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Science

Scientists Find Evidence of Black Holes Sucking 161

Posted by CmdrTaco from the blinded-me-wtih-science dept.
Sawopox writes "A bunch of guys a lot smarter than I am managed to find evidence of matter being sucked into a blackhole at roughly 6.5 million mph. " Yeah, but what kinda mileage does that matter get?
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Scientists find evidence of black holes really suc More

Scientists find evidence of black holes really suc

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  • So does this mean that matter can travel faster than light? Why of course it does... :)
  • Well, if you're starting from rest (i.e. zero kinetic energy), it's actually an infinite percent increase in KE, but that wasn't my point (besides, it's the *total* energy that's increased by just 0.005%). Consider this: accelerating a 1 kg object to 0.01c will require 4.5x10^12 joules of energy. To put things in perspective, that's 1,250,000 kilowatt hours. A typical household uses around 1000 kWh per month (that's a rough figure). So the energy needed to get that 1 kg block up to 6.5 million mph could power a dwelling for over 100 years! If you ask me, that's pretty impressive.
  • Actually, gravity is merely a manifestation of the curvature of space-time (if we believe Einstein), so it is not "created" in this sense. It is "caused" (this is bad terminoligy) by the mass concentration of every piece of matter. So, yes the pen "attracts" you (meaning, that it curves space time, but not enough so that you are drawn to the curvature. Actually, you "attract" the pen far more than it "attracts" you (you have a much greater mass)

  • About the whole acceleration thing, it's a vague memory here, but apparently the object that undergoes acceleration experiences the time dialation.

    You're thinking of the twin paradox, most likely. Here it is, in one phrasing:

    Two identical twins are born on earth. One of them is placed on a spaceship and sent to a faraway planet, and then returns. During the journey, the spaceship experiences relativistic speeds.

    Now, from the reference frame of earth, the twin on the spaceship is traveling at relativistic speeds. Therefore, according to Lorentz's time dilation equation, time passes more slowly for the twin on the spaceship, and therefore when the twins are reunited, the one who traveled will be younger.

    But from the reference frame of the twin on the spaceship, the one on the earth is traveling at relativistic speed. (The earth is traveling away from the spaceship at near-light speed, from the point of view of an observer on the spaceship.) So, according to Lorentz, the twin on earth should be experiencing time dilation, and when the twins are reunited, the twin who stayed home should be younger.

    The solution to the paradox is, as you observed, based on the fact that one of the twins underwent acceleration, whereas the other did not. But I'm dredging this up out of my memory from my undergraduate physics courses, which took place a few years ago -- so I can't cite the full details.

  • light speed is actualy..... 300,000 feet per second per second.... i dont' know where ya'll are getting these other #'s....

    Speed is measured in units of distance/time. "Distance over time" -- not "distance over time over time". Your figure of 3x10^5 ft/s^2 would be an acceleration, not a speed.

    The speed of light, to 3 significant figures, is 3.00x10^8 m/s. You can convert that to whatever units you like.

  • What makes a black hole is not a certain amount of mass, just a certain amount of mass concentrated within a certain area. There's a certain critical density, you see.

    Assuming you could pack the matter tightly enough, you could make a black hole massing only a few grams or less. In fact, for practical reasons, a laboratory-created black hole probably wouldn't have much more mass than that.
    ---
  • for us 'merkins
    ---

  • according to the BIG Bang theory, the universe was once as small as a pea. All that matter in so little space = enormous gravity. And I do mean _ENORMOUS_. But then, it exploded. Gravity didn't do shit all to prevent it. I guess it was on a coffee break...


    Gravity literally didn't exist prior to the big bang (or for a short period afterwards), nor did mass.




    ---
  • Oddly enough, falling into a black hole is one of the most efficient ways to get energy out of matter (the only better one I know of being to react it with antimatter). You get something like a third the e=mc^2 energy with the black hole, compared with 1 percent-like numbers for nuclear and 1e-10 for chemical fuels.
  • Here's a slightly more technical report [bbc.co.uk] on this from the BBC if anyone is still interested.
  • anything else could account for the redshift in the matter that they saw

    I'm just a CS student, but it still sounds pretty reasonable. Element compositions and temperature determine the wavelength of light that will be emitted from the matter. For generic space debris/gasses, the spectra tend to be pretty simple, so we can determine their composition by looking at which frequencies are emitted. Overall variation from the expected wavelengths are caused by the doppler effect (red/blue shifts). (sorry for the physics lecture)

    There's really only one cause for 'bogus' redshifts: our expected wavelength for a given band isn't really the right wavelength (i.e. we think we're looking at a shifted band from helium instead of a slightly-shifted sodium band).

