Blackholes, Jets and Dark Matter.

In summary, the conversation revolves around the ejection of jets of matter from super massive black holes and the question of how this matter, traveling at 99% of the speed of light, can escape the gravitational pull of the black hole. It is suggested that dark matter, or possibly anti-matter, could be responsible for the ejection of this matter. However, it is pointed out that this scenario would violate conservation of mass and energy. The conversation also touches on the idea that the matter in the jets may actually be coming from the surrounding area of the black hole rather than from within it. Overall, the discussion delves into the complexities and mysteries surrounding black holes and their behavior.
  • #1
blimkie.k
130
0
this topic relates to my post in a threat relating to GLAST
https://www.physicsforums.com/showthread.php?t=240620

Super massive black holes eject jets of matter back out into space. The matter in these jets shoot out of the black hole at 99% the speed of light. However the escape velocity for a black hole is the speed of light so how could any type of matter wheter it being gas or radiation escape a black hole propogating at just under the speed of light.

If the jets are a form of radiation wouldn't that mean it would be traveling the speed of light because that's the speed radiation and light travel. Also what happens to an object trying to escape the event horizon traveling exactly the speed of light ie. black hole escape velocity. I guess it falls in considering light itself can't escape the horizon.

I have read that dark matter could possibly interact with matter and the result would be the two canceling each other out and then being converted into pure energy

Matter canceling itself out and converting to energy violates conservation of mass because matter is destroyed and also violates conservation of energy because energy is created so that is also odd.

" some scientists think dark matter is in the form of massive objects, such as black holes" http://www.eclipse.net/~cmmiller/DM/

If dark matter lurks in black holes is it possible that as matter from a galaxy is pulled into the balckhole it reacts with the darkmatter canceling one another out and creating energy which is then ejected out of the black hole back into space or the energy could be responsible for propelling whatever matter the jets are made up of back out into space.

I tryed to pot some links to where i read about dark matter canceling matter but can't remember where it was. Maybe someone can post some literature.
 
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  • #2
blimkie.k said:
Super massive black holes eject jets of matter back out into space. The matter in these jets shoot out of the black hole at 99% the speed of light. However the escape velocity for a black hole is the speed of light so how could any type of matter wheter it being gas or radiation escape a black hole propogating at just under the speed of light.

There is no escape velocity for somthing within the event horizon of a black hole. The matter that gets ejected never enters the event horizon, and therefore can escape at whatever speed is necessary to clear the gravitational well.

I have read that dark matter could possibly interact with matter and the result would be the two canceling each other out and then being converted into pure energy

Matter canceling itself out and converting to energy violates conservation of mass because matter is destroyed and also violates conservation of energy because energy is created so that is also odd.

I think you're referring to anti-matter and not dark matter. So, operating on that assumption...

Nothing is violated because of Einstein's famous equation E=mc^2. That demonstrates that matter can be converted into energy and the reverse also holds true. We've done both of these things here on earth.

If dark matter lurks in black holes is it possible that as matter from a galaxy is pulled into the balckhole it reacts with the darkmatter canceling one another out and creating energy which is then ejected out of the black hole back into space or the energy could be responsible for propelling whatever matter the jets are made up of back out into space.

Again assuming that you mean anti-matter as opposed to dark matter:

Although it is true that they do destroy each other when anti-matter and matter collide, I believe the general consensus in the scientific community is that there really is no appreciable amount of anti-matter flying around the universe. If there was, it would be very likely that it would have interacted with "regular" matter by now.

Even if there was, and the scenario you described occurred, it still wouldn't allowing anything to escape from the event horizon because the escape velocity from that point is greater than the speed of light.
 
  • #3
Your absolutely correct i was confusing anti matter and dark matter i have limited knowledge on the subject so i thought they were the same thing.
Yea i guess i just realized the matter to energy conversion i believe that happens everyday when i eat food and the calories are converted to energy haha
Thanks for clearing up the part about the jets being ejected from the balck hole i thought they were actually coming from within the black hole past the event horizon.
 
  • #4
Hi...
What I could get from this discussion is that there is black hole at the centre and since the matter of jet is not actually coming from the BH itself so what I thought is that the matter which is spiralling around it at very high speeds is ejected out due to its inertia before it is engulfed by the BH. Am I right? If not ..please tell what leads to matter to move at such high speeds in a beamed path. I have a keen interest in astrophysics specially AGNs.
 

1. What is a black hole?

A black hole is an extremely dense object in space with a gravitational pull so strong that nothing, including light, can escape from it. It is formed when a massive star collapses in on itself.

2. How are black holes detected?

Black holes cannot be directly observed, but their presence can be detected through their effects on nearby matter. This includes the way they affect the motion of stars and gas, and the radiation they emit as they consume matter.

3. What are jets in relation to black holes?

Jets are narrow beams of high-energy particles that are ejected from the poles of some black holes. They are formed when material from a surrounding disk is funneled towards the black hole's poles and accelerated to nearly the speed of light.

4. What is dark matter and how does it relate to black holes?

Dark matter is a mysterious substance that makes up about 85% of the total mass of the universe. It does not interact with light, making it invisible to telescopes. While it is not directly related to black holes, they are often found in the same regions of space and their gravitational pull can affect the behavior of dark matter.

5. Can anything escape from a black hole?

Once something crosses the event horizon of a black hole, it cannot escape. This includes light, which is why black holes appear completely black. However, some theories suggest that tiny particles called Hawking radiation can escape from a black hole, but this has yet to be confirmed.

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