Posted by
chrisd
on from the infinite-radius-finite-diameter dept.
paradox writes "Reuters is reporting that scientists have found a massive black hole 40,000 light-years away that could change the way scientists think about black holes. The mass of this particular black hole is 14 times the mass of the sun, compared to the typical mass of 3 to 7 suns."
Potential energy source?
by
Original+O.+P.+P.
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· Score: 0, Insightful
Here's an interesting idea. It seems to me that black holes would provide a near infinite source of green (haha) power. Considering the fact that their gravitational power only increases, it is obvious that they constitute a never-ending supply of kinetic power; scientists have speculated that the black holes might be the only thing stopping the universe from eventually ending its life as a huge, diffuse gas cloud. Unfortunately, the converse is true.
A massive black hole this close to Earth would probably be quite useful in developing high energy procedures, and also as a interstellar navigational tool, since it could be use to perform very effective "gravity whip" manoevres, such as are used by NASA deep space probes.
Does anyone have any thoughts as to what sorts of usage a source of energy this large could be put to?
Re:Potential energy source?
by
jdrogers
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· Score: 2, Insightful
A massive black hole this close to Earth would probably be quite useful in developing high energy procedures, and also as a interstellar navigational tool, since it could be use to perform very effective "gravity whip" manoevres, such as are used by NASA deep space probes.
Well, thats all well and good, but it would still take 40,000 years for light to get there, let alone a probe traveling much slower. I think we can safely say this won't get much use as a gravity sling-shot anytime soon.
As far as an energy source, a black whole doesn't really offer much (that I know of) that any other mass out there would. I think we are better off trying to capture the energy of a much closer object, the sun. Hey, its green too, even if it is fusion.:-) The more exciting thing about this is that since it is relatively close, it will be easier to resolve with telescopes the miscellaneous things that go on around a black hole. We can learn a lot about how the universe works from watching how stuff falls into it and what things come shooting out from near the event horizon.
It's worth noting that the center of the galaxy is 26,000 lightyears from us, see: space.com. So 40,000 LY is not exactly nearby, as the story seems to imply.
So, don't worry about being sucked into infinitely long strings of goo just yet.
-- Mmmmmmm. Floor pie!
I've always had doubts...
by
fireboy1919
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· Score: 3, Insightful
...about extrapolated data.
How do we find stars and planets? We make assumptions about stellar phenomena and then predict other phenomena using those assumptions as long as they seem to work.
We do the same thing with everything we use. We've done the same thing with other stuff, but most of the time, we can observe a lot more dimensions of the data than we can with stellar phenomenon to make our predictions.
So I suggest that there are any number of reasons that could indicate why this answer makes sense: the model for detecting mass may be wrong, or the model of the formation of black holse, or somethinig else that I haven't considered.
At any rate, we have a long way to go to learn to understand stellar phenomena.
-- Mod me down and I will become more powerful than you can possibly imagine!
Re:I've always had doubts...
by
LMCBoy
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· Score: 4, Insightful
"How do we find stars and planets? We make assumptions about stellar phenomena and then predict other phenomena using those assumptions as long as they seem to work."
Huh? We find stars and planets by stepping outside at night and looking up. What exactly are the "stellar phenomena" that we have a long way to go before understanding?
I suppose, since you're questioning the mass determination of the black hole, you must be saying that we don't yet understand Kepler's 3rd law of motion (that is the only theory needed for the measurement). Hmm...Kepler came up with that in 1609. In 400 years, his laws have been used to: construct the first accurate mathematical model of the solar system (still in use today), predict a planet beyond Uranus (Neptune was discovered exactly where Keplerian physics said it had to be), send humans to the moon, send probes to the outer planets and beyond, and determine masses of binary stars throughout our galaxy.
In short, there's nothing in this particular measurement that requires *any* understanding of stellar physics. It's a simple application of 400-year old Newtonian gravity. If you want to question the result, I suggest looking at the systematic errors of the observations (e.g., is the inclination angle of the system known? if not, the black hole could be more massive than measured).
Oh, and the process you describe (start with an assumption, make a prediction based on the assumption, test prediction by experiment/observation, refine assumption) is called the scientific method, not "extrapolating data".
-- Liberal (adj.): Free from bigotry; open to progress; tolerant of others.
Re:Where the hell did those figures come from?
by
Anonymous Coward
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· Score: 1, Insightful
Not true. Most black holes form from large stars, and so are only a few solar masses. Then there are the supermassive ones at the centers of galaxies, that are millions of solar masses. We don't really know of any in between those two ranges.
Re:Making stars
by
Suidae
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· Score: 2, Insightful
In essence stick a very large mirror in orbit round the black hole, and when the mirror is in the right position, dump some matter into the hole. When the matter gets swallowed, you get a burst of radiation which pushes the mirror in the desired direction. As the mirror is in orbit round the black hole, the hole gets pushed along as well
Wait, why would the hole move? seems like it might move toward the incoming matter a bit, due to mutual attraction (but not very much), and the burst of radiation presumably has an 'equal and opposite' push on the hole. The radiation pushes the mirror to a higher orbit. Seems like a way to move the mirror, but I don't see how it moves the hole. Its like a solar sail but you have to throw junk into the hole to get a push.
Re:Making stars
by
Anonymous Coward
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· Score: 1, Insightful
It would cheaper to search 1 million normal stars for terra-compatible planets than it would be to do this.
Think about the force required to accelerate and slow the 3-14x the sun mass. Think about how much stronger than existing materials it must be to hang in that gravity field, and survive the inevitable radiation.