    This misinterpretation probably won't happen. Relative to earth, matter is moving into the black hole from all directions, one half producing redshifts, the other producing blueshifts, and the region in between producing no shifts at all.

    The region producing blueshifts (matter coming towards both us and the black hole) won't really be seen, because it's "behind" the black hole, and its light generally is absorbed inside the event horizon. But we'll still have emissions from matter moving perpendicular (no shift) and away from us (redshifted). We therefore have a background spectrum to compare the redshifts to, and can thereby rule out other sources.

    Finally, those speeds are also reasonable. Stuff that we rocket into space can travel over 100,000 mph, and we can do that with the Earth's gravitational pull (Cassini does this tomorrow). Black holes have some serious pull ;)

  • Re:Supermassive Blackholes (Score:1)

    by Anonymous Coward
    A black hole is no better at "sucking things in" than a star of the same mass, since the strength of its gravitational field at some distance is the same as that of a star of the same mass at the same distance.

    Anyway, even if a black hole had really strong gravity, that doesn't mean it would "suck in" the whole universe. Gravity is attractive, but that doesn't mean that things will always travel toward something with gravity. Planets orbit the Sun rather than falling into it, for example. (Of course, in the long term their orbits would decay.)

    If two black holes collide, you get one black hole and a bunch of gravitational waves.

  • That's where the aliens are. Better form a government committee to investigate ;)
  • black holes are just really heavy chunks of stuff. there is no other side. You just eventually smack into a chunk of stuff.
  • It won't go through the floor if you put it in orbit. You also won't have to put brakes in your car.
  • HOWEVER, if you are the terd going 99.99....% c, you could cross the universe in a sneeze, but when you got to the other 'end', time would have gone billions if not maaaaaaaaaaaany more years by..so the only things left could be ancient black holes or ?

    99.99...% of c would still take you over 4 years to get to the nearest star. Hardly a "sneeze"

    TheGeek
    http://www.geekrights.org [geekrights.org]

  • The most important question (Score:1)

    by Anonymous Coward
    Would the matter make a good beowulf cluster?
  • ahhh yeah, that sounds like it

    wooohoo i'm not completely insane :)

    glad to know my incoherent ramblings about incoherent ramblings are familiar enough to get a coherent statement out of them :)
  • Maybe it's beacuse most of my friends (and me included) learned BASIC as our first programming language. Hmm....In fact, I bet a lot of geeks learned like me, with an early version of DOS (2.0) and an Apple IIE (sorry, I was 5, I couldn't program in Binary or Hexadecimal yet!!!) learned to program BASIC.

    That's my 1/50 of $1.00 US
    JM
    Big Brother is watching, vote Libertarian!!
  • >>Yes, I've got a device that shoots out particles at damn near the speed of light - a torch ;)

    Er, your torch emits photons AT the speed of light. A flashlight would do the same thing.


  • I was wondering if anything else could account for the redshift in the matter that they saw. I don't doubt the scientists, there's just something about that I can't put my finger on that feels a little weird. Not a physicist (or a good speller), just curious.
  • The title to your reply fits your posting perfectly.... Utter BS!!!
  • Doesn't matter, its all downhill.

    the AC
  • NO,NO,NO!!! You would ripped apart (stretched) due to the gradient from the tidal forces. Oh, and don't forget exposure to high levels of radiation being emitted from the accretion disk.

  • mileage (Score:1)

    by rark ( 15224 )
    well, since the matter is powered by gravity, which is caused (created? what's the word here? I didn't major in physics ) by the matter inside the black hole and a *lot* of matter is required to create gravity, I'd think you'd get the mileage (which I'm assuming to mean miles per x amount of fuel) by dividing the mass in the black hole by the combined distance traveled by the mass of the matter being sucked into the black hole, and since there's a *lot* of mass needed to make that much gravity, it's possible that my 1980 longbed pickup gets better mileage



    I'm going to go find a life now.
  • Here in L.A. it's the Black Hoes that do the sucking! I know, a bad attempt at humor.
  • Well, since nobody else has said anything relevant,
    I bought "The Black Hole" last week, so I guess I should watch it now.

    Pope
  • I'll second that =)
  • Very slow. Light travels at 186,000 miles a second, so that in hours would be...........669,600,000 million MPH.
  • at that speed you wouldn't feel it coming. You would be crushed before you even felt yourself being pulled towards it.
  • No, I'm really not smart enough to be authoritative on this, but I'll give it a shot:

    Black holes aren't really "black." Stuff come out of them. That how they first discovered them a few years ago, by the radiation spewing out of one. If I remember correctly:

    In empty space particles and anti-particles can be created and distroyed from essentially nothing (meaning no net change). If this happens right outside the event horizon one particle escapes while the other does not. It rushes off. While interesting, that doesn't seem to be getting me anywhere.

