Relativistic Mass-Energy: Charge & Particles

  • Context: High School 
  • Thread starter Thread starter 1977ub
  • Start date Start date
  • Tags Tags
    Charge Relativistic
Click For Summary
SUMMARY

The presence of charge contributes to relativistic mass-energy due to the associated electromagnetic field, which possesses stress-energy. It is established that charge does not require two particles to attract or repel to generate charge-related mass-energy. The Reissner–Nordström metric illustrates this concept, providing a vacuum solution for charged black holes, where the gravitational field is influenced by both mass and charge. Additionally, the transition from a charged black hole to a Schwarzschild black hole reveals a significant reduction in the gravitational field when charge is removed.

PREREQUISITES
  • Understanding of relativistic mass-energy concepts
  • Familiarity with electromagnetic fields and their stress-energy
  • Knowledge of black hole metrics, specifically Reissner–Nordström and Schwarzschild
  • Basic grasp of geometric units in physics
NEXT STEPS
  • Study the Reissner–Nordström metric in detail
  • Explore the Kerr-Newman metric and its implications for rotating charged black holes
  • Investigate the concept of irreducible mass in black holes
  • Learn about the relationship between charge and gravitational fields in general relativity
USEFUL FOR

Physicists, astrophysicists, and students studying general relativity and black hole physics will benefit from this discussion, particularly those interested in the interplay between charge and mass-energy in relativistic contexts.

1977ub
Messages
530
Reaction score
22
Does The Presence of Charge Add To Relativistic Mass-Energy, or does it take two particles attracting or repelling one another to generate charge-related mass-energy?
 
Physics news on Phys.org
1977ub said:
Does The Presence of Charge Add To Relativistic Mass-Energy,

Yes. The presence of charge means there is an electromagnetic field, and the electromagnetic field has stress-energy.

1977ub said:
does it take two particles attracting or repelling one another to generate charge-related mass-energy?

No.
 
  • Like
Likes   Reactions: 1977ub
1977ub said:
Does The Presence of Charge Add To Relativistic Mass-Energy, or does it take two particles attracting or repelling one another to generate charge-related mass-energy?

While PeterDonis has answered the question, you can see this at work in the Reissner–Nordström metric which is the vacuum solution for a charged black hole. Gravity for a charged black hole is-

a_g=\frac{M}{r^2\sqrt{1-\frac{2M}{r}-\frac{Q^2}{r^2}}}

where M=Gm/c^2 (mass in geometric units) and Q=C\sqrt(Gk_e)/c^2 (charge in geometric units) where G is the gravitational constant, c is the speed of light, C is the charge in Coulombs and k_e is Coulomb's constant (as a rule, M\geq Q). Multiply the answer by c^2 for S.I. units of gravity (m/s2).

If charge is removed and the black hole is reduced to it's irreducible mass (the same black hole becoming a Schwarzschild black hole) where-

M_{\text{ir}}=\frac{r_+}{2}\ \ \rightarrow\ \ M=\frac{Q^2}{4M_{\text{ir}}}+M_{\text{ir}}

where M_{\text{ir}} is the irreducible mass and r_+=M+\sqrt{M^2-Q^2} is the outer event horizon, the equation for gravity becomes-

a_g=\frac{M{\text{ir}}}{r^2\sqrt{1-\frac{2M{\text{ir}}}{r}}}

you'll notice a distinct drop in the gravity field at a specific r some distance from the black hole. It might also be worth looking at Kerr-Newman metric which also includes for spin. Up to 50% of RN black hole's 'mass' can be attributed to charge though charged black holes are not considered realistic.

More info-
https://www.physicsforums.com/threads/what-is-irreducible-mass.762993/
 
  • Like
Likes   Reactions: 1977ub

Similar threads

  • · Replies 102 ·
4
Replies
102
Views
7K
Replies
9
Views
2K
  • · Replies 55 ·
2
Replies
55
Views
6K
Replies
3
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 20 ·
Replies
20
Views
3K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 45 ·
2
Replies
45
Views
5K
  • · Replies 25 ·
Replies
25
Views
3K