An old way to see black holes, Full story at http://www.physorg.com/news6924.html

http://www.physorg.com/news6924.html

Between accretion and Hawking radiation, I am surprised that black holes can still be considered "dark matter".

Miles, eh? Oh, dear. When will these poor journos in the US accept the metric system? 95% of the world use the metric system without a problem. When?

Hawking radiation does not play a role persay until the black hole's mass becomes very small.... it is also tied into the cosmic microwave background... that needs to cool down more as well.... Hawking radiation has never been (nor will it for quite some time more then likely) been experimentally verified..... the thermal output of a average black hole would only be very finite amount above absolute zero... i THINK its cooler then space infact... hence the need for the CMB to drop even further...

Accretion disks only form on the plane of rotation... perpendicular to the axis of rotation.... depending on what angle u view them at... they aren't all that useful... besides... the best they can do is silohette the black hole..... infact resolution on ALL types of telescopes has not achieved a degree of accuracy to be able to resolve the image of the black hole (the presumably near to perfect black sphere one would expect to see at the center of the accretion disk...) against the backdrop of a gas cloud (likely source of the accretion disk). So... those are a few of the reasons black holes are still considered black... and will likely stay that way for the immediate future).

F U

There are a couple of things I'd like to know that are NEVER mentioned.....the first of which is, of course, that the people of Earth are NEVER told that our entire solar system is within the accretion disk of the supermassive black hole at the galactic center, and that we're already more than halfway toward being sucked in...
I suppose it should be comforting that those of us who live at this point in time will never live to see the solar system being sucked into the supermassive black hole at a later date....which only means that if there are Homo Sapiens who actually survive that far into the future, we can only pray fervently that they have developed the means to travel to regions far beyond the influence of the galactic Charybdis...
Then again...maybe that's the way it started the first time...first the "Great Crunch"...followed by a time of compression and a building of pressure...before the "first" Big Bang....as we as humans understand the process.....
Hawking, Thorne and others have made it abundantly clear that of the secrets of the universe that we understand, are far, far outstripped by the secrets that we don't have the answers to ...at least yet...OR there are those secrets that they HAVE found the answers to...but for their own selfish reasons haven't shared with the rest of humanity...
In any case...there are fundamental parts of the story that should be told...such as the fact that our sun will burn out eventually....which will mean the end of all life on this planet. That much the scientific community will share...mainly because any thinking person already knows that to tell any other story would be pure idiocy...since children are taught at an early age that our sun is a ball of gas that has a finite supply of fuel, and that eventually the fuel will be used up, and after that, gravity will take over...making our once-warm and life-giving Sun a brown dwarf...or a red giant...the bottom line of which, of course, that before it's over, "even Mars will get very warm".....as I've heard somewhere else....

Ignorance,

I agree wholeheartedly that we will not be able to see any emitted radiation from the black holes or nearby accreted matter with current techniques.

Still, I would not consider them "dark" in principle, but definitely in practice.

Microlensing allows us to capture gravitational signature of compact objects such as black holes in the halo, and the published results suggest they cannot be a dominant dark component in the halo.

Could there be one at the galaxy center? Maybe, but then the rotation curve should tell us so.

g_l

Another way to see black holes: http://www.physorg.com/news6626.html

crazy thought maybe black holes are the sun's of dark mater ??