the event horizon of a black hole should be colorful

[bwanaaa]

the event horizon is where gravity is strong enough to suck light back into the hole.

that means just outside, the light is in orbit around the hole.

as time goes by, more light accumulates at this layer. (any photon foolish enough to approach the black hole at just the right angle and distance from it s center gets captured)

this light will never be absorbed because nothing else is in this layer.
particles traverse this layer much less frequently than photons because there are many more photons than particles in our universe. so there is a net increase in orbiting photons over time. Black holes should increase in energy.

And more energetic light (higher frequency) should have a higher orbit than redder light.

So, if you could travel through the event horizon, you would see a rainbow. but since you can't, you have to look for light that is deflected out of its orbit by a particle crashing into a black hole.

why isnt this seen?

 

[aigomorla]

there is no way we can see a black hole...

All the images we have of suspected black holes are just large spots of highly distorted gravity causing lensing effects... or extremely chaotic radio transmission from the results of massive amounts of gama.

We dont even know what a black hole really is.. what function it serves in the universe, or if its even possible to transverse though one in some fluke sci fi worm hole.

You could even state a black hole is a weapon of mass destruction set about by god to wipe out all existence of reality, and really none one could prove it to be false as it does just that.

Setting up theories behind theories is fun... but it doesnt reach a point anywhere until the first theory ur basing your truth upon applies.

However for us to see a black hole in person up front means we already signed a death wish to god.

 

[SecurityTheatre]

the event horizon is where gravity is strong enough to suck light back into the hole.

that means just outside, the light is in orbit around the hole.

as time goes by, more light accumulates at this layer. (any photon foolish enough to approach the black hole at just the right angle and distance from it s center gets captured)

this light will never be absorbed because nothing else is in this layer.
particles traverse this layer much less frequently than photons because there are many more photons than particles in our universe. so there is a net increase in orbiting photons over time. Black holes should increase in energy.

And more energetic light (higher frequency) should have a higher orbit than redder light.

So, if you could travel through the event horizon, you would see a rainbow. but since you can't, you have to look for light that is deflected out of its orbit by a particle crashing into a black hole.

why isnt this seen?

Are you saying that a simple collission between particles would send one jetting outward with sufficient energy to escape a black hole?

I'm not sure that's possible. Otherwise it wouldn't be black.

To be fair, I don't think the "different colors orbit a different levels" is true either.

A higher frequency does not change the velocity of a photon, nor the mass (since it is essentially zero), so there is no additional inertia or any other property that would change its "orbit" in a black hole.

Can you explain your idea more?

 

[Biftheunderstudy]

I think he means the last stable orbit of a black hole is one where your orbital velocity is the speed of light. Thus, there should be a "ring" of photons at this radius. They won't be separated by frequency though, only the speed matters and like you said, c.

But, even if you expect some photons to come out to be observed, this is easily washed out by the accretion disk blasting out x-rays etc.

There is a observing experiment uderway to attempt to image the event horizon of our galaxy's own supermassive blackhole, SgA*. It's using some fancy adaptive optics tricks and other really cool astronomy. Should be exciting!

 

[aigomorla]

Are you saying that a simple collission between particles would send one jetting outward with sufficient energy to escape a black hole?

I'm not sure that's possible. Otherwise it wouldn't be black.

To be fair, I don't think the "different colors orbit a different levels" is true either.

A higher frequency does not change the velocity of a photon, nor the mass (since it is essentially zero), so there is no additional inertia or any other property that would change its "orbit" in a black hole.

Can you explain your idea more?

acording to Michio Kaku he said he thinks if u were to enter a black hole... the universe would extend around you in a sphere... and u would see everything at once because light would be traveling the same speed as you, and would also be trapped to circle that event horizon for eternity.

You could see past, present and the future at the same.

However the object were looking at outside the blackhole would appear to freeze in time as it got closer to the event horizon.

The light photon ur wondering would be stuck and no way to observe it, because any evidence of it leaving or escaping isnt possible at the event horizon.

observation is a factor based on time.... at the event horizon there is no notion of time, so hence you cant observe anything as the object your observing doesnt exist in the laws of time.

 

[bwanaaa]

I think he means the last stable orbit of a black hole is one where your orbital velocity is the speed of light. Thus, there should be a "ring" of photons at this radius. They won't be separated by frequency though, only the speed matters and like you said, c.

