blackholes existing within close proximity?

from the little research that I have done and looked over about
blackholes, I is to my understand that the bigger the body, the larger
the graviational pull would be to pull in other objects.

my question stems to this. is it possible for 2 (or more) blackholes to
exist withn a close proximity. the gravitational collapse of a star or
even greater, a galaxy does cause a blackhole, unless I am mistaken...
but, say it were to happen in close proximity of another star? say 2
stars begin a gravitational collapse at the same time?

will one star more rapidly collapase, thus "sucking" the other star into
its force? or do they for lack of a better term, happily co-exist?

can someone explain to me in the most detail possible how they can or
cannot exist in the same proximity?

thank you in advance.

Joseph.


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Joseph Devaney wrote:
from the little research that I have done and looked over about
blackholes, I is to my understand that the bigger the body, the larger
the graviational pull would be to pull in other objects.

my question stems to this. is it possible for 2 (or more) blackholes to
exist withn a close proximity. the gravitational collapse of a star or
even greater, a galaxy does cause a blackhole, unless I am mistaken...
but, say it were to happen in close proximity of another star? say 2
stars begin a gravitational collapse at the same time?

It is thought that the conditions in the core of galaxies and possibly globular
clusters would allow black holes (and white dwarfs and neutron star) to form in
close proximity to each other when compared to the stellar distances in our
neighborhood. In particular, mergers of black holes with other black holes,
with neutron stars, with white dwarfs, with gas that would have otherwise
possibly collapsed and formed into stars, and possibly even with stars
themselves are highly probable and may help explain the observation of what
appear to be supermassive black holes at the cores of some galaxies and globular
clusters where such observations have been done.


will one star more rapidly collapase, thus "sucking" the other star into
its force? or do they for lack of a better term, happily co-exist?

There is at least one known example of coorbiting pulsars (rotating neutron
stars), so there would be no exclusion of this possibility with black holes. As
to whether they would each evolve independent of each other and remain in orbit
after becoming black holes as they were as individual stars, or whether they
will merge, or whether one will form first and strip material from its partner
all depends on initial distances and mass of the stars prior to that formation.

In article
ilgate.org,
"Joseph Devaney" wrote:

from the little research that I have done and looked over about
blackholes, I is to my understand that the bigger the body, the larger
the graviational pull would be to pull in other objects.

Well, if by "bigger" you mean "more massive" then yes.

my question stems to this. is it possible for 2 (or more) blackholes to
exist withn a close proximity.

Sure.

the gravitational collapse of a star or
even greater, a galaxy does cause a blackhole, unless I am mistaken...

Well, a sun-sized star wouldn't form a black hole; below a certain
threshold the best you could get is a neutron star. I don't recall what
the minimum mass is for forming a black hold, but I think it's on the
order of several solar masses.

but, say it were to happen in close proximity of another star? say 2
stars begin a gravitational collapse at the same time?

That's highly unlikely. But I suppose it could happen. (Actually, I
suppose it's even possible that one star going supernova could actually
trigger its companion to supernova as well...)

will one star more rapidly collapase, thus "sucking" the other star into
its force?

No, gravity doesn't work that way. The black hole has no more mass (and
therefore, no more gravity) than whatever went into it (i.e. the star it
formed from). It doesn't "suck things in" any more than it did before.
If the Sun suddenly collapsed into a black hole today, Earth and all its
planets would continue in their orbits unperturbed. (Though it would
get mighty cold!)

or do they for lack of a better term, happily co-exist?

Yes, and the better term you're looking for is "orbit". They'd continue
to orbit their center of mass, just like they did before.

Of course there is a bit of a hitch: black holes don't last forever.
They evaporate -- and the smaller the black hole, the more rapidly it
evaporates, converting its mass into energy (radiation). So that
*would* disrupt the orbits of stuff orbiting it, over large time scales.
Not by sucking them in, but by setting them loose as the black hole
disappears.

can someone explain to me in the most detail possible how they can or
cannot exist in the same proximity?

You're thinking of black holes as magic sucking machines. They're not.
They're just very dense concentrations of mass. From a distance, they
cause no more gravitational attraction than the mass that went into them.

The only thing special about a black hole is that you can get much
closer to one -- where the gravitational attraction is very strong --
before you actually hit anything. I.e., for their mass, they are
extremely small (theoretically, a point). But that only matters for
things which are actually that close. Further away, the behavior is no
different from a similar amount of ordinary matter.

Cheers,
- Joe

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"Joseph Devaney" writes:

from the little research that I have done and looked over about
blackholes, I is to my understand that the bigger the body, the larger
the graviational pull would be to pull in other objects.

Replace "bigger" with "more massive," and you'll be more or less correct.


my question stems to this. is it possible for 2 (or more) blackholes to
exist withn a close proximity.

Sure, for a little while, as long as their event horizons don't get close
enough to each other to merge. Once their event horizons merge, you get a
single black hole with a horizon areas at _least_ as large as the combined
areas of the two black holes, and a =LOT= of gravitational radiation !!!


the gravitational collapse of a star or even greater, a galaxy does cause
a blackhole, unless I am mistaken...

I am sorry, but I cannot parse that sentence. Yes, a big enough star can
collapse to become a black hole, most galactic cores appear to contain
really, REALLY big black holes with masses of millions or even BILLIONS
of stars, and at least one galaxy appears to contain two black holes
spiraling in toward each other that should collide and merge in about
10 million years, relative to our time. What's your point ???


but, say it were to happen in close proximity of another star? say 2
stars begin a gravitational collapse at the same time?

It is false _Star Drek_(tm) pseudo-physics that a star's gravity somehow
gets magically "stronger" when it collapses. If the Sun were somehow
magically collapsed to form a black hole without loss of mass, the Sun's
gravitational field strength at any give point outside its original surface,
which is directly proportional to its mass and inversely proportional to
the distance from its center squared, would not change even one little bit.


will one star more rapidly collapase, thus "sucking" the other star into
its force? or do they for lack of a better term, happily co-exist?

No, the giant sucking sound you hear on _Star Drek_(tm) when a
star collapses is the air in the studio rushing in to fill the
vacuum represented by the complete and utter scientific ignorance
of the script-writers.


can someone explain to me in the most detail possible how they can or
cannot exist in the same proximity?

The gravitational field of an object depends only on its total mass and the
distance you are for it, not its physical state. It doesn't matter whether
a one solar-mass object is a star or a black hole; it exerts _EXACTLY- the
same gravitational force at a given radius.


-- Gordon D. Pusch

perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;'

"Joseph Devaney" wrote:
from the little research that I have done and looked over about
blackholes, I is to my understand that the bigger the body, the larger
the graviational pull would be to pull in other objects.

my question stems to this. is it possible for 2 (or more) blackholes to
exist withn a close proximity. the gravitational collapse of a star or
even greater, a galaxy does cause a blackhole, unless I am mistaken...
but, say it were to happen in close proximity of another star? say 2
stars begin a gravitational collapse at the same time?

will one star more rapidly collapase, thus "sucking" the other star into
its force? or do they for lack of a better term, happily co-exist?

can someone explain to me in the most detail possible how they can or
cannot exist in the same proximity?

There's nothing special about the gravitational force from a
blackhole. They don't "suck in" objects any more than any
other body of the same mass. In fact, because a blackhole
is smaller than a star of the same mass, they actually
"suck in" less, because objects which are pulled close enough
to hit the body of a star would likely miss even the accretion
disc of a blackhole. From a distance, you cannot tell
gravitationally when a star has collapsed into a blackhole,
it's the same mass.

So yes, blackhole's can coexist.