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Could a small black hole surprise us on earth.



 
 
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  #1  
Old February 22nd 04, 11:58 PM
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Default Could a small black hole surprise us on earth.

I have a question.

We would probably get some warning about a comet or an asteroid - but what
about a pea size black hole? If one hit the moon would it be like a match
to paper and suck the entire moon into itself even if it took some time?
Could an invisible small black hole just show up over the Sierra Nevada and
no one would have foreseen it and it would destroy the earth? Would it
destroy the earth instantly or would there be some fantastically horrible
slow whirlpool of matter into a small black hole so that we would all have
time to feel intense fear?

I suspect these questions have been answered many times before but I have
been looking for several months and I bet other's are wondering too.



  #4  
Old February 23rd 04, 01:14 AM
Chris L Peterson
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Default Could a small black hole surprise us on earth.

On Sun, 22 Feb 2004 22:58:21 GMT, wrote:

I have a question.

We would probably get some warning about a comet or an asteroid - but what
about a pea size black hole? If one hit the moon would it be like a match
to paper and suck the entire moon into itself even if it took some time?
Could an invisible small black hole just show up over the Sierra Nevada and
no one would have foreseen it and it would destroy the earth? Would it
destroy the earth instantly or would there be some fantastically horrible
slow whirlpool of matter into a small black hole so that we would all have
time to feel intense fear?


First, I don't believe it is possible to have such a small black hole. Anything
this small (1e33g) would have formed only during processes very early in the
Universe, and would have evaporated by now. If there remain any natural
processes capable of producing such low mass objects, they are presumably very
rare, as would be our chance of encountering one such a black hole.

That said, the effect of such an object striking the Earth (or the Moon) is
difficult to judge. If this black hole were in an Earth crossing orbit around
the Sun, it would strike at typical meteor speeds. While the mass is around 50
times that of the Moon, the momentum is very high, and I think it probable that
only a relatively small amount of energy would actually be dissipated. The
object might simply crash through the Earth and out the other side, doing
relatively little damage. It certainly wouldn't swallow the Earth up. If the
black hole was passing through from somewhere else, it might have just about any
velocity. The most interesting case would be if its approach was at a low speed.
Then, it would strike the Earth at about our escape velocity (11.2 km/s). It
would probably end up in an orbit around the Earth's center of mass, but that
orbit would actually be inside the Earth. Although it would take a very long
time to swallow up all the Earth's mass, the gravitational effects would be
devastating.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
  #5  
Old February 23rd 04, 01:14 AM
Chris L Peterson
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Posts: n/a
Default Could a small black hole surprise us on earth.

On Sun, 22 Feb 2004 22:58:21 GMT, wrote:

I have a question.

We would probably get some warning about a comet or an asteroid - but what
about a pea size black hole? If one hit the moon would it be like a match
to paper and suck the entire moon into itself even if it took some time?
Could an invisible small black hole just show up over the Sierra Nevada and
no one would have foreseen it and it would destroy the earth? Would it
destroy the earth instantly or would there be some fantastically horrible
slow whirlpool of matter into a small black hole so that we would all have
time to feel intense fear?


First, I don't believe it is possible to have such a small black hole. Anything
this small (1e33g) would have formed only during processes very early in the
Universe, and would have evaporated by now. If there remain any natural
processes capable of producing such low mass objects, they are presumably very
rare, as would be our chance of encountering one such a black hole.

That said, the effect of such an object striking the Earth (or the Moon) is
difficult to judge. If this black hole were in an Earth crossing orbit around
the Sun, it would strike at typical meteor speeds. While the mass is around 50
times that of the Moon, the momentum is very high, and I think it probable that
only a relatively small amount of energy would actually be dissipated. The
object might simply crash through the Earth and out the other side, doing
relatively little damage. It certainly wouldn't swallow the Earth up. If the
black hole was passing through from somewhere else, it might have just about any
velocity. The most interesting case would be if its approach was at a low speed.
Then, it would strike the Earth at about our escape velocity (11.2 km/s). It
would probably end up in an orbit around the Earth's center of mass, but that
orbit would actually be inside the Earth. Although it would take a very long
time to swallow up all the Earth's mass, the gravitational effects would be
devastating.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
  #6  
Old February 23rd 04, 05:05 AM
Davoud
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Posts: n/a
Default Could a small black hole surprise us on earth.

