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It not the complete list: http://en.wikipedia.org/wiki/List_of_most_massive_black_holes#List http://en.wikipedia.org/wiki/List_of_most_massive_black_hole... On

It not the complete list: http://en.wikipedia.org/wiki/List_of_most_massive_black_holes#List http://en.wikipedia.org/wiki/List_of_most_massive_black_hole... On a related note, I never understood how a black hole (or frozen stars like the Russians call them) could potentially orbit or be swallowed by another black hole. If they "infinitely" deform space-time, shouldn't they be unable to move at all? If time stands still past the event horizon as they say and they also rip the space-time fabric so much, they shouldn't be able to "get out of the hole". This is just too mind-bogging for me I guess.

Sniffnoy 12y ago
Also, according to that list, the central black hole of NGC 1277 is only 1/3 as large as claimed in the article, taking it out of contention entirely.
oakwhiz 12y ago
What I would like to know is what happens when the two black holes collide.
autokad 12y ago
i believe stephen hawking stated that matter does/or could escape black holes, but this subject matter is beyond my expertise so i suggest you ask him. with that being said, it would seem to me that yes, black holes can move, our milky way is not stationary, and black holes have been known to have very fast rotation speeds.
DanielRibeiro 12y ago
I wondered the same thing! This article seems to do a fine job on talking about black hole collisions: http://www.universetoday.com/13002/what-happens-when-supermassive-black-holes-collide/ http://www.universetoday.com/13002/what-happens-when-superma... TL;DR: blackhole mergers are really rare, because one often kicks the other out.
wyager 12y ago
I believe black holes can be treated as normal astronomical objects outside their event horizon. The weird singularity behavior only applies within the event horizons.
- carljoseph 12y ago
  This is pretty much true. You could replace our sun with a black hole of the same mass, and nothing would change in terms of planet's orbits. The image of a black hole "sucking" things in like a vacuum cleaner is hugely incorrect. I think this perception comes about from the funnel image we often see representing black holes.
  - alixaxel 12y ago
    A black hole with the same mass as the sun wouldn't be a black hole at all, would it?
deepsun 12y ago
I'm Russian, and I've never heard "frozen star". In Russian, black hole is literally "black hole". But I greet the new legend about Russians that just born here!
- gjm11 12y ago
  Not just born here. I've heard it before, at least 20 years ago. The version of the legend I heard is that "black hole" in Russian is (or suggests) an obscenity, so for a long time Russian physicists didn't want to use that term. The term "frozen star" has certainly been used for black holes. If you Google both terms you'll find an article from 1971 called "Introducing the black hole", by Ruffini and Wheeler, which mentions that term. (It doesn't say anything about Russian obscenities, though.)
  - ay 12y ago
    "Black hole" is not really an obscenity in Russian as much as it isn't in English. But the paper you quoted does seem to explain the logic for this term's existence: "The resulting system has been variously termed “continuing collapse,” a “frozen star,” and a “black hole.” Each name emphasizes a different aspect of the collapsing system. The collapse is continuing because even after an infinite time, as measured by a distant observer, the collapse is still not complete. Rather, the departure from a static configuration of Schwarzschild radius r=2m as seen by a distant observer diminishes exponentially in time, with a characteristic time of the order of 2m, or about 10 microseconds for an object of one solar mass. The box explains the purely geometrical system of units employed in general relativity. In this sense, the system is a “frozen star.” In another sense, the system is not frozen at all. On the contrary, the dimensions shrink to indefinitely small values in a finite and very short proper time for an observer moving with the collapsing matter (see figure 3). Moreover, a spherical system appears black from outside; no light can escape. Light shot at it falls in. A particle shot at it falls in. A “meter stick” would be let down in vain to measure the dimensions of the object. The stick is pulled to pieces by tidal forces, and the broken-off pieces fall in without a trace. In these senses, the system is a black hole" So this seems to be an international term, and indeed both the Russian wikipedia http://ru.wikipedia.org/wiki/%D0%A7%D1%91%D1%80%D0%BD%D0%B0%D1%8F_%D0%B4%D1%8B%D1%80%D0%B0 http://ru.wikipedia.org/wiki/%D0%A7%D1%91%D1%80%D0%BD%D0%B0%... and English-language one mention it. Couple of other hits in search do mention that the term was used in 1960s - which probably explains the reason why it does sound a bit strange :-) Anyway, it was fun to do this little investigation, thanks!

