Posted by
timothy
on from the that's-an-immense-candy-bar dept.
ChazeFroy writes: "A black hole with a mass of more than 2 million suns has been pinpointed at the center of the Milky Way. Scientists used triangulation based on the acceleration of infrared images of three stars and to find the center. CNN has the story here."
2.6 million stars in that space? try 10x that!
by
Bluedove
·
· Score: 5
The CNN article says: The black hole could hold 2.6 million stars the mass of the sun inside a relatively tiny area -- less than the distance from the sun to Mars.
That shouldn't be at all shocking. Even if we take the minimum orbital distance of Mars (~206.7e6 kms), you can fit the equivalent of 26,193,511 Sol volumes within that space. (given the radius of Sol to be 6.96e5 kms)
So, even NOT counting on compression from the incredible amount of mass, you could fit 26 million stars the mass of the sun into the "relatively tiny space".
Given that the numbers match so closely, except for the decimal place, i suspect one of two things:
1) The article writer is amazed you can fit the volume of a marble into the volume of a basketball.
or
2) The article writer put the decimal in the wrong spot, and discovered you can put volume "V" into the space of volume "V"
Re:Detecting black holes
by
re-geeked
·
· Score: 5
You said:
"The theory goes (extremely roughly) that as individual particles reach the "edge" (event horizon?) of the black hole (crossing this line means you never come back), some of them are torn apart, half of the particle going in, half going out, and some energy is released during this fission"
Sorry, but that's a little too rough. Particles are not ripped in two. Rather, at the event horizon, just like everywhere else, virtual particle/antiparticle pairs are constantly being formed and annihiliated as allowed by the uncertainty principle (they don't last long enough to be detectable, so they don't violate any conservation laws). However, being at the event horizon, some of these pairs get formed, and then one of the two particles gets trapped by the black hole, and its partner does not annihilate undetectably quickly, but rather sticks around long enough to collide with other matter or decay or both, thus producing Hawking radiation.
Now someone can correct my rough explanation and eventually we'll get this straight...
-- "You can't get something for nothing." - my grandfather, on the stock market and Reaganomics.
Black holes can be detected (in theory of course) by looking for the emissions they give off. The theory goes (extremely roughly) that as individual particles reach the "edge" (event horizon?) of the black hole (crossing this line means you never come back), some of them are torn apart, half of the particle going in, half going out, and some energy is released during this fission. It is these fissions at the edge that make a black hole appear to give off energy, and make it detectable.
That type of radiation is called Hawking Radiation (after Stephen Hawking, naturally). However, this isn't what lets us detect black holes, as Hawking Radiation is ridiculously faint. Black holes can be detected by the X-Rays that they "inadvertantly" produce. When matter is falling into a black hole it is accelerated, heated, and compressed to such a degree that it gives off large amounts of X-Rays. I believe the first black hole we detected (again, assuming black holes exist), was Cygnus X-1 (or cygnus something), and we detected it by the x-rays it gave off.
Another method of detecting black holes is to look for graviational lensing effects. Because black holes are so massive, they bend the fabric of space time. (Imagine a sheet suspended in the air. Place marbles on the sheet. The marbles make depressions on the sheet, like stars make "depressions" in space-time. A black hole is so heavy, it's like dropping something that is the size of a marble but with the weight of a bowling ball onto the sheet. The sheet bends A LOT, and it actually will have a hole where the singularity is.) Light travels in a straight line, so if space-time curves, light also curves with space-time. Gravitational lensing was proved during a solar eclipse. Astronomers observing the eclipse noted that they were able to see stars that should have been blocked by the eclipsed sun. The sun's gravitational field caused enough "lensing" so that stars directly behind the star could be seen to either side of the star. So, if we find something out in space that is causing a LARGE amount of gravitational lensing, but we can't see anything, there's a chance it's a black hole. At that point we normally observe it more to determine if it is or isn't a black hole.
Re:2.6 million stars in that space? try 10x that!
by
Christopher+Thomas
·
· Score: 4
So, even NOT counting on compression from the incredible amount of mass, you could fit 26 million stars the mass of the sun into the "relatively tiny space".
