Black Hole Suns

User avatar
Jason
Destroyer of words
Posts: 17782
Joined: Sat Apr 16, 2011 12:46 pm
Contact:

Black Hole Suns

Post by Jason » Wed Jan 08, 2014 10:31 pm

Laying in bed the other night I had a random thought: Shouldn't black holes have halos (actually spheres of light, but halos from any one perspective) as light the just grazes the event horizon escapes in a sort of hyperbolic arc? Black holes wouldn't be invisible if this were true, and it seems to me it should be, but would have bright 'rings' or 'halos' of light at the edge of the event horizon.

User avatar
mistermack
Posts: 15093
Joined: Sat Apr 10, 2010 10:57 am
About me: Never rong.
Contact:

Re: Black Hole Suns

Post by mistermack » Wed Jan 08, 2014 11:17 pm

For it to have a visible halo, brighter than the background, the light would need to be focused in some way. There's nothing I can think of that would do that. I would think that any light that escaped would be scattered in completely random fashion.

I do remember reading that when a giant gas cloud falls into a black hole, it gives off an extremely powerful burst of light as it is accelerated to close to the speed of light, and that that has been seen and used to confirm the existence of the black hole.
While there is a market for shit, there will be assholes to supply it.

User avatar
JimC
The sentimental bloke
Posts: 73015
Joined: Thu Feb 26, 2009 7:58 am
About me: To be serious about gin requires years of dedicated research.
Location: Melbourne, Australia
Contact:

Re: Black Hole Suns

Post by JimC » Wed Jan 08, 2014 11:31 pm

The idea of gravitational lensing may be relevant here: http://en.wikipedia.org/wiki/Gravitational_lenses
Nurse, where the fuck's my cardigan?
And my gin!

PsychoSerenity
"I" Self-Perceive Recursively
Posts: 7824
Joined: Tue Feb 23, 2010 1:57 am
Contact:

Re: Black Hole Suns

Post by PsychoSerenity » Wed Jan 08, 2014 11:54 pm

Actually, what happened about the super massive black hole gas cloud thing this summer? I heard loads beforehand about the scientists excitedly looking forward to it, but nothing about the event or any images.
[Disclaimer - if this is comes across like I think I know what I'm talking about, I want to make it clear that I don't. I'm just trying to get my thoughts down]

User avatar
Jason
Destroyer of words
Posts: 17782
Joined: Sat Apr 16, 2011 12:46 pm
Contact:

Re: Black Hole Suns

Post by Jason » Thu Jan 09, 2014 12:45 am

JimC wrote:The idea of gravitational lensing may be relevant here: http://en.wikipedia.org/wiki/Gravitational_lenses
That's exactly what I was thinking. I'm only some 80 years late on the theory.

Thanks Jim. :tup:

User avatar
pErvinalia
On the good stuff
Posts: 59295
Joined: Tue Feb 23, 2010 11:08 pm
About me: Spelling 'were' 'where'
Location: dystopia
Contact:

Re: Black Hole Suns

Post by pErvinalia » Thu Jan 09, 2014 2:46 am

Your idea makes sense, but where is this light source coming from? I wouldn't think the collection of stars behind a black hole would make enough light to cause a halo.
Sent from my penis using wankertalk.
"The Western world is fucking awesome because of mostly white men" - DaveDodo007.
"Socialized medicine is just exactly as morally defensible as gassing and cooking Jews" - Seth. Yes, he really did say that..
"Seth you are a boon to this community" - Cunt.
"I am seriously thinking of going on a spree killing" - Svartalf.

User avatar
pErvinalia
On the good stuff
Posts: 59295
Joined: Tue Feb 23, 2010 11:08 pm
About me: Spelling 'were' 'where'
Location: dystopia
Contact:

Re: Black Hole Suns

Post by pErvinalia » Thu Jan 09, 2014 2:47 am

mistermack wrote: I do remember reading that when a giant gas cloud falls into a black hole, it gives off an extremely powerful burst of light as it is accelerated to close to the speed of light, and that that has been seen and used to confirm the existence of the black hole.
Hawking Radiation.
Sent from my penis using wankertalk.
"The Western world is fucking awesome because of mostly white men" - DaveDodo007.
"Socialized medicine is just exactly as morally defensible as gassing and cooking Jews" - Seth. Yes, he really did say that..
"Seth you are a boon to this community" - Cunt.
"I am seriously thinking of going on a spree killing" - Svartalf.

User avatar
JimC
The sentimental bloke
Posts: 73015
Joined: Thu Feb 26, 2009 7:58 am
About me: To be serious about gin requires years of dedicated research.
Location: Melbourne, Australia
Contact:

Re: Black Hole Suns

Post by JimC » Thu Jan 09, 2014 2:57 am

rEvolutionist wrote:Your idea makes sense, but where is this light source coming from? I wouldn't think the collection of stars behind a black hole would make enough light to cause a halo.
A galaxy directly behind can produce the effect...
Nurse, where the fuck's my cardigan?
And my gin!

