it gradually spirals into the black hole. Such a disk is also the reason that stellar-mass black holes are often a source of hard X-ray emission, and supermassive black holes are often spectacular sources of visible light, in contrast with their name.
 
abhiroop_k said:
recently i came to know that the jets of gases from black holes are due to magnetic fields...so in effect does this field overpower the effect of the gravitational pull of the BH?
Not really. The Magnetic fields primarily 'collimate' the ejected material into jets. The ejection energy arrises from the high densities, pressures and temperatures during the accretion process (and especially from shock phenomena). In many situations, however, magnetic fields are required to achieve this situation.

In the absence of a strong (or ordered) magnetic field, there can still be strong outflows---but they'll be much more diffuse and isotropic.
 
so does the matter in these jets eventually go into the BH?...or can it escape completely?
 
The matter in the jets escapes completely, usually at relativistic speed.
 
i.e it is free of the gravitational pull of the BH?...are these jets then visible to a distant observer?
 
Yes, on both counts-- that is in fact why we know they are there, we are the distant observer.
 
thanks
 

Similar threads

Undergrad What powers the quasar magnetic beams that power jets?
  • · Replies 3 ·
Replies
3
Views
2K
High School I Need Help on Understanding Some Basic Astrophysics / Sand Clock Universe
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad The initial density of an object and its compression into a black hole
  • · Replies 17 ·
Replies
17
Views
5K
Undergrad Does light bend around black holes?
  • · Replies 49 ·
2
Replies
49
Views
6K
Insights Black Holes Are Not Empty Voids
  • · Replies 11 ·
Replies
11
Views
4K
Undergrad Where Are the Missing Black Holes in the Milky Way?
  • · Replies 87 ·
3
Replies
87
Views
10K
Undergrad Light curving around vortex simulating a black hole
  • · Replies 5 ·
Replies
5
Views
3K
High School Can a Stronger Black Hole Turn a Weaker One into a White Hole?
  • · Replies 14 ·
Replies
14
Views
3K
High School What is the definition of a black hole?
  • · Replies 27 ·
Replies
27
Views
6K
Undergrad Information loss in black hole, why is it a problem?
  • · Replies 10 ·
Replies
10
Views
3K