Exploring the Mysteries of Black Holes: Gravity, Light Absorption, and More

In summary, black holes have many times bigger gravity force...and they are black.. and inside of them there's lots of light. Is this because they absorb the light? I mean if the gravity can attract the light. and other thing, isn't black hole something like mega sun or just an object with mega gravity force that attracts all the light and therefore its black?Welcome to PF!
  • #1
Marshallaw4
8
0
black holes have many times bigger gravity force...and they are black.. and inside of them there's lots of light. Is this because they absorb the light? I mean if the gravity can attract the light. and other thing, isn't black hole something like mega sun or just an object with mega gravity force that attracts all the light and therefore its black?
 
Astronomy news on Phys.org
  • #2
Welcome to PF!

Hi Marshallaw4! Welcome to PF! :smile:
Marshallaw4 said:
black holes have many times bigger gravity force...and they are black.. and inside of them there's lots of light.

no, there's no light inside a black hole, there's nothing inside a black hole except the singularity

any light that gets into a black hole heads straight for the singularity and disappears
… isn't black hole something like mega sun or just an object with mega gravity force that attracts all the light and therefore its black?

it can be "mega" (there seems to be a mega black hole at the centre of every galaxy), but an ordinary star can also become a black hole if it becomes dense enough

it's black because nothing can get out of it
 
  • #3
A black hole is formed when a supermassive star uses up all of its 'fuel.' During a star's lifespan, countless fusion reactions take place in the core. These fusion reactions create an outward pressure. This pressure is balanced by the force of gravity that is pressing on the star. Once the star runs out of 'fuel,' it no longer has enough power to support it's own mass and it collapses in on itself due to gravity. The entire mass of the star is then concentrated on an incredibly small point. The radius of the star decreases to what is known as the "Schwarzschild Radius." The Schwarzschild Radius is the critical density in which an object will become a black hole.

They are black because they absorb anything that comes within reach of their gravitational force, including light.

Here are some links for further reading:

http://www.universetoday.com/33454/how-do-black-holes-form/
http://www.universetoday.com/39861/schwarzschild-radius/
 
  • Like
Likes Demian
  • #4
Helpful mental image for you: pretend you're a fish swimming up hill.

The steeper the hill, the more difficult it is to swim against the current, yes?

What if you were washed back into a hole with a sheer drop?

Could you swim back out? A black hole is an object with such a deep gravity well that it produces an "edge" we call an event horizon, and anything which crosses that edge, even light, can't "swim" back out.
 
  • #5


tiny-tim said:
no, there's no light inside a black hole, there's nothing inside a black hole except the singularity

any light that gets into a black hole heads straight for the singularity and disappears

You sure about this tiny-tim?
 
  • #6


Drakkith said:
You sure about this tiny-tim?

Well, I don't even know if it's clear to me that this is a meaningful question to ask. For example, let's say I throw a baseball into a black hole from an exterior position. We know that I'll see the ball get redshifted and redshifted but never cross the horizon. On the other hand, I could calculate, according to a watch that might be attached to the baseball, the proper time it would take for it to impact the singularity.

These two descriptions of these events are mutually exclusive, since they cannot ever communicate with each other. It seems therefore ill posed to ask the question of what is 'really' going on, or by extension to the present subject, what is 'really' inside the black hole.
 
  • #7
At a distance of 1.5 times the schwarzschild radius there exists a region called the photon sphere. This is the distance at which a photon can orbit the singularity. It is, however, an unstable orbit. The least little perturbation [like infalling matter] would knock it out of orbit. Inside the photon sphere there are no possible orbits for anything, save perhaps the hypotheoretical tachyon.
 

1. What is a black hole?

A black hole is a region of space where the gravitational pull is so strong that nothing, including light, can escape from it. This happens when a massive star collapses in on itself, creating a singularity with infinite density and zero volume.

2. How do black holes affect light?

The intense gravitational pull of a black hole bends and distorts the path of light, making it appear to be bent or stretched. This is known as gravitational lensing and is one of the ways scientists are able to detect the presence of black holes.

3. What happens if you enter a black hole?

If you were to enter a black hole, you would experience extreme stretching and squeezing due to the intense gravitational forces. Eventually, you would reach the singularity where the laws of physics as we know them break down and we are unable to predict what would happen.

4. Can anything escape from a black hole?

Nothing can escape from a black hole once it has passed the event horizon, which is the point of no return. However, there are some theories that suggest information may be able to escape through quantum effects.

5. How do scientists study black holes?

Scientists use a variety of methods to study black holes, including observing the effects of their gravity on surrounding matter, detecting gravitational waves, and using simulations to better understand their behavior. They also study the effects of black holes on the larger structure of the universe.

Similar threads

  • Astronomy and Astrophysics
Replies
27
Views
3K
  • Special and General Relativity
2
Replies
62
Views
2K
  • Special and General Relativity
Replies
4
Views
251
Replies
2
Views
722
  • Astronomy and Astrophysics
Replies
6
Views
2K
  • Astronomy and Astrophysics
Replies
15
Views
3K
  • Astronomy and Astrophysics
Replies
1
Views
2K
  • Astronomy and Astrophysics
Replies
12
Views
3K
  • Special and General Relativity
Replies
19
Views
1K
  • Poll
  • Astronomy and Astrophysics
Replies
2
Views
2K
Back
Top