If photons have no mass,why would black holes attract light?

Click For Summary
SUMMARY

Black holes attract light despite photons having no mass due to the effects of gravity as described by general relativity. The gravitational force exerted by a black hole is independent of the mass of the objects it influences, including massless particles like photons. This phenomenon is explained in detail in the Relativity FAQ on Physics Forums, which clarifies that the trajectory of light is affected by gravitational fields. Understanding this principle is crucial for grasping the nature of black holes and light interaction.

PREREQUISITES
  • Understanding of general relativity principles
  • Familiarity with the concept of gravitational force
  • Basic knowledge of photon behavior in physics
  • Awareness of mass-energy equivalence
NEXT STEPS
  • Read the Relativity FAQ on massless photons and gravity
  • Explore the concept of spacetime curvature in general relativity
  • Investigate the implications of black hole physics on light and matter
  • Study gravitational lensing and its effects on light from distant stars
USEFUL FOR

Students of physics, astrophysicists, and anyone interested in the fundamental principles of gravity and light interaction with black holes.

Murtuza Tipu
Messages
47
Reaction score
2
If photons have no mass, why would black holes attract light?
I was told that photons have no mass. However I thought that black holes are called "black" because no light can go escape the gravity force in their vicinity. I somehow think that, if light is just photons, then it should not be affected by gravity. Hence black holes could catch everything but light.

Do I miss something? Is light more than a bunch of photons? Or maybe black holes are not exactly what I think.
 
Physics news on Phys.org
Murtuza Tipu said:
If photons have no mass, why would black holes attract light?

Mass is not necessary to be attracted. The trajectory is independent from mass (both in classical mechanics and relativity).
 
What makes a black hole to attract anybody ? Gravitational force and it depends on mass
 
Murtuza Tipu said:
If photons have no mass, why would black holes attract light?
I was told that photons have no mass. However I thought that black holes are called "black" because no light can go escape the gravity force in their vicinity. I somehow think that, if light is just photons, then it should not be affected by gravity. Hence black holes could catch everything but light.

Do I miss something? Is light more than a bunch of photons? Or maybe black holes are not exactly what I think.

What you missed is reading our Relativity FAQ on this entry:

https://www.physicsforums.com/threads/why-are-massless-photons-affected-by-gravity.511173/

This question has been asked many times and it is sufficiently addressed at the simplest level in that entry.

Zz.
 
What ZapperZ said. This thread is closed.
 

Similar threads

High School A photon always travels in a black hole
  • · Replies 9 ·
Replies
9
Views
1K
Undergrad Can light be reflected in a black hole?
  • · Replies 22 ·
Replies
22
Views
2K
Undergrad Supermassive black hole, surface gravity and tidal forces
  • · Replies 62 ·
3
Replies
62
Views
8K
Undergrad Can Gravity Escape a Black Hole?
  • · Replies 21 ·
Replies
21
Views
3K
High School Black hole electromagnetic spectrum
  • · Replies 4 ·
Replies
4
Views
2K
High School Theories about light and time near a black hole
  • · Replies 20 ·
Replies
20
Views
2K
High School Is there a white hole inside every black hole?
  • · Replies 22 ·
Replies
22
Views
943
Undergrad How Does Mass Loss from Black Hole Mergers Affect Orbits?
  • · Replies 13 ·
Replies
13
Views
2K
Graduate Error in Landau-Lifshitz Vol 2, Fig. 20, page 310
  • · Replies 7 ·
Replies
7
Views
956
High School Photons on a perpendicular bisector path from a black hole's core
  • · Replies 4 ·
Replies
4
Views
2K