Chris L Peterson:
...The most interesting case would be if its approach was at a low speed.
Then, it would strike the Earth at about our escape velocity (11.2 km/s). It
would probably end up in an orbit around the Earth's center of mass, but that
orbit would actually be inside the Earth. Although it would take a very long
time to swallow up all the Earth's mass, the gravitational effects would be
devastating.


*****

Pub Patron: "Is the world really going to end?"

Ford Prefect: "Yes."

PP: "Couldn't we put a paper bag over our heads?"

FP: "Yes."

PP: "Would that help?"

FP: "No."

(Or words to that effect) - Douglas Adams, HHGG

I, for one, will be sleeping with a paper bag over my head tonight.

Davoud

--
usenet *at* davidillig dawt com
  #7  
Old February 23rd 04, 06:11 AM
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Posts: n/a
Default Could a small black hole surprise us on earth.


"Chris L Peterson" wrote in message
...
On Sun, 22 Feb 2004 22:58:21 GMT, wrote:

I have a question.

We would probably get some warning about a comet or an asteroid - but

what
about a pea size black hole? If one hit the moon would it be like a

match
to paper and suck the entire moon into itself even if it took some time?
Could an invisible small black hole just show up over the Sierra Nevada

and
no one would have foreseen it and it would destroy the earth? Would it
destroy the earth instantly or would there be some fantastically horrible
slow whirlpool of matter into a small black hole so that we would all

have
time to feel intense fear?


First, I don't believe it is possible to have such a small black hole.

Anything
this small (1e33g) would have formed only during processes very early in

the
Universe, and would have evaporated by now. If there remain any natural
processes capable of producing such low mass objects, they are presumably

very
rare, as would be our chance of encountering one such a black hole.

That said, the effect of such an object striking the Earth (or the Moon)

is
difficult to judge. If this black hole were in an Earth crossing orbit

around
the Sun, it would strike at typical meteor speeds. While the mass is

around 50
times that of the Moon, the momentum is very high, and I think it probable

that
only a relatively small amount of energy would actually be dissipated. The
object might simply crash through the Earth and out the other side, doing
relatively little damage. It certainly wouldn't swallow the Earth up. If

the
black hole was passing through from somewhere else, it might have just

about any
velocity. The most interesting case would be if its approach was at a low

speed.
Then, it would strike the Earth at about our escape velocity (11.2 km/s).

It
would probably end up in an orbit around the Earth's center of mass, but

that
orbit would actually be inside the Earth. Although it would take a very

long
time to swallow up all the Earth's mass, the gravitational effects would

be
devastating.





This is very interesting. It is interesting to think of the world's cities,
not to mention its lifeforms, if the gravity suddenly went up some huge
fraction of what it is now. I can see it pulling all the skyscrapers
colllapsing straight down into the ground like spears. Or maybe the
structures are overbuilt but the gravitational pull sucks the file cabinets
though the floor panels along with the water coolers down into the basement?
And while you might be ok supported by your car seats, and the car
suspension might be able to handle slow driving - what happens when you step
out of the car and you now weigh triple what you joints and bones are use
to?

What a way to go. I wonder if the dinosaurs wouldn't have had an easier
time with the asteroid?

I wonder what would happen to planes in the air? Would the gravity make the
atmosphere now three times as dense so that the planes, while weighing three
times as much, would have that much more lift on their wings? I guess the
wings might just rip off?

Thx for the info.



  #8  
Old February 23rd 04, 07:06 AM
Chris L Peterson
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Posts: n/a
Default Could a small black hole surprise us on earth.

On Mon, 23 Feb 2004 05:11:29 GMT, wrote:

This is very interesting. It is interesting to think of the world's cities,
not to mention its lifeforms, if the gravity suddenly went up some huge
fraction of what it is now. I can see it pulling all the skyscrapers
colllapsing straight down into the ground like spears. Or maybe the
structures are overbuilt but the gravitational pull sucks the file cabinets
though the floor panels along with the water coolers down into the basement?
And while you might be ok supported by your car seats, and the car
suspension might be able to handle slow driving - what happens when you step
out of the car and you now weigh triple what you joints and bones are use
to?

What a way to go. I wonder if the dinosaurs wouldn't have had an easier
time with the asteroid?

I wonder what would happen to planes in the air? Would the gravity make the
atmosphere now three times as dense so that the planes, while weighing three
times as much, would have that much more lift on their wings? I guess the
wings might just rip off?


