Trap photons in orbit...

[Darnok]

Is it possible to trap photons in orbit around gravity source?

Photons should move in circular orbits around for example a microscopic black hole.

Interesting like they have been behaving?

And what would happen when shoot exactly the same number of photons in the opposite direction, but in inclined orbit in such a way that the two groups never collide?

[lajoswinkler]

Yes, the theory predicts it. It's called a photon sphere (not photosphere).

http://en.wikipedia.org/wiki/Photon_sphere

[Deutherius]

So, if the conditions are just right and the photons just orbit and don't escape... We wouldn't be able to see the photon sphere. Unless we get right in in. Or do photons interact in such a way that we would be able to observe the sphere, be it directly or indirectly?

[AngelLestat]

they escape eventually not matter how perfect is their location, but the orbit will be very bright (not sure if it is the word).

[pincushionman]

What would probably happen is: uncertainty would destabilize the orbits quickly; the wave nature would exhibit itself, causing energy to be radiated towards/away from the center, destabilizing the orbits quickly; photons would interfere with one another, destabilizing the orbits quickly.

But I am not a quantum physicist, so my interpretation may not be worth much.

Edited April 12, 2015 by pincushionman

[lajoswinkler]

Even if there is some destabilization occuring, there's a constant surplus of photons pouring at the event horizon so the photon sphere is stable as a dynamic equilibrium.

There would be some serious ionizing radiation in that sphere. Matter, falling towards the black hole, emits x-rays. I bet there's an unbelieveably enormous intensity in that sphere, a lot more than around the hole.

[Teamwork]

You can trap photons in orbit around a black hole. They orbit right where the event horizon is.

[AngelLestat]

You can trap photons in orbit around a black hole. They orbit right where the event horizon is.

No is not.

Not rotating black hole.

A most real Rotating blackhole

Edited April 14, 2015 by AngelLestat

[NFUN]

The photon sphere wouldn't be bright unless many photons were escaping (and thus the sphere were decaying if not being refueled). Unless some photons left the sphere and made it to an observer, they would be unable to be seen. If they were around a black hole, of course, some crazy crap would probably happen and this post would likely not apply.

[AngelLestat]

yeah as NFUN said.. I guess there is always a bit of light from the star background which we would see as an unfinish ring around the black hole..

If it has an active or old accretion disk as photon source then there is not necesary to imagine, Interstellar did a great job showing how it will looks like.

Movie

http://www.dneg.com/wp-content/uploads/2015/01/Interstellar-FLprStills42.gif

With the effect from the rotation effect which was not added in the movie and is not fully renderized here:

Rotation: Bright space comming to you, dark in opossite direction.

[Fel]

yeah as NFUN said.. I guess there is always a bit of light from the star background which we would see as an unfinish ring around the black hole..

If it has an active or old accretion disk as photon source then there is not necesary to imagine, Interstellar did a great job showing how it will looks like.

Movie

http://astronomynow.com/wp-content/uploads/2015/02/Interstellar_black_hole_940x400.jpg

http://www.dneg.com/wp-content/uploads/2015/01/Interstellar-FLprStills42.gif

With the effect from the rotation effect which was not added in the movie and is not fully renderized here:

https://cdn3.vox-cdn.com/thumbor/3skcmzVBZAcl0YZWER7zHDGIeZc=/cdn0.vox-cdn.com/uploads/chorus_asset/file/3414736/Screen_Shot_2015-02-16_at_5.34.56_PM.0.png

Rotation: Bright space comming to you, dark in opossite direction.

But something like that is still assuming the majority of photons are escaping. Photons are invisible until they hit your retina which further means that only photons whose orbitals are such that they would intercept your retinas would apply. If we complicate things further by pointing out that an escaping photon should have a pseudo-random exit trajectory (assume something like a collision is what released the photon) then we shouldn't even see the structured "orbits" as much as simply points of light.

Even if you are inside the orbital (which, you know, would mean you'd be going c) you couldn't see anything because the light would never reach you.