    How about Hawking radiation? Black holes should have a non-zero temperature. Faster than light travel being possible allows radiation to escape, which is what has evidently been observed (no, I don't have a link handy). Black holes evaporate, supposedly. I suggest someone with more knowledge correct me before I inflict myself further on the general /. populace.
  • Yes, but it is scale that matters. At synchrotrons, electrons hit 5-7 9's or so (.99999-.9999999 c), and protons can be accelated to tremendous rates (a few 9's) as well. Accelerating a kilogram of matter is a vastly, vastly more difficult procedure. Think of it instead of the kinetic energy that the matter has. Each kilogram has a kinetic energy of ~1*10^13 kj. This is equivalent to combusting 10^7 moles of octane, or 6*10^5 kg of gasoline.
    I think it is about enough to vaporize one olympic size swimming pool of water. Consider, however, that a good fraction of a stars mass is accelerated, this is a number on the order of 10^30th kg, so the total energy is of the order 10^43 kJ. That _is_ alot. That is about enough to vaporize the earths ocean 10^20 times, or the entire solar system 10^10 times, give or take an order of magnitude or two
  • To observers outside the terd. Yes, it would take 4 years time to travel to the closest star. But, The terd itself would only experience a few days time because of the time compression effects at relativstic speeds.
  • The black hole should be running Windows. Then it would suck MORE.
    --
  • I dunno about that... I get better Millage per gallon rolling down a hill with the engine off than "driving" down the hill. Even if only a quater mile, the miles per gallon is 1/4/0. Division by zero is undefined, but 1/4/x as x approaches 0 is infinate. Sounds pretty good to me.
    Time flies like an arrow;
  • But it's not operating in a vacuum...
  • Whatever happened to LISA?
    It was a proposal to build a space-based zero-drag iterferometer for observing gravitational waves (eg colliding neutron stars) that would follow the Earth by orbiting at one of the La Grange points in the Earth's orbit...
  • actually, the light has no trouble moving around just as fast as ever, whether it's inside or outside the event horizon. It's just that space inside the edge of the hole is curved so badly that it spirals right into the singularity. Outside the hole, space is merely slightly curved, so that the light (when it follows the geodesic) can move away from the hole. It's not really "escaping" or even trying to. Light just follows the various "bends" in spacetime.
  • Looks like a reply to this comment got sucked into a black hole.
  • No large (star-sized) black holes emit detectable amounts of "stuff". However, in the process of falling in, dust and gas outside the hole can be heated up so much that it (the dust and gas) glows brightly, even in the X-ray spectrum. Evaporation through Hawking radiation takes place *very* slowly, and will only be significant long after all the stars have burned out.
  • Astronomers sort of know about the other extreme forms of matter. They probably already tried to eliminate those possibilities. Perhaps they calculated that the largest possible neutron star could not accelerate to that speed. Perhaps they looked for the blasts which would be caused by so much matter accumulating on the surface of a neutron star. Or they see a doppler shift away, but none toward so it's not a stream or rotating object with a corresponding approaching emission.

    I try to remember that people who deal with their area of specialty do have experience with things which are novel to me. Just last week I noticed there were two astronomical research projects with similar purposes operating independently. I was able to connect them, and left them to figure out for themselves how their differing techniques benefit both of them. They know how to do their jobs.

  • >If two black holes collide, you get one black hole and a bunch of gravitational waves. Assuming they do not collide directly. The gravitational waves are created by the black holes orbiting one another, the orbit shrinking and speeding up until they coalesce.
  • "Hawking" radiation occurs when a virtual particle/antiparticle pair reacts with strong field OUTSIDE of the black hole and becames real: they may escapes then. Such particle pair always are created and annihilated in vacuum: due to Heisenberg principlethe law of energy conservation does not hold on very small time scales.
    THis radiation is inversly proportional to the hole size (it will be very bright on ultra small holes, and it is speculated that all really small holes dissapeared this way: the act of creating a real particle out of vacuum consumes energy/mass of the hole. It was never observed, and probably will be undertectable comapred with the glow of compressed matter that is being sucked in.