Given that the numbers match so closely, except for the decimal place, i suspect one of two things:
1) The article writer is amazed you can fit the volume of a marble into the volume of a basketball.
or
2) The article writer put the decimal in the wrong spot, and discovered you can put volume "V" into the space of volume "V"
I vote for option 3), 4), or a combination of the two:
3) The amount of space is "tiny" compared to the amount of space taken up by stars in the rest of the galaxy. Stars are seldom packed one against the other.
4) The writer is using copy from descriptions of smaller black holes. The even horizon's radius grows in linear proportion to a black hole's mass, if I remember correctly.
This means that volume grows far faster than mass. Black holes with the mass of a mountain are smaller than an atom; a black hole the mass of the sun have a radius of about 3 km. More massive black holes, however, have less density. In fact, if the universe is closed (i.e. returning to a "Big Crunch"), it would be the perfect example of a very sparse black hole - transplant a sufficiently large chunk of it to a reasonably flat space, and an observer outside of the transplanted chunk would see an event horizon surrounding it.
Internet Troll Hole Pinpointed at Slashdot.org
by
Chris+Pimlott
·
· Score: 5
A joint team of network specialists, consisting of employees from Cisco Systems, Hewlett-Packard, 3Com and others have located an immensive Troll Hole on the Internet, centered directly on the popular weblog Slashdot. While the presences of the hole has long been suspected, today's announcement has confirmed its status as the largest Troll Hole on the Internet.
Experts say the Slashdot Troll Hole has been continually drawing hundreds of trolls to the site for over three years. "It seems to present an incredible attractive force to individuals with an abundance of spare time," explained Michael Czekjum of the Internet Engineering Task Force. "Once drawn, they find themselves compelled to inundate comments with disguised obscene hyperlinks, single-minded knee-jerk insulting replies and vacuous first post attempts."
While today's pinpointing of the hole represents a great triumph, officials stress there is still much to learn. Early analysis seems to suggest it is expanding. Datapoints from Slashdot's founding in late 1997 show an almost complete lack of trolls. Since then, their numbers have expanded at a geometric rate. The types of individuals being attracted is also being studied. "While traditional text-based trolls are still in the majority, the past six months have seen a great increase in graphical trolls, using primitive ASCII representations," wrote Ari T'teyel of Sun Microsystems in a paper published last week. "In addition, the hole's effect on other individuals, such as karma whores, is as yet unknown."
The Troll Hole draws in
Slashdot Mirror
That shouldn't be at all shocking. Even if we take the minimum orbital distance of Mars (~206.7e6 kms), you can fit the equivalent of 26,193,511 Sol volumes within that space. (given the radius of Sol to be 6.96e5 kms)
So, even NOT counting on compression from the incredible amount of mass, you could fit 26 million stars the mass of the sun into the "relatively tiny space".
Given that the numbers match so closely, except for the decimal place, i suspect one of two things:
1) The article writer is amazed you can fit the volume of a marble into the volume of a basketball.
or
2) The article writer put the decimal in the wrong spot, and discovered you can put volume "V" into the space of volume "V"
Demonstrant's Open Source Tools
You said:
"The theory goes (extremely roughly) that as individual particles reach the "edge" (event horizon?) of the black hole (crossing this line means you never come back), some of them are torn apart, half of the particle going in, half going out, and some energy is released during this fission"
Sorry, but that's a little too rough. Particles are not ripped in two. Rather, at the event horizon, just like everywhere else, virtual particle/antiparticle pairs are constantly being formed and annihiliated as allowed by the uncertainty principle (they don't last long enough to be detectable, so they don't violate any conservation laws). However, being at the event horizon, some of these pairs get formed, and then one of the two particles gets trapped by the black hole, and its partner does not annihilate undetectably quickly, but rather sticks around long enough to collide with other matter or decay or both, thus producing Hawking radiation.
Now someone can correct my rough explanation and eventually we'll get this straight...
"You can't get something for nothing." - my grandfather, on the stock market and Reaganomics.
Black holes can be detected (in theory of course) by looking for the emissions they give off. The theory goes (extremely roughly) that as individual particles reach the "edge" (event horizon?) of the black hole (crossing this line means you never come back), some of them are torn apart, half of the particle going in, half going out, and some energy is released during this fission. It is these fissions at the edge that make a black hole appear to give off energy, and make it detectable.