I don't think it is this simple. What you have is an object massing the same as
the earth and traveling with a fairly high relative velocity. So first of all,
there is going to be a transfer of momentum, and the Earth is going to be
slingshot out of its orbit- whether that takes us out of the Solar System, or
simply into a new solar orbit, we're in deep doo doo.

Second, because the black hole and the Earth are moving rapidly with respect to
each other, the effect isn't going to be a simply increased gravitational field,
but some kind of vector that changes over several minutes. If the black hole
ends up orbiting inside the Earth, the tidal effects are going to cause all
manner of tectonic events that will be much more effective at collapsing
buildings than the gravitational fluctuations alone.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
  #9  
Old February 23rd 04, 07:40 AM
external usenet poster
 
Posts: n/a
Default Could a small black hole surprise us on earth.


"Chris L Peterson" wrote in message
...
On Mon, 23 Feb 2004 05:11:29 GMT, wrote:

This is very interesting. It is interesting to think of the world's

cities,
not to mention its lifeforms, if the gravity suddenly went up some huge
fraction of what it is now. I can see it pulling all the skyscrapers
colllapsing straight down into the ground like spears. Or maybe the
structures are overbuilt but the gravitational pull sucks the file

cabinets
though the floor panels along with the water coolers down into the

basement?
And while you might be ok supported by your car seats, and the car
suspension might be able to handle slow driving - what happens when you

step
out of the car and you now weigh triple what you joints and bones are use
to?

What a way to go. I wonder if the dinosaurs wouldn't have had an easier
time with the asteroid?

I wonder what would happen to planes in the air? Would the gravity make

the
atmosphere now three times as dense so that the planes, while weighing

three
times as much, would have that much more lift on their wings? I guess the
wings might just rip off?


I don't think it is this simple. What you have is an object massing the

same as
the earth and traveling with a fairly high relative velocity. So first of

all,
there is going to be a transfer of momentum, and the Earth is going to be
slingshot out of its orbit- whether that takes us out of the Solar System,

or
simply into a new solar orbit, we're in deep doo doo.

Second, because the black hole and the Earth are moving rapidly with

respect to
each other, the effect isn't going to be a simply increased gravitational

field,
but some kind of vector that changes over several minutes. If the black

hole
ends up orbiting inside the Earth, the tidal effects are going to cause

all
manner of tectonic events that will be much more effective at collapsing
buildings than the gravitational fluctuations alone.



Well, I know that massive earthquakes right above their epicenters produce
land waves. I think the biggest is eight feet? I wonder if this is what you
mean by tidal effects? That would be spectacular. I wonder if anybody has
ever modeled that on a computer. I know the national lab at Los Alamos had
their programs model the asteroid impact several years ago when the two
Hollywood movies came out. I think that was after the public consciousness
was raised with the Shoemaker-Levy impact on Jupiter.

I wonder if anybody ever animated what your talking about? Maybe it would
just be total devastation.




  #10  
Old February 23rd 04, 08:49 AM
jerry warner
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Posts: n/a
Default Could a small black hole surprise us on earth.

any black hole of palpable size would be detected long before it got here.
a pea is of palpable size when it comes to black holes, especially within the
confines of a solar system.

black holes smaller than a pea would do significant damage if not destroy the
earth
if the two collided, however such entities are probably rare at this age in the
universe
some 13 billion years old?, and their numbers in our galaxy would be
statistically
nonexistent. Thats my opinion anyway -

Black holes or related high energy entities on the order of a molecule or an
atom or
smaller, must be exceedingly rare, as compared with say neutrons? Neutrons do
pass through the Earth daily without any short term recognition. I believe the
processes which may have once generated very small singularities, are long
gone.

But I could be wrong about all of this -
Jerry





wrote:

I have a question.

We would probably get some warning about a comet or an asteroid - but what
about a pea size black hole? If one hit the moon would it be like a match
to paper and suck the entire moon into itself even if it took some time?
Could an invisible small black hole just show up over the Sierra Nevada and
no one would have foreseen it and it would destroy the earth? Would it
destroy the earth instantly or would there be some fantastically horrible
slow whirlpool of matter into a small black hole so that we would all have
time to feel intense fear?

I suspect these questions have been answered many times before but I have
been looking for several months and I bet other's are wondering too.


 




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