...

yes that is exactly what i mean. In my comment about spectral separation, I imagined that E=hv so that higher frequency light is more energetic. But I guess I forgot that higher frequency light would also be more 'massive'. It reminds me a little of how galileo showed that a bowling ball and a pebble reach the ground from a tower at the same time and the same velocity. And certainly, objects of different mass can all orbit the earth in the space station at the same radial distance from the earth's center because they all have the same velocity. So photons too, travel at the same velocity regardless of their frequency. So all photons should orbit the black hole at a single specific distance. And my thesis that the event horizon should be colorful, is wrong.

As to the separation of photons by frequency I am too theoretically challenged to analyze the the different implications yet. A simplistic explanation is here:
http://www.hyperflight.com/starlight.htm
halfway down the page it says:
~~~~~~~~~~~~~~~~~
In 1975, an experiment was performed – at Harvard, no less – that attempted to differentiate between two components that may bend light (or bend light's path).

1) Corona, and
2) Light-bending gravitation theory
~~~~~~~~~~~~~~~~~


Some more scientific articles dancing around this idea are:
http://arxiv.org/pdf/astro-ph/9311035v1.pdf
http://cds.cern.ch/record/795085/files/0409124.pdf

Certainly, the review articles of which I am not aware, the long expositions that may be part of someone's doctoral thesis, or the introductory sections of certain grant applications may have a more lucid and concise discussion of light bending due to gravity. Spectral separation would imply a corona which black holes do not have, right?

And I dont even know why matter would spiral into a black hole as a disk, basically becoming a 2D flow instead of 3d spherical implosion from all directions.

I am enchanted by the idea that photons orbit at a specific distance from the center of a black hole. This distance could be a measure of its mass. if you could disturb this layer, you could detect it and thus measure its distance from the black hole center. And that way get an idea of mass?

 

[disappoint]

I find it funny that you take a guess first then try to find the observation that fits. This is the exact opposite of the scientific method.

 

[SecurityTheatre]

And I dont even know why matter would spiral into a black hole as a disk, basically becoming a 2D flow instead of 3d spherical implosion from all directions.

This is because almost all (maybe all) black holes are formed from spinning debris- probably spinning quite rapidly.

Also, when you subject a cloud of gas and dust to the gravity of a black hole, anything that is stationary to the object falls into it rapidly.

So after a short time, the only objects left are those that are in orbit, and the vast majority of objects will be in a single equatorial orbit (hence, rings).

It is also worth pointing out that any large orbital bodies that have sufficient orbital velocity to maintain orbit (rather than falling in), will be torn to dust by the immense tidal forces and will then also turn into rings.

This is why many (especially massive) planets have rings. It's also why the solar system exists primarily on a spinning plane.

And probably why many galaxies exist on a spinning plane as well.

If you could disturb this layer, you could detect it and thus measure its distance from the black hole center. And that way get an idea of mass?

If you could reach into a black hole and extract photos from their orbit beyond the event horizon..... I think you would already know the mass of the black hole, because you can measure it based on its gravity OUTSIDE the event horizon. :-D And if you could do that you would also be a god too, so that would help with the knowledge and measuring part.

 

[SMOGZINN]

And I dont even know why matter would spiral into a black hole as a disk, basically becoming a 2D flow instead of 3d spherical implosion from all directions.

Gravity averages. It would only form a sphere if there was an even amount of mass in all directions, otherwise if there is just a tiny amount more pull in one direction mass will over time move towards the center. Since it is spinning (because it is all orbiting the black hole) with enough time this will cause a disk. Each new particle that orbits the black hole will slowly get pulled into that center line by all the mass that is already there.

We know that their is not an even distribution of mass around the black hole because the star that it formed from was spinning and therefore had more mass near it's equator then it's poles, and that caused matter orbiting it to clump in that equatorial line.

I am enchanted by the idea that photons orbit at a specific distance from the center of a black hole. This distance could be a measure of its mass. If you could disturb this layer, you could detect it and thus measure its distance from the black hole center. And that way get an idea of mass?

I am not sure of this, but I think that photons would orbit the black hole inside (or really exactly at) the event horizon. Once a photon hits the point where instead of escaping the black hole it is pulled back towards it (thus an orbit) you are at the point where no force in the universe is powerful enough to escape the gravity of the black hole, and that is the definition of the event horizon.

 

[aigomorla]

I am not sure of this, but I think that photons would orbit the black hole inside (or really exactly at) the event horizon. Once a photon hits the point where instead of escaping the black hole it is pulled back towards it (thus an orbit) you are at the point where no force in the universe is powerful enough to escape the gravity of the black hole, and that is the definition of the event horizon.

time also stops at the event horizon.

u cant observe anything when its frozen in time.

 

[SMOGZINN]

time also stops at the event horizon.

u cant observe anything when its frozen in time.