*Then again, you could break physics and have one particle approach you at c while you also approach that particle at c resulting in a relative speed of 2c... but you'd also have to deal with time dilation which, I believe, is sqrt(1 - v/c), meaning you're now unable to see the proton because time has effectively stopped.

Just as a note though, we ARE mixing quantum physics; newtonian mechanics; general relativity; and special relativity here.

People have different debates over how "mixable" these fields really are. They do predict different outcomes based on scope and are most accurate when dealing with the extremes they were developed in. This is most notable with Hawking Radiation which dealt with very similar issues as this question; in the most part though, the dispute came because it relies on various aspects of both special relativity and quantum mechanics, but alone neither agreed with his conclusions.

Edited April 15, 2015 by Fel

[AngelLestat]

Is what I said in my first, also I was agree with Nful explanation. All photons escape eventually.. they may do 1 or 5 turn around the blackhole, but then escape and some reach you.

Remind that there is a huge amount of photons, even for a distant start. So it will be many photons which are comming from behind you,, then their turn around the black hole and back to you. That is way that zone is brighter, because you can see photons comming from all directions from the universe and escaping in your direction.

If you are in the same photon orbit, it will be more bright (as any light source where you get closer), the speed of light is always the same), so you can see the photons there..

And remember that there is 2 photon sphere, one which photons orbit in the same direction of the BH rotation, and a second one farthest, which photons rotate in opposite direction from the blackhole spin..

About quamtum and relativity.. that only counts from the even horizon and beyond. The photon sphere is in einstein ground.

[Teamwork]

No is not.

Not rotating black hole.

http://www.gothosenterprises.com/black_holes/images/static.gif

A most real Rotating blackhole

http://www.gothosenterprises.com/black_holes/images/rotating.gif

http://www.engr.mun.ca/~ggeorge/astron/lkjh.gif

AngelLestat

Is what I said in my first, also I was agree with Nful explanation. All photons escape eventually.. they may do 1 or 5 turn around the blackhole, but then escape and some reach you.

Remind that there is a huge amount of photons, even for a distant start. So it will be many photons which are comming from behind you,, then their turn around the black hole and back to you. That is way that zone is brighter, because you can see photons comming from all directions from the universe and escaping in your direction.

If you are in the same photon orbit, it will be more bright (as any light source where you get closer), the speed of light is always the same), so you can see the photons there..

And remember that there is 2 photon sphere, one which photons orbit in the same direction of the BH rotation, and a second one farthest, which photons rotate in opposite direction from the blackhole spin..

About quamtum and relativity.. that only counts from the even horizon and beyond. The photon sphere is in einstein ground.

If the photons are leaving, then aren't they technically on an escape trajectory and not in orbit.

[YNM]

"Orbiting" itself is even quite vague - at those potentials, every trajectory (or, well, orbit) should precess. And the only orbit that ignores precession is a perfectly circular orbit - fairly not possible, you know. Also the fact that photons have a fair amount of uncertainty in them, if the most potential site moves a bit outward or inward it'd be either absorbed or get away... And arrive at your eye (hopefully).

Edited April 15, 2015 by YNM

[Fel]

Is what I said in my first, also I was agree with Nful explanation. All photons escape eventually.. they may do 1 or 5 turn around the blackhole, but then escape and some reach you.

Remind that there is a huge amount of photons, even for a distant start. So it will be many photons which are comming from behind you,, then their turn around the black hole and back to you. That is way that zone is brighter, because you can see photons comming from all directions from the universe and escaping in your direction.

If you are in the same photon orbit, it will be more bright (as any light source where you get closer), the speed of light is always the same), so you can see the photons there..

And remember that there is 2 photon sphere, one which photons orbit in the same direction of the BH rotation, and a second one farthest, which photons rotate in opposite direction from the blackhole spin..

About quamtum and relativity.. that only counts from the even horizon and beyond. The photon sphere is in einstein ground.