    As for the article, this is not a real breaktrough - observation are not 100%
    conclusive - it just says there is a very big compact object with high mass and a very rapid accretion on it. To prove it is indeed a black hole - as predicted by theory - much more different evidence is needed. It is still an open question. Well, at least that's what I wrote in my thesis :)
  • According to my calculations, my jizz leaves my penis at 0.0000093 c.
  • Don't loose your temper - its only spelling. :-)
  • I've always known black holes suck...now there's proof! :-)
  • Is it a bug or new moderation feature ?

  • Re:mileage (Score:1)

    by Anonymous Coward
    the pen on the desk does pull you toward it, just not with enough force for you to notice... My question is, do 'thoughts' exert a gravitational force.. Is that why I keep banging my head against the wall ;)

  • Science reporting... (Score:3)

    by curril ( 42335 ) on Monday August 16, 1999 @05:13PM (#1743629)
    I always hate getting science news from the regular press because they use hyperbole to describe scientifically precise terms.

    ...direct evidence for the first time of matter being pulled into a black hole.
    Accretion disks, almost by definition, are direct evidence of matter being sucked into a massive object, black hole, neutron star, white dwarf, etc. What the article doesn't say is that accretion disks are so hot and dusty that we haven't been able to see what's going on inside them. The finding of Doppler-shifted light allows us to determine, experimentally as opposed to theoretically, the speed of matter within the disk.

    ...extremely strong gravity sucks in everything, including light.
    Light is not "sucked" into a black hole. It is red-shifted by the gravitational field. Any light that crosses the event horizon is red-shifted to undetectablity by the time it leaves the gravitational field. Light can also be "bent" by going near the strong gravitational field.

    ...gravity is so strong that nothing, not even light, can escape
    Current theory allows for Hawking radiation to escape, at a rate inversely proportional to mass. Black holes of small mass should lose energy so quickly that they explode.

    ...a million to a billion suns compressed into a tiny region.
    The "tiny region" is relative. The more massive the black hole, the greater the radius of the event horizon, and the more even the gravitational gradient at the event horizon. It is possible that our entire universe is contained within the event horizon of a gigantic black hole. Current theory has difficulty explaining what happens to matter inside the event horizon. The density of matter inside a super-massive black hole would not have to be that great.

    ...light is stretched, or red-shifted, as it speeds away from the Earth
    Light is not red-shifted as it "speeds away from the Earth", except for a very minor gravitational effect. Red (or blue) shifting is due entirely to the relative velocities of the observers.

    ...the light seemed to be moving at a clip of about 6.5 million mph...
    Since the speed of light is constant, one must assume that they mean the red-shift from the light indicated that the matter was moving along at this speed relative to "stationary" gas of the disk.

    The only way scientists have been able to ``see'' them up to now is by looking at the accretion disks
    Or by observing the wobble of a star paired to a singularity. Other, so far unsuccessful, possibilities include observing gravitational lensing effects, and gravitons.

    "How old are you in light-years?" "Why, about 30 feet."
  • actually IIRC from when my calculus based physics teacher was rambling on and on and i was generally not paying very much attention.....

    Time compression only happens when there is relative acceleration between the two frames of refrence (the 'terd' and the earth), so for the duration of the trip (at a sustained velocity one would assume), the advancement in time is the same for both frames......

    What that means, i have no idea
  • since black holes are exerting so much gravitational force, this would have to be an incredibly "rigid" city. i think impossible by any technological standard, since black holes would possess enough pull to tear apart planets and stars. now, i can lessen the criteria to naturally occurring black holes as they require immense mass to occur ... and i could theorize it is possible to create smaller ones than the natural ones, but it is well beyond us at this point.
  • Welllllllll Mabbby. You also have to consider that time would be going much slower in your pants than in your brains. So maby your head could keep up with your pants. But it's been too long sense I took my physics courses, and I don't care too look it up again. Anyone care to do the math, would time slow down relative to position to keep you intact? (Not the mention the fact that to an outside observer you would never reach the center.)

  • Re:This is utter BS (Score:1)

    by Anonymous Coward
    Bravo! That was a very well planned attempt at fooling us into believing that you actually know what you are talking about by using BIG complicated words! Nice job! You have an extremely well developed vocabulary! Sorry, but it didn't fool me, but since nobody else is going to argue with you I assume that everyone here is a computer geek who knows nothing about physics or astronomy, and yes, I am an anomymous coward, and I am proud of it!!!!!!!!!!
  • that enough people don't know what a light year is that Yahoo felt compelled to explain it in the article.
  • In this universe black holes suck; in another universe, they rule!
  • Here's a good phrase to remember considering matter and gravity: Space tells matter how to move, matter tells space how to curve.