Time is relative. To the particle it looks like time is moving really fast and the entire universe passes by in an instant. If you could look in and see something 'frozen in time' you would see the opposite, the item appears to be moving really slowly and things that we expect to happen very quickly take the entire life of the universe to occur.

 

[aigomorla]

Time is relative. To the particle it looks like time is moving really fast and the entire universe passes by in an instant. If you could look in and see something 'frozen in time' you would see the opposite, the item appears to be moving really slowly and things that we expect to happen very quickly take the entire life of the universe to occur.

that's exactly the point..

For a rainbow flashy type of occurance, you would need time to not be relative..

 

[Unitary]

For a static black hole a photon would have a circular orbit at radius 3Gm (or 50% larger than the Schwarzshild radius) Unfortunately, no photons are trapped by this orbit as it is unstable. In other words, any perturbation from this orbit causes the photon to fall into the black hole or fly away to infinity.

 

[aigomorla]

For a static black hole a photon would have a circular orbit at radius 3Gm (or 50% larger than the Schwarzshild radius) Unfortunately, no photons are trapped by this orbit as it is unstable. In other words, any perturbation from this orbit causes the photon to fall into the black hole or fly away to infinity.

lol hence time would NOT have to be relative... :biggrin:

 

[Z15CAM]

Here's an interesting Question I found very interesting submitted by Phillip Henry, Staff, Physics, Lockheed Martin & Florida Tech in 2009: "Can Neutrinos travel through black holes?"

Answer from MadSci Network: "Thank you Bishant, an excellant question.

Neutrinos are weakly (very weakly) interacting particles. However they do interact with matter. Beyond the event horizon of a black hole, neutrinos would be trapped on an eternal orbit to a virtually infinite density core.

That said, neutrinos likely are produced in copious amounts in the events which lead up to the formation of black holes and neutron stars. However there is little hope for anything unfortunate enough to pass beyond the event horizon of a black hole, although there have been some scientific speculation about special cases of black holes which might permit such. From what we know currently, once any matter or energy passes the event horizon of a black hole, it is trapped in twisting space and time - unable to escape and on course for the virtually infinite density core. However, by its very nature, science can only see to the vicinity of the event horizon. The nature of the interior and core is only slowing being revealed in theory."

I don't necessarily agree with the answer particularly when they say " However they do interact with matter."
What flavor (oscillation); Electron, Muon or Tai are they referring to. It's not even established whether a Neutrino is Matter or primarily Dark Matter. Can Dark Matter can be eaten by a Black Hole - siish - I'm confused ;o)

 

[Biftheunderstudy]

The flavour of the neutrino doesn't matter all that much, they are sort of different sides of the same particle.

As to the whether they are dark matter or not:
Whether they have mass is critical to if they could be dark matter (Dark matter is simply matter that we can not see, or it interacts very weakly which we infer from its gravitational influence). That said, the currently favoured model rules out neutrinos for a number of reasons which I will not get into.

Finally, even if they were dark matter, that would not save them from the black hole. Dark matter by its definition interacts only with gravity, and so it is not safe from the event horizon.

 

[Z15CAM]

OK so back to Relativity: Here's an excellent explantion from Scientific American in regards to Einstein's Theory of Relatively where Gravity is a Distortion in Space Time Geometry that may offer the best explain to the Op's Interesting Question:

http://www.youtube.com/watch?feature=player_embedded&v=GOtVixURVzk

However; other then for Neutron Stars it seems to me that, Neutrinos appear traveling in straight lines through matter at the speed of light and apparently unaffected by gravity - I suppose we could think of a Black Hole as being the opposite of a Neutron Star where "Everything is affected by gravity. Gravity warps of space-time according to the Einstein Field Equations, and traveling on "geodesics" (shortest path curves) on that curved surface is how gravity is manifested.Thinking as though there is some sort of euclidean space underneath the non-euclidean space-time in which neutrinos can take a more direct "straight line" between the points is not at all supported. Everything we know of travels on this curved spacetime."

It just seems Neutrinos have relevancy why Physicists are exploring the possibility of Dimensional Shortcuts.

 

[PrincessFrosty]

My modern understanding is that nothing special happens at the event horizon of a black hole, to anyone passing through it. You'd not be able to tell you'd passed the horizon, but as Leonard Susskind explains, you're surely doomed.

However to observers on the outside you simply appear to approach the "surface" of the event horizon slower and slower until your image slowly flattens and shifts wavelength.

This is because the closer you get the slower the photons leaving your body move towards an external observer, stretching their wavelength and making you appear to move slower and slower.