User avatar
JimC
The sentimental bloke
Posts: 73015
Joined: Thu Feb 26, 2009 7:58 am
About me: To be serious about gin requires years of dedicated research.
Location: Melbourne, Australia
Contact:

Re: Black Hole Suns

Post by JimC » Thu Jan 09, 2014 3:01 am

rEvolutionist wrote:
mistermack wrote: I do remember reading that when a giant gas cloud falls into a black hole, it gives off an extremely powerful burst of light as it is accelerated to close to the speed of light, and that that has been seen and used to confirm the existence of the black hole.
Hawking Radiation.
No, rEv. Hawking radiation is an odd quantum phenomenon, to do with the production of particle pairs from empty space; when this happens just beyond the event horizon, it has the effect of very slowly decreasing the mass/energy of the black hole. It would be very weak in comparison to gravitational lensing.

http://en.wikipedia.org/wiki/Hawking_radiation
Nurse, where the fuck's my cardigan?
And my gin!

User avatar
pErvinalia
On the good stuff
Posts: 59295
Joined: Tue Feb 23, 2010 11:08 pm
About me: Spelling 'were' 'where'
Location: dystopia
Contact:

Re: Black Hole Suns

Post by pErvinalia » Thu Jan 09, 2014 3:08 am

I don't think mm was referring to gravitational lensing. Perhaps he was right, though. I think I've heard accounts of black holes and/or neutron stars etc stripping the gas of nearby stars. I guess when the gas accelerates enough, it probably turns to some sort of plasma and emits a lot of radiation.
Sent from my penis using wankertalk.
"The Western world is fucking awesome because of mostly white men" - DaveDodo007.
"Socialized medicine is just exactly as morally defensible as gassing and cooking Jews" - Seth. Yes, he really did say that..
"Seth you are a boon to this community" - Cunt.
"I am seriously thinking of going on a spree killing" - Svartalf.

User avatar
mistermack
Posts: 15093
Joined: Sat Apr 10, 2010 10:57 am
About me: Never rong.
Contact:

Re: Black Hole Suns

Post by mistermack » Thu Jan 16, 2014 2:13 pm

I don't think that gravitational lensing qualifies for what Făkünamę described in the op.

It's a lens effect, caused by the progressive bending of spacetime, around an extremely massive object, like a galaxy cluster or super super massive black hole, or summat simliar. So it doesn't cause a halo effect around a black hole from any direction, it just produces false images of bright objects that are perfectly in line with the observer and the massive object.

For a black hole to have a halo of light, that just evaded being sucked in, you would need a lot of very bright light sources, very close to it, and they would drown out any halo effect, even if it existed.

Looking backwards at it, if you tracked the light back to the black hole, there would need to be some kind of focussing effect, of most or all of the available light being concentrated to a small area around the black hole, and then released into space to be observed. I don't think there's any mechanism for that.
While there is a market for shit, there will be assholes to supply it.

User avatar
Mysturji
Clint Eastwood
Posts: 5005
Joined: Thu Feb 26, 2009 4:08 pm
About me: Downloading an app to my necktop
Location: http://tinyurl.com/c9o35ny
Contact:

Re: Black Hole Suns

Post by Mysturji » Thu Jan 16, 2014 2:33 pm

I think gravitational lensing is EXACTLY what Făkünamę described in the OP.
But there would have to be a fairly bright light source behind the black hole for it to be noticable.
Check out these images of gravitational lensing:
http://apod.nasa.gov/apod/ap130917.html
http://apod.nasa.gov/apod/ap111221.html
http://apod.nasa.gov/apod/ap111017.html
http://apod.nasa.gov/apod/ap100620.html
Sir Figg Newton wrote:If I have seen further than others, it is only because I am surrounded by midgets.
Cormac wrote:Doom predictors have been with humans right through our history. They are like the proverbial stopped clock - right twice a day, but not due to the efficacy of their prescience.
IDMD2
I am a twit.

User avatar
Scott1328
Posts: 1140
Joined: Tue Jul 30, 2013 4:34 am
Contact:

Re: Black Hole Suns

Post by Scott1328 » Thu Jan 16, 2014 7:13 pm

Wouldn't the light that approached so close to the even horizon become deeply red shifted?

Gravitational lensing can happen over inter galactic distances and a black hole is not required and certainly wouldn't result in a halo.

User avatar
Animavore
Nasty Hombre
Posts: 39234
Joined: Sun Mar 01, 2009 11:26 am
Location: Ire Land.
Contact:

Re: Black Hole Suns

Post by Animavore » Thu Jan 16, 2014 7:18 pm

I've tried all day to resist, but I can't.

Libertarianism: The belief that out of all the terrible things governments can do, helping people is the absolute worst.

User avatar
Animavore
Nasty Hombre
Posts: 39234
Joined: Sun Mar 01, 2009 11:26 am
Location: Ire Land.
Contact:

Re: Black Hole Suns

Post by Animavore » Thu Jan 16, 2014 7:19 pm

Lol! Unintentional double entendre.
Libertarianism: The belief that out of all the terrible things governments can do, helping people is the absolute worst.

Post Reply

Who is online

Users browsing this forum: No registered users and 12 guests