How Can We See Light from Black Holes?

[DurgeshVYadav]

Whenever I see any image of a black hole or in television or anywhere, I found there is a ring of light around the black hole. In discovery channel, I heard them saying that scientist found rings of light in space which had black region inside it. It was also one of the evidence with the help of which we can say that black holes are there in the universe.

My question is that, when we know that black hole has sooo... much of gravity that even light cannot escape from it, how can we see those rings of light ? Means how that light is able to reach our eyes ?

 

[Ryan_m_b]

The ring around a black hole is formed from an accretion disc.

 

[tiny-tim]

Welcome to PF!

Hi Durgesh! Welcome to PF!

The light comes from round the black hole, not from inside it …

matter about to fall into the black hole can emit light,

and also light from objects behind the black hole can get focussed to appear to come from the https://www.physicsforums.com/library.php?do=view_item&itemid=268" at r = 3M

 

[Drakkith]

While any light that is makes it beyond the event horizon will not escape, light that "skims" the surface so to speak is simply bent from its path. The closer the light is to the event horizon the more it is bent. See here: http://en.wikipedia.org/wiki/Gravitational_lens

 

[pmacias]

First of all, it is important to clarify that the rings of light around black holes that you may have seen in images or on television are not actually the black holes themselves. They are actually the accretion disks, which are made up of gas and dust that is being pulled into the black hole's strong gravitational pull. As this material falls towards the black hole, it heats up and emits light, creating the bright rings that we can see.

Now, to address your question about how light can reach our eyes from a black hole, it is important to understand that not all light is affected by a black hole's gravity in the same way. Light that is emitted from the accretion disk can still escape the black hole's gravitational pull, as it is not close enough to be pulled in completely. This light then travels through space and can eventually reach our eyes or telescopes, allowing us to see the rings of light.

Additionally, the light that we see from black holes is not just from the accretion disk. Scientists also use other types of light, such as X-rays and radio waves, to study black holes. These types of light can also escape the black hole's gravity and provide us with valuable information about these mysterious objects.

In summary, while it may seem counterintuitive that we can see light from black holes, it is actually the light emitted from the accretion disk and other sources that allows us to study and understand these fascinating objects in the universe.