# What do black holes look like?

1. May 25, 2013

### DeeAytch

They have to have some color, yeah?

2. May 25, 2013

### phinds

No, why would you think they have color when they are called "black"??? To have color a thing has to radiate. Black holes may do Hawking Radiation but that certainly could not be called a color and they do not otherwise radiate (the ACCRETION DISK may radiate but that is outside the BH).

What DO they look like? They look like a hole in space. A black hole. See how simple some things are?

3. May 26, 2013

### Danger

Yeah, you can't "see" one. The predominant colour, which comes from the accretion disc rather than the hole itself, is gamma/X-ray.

4. May 26, 2013

### OmCheeto

According to this website, black is a color.

ps. Black holes look like the eye of the bird that smacked into my window this morning. I held her for at least half an hour before she flew away. She was quite stunned by her near instantaneous deceleration.

5. May 26, 2013

### Danger

Clever, my son... fiendishly clever. You have, however, overlooked the cause of your doom. (Where is the smilie for wringing one's hands in evil glee?)
The colour or lack thereof regarding a black hole is irrelevant. Since it (the singularity) is literally a "mathematical point" of zero size, it is too small to be seen. :tongue:

6. May 26, 2013

### WannabeNewton

A black hole singularity need not be a point, see Kerr black holes. With regards to its near thermal black body nature, see the discussion here: http://physics.stackexchange.com/questions/61582/is-a-black-hole-a-perfect-black-body

A black hole has a very precise, mathematical definition which, unfortunately, will be too difficult to understand if you have never studied GR. This wiki article describes things rather well without using much math: http://en.wikipedia.org/wiki/Black_hole#Properties_and_structure

7. May 26, 2013

### OmCheeto

Unfortunately, I don't believe in "mathematical points" of zero size.

That would yield an infinity.

And I don't believe in that either.

And I need a new brain. The image of my birds eye looks nothing like a black hole...

8. May 26, 2013

### Naty1

9. May 26, 2013

### Bill_K

See this paper by Bill Ames, for a complete analysis.

10. Jun 2, 2013

### stevebd1

The top image from this website is '..a general relativistic visualization of a supercomputed magneto-hydrodynamic simulation of a disk and jet around a black hole.'-