There's a great free resource called the theoretical minimum by Leonard Susskind, university lecture series on cosmology and black holes, he also done another lecture in a number of places called the universe as a hologram which is to do with the information of objects approaching black holes essentially to observers being simply flattened and spread out on to the horizon.

There seems to be ongoing discussion about firewalls at the event horizion of black holes which he's also lectured on recently, again you can find them from his site the theoretical minimum.

Easily one of the best free educational resources for people not already too familar with physics or cosmology, but have a reasonably decent grasp of math.

 

[alkemyst]

Are you saying that a simple collission between particles would send one jetting outward with sufficient energy to escape a black hole?

I'm not sure that's possible. Otherwise it wouldn't be black.

To be fair, I don't think the "different colors orbit a different levels" is true either.

A higher frequency does not change the velocity of a photon, nor the mass (since it is essentially zero), so there is no additional inertia or any other property that would change its "orbit" in a black hole.

Can you explain your idea more?

It could be possible. 'black' doesn't really mean that much in science.

I don't think you really understand the whole physics behind it.

 

[KIAman]

As I understand it, black holes have so much gravitational power, that it is bending space to the point that even a photon traveling at the speed of light cannot escape.

So even if debris disrupted the photons, the photons would somehow require to exceed the speed of light to escape and most likely the collision would send them into the singularity.

 

[TheEinstein]

meh, the Sun or normal stars do not grow in mass, therefore orbiting bodies are stable.

However a blackhole is presumed to grow due to absorbtion of materials into the core. Therefore by gaining size and power it will continue to destabilize any orbiting materials and inhale them.

There may be a light amount of light (no pun intended) hovering in temporary orbit around a black hole, as well as maybe even matter. This does not mean it will stay there endlessly.

 

[aigomorla]

It could be possible. 'black' doesn't really mean that much in science.

I don't think you really understand the whole physics behind it.

+1

my physics teacher tried to explain a black hole to us, because we all assumed its a big black sphere in space, when its not...
There is nothing to explain it.. the black doesn't represent darkness, it represents nothing... 0 information, no way to get information, and information which doesn't exist in our physics hence the black is a representation of nothing.

He said pretend our 3D world is 2D and we live on a sheet of paper.
Now put a drop of water on that paper... watch the paper soak up the water, get denser and then eat a hole right though the paper.

All vectors going to it, would distort on the wet paper, and once u got to the hole, it would terminate.
There can be 0 vectors coming out of a hole, because u can plot a starting point inside the hole.

Now if were 2D beings viewing this event... what would it look like..

That is a black hole.

 

[SecurityTheatre]

It could be possible. 'black' doesn't really mean that much in science.

I don't think you really understand the whole physics behind it.

I don't think I UNDERSTAND the physics behind it at an expert level, no.

I know, however, that Hawking radiation is one of the only things theorized to escape from a black hole and that photons certainly don't, and that was the essence of the response you quoted. And yes, calling it "black" was a joke (notice the goofy smiley)

What hawking radiation is comprised of, nobody knows, but I believe it is essential to avoid violating several laws of thermodynamics.

Do you know any different?

 

[Biftheunderstudy]

As was mentioned before, Leonard Susskind has an excellent video series where he outlines his holographic principle as a way of avoiding nasty information theory issues with black holes.

But first, Hawking radiation is actually pretty simple to understand in a basic, if somewhat flawed way. It goes something like:
You have your black hole, on the event horizon you create a particle antiparticle pair via the Time-Energy Uncertainty principle. One particle goes into the black hole, the other goes the other direction and escapes. The universe wants its energy back, which comes from the black hole. -- This is wrong in several ways, but it gets the point across.

Finally, stars don't have to gain mass to become a black hole. It's really all about pressure support against gravity, and density. When a star can no longer produce any outward pressure (from fusion or degenerate matter) it collapses, all the way.

 

[SecurityTheatre]

Finally, stars don't have to gain mass to become a black hole. It's really all about pressure support against gravity, and density. When a star can no longer produce any outward pressure (from fusion or degenerate matter) it collapses, all the way.

As far as I understand the collapse of stars, there is a minimum mass, below which you won't ever form a black hole.



Edit: A brief Google turns up the Tolman-Oppenheimer-Volkoff limit.

From wikiedpedia: "A black hole formed by the collapse of an individual star must have mass exceeding the Tolman–Oppenheimer–Volkoff limit."

I read that to mean that without gaining mass at some point, a stellar body smaller than 1.5-3.0 solar masses simply won't collapse into a black hole due to force effects between the particles within the star.