Think about it falling in if it wasn't orbiting. Think about the balance problem, of balancing millions of tons of mirror, magnified by the excessive gravity field, with an explosion. Think about how unpredictable the accretion area of a black hole must be.
Think about the mirror orbiting, so it doesn't fall in - which means you can't push against it (otherwise its orbit will change).
Think about the size of the M in the F=MA equation, and derive what you think the F might need to be.
Think about the unpredictability of energy output once you got the two together. Black hole flares and jets would keep cooking your people. The planet would shrink, and its gravity would change, thus affecting the orbits of the moons.
Given all of those problems, I suspect that it would cost more usable energy - to create and position the mirror, and throw raw material at the black hole than it would output for the purposes of living. Ie using the same energy in some sort of localised fusion reactor would probably keep more people alive longer.
Re:we could be living in one big black hole
by
junkgrep
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· Score: 2, Insightful
---On the subject of black holes, it's interesting to note that our entire (known) universe could be inside of a black hole.---
This isn't really a good way to phrase it. "Inside" is not a concept that conveys any helpful meaning about this possibility, and in fact it sort of really confuses the issue. The basic physics point is this: it looks as if an entire universe can start from just a single singularity: that our universe could have started as a result of a quantum event. Victor Sternger has discussed this idea at length.
---We'd still have to find some exotic matter or something to counteract the tidal forces, and there's time discrepancy issues to deal with, but that's a somewhat moot point.---
Moot because it doesn't seem in the least possible? This "matter" would have be so exotic that it would be unlike any "matter" that anyone has ever even concieved of before to survive the tidal forces.
Slashdot Mirror
Here's an interesting idea. It seems to me that black holes would provide a near infinite source of green (haha) power. Considering the fact that their gravitational power only increases, it is obvious that they constitute a never-ending supply of kinetic power; scientists have speculated that the black holes might be the only thing stopping the universe from eventually ending its life as a huge, diffuse gas cloud. Unfortunately, the converse is true.
A massive black hole this close to Earth would probably be quite useful in developing high energy procedures, and also as a interstellar navigational tool, since it could be use to perform very effective "gravity whip" manoevres, such as are used by NASA deep space probes.
Does anyone have any thoughts as to what sorts of usage a source of energy this large could be put to?
So, don't worry about being sucked into infinitely long strings of goo just yet.
Mmmmmmm. Floor pie!
...about extrapolated data.
How do we find stars and planets? We make assumptions about stellar phenomena and then predict other phenomena using those assumptions as long as they seem to work.
We do the same thing with everything we use. We've done the same thing with other stuff, but most of the time, we can observe a lot more dimensions of the data than we can with stellar phenomenon to make our predictions.
So I suggest that there are any number of reasons that could indicate why this answer makes sense: the model for detecting mass may be wrong, or the model of the formation of black holse, or somethinig else that I haven't considered.
At any rate, we have a long way to go to learn to understand stellar phenomena.
Mod me down and I will become more powerful than you can possibly imagine!
Not true. Most black holes form from large stars, and so are only a few solar masses. Then there are the supermassive ones at the centers of galaxies, that are millions of solar masses. We don't really know of any in between those two ranges.
In essence stick a very large mirror in orbit round the black hole, and when the mirror is in the right position, dump some matter into the hole. When the matter gets swallowed, you get a burst of radiation which pushes the mirror in the desired direction. As the mirror is in orbit round the black hole, the hole gets pushed along as well
Wait, why would the hole move? seems like it might move toward the incoming matter a bit, due to mutual attraction (but not very much), and the burst of radiation presumably has an 'equal and opposite' push on the hole. The radiation pushes the mirror to a higher orbit. Seems like a way to move the mirror, but I don't see how it moves the hole. Its like a solar sail but you have to throw junk into the hole to get a push.
It would cheaper to search 1 million normal stars for terra-compatible planets than it would be to do this.
Think about the force required to accelerate and slow the 3-14x the sun mass. Think about how much stronger than existing materials it must be to hang in that gravity field, and survive the inevitable radiation.
Think about it falling in if it wasn't orbiting. Think about the balance problem, of balancing millions of tons of mirror, magnified by the excessive gravity field, with an explosion. Think about how unpredictable the accretion area of a black hole must be.
Think about the mirror orbiting, so it doesn't fall in - which means you can't push against it (otherwise its orbit will change).
Think about the size of the M in the F=MA equation, and derive what you think the F might need to be.
Think about the unpredictability of energy output once you got the two together. Black hole flares and jets would keep cooking your people. The planet would shrink, and its gravity would change, thus affecting the orbits of the moons.
Given all of those problems, I suspect that it would cost more usable energy - to create and position the mirror, and throw raw material at the black hole than it would output for the purposes of living. Ie using the same energy in some sort of localised fusion reactor would probably keep more people alive longer.
---On the subject of black holes, it's interesting to note that our entire (known) universe could be inside of a black hole.---
This isn't really a good way to phrase it. "Inside" is not a concept that conveys any helpful meaning about this possibility, and in fact it sort of really confuses the issue. The basic physics point is this: it looks as if an entire universe can start from just a single singularity: that our universe could have started as a result of a quantum event. Victor Sternger has discussed this idea at length.
---We'd still have to find some exotic matter or something to counteract the tidal forces, and there's time discrepancy issues to deal with, but that's a somewhat moot point.---
Moot because it doesn't seem in the least possible? This "matter" would have be so exotic that it would be unlike any "matter" that anyone has ever even concieved of before to survive the tidal forces.