    I think a common misconception is that the matter still has to exist at the singularity. There is no requirement. Some may describe a black hole as a point in which a certain radius, no communication can exist outside thereof. But I think the best definition of a black hole would be the set of all points in which space-time converges instead of diverges. All that is needed is the point of convergence, in which a large mass initially created. Any point traveling within the even horizon has no choice but to hit the singularity. The more mass entering curves the point of convergance steeper, but, its not the mass that may or not exist that affects the further warping. Its the mass flowing down into the black hole. To go into further detail, gravity is bound to particles by the hypothetical particle called the graviton. Further there is a field called the Higgs field that affects only particles that gravitons may attach. The Higgs field could either rule out the graviton, the graviton it, they both might exist, or neither. But the interesting thing is that the Higgs fields seems to be a more-or-less overlay of spacetime that affects the warping of space-time. It also seems that the speed of light limitation is connected to the Higgs field. The three neutrinos for example, do not appear to be connected to the Higgs field. The photon does appear to be connected to the Higgs field but not to a graviton as a photon has no mass yet is affected by gravity.

  • Re:Science reporting... (Score:1)

    by Anonymous Coward
    Your statements have problems themselves. Accretion disks are not direct evidence of matter being sucked into anything. They are evidence of matter orbiting something closely. We actually don't have many examples of "stuff falling into/onto something".

    Hawking radiation does not escape from within the black hole; it is a horizon effect.

    It's misleading to speak of anything "paired to a singularity"; we have no real evidence of singularities, and black holes are not singularities (though relativity predicts they contain them).

    We have no realistic hope of detecting black holes through graviton emissions (and I'm not even sure why you think they would be evidence of a black hole anyway). It's hard enough for us to detect gravitational waves, which would be made up of countless gravitons (if gravitons exist).

  • Well accually we guess mass of stars based upon how they affect other stellar objects. And to figure that out we have to figure out the mass of the stellar objects its affecting. Ultimatly the mass of most stars have been figured out, but honestly its alot of guess work. Pretty damn good, scientifically based guess work, but never the less alot fo guess work.
  • I forget who to attribute this idea to but here it is in a condensed form:

    You build a large city around black hole that is circular in cross-section from any particular reference around the black hole (or non existent for part-spheres). If your city is rigid enough it won't go crashing into the black hole. Now have people live in the city. Lots of trash. Fill up a cargo ship with the trash and undock it. Let the ship descend relatively close (for a ship of course) to the event horizon. At this point release all the trash (as in detaching 95% of your ship) and soar away. The important thing here is that you are travelling tangentally with the event horizon so that the trash drops off in an almost direct path to the black hole and your ship travels in an upward arc toward your space station. Once you recapture the energy of the ship (which will be VERY economical if I remember correctly) you shouldn't have too many power requirements for your city. You'll have to remember to bring in alot of materials to make alot of trash.
  • I am no scientist, but from what I hear is that the potential force that existed in singularity outweighted the gravitational force being exerted. Basically you had what was a spring that was being wound tighter and tighter until the force of that spring pushing out was greater than the force pushing in till it finally split, suppositivly the force was go great that the singularity, or whatever you want to call it, litterly turned inside out, and errupted into our universe.
  • >Wouldn't a Blackhole eventually consume
    >all the matter in its galaxy?

    I sort of doubt it since, as somebody else pointed out, the black hole would have no more mass than the stars it picked up so that stars in the arms would probably just stay in their orbits. The high energy radiation from the collisions of the matter as it got sucked in might give you more than a nasty sunburn if you were in close enough. Tidal forces might trigger novas in large suns as they got closer in which also wouldn't be too healthy.

    >And then wouldn't it start sucking in other galaxies?
    Not unless they were already on a collision course. I read something recently which gave
    me the impression that that's a relatively rare occurence nowadays with the expansion of the universe, but that it was more common in the early universe.

    >What happens when 2 blackholes collide?
    Actually, I knew Jonathan Thornburg at the University of British Columbia, while he was working on his PhD thesis with that very subject. It took him a while longer than usual to complete it but (thinking about it) maybe he was just stalling for time until the computers got fast enough to do the number crunching. Jonathan had a combined CS and Astronomy background so (he claimed due to inspiration by some AI courses he took) he created a language for describing the mathematical interactions, and then wrote a compiler for it which generated C, with loop unrolling and a few other tidbits. He also created some tools to analyze the output which created pretty pictures. This was about 8-10 years ago so my memory is a bit vague, but you could probably order a copy of his PhD thesis from the UBC library if you're really keen on it :-)

    >Do astrophysisists need to have good spelling and gramar?