Sniffnoy 12y ago

Also, according to that list, the central black hole of NGC 1277 is only 1/3 as large as claimed in the article, taking it out of contention entirely.

oakwhiz 12y ago

What I would like to know is what happens when the two black holes collide.

autokad 12y ago

i believe stephen hawking stated that matter does/or could escape black holes, but this subject matter is beyond my expertise so i suggest you ask him. with that being said, it would seem to me that yes, black holes can move, our milky way is not stationary, and black holes have been known to have very fast rotation speeds.

DanielRibeiro 12y ago

I wondered the same thing! This article seems to do a fine job on talking about black hole collisions: http://www.universetoday.com/13002/what-happens-when-supermassive-black-holes-collide/ http://www.universetoday.com/13002/what-happens-when-superma... TL;DR: blackhole mergers are really rare, because one often kicks the other out.

wyager 12y ago

I believe black holes can be treated as normal astronomical objects outside their event horizon. The weird singularity behavior only applies within the event horizons.

carljoseph 12y ago
This is pretty much true. You could replace our sun with a black hole of the same mass, and nothing would change in terms of planet's orbits. The image of a black hole "sucking" things in like a vacuum cleaner is hugely incorrect. I think this perception comes about from the funnel image we often see representing black holes.
- alixaxel 12y ago
  A black hole with the same mass as the sun wouldn't be a black hole at all, would it?

deepsun 12y ago

I'm Russian, and I've never heard "frozen star". In Russian, black hole is literally "black hole". But I greet the new legend about Russians that just born here!

gjm11 12y ago
Not just born here. I've heard it before, at least 20 years ago. The version of the legend I heard is that "black hole" in Russian is (or suggests) an obscenity, so for a long time Russian physicists didn't want to use that term. The term "frozen star" has certainly been used for black holes. If you Google both terms you'll find an article from 1971 called "Introducing the black hole", by Ruffini and Wheeler, which mentions that term. (It doesn't say anything about Russian obscenities, though.)
- ay 12y ago
  "Black hole" is not really an obscenity in Russian as much as it isn't in English. But the paper you quoted does seem to explain the logic for this term's existence: "The resulting system has been variously termed “continuing collapse,” a “frozen star,” and a “black hole.” Each name emphasizes a different aspect of the collapsing system. The collapse is continuing because even after an infinite time, as measured by a distant observer, the collapse is still not complete. Rather, the departure from a static configuration of Schwarzschild radius r=2m as seen by a distant observer diminishes exponentially in time, with a characteristic time of the order of 2m, or about 10 microseconds for an object of one solar mass. The box explains the purely geometrical system of units employed in general relativity. In this sense, the system is a “frozen star.” In another sense, the system is not frozen at all. On the contrary, the dimensions shrink to indefinitely small values in a finite and very short proper time for an observer moving with the collapsing matter (see figure 3). Moreover, a spherical system appears black from outside; no light can escape. Light shot at it falls in. A particle shot at it falls in. A “meter stick” would be let down in vain to measure the dimensions of the object. The stick is pulled to pieces by tidal forces, and the broken-off pieces fall in without a trace. In these senses, the system is a black hole" So this seems to be an international term, and indeed both the Russian wikipedia http://ru.wikipedia.org/wiki/%D0%A7%D1%91%D1%80%D0%BD%D0%B0%D1%8F_%D0%B4%D1%8B%D1%80%D0%B0 http://ru.wikipedia.org/wiki/%D0%A7%D1%91%D1%80%D0%BD%D0%B0%... and English-language one mention it. Couple of other hits in search do mention that the term was used in 1960s - which probably explains the reason why it does sound a bit strange :-) Anyway, it was fun to do this little investigation, thanks!