# Blackholes, Jets and Dark Matter.

1. Jun 20, 2008

### blimkie.k

this topic relates to my post in a threat relating to GLAST

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

If the jets are a form of radiation wouldnt that mean it would be traveling the speed of light because thats 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. blackhole escape velocity. I guess it falls in considering light itself cant 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 its self 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 blackholes 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 blackhole 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 cant remember where it was. Maybe someone can post some literature.

Last edited by a moderator: Apr 23, 2017
2. Jun 20, 2008

### Quisquis

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 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.

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. Jun 20, 2008

### blimkie.k

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 beleive 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 blackhole past the event horizon.

4. Jun 22, 2008

### sudeshiitr

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.