    Well, UBC expected everybody to pass an english competency test after first year. The test required you to demonstrate good spelling and grammar and basic expository skills in writing a composition and a precis.

    Most of the science students got through on the first try, it was the engineers who were notorious for repeating the test 1 or more times. I am not sure how the standings were within the various science branches, or how the science faculty compared to the business or arts faculties.

    Most academics realize after a while that if you want others to read what you publish, the onus is on you to make it readable with good grammar and spelling. There aren't many jobs for astronomers outside of academe. Thus...


    Did you know that black holes have no hair?

  • True source of the information... (Score:1)

    by Anonymous Coward
    Of course, this information was actually dug up by Ken Starr as a part of the impeachment hearings...
  • Actually, the previous poster was right.

    Think of a photon bouncing between 2 parallel mirrors. Someone looking at that would count a certain number of cycles per second.

    Imagine if this contraption were on a space ship flying to the nearest star at .9999...c. An observer on earth would calculate a much different number of cycles per second.

    About the whole acceleration thing, it's a vague memory here, but apparently the object that undergoes acceleration experiences the time dialation.

    As a simpler case, picture an object traveling at the speed of light. Since nothing can travel faster, nothing in the object can move... no time. Traveling at .9999c is almost like that. Time for the object flows very slowly to an outside observer.
  • Time is relative. See my post above.

    As you approach the speed of light in a given direction, the universe also contracts in that direction.

    Relativity is very messed up. But, given enough energy, relativity does say that you can cross the universe in an infinitely small amount of time (relative to yourself).
  • I feel competent to comment on this...
    Black holes do not suck, any more than vacuum sucks. It just irritates me when people say that.

    Science doesn't suck. It blows.
  • since black holes are exerting so much gravitational force, this would have to be an incredibly "rigid" city. i think impossible by any technological standard, since black holes would possess enough pull to tear apart planets and stars.

    No problem. The key here is distance. A black holde will rip apart a star that gets too near. We are not ripped apart by distant black holes, and a city built on a ring/sphere around a black hole will do just fine with enough distance. A star-sized black hole would of course force a city-ring similiar in size to the solar system...
  • As far as I know, the Large Hadron Collider at CERN will collide two 5 TeV streams into each other. That's a lot of energy. Even older particle accelerators like the one in the facility I work at, TRIUMF [triumf.ca], can do 75% of the speed of light. BTW, TRIUMF is now home to the most intense radioactive beams facility in the world! Book your experiments now for a low, low price of only three million dollars. Space is limited.
  • well, my rough quick calculation give 0.01c, but it's still pretty fast.

    GRH
  • I believe light speed is roughly 3x10^8 m/s or 186,000 miles per sec for you non-metric wanks. :)
    - Strangely enough that comes to 6.696 billion miles per hour. I suppose the light is trying to escape and is slowly being pulled in???

    Kashani
  • er.. I mean, 669,600,000 MPH, forget the million part.
  • Light speed is 670.615.200 mph, I believe
  • eek... I mean 696.6 million. My bad.. I spent the week end in Vegas... still hung over.
  • If we could harness the energy of Black Holes, that would be one heck of a power plant. Hmmm...somebody A LOT smarter then me will have to figure out the specifics, however, it would be amazing.

    That's my 1/50 of $1.00 US
    JM
    Big Brother is watching, vote Libertarian!!
  • Modern Science (or Modem Science, for those of you that like to mispel things) continues to amaze me. They 'know' so much about black holes even though no one has ever touched them. I wonder how much of this is idle conjecture?
  • Well, we measure gas by the gallon... volume... What's the volume of a blackhole? undefined... We can just call it zero.. or perhaps for fun we could call it the schwarzschild(sp) radius (cubed and 4/3'd)... One would be infinite mileage, one would be pretty damn low.. :-)

  • Why is 6.5 Million MPH so impresive (Score:5)

    by quade]CnM[ ( 66269 ) on Monday August 16, 1999 @02:37PM (#1743664) Homepage
    some quick calulations....


    6,500,000 MPH = 2,905,760 Meters/Sec = 2.9e6

    Speed of Light = 299,792,458 Meters/Sec = 3.0e8


    if you figure this out, you get the fact that it is only traveling at less then 1% the speed of light (the theoretical limit). now lets see how Relatively stacks up agenst say a 1 kg particle.


    m=mo/sqrt(1-(v^2)/(c^2))


    This brings the relative Mass to 1.000047 kg or a ~.005% diffrence in mass. No big deal... Havent they goten particals up to 10% the speed of light before in mass accelerators.
  • I should think not much. You'd be amazed at what they can figure out about this kind of stuff just from a single picture. Astronomy is much more complicated than it first seems.

