All Questions
24
questions
1
vote
3
answers
221
views
Is there a frequency limit for the pendulum near a black hole, and is this related to photons and the UV-cutoff?
I imagine a swinging pendulum being held outside a black hole, supported by the normal force of a rocket. The rocket is hovering the swinging pendulum right above the event horizon in the strong ...
- 95
1
vote
1
answer
188
views
Can photons form a black hole?
Can photons form black holes the same way as other matter? If there happens to be enough of them concentrated in an area of space so that enough energy exists within a radius to form an event horizon, ...
- 113
-2
votes
1
answer
65
views
Black holes bending light [duplicate]
Ok so I've been watching some videos about black holes but there is one thing I don't get: how can light be bent by black holes since photons don't have any mass?
- 1
0
votes
1
answer
76
views
Photons past the event horizon [duplicate]
What would happen if, beneath the event horizon, a photon was emitted outwards along the radius of the black hole? It's speed can't change to any observer in any reference frame, but it surely cannot ...
- 545
1
vote
1
answer
140
views
Why is a black hole referred to as massive? [duplicate]
I am reading Brief Answers To The Big Questions by Stephen Hawking. In the very first chapter he writes,
A typical black hole is a star so massive it has collapsed on itself. It's so massive that not ...
- 121
-1
votes
1
answer
175
views
Why doesn’t light escape a black hole? [duplicate]
When an object is squeezed to its Schwarzschild radius it becomes a black hole (made by density) and its mass does not change (its gravity doesn’t change), but if its mass doesn’t change (its gravity ...
1
vote
0
answers
72
views
The event horizon of a black hole supposes an absolute zero in some field?
Based on the Schwarzschild black hole theory, if the gravitational pull of the singularity were to equalize the energy that a photon has by approaching the event horizon from a special angle, would it ...
0
votes
1
answer
37
views
Pulling of Light by a Black Hole? [duplicate]
We all know that light has no mass at all. Yet we say that the gravitational pull of a Blackhole within Schwarzschild radius doesn't let light to pass. If the light has no mass, how can it experience ...
- 33
0
votes
1
answer
671
views
How does black hole suck light? [duplicate]
I was asked the same by my friend. I said that gravitational attraction also occurs for high energy particles .
My friend said photon is not so very high energy particle which I found on net. He ...
- 1,149
3
votes
1
answer
109
views
Regarding black holes and the speed of light [duplicate]
Prior to a black hole reaching sufficient (size ) to stop radiating light (due to excessive gravity ) would the speed of radiation of light slow smoothly down to zero (as the hole draws closer to the ...
- 470
2
votes
3
answers
107
views
How would a photon act to the gravitational influence of a black hole which is attracting it 180° to it's direction?
With all this situation, it’s also given that the gravitational influence is strong enough to turn the photon back. Now, the photon is being attracted directly from behind the path it is travelling on,...
- 23
-2
votes
2
answers
93
views
If black hole sucks in all masses, why does it suck in light if it is a form of energy (energy does not have mass)? [duplicate]
I have been searching for a long time for the answer.
12
votes
1
answer
327
views
Can gravitational waves orbit a black hole?
Assume (for the sake of simplicity) a Schwarzschild black hole (non-rotating, non charged). This black hole has a photon sphere in $r=1.5r_s$, where photons may travel in a circular orbit.
Will a ...
- 653
1
vote
1
answer
55
views
Is it possible for light to fall into a geo-synchronous orbit around a sufficiently massive planet?
Is it possible for (visible) light to fall into a geo-synchronous orbit around a sufficiently massive planet?
Can a planet or heavenly body be massive enough for it to happen?
What will that ...
- 171
-3
votes
2
answers
234
views
If gravity of the Earth is so strong and pulling the moon [closed]
If the gravity of the earth is so great that it is pulling the moon, then why aren't we - humans - so strongly attracted to earth that we can't even lift ourselves up?
- 43