Quantum Physics: "Complex interactions between wave-particles that create astonishing things on the subatomic level"

Newtonian Physics: "Gravity is a Force, photons are purely energy, matter consists of uniform and indivisible material (or rather, the laws don't apply to subatomic particles)"

General Relativity: "You both are wrong! (for objects on the planetary scale)"

Special Relativity: "EVERYONE is wrong for objects going the speed of light"

*May or may not be completely accurate here*

The point is, you NEED General Relativity to accurately describe the effects a black hole has upon an object (Newtonian Physics are an approximation), but you also NEED Quantum physics to describe the effects that gravity will have upon subatomic particles; and as these particles are going the speed of light you now need special relativity which describes such matter. Newtonian physics gets thrown in here and there to "fix" transitions.

There's also an issue you didn't quite get. If the system is in equilibrium then the blackhole is no more brighter than the surrounding area. That is to say, if there was tons of light all around you, that the moon should reflect ALL of that light just the same as a blackhole would trap and release it.

Edited April 15, 2015 by Fel

[AngelLestat]

I cant not understand the reply, if you want to add some info to explain better all this your are welcome.. But is like you are correct me from things that I dint mention.

When I said that you need einstein relativity with quamtum mechanics for anything from the event horizon and beyond.. I was talking about the fusion of those 2 theories into a new one.

Then to resume I just said relativity is enoght if you are close but not in the event horizon.. Of course that if you wanna study something small in the universe you will always need quamtum mechanic, but you dont need a new fusion theory.

Also Newtonian Physics does not have into account that the light can be bend due gravity.

About the equilibrium example I dont get it.. I am not talking about the black hole.. Just the photon sphere which that area will looks brighter.

Another way to explain this, forget the accretion disk, just imagine 6 stars, one in front, back, right, left, down and up according to the black hole.

From your point of view far from the black hole you will see only the star that is in from of you in case the black hole is not there.

So only 1 point of light without the black hole.

Now if you put the black hole you will see some photons from the 6 stars reaching your eyes. And the point where you see these photons is in the photon sphere, because all comes from there.

So yes... that area it will be brighter.

[YNM]

Quantum Physics: "Complex interactions between wave-particles that create astonishing things on the subatomic level"

Newtonian Physics: "Gravity is a Force, photons are purely energy, matter consists of uniform and indivisible material (or rather, the laws don't apply to subatomic particles)"

General Relativity: "You both are wrong! (for objects on the planetary scale)"

Special Relativity: "EVERYONE is wrong for objects going the speed of light"

General Relativity, as it name implies, is a generalization of Special Relativity. Can be seen from it's properties, SR do applies on sites where GR works, just for a very, very small site.

Newtonian Physics only fiddle with very macroscopic, very sparse things, and things that interacts everyday with humans.

Quantum Physics... is a very sophisticated form of statistics (probability), as one of it's main point. I'm not talking about how things interact in there bar those affected by probability - I'm no expert.

The point is, you NEED General Relativity to accurately describe the effects a black hole has upon an object (Newtonian Physics are an approximation), but you also NEED Quantum physics to describe the effects that gravity will have upon subatomic particles; and as these particles are going the speed of light you now need special relativity which describes such matter. Newtonian physics gets thrown in here and there to "fix" transitions.

Look up gravitational lensing - it's purely derived form GR, while it have something to do with light.

There's also an issue you didn't quite get. If the system is in equilibrium then the blackhole is no more brighter than the surrounding area. That is to say, if there was tons of light all around you, that the moon should reflect ALL of that light just the same as a blackhole would trap and release it.

It does, locally. Like, very local, just within the "photon sphere" itself - GR applies very strongly so even in a distance of a few kilometers, you get a different reality (different proper time -> different frequency, different proper distance (wrt metric scales) -> different way for photon to travel and spread).

Edited April 17, 2015 by YNM

[BlueCosmology]

Newtonian physics is never used to "fix transitions". Where have you heard that? Newtonian physics just plain and simply does not work at all in the regimes you're talking of. Special relativity is incorporated in quantum physics, and also it is just a subset of general relativity, it does not say anything is wrong about either.

Very close to a blackhole is brighter than the surroundings area, accretion discs are heated up to the point where they emit tremendous amounts of visible light, and there are orbits of light trapped near it.