  • Okay, so it makes you insane, than what happens ? :-)

  • Wouldn't a Blackhole eventually consume all the matter in its galaxy? And then wouldn't it start sucking in other galaxies?

    How the universe will end is, I think, still an open question.

    If the universe is "closed", it will end at some point with a big crunch as everything collapses together due to gravity.

    If the universe is "open", it will continue expanding forever.

    If I remember correctly, current thinking is that the universe is "open".

    Disclaimer: I am not a physicist.

  • something with that much gravity would have to be orbiting rather fast to stay in orbit.
  • As a believer in the Heisenberg-Bohr tranquilizing philosophy I can only contest this statement. It was contrived many years ago that black holes were not actually of physical existence but of a pseudo-perceptual existence, one which could only be brought upon by an intellectual being or beings (in this case the so-called 'astronomers' who are making this claim) thinking about seeing this phenomena taking place. However if we allow for an assumption that these so-called 'black holes' really do exist, we can easily put down the statement they've made regarding 'seeing matter being sucked into a black hole', where the 'black hole' they make reference to is claimed to be 'a dense region where extremely strong gravity sucks in everything, including light'. We can do this by applying this basic principle: consolidated holes in Heisenberg antiferromagnets are always drawn towards each other at rather large distances. This goes hand in hand with the Casimir force, which further substantiates my claim, it is caused by the alteration of the quantum zero-point spin wave energy. With the deficiency of a long-range Coulomb repellency among the holes, such an inclination introduces an instability of any charge-ordered state in the dilute doping hindrance. Therefore the 'black hole' of everyday understanding can not 'suck' at more than 6 million mph, or even 3 million mp3.
  • If it was beyond lightspeed that would mean that it's mass was more than infinite because mass is proportional to energy. That can not happen without some weird Quantum physics. Besides Sucking can not happen without a complete vaccume. Ditto about the Quantum Physics. You should know that. E(nergy) = m(ass) * c(speed of light squared)
  • Nothing can ever suck without some stange act or quantum physics because "sucking" can only occur in a complete vaccume. Ditto about the quantum stuff. Geeze you guys. I know that and I am in high school.
  • Wouldn't a Blackhole eventually consume all the matter in its galaxy?

    Nope. A black hole doesn't have any more mass than the star it originally came from (plus whatever matter has been sucked in).

    Now, since stars are roughly spherical in shape, the center of mass is the center of the star, which is where the black hole is now. So once you get as far away from the black hole as the surface of the star was from its center, a black hole's gravitational pull is no stronger than that of the star itself. It's only when you get inside that radius that trouble begins.

    Naturally the radius grows as more matter gets sucked into the black hole, but nothing short of an entire planet (and even then we're talking a planet the size of Saturn) is going to change the radius by any significant amount.

    No, I'm not a physicist, by the way.
  • . I mentioned the possibility because of an experiment that hoped that two black holes in tight orbits would generate measureable gravitational waves.


    fx: Repton blinks

    I'd like to see the labratory that could conduct that experiment...

    --
    Repton.

  • well, if you think about it, with the mass of a black hole, and the gravitational pull it exerts, it would be more like the earth orbiting the black hole. This would have a tendency to cause a few problems though. first, where would the moon go (oops there went the tides) secondaly wouldent it slow down the earths rotation after a while. 48 Hour days would get old after a while....
  • Sigh. I hate it when other people show me up when I am being smug. But it in a weak attempt to salvage my self-esteem...

    Accretion disks tend to lose matter to the center from collisions and tidal effects. Generally, a hotter disk implies higher energy collisions and a greater chance that matter will fall out of orbit. In very strong gravitational fields, matter will fall in from general relativistic effects. But no, I suppose that they aren't direct evidence of matter falling into anything.

    Hawking radiation carries energy/mass away from a black hole even though it originates at the boundary, so it could be thought of as "escaping" the black hole. Or not, depending on how you look at it.

    I admit that I should not have used singularity as a synonym for black hole. I was trying to follow the journalistic practice of not overusing a term and look where it got me ;-)

    I should not have used the buzz-word gravitons instead of the more correct term gravitational waves. I mentioned the possibility because of an experiment that hoped that two black holes in tight orbits would generate measureable gravitational waves. And because it sounded cool.