That type of radiation is called Hawking Radiation (after Stephen Hawking, naturally). However, this isn't what lets us detect black holes, as Hawking Radiation is ridiculously faint. Black holes can be detected by the X-Rays that they "inadvertantly" produce. When matter is falling into a black hole it is accelerated, heated, and compressed to such a degree that it gives off large amounts of X-Rays. I believe the first black hole we detected (again, assuming black holes exist), was Cygnus X-1 (or cygnus something), and we detected it by the x-rays it gave off.
Another method of detecting black holes is to look for graviational lensing effects. Because black holes are so massive, they bend the fabric of space time. (Imagine a sheet suspended in the air. Place marbles on the sheet. The marbles make depressions on the sheet, like stars make "depressions" in space-time. A black hole is so heavy, it's like dropping something that is the size of a marble but with the weight of a bowling ball onto the sheet. The sheet bends A LOT, and it actually will have a hole where the singularity is.) Light travels in a straight line, so if space-time curves, light also curves with space-time. Gravitational lensing was proved during a solar eclipse. Astronomers observing the eclipse noted that they were able to see stars that should have been blocked by the eclipsed sun. The sun's gravitational field caused enough "lensing" so that stars directly behind the star could be seen to either side of the star. So, if we find something out in space that is causing a LARGE amount of gravitational lensing, but we can't see anything, there's a chance it's a black hole. At that point we normally observe it more to determine if it is or isn't a black hole.
So, even NOT counting on compression from the incredible amount of mass, you could fit 26 million stars the mass of the sun into the "relatively tiny space".
Given that the numbers match so closely, except for the decimal place, i suspect one of two things:
1) The article writer is amazed you can fit the volume of a marble into the volume of a basketball.
or
2) The article writer put the decimal in the wrong spot, and discovered you can put volume "V" into the space of volume "V"
I vote for option 3), 4), or a combination of the two:
3) The amount of space is "tiny" compared to the amount of space taken up by stars in the rest of the galaxy. Stars are seldom packed one against the other.
4) The writer is using copy from descriptions of smaller black holes. The even horizon's radius grows in linear proportion to a black hole's mass, if I remember correctly.
This means that volume grows far faster than mass. Black holes with the mass of a mountain are smaller than an atom; a black hole the mass of the sun have a radius of about 3 km. More massive black holes, however, have less density. In fact, if the universe is closed (i.e. returning to a "Big Crunch"), it would be the perfect example of a very sparse black hole - transplant a sufficiently large chunk of it to a reasonably flat space, and an observer outside of the transplanted chunk would see an event horizon surrounding it.
A joint team of network specialists, consisting of employees from Cisco Systems, Hewlett-Packard, 3Com and others have located an immensive Troll Hole on the Internet, centered directly on the popular weblog Slashdot. While the presences of the hole has long been suspected, today's announcement has confirmed its status as the largest Troll Hole on the Internet.
Experts say the Slashdot Troll Hole has been continually drawing hundreds of trolls to the site for over three years. "It seems to present an incredible attractive force to individuals with an abundance of spare time," explained Michael Czekjum of the Internet Engineering Task Force. "Once drawn, they find themselves compelled to inundate comments with disguised obscene hyperlinks, single-minded knee-jerk insulting replies and vacuous first post attempts."
While today's pinpointing of the hole represents a great triumph, officials stress there is still much to learn. Early analysis seems to suggest it is expanding. Datapoints from Slashdot's founding in late 1997 show an almost complete lack of trolls. Since then, their numbers have expanded at a geometric rate. The types of individuals being attracted is also being studied. "While traditional text-based trolls are still in the majority, the past six months have seen a great increase in graphical trolls, using primitive ASCII representations," wrote Ari T'teyel of Sun Microsystems in a paper published last week. "In addition, the hole's effect on other individuals, such as karma whores, is as yet unknown."
The Troll Hole draws in
the milky way "technically" has a milk chocolate core with chewy nougat and peanuts.
scientists have triangulated it's ooey gooey goodness using several rats and a nougascope.
FluX
After 16 years, MTV has finally completed its deevolution into the shiny things network
"It is seldom that liberty of any kind is lost all at once." -David Hume
Of course, if I did that less often she might be able to think more clearly about classical mechanics...
This next song is very sad. Please clap along. -- Robin Zander