    I meant to do that. I was just checking to see if anybody would catch my mistakes...
  • "I think they've managed to get particles up pretty damn close to the speed of light in some of the high-energy accelerators"

    Yes, I've got a device that shoots out particles at damn near the speed of light - a torch ;)
  • Why be scared by that? I find it frightening enough that apparently 99% of the population have bought into the idea that the year 2000 is the first year of the new decade/century/millenium, when it is actually the last year of the current decade/century/millenium.

  • TN^T users know different...


  • Technically all matter "creates" gravity (I'm with you on the create or cause thing, I have no idea). The pen on your desk attracts you too, it's just small so you don't get pulled toward it. Not important to the discussion, but details rarely are...

  • Please.... (Score:3)

    by mrsam ( 12205 ) on Monday August 16, 1999 @02:41PM (#1743687) Homepage
    matter being sucked into a blackhole at roughly 6.5 million mph.

    Please, let's not make any Monica Lewinsky jokes here, OK?
    --

  • You question is very valid... until now, there's been only conjecture.. no hard observations.
    It's going to be very difficult for them to make sure what they're looking at is actually a black hole... not a brown dwarf... of a neutron star... or whatever they call those atomically collapsed monstrosities..
    I'm guessing they're looking for a particular way in which this gas will doppler shift... something that won't follow the newtonian laws of gravity?
    Or possibly they expect this gas to actually dissappear as it enters the schwartschild radius thingy?
  • but we measure all matter by mass, and since mass and gravity are directly relational, that would strike me as the most logical way of doing it...

    of course, this is purely theoretical from someone who really has no clue anyway, but since no one else was trying :)

    (heck, I definetly get more energy-in-the-form-of-motion from burning gasoline than from relying on it's gravitational pull )

  • I think they've managed to get particles up pretty damn close to the speed of light in some of the high-energy accelerators (above 0.9c, though don't quote me on that). However, we're talking about protons and electrons here, and not a whole heck of a lot of them. It still takes a great deal of energy to reach those kinds of speeds even for a microamp electron beam, but it's no where near the kinds of energy needed to
    achieve 0.01c on a macroscopic scale. As you pointed out, the relative mass increase is pretty small, but that small increase represents a very impressive increase in kinetic energy.

  • Kip Thorne has written about this - if you have a spinning black hole, you can build a large superconducting ring around it and extract the spin energy electromagnetically (something like 29% of the hole's mass, if it's spinning at the theoretical maximum rate).

    Another way to make a power plant might be to find or make a small black hole, such that it was radiating macroscopic amounts of Hawking radiation, then feed it matter (old computer cases, AOL disks, etc.) at exactly the rate that it is emitting energy (thus keeping its temperature constant, and preventing it from exploding).

    Of course, there's always the old standby method of running a long chain around a generator shaft then dropping it into the black hole - your generator will keep turning until you run out of chain.
  • Brown Dwarfs are small, not quite big enough to become stars, type objects (maybe 50 times the size of Jupiter to about 0.08 times the size of the sun) and so wouldn't have the gravitational pull to cause those sort of speeds (and if they did they'd gain so much mass that the would become proper sdtars fairly quickly anyway).

    A neutron star is a bit more possible but again they dont have the gravitational pull talked about in the article, and again a neutron star that accreted matter in the sorts of quantities that are detectable would pretty soon collapse into a black hole anyway.

    I guess they figure out the gravitational force needed to cause these sorts of masses of gass to move at these sorts of speeds then figure out the mass of the object needed to cause that force, if its above a certain amount (100 times that of the sun?) then the object would collapse under its own gravity and become a black hole.

    Disclaimer: Some of the numbers might be wrong, I'm at work and my books are at home.

    Bil
  • Did you know that black holes have no hair?


    A quote worthy of John Archibald Wheeler, If im not mistaken.

  • Ouch you hurt my little head!!!

  • Re: Why is 6.5 Million MPH so impresive (Score:3)

    by rw2 ( 17419 ) on Monday August 16, 1999 @03:15PM (#1743712) Homepage
    Re: the subject.

    Because that speed is very different than the speed of the surrounding area and, since gravity falls off so quickly with distance, (Newton [itsnet.com] is sufficient here) the fact that the particles in question are moving so quickly is amazing.

    Re: No big deal... Havent they goten particals up to 10% the speed of light before in mass accelerators.

    I don't know the term mass accelerator, but if you mean particle accelerator then yes, they have gone faster than 10%. Much. The percentage of the speed isn't really important at the level of most detectors but it is more than 99.99%. What is measured is the energy of the accelerator, which for Fermilab [fnal.gov] is ~2TeV and in the future CERN [www.cern.ch] will run at ~7TeV. See either site for great intros to high energy physics pages.

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