| Black holes...help!
Posted: 1/24/2009 6:15:20 PM | I find it interesting that some scientists now believe, that there is a black hole at the center of every galaxy, and eventually, over billions of years, these galaxies start "falling" into that black hole as the stars closest to revolving around it, eventually start to get pulled in. (that's one theory anyway)
I always find this fascinating. I think the idea that black holes, are actually black spheres instead of "holes", could also make sense. | |
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| Black holes...help!
Posted: 1/26/2009 2:51:29 PM | I read a few threads and thought I'd throw-in my two bits...
A Black Hole is not exactly a 'Black Sphere,' but it basically acts like one.
The 'singularity' sits in a "bubble" of sub-space and spins.
The 'spin' makes this bubble more disk-like, like two dinnerplates back-to-back.
-think of spinning a ball of pizza dough-
If you find yourself between the "plates," you get sucked in anyways.
The tops of these "plates" form 'accreation disks' in space.
The 'accreation disks' are the Event Horizon, Ergospere and Killing Field that lead into the 'singularity' "bubble."
Seeing the 'accreation disk' depends on what vantage in space that you view them.
If you find yourself between the 'disks,' you would likelly get pulled towards them before you got into the "bubble."
This "bubble" occupies little space. But, inside is a collapsed star.
Inside the "bubble" is more volume than it appears to be from outside the "bubble."
This phennomena is 'warped space.'
Any believers?? | |
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| Black holes...help!
Posted: 1/26/2009 3:35:46 PM |
Any believers??
There are bits of truth to your list, but everything can be made more precise. First, a Schwarzschild black hole is spherical. It's the exact solution for a spherically symmetric matter distribution in a static spacetime. The type of black hole you are talking about is one which rotates. That's called a Kerr black hole. Either way, things do not get ``sucked in.'' The future of anythiing that crosses the horizon lies within the horizon, so you can't get out because you would have to go backward in time to do it.
There is no point in me trying to do this in detail, since the wikipedia article on Kerr black holes is quite good and includes some graphics:
http://en.wikipedia.org/wiki/Kerr_metric | |
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| Black holes...help!
Posted: 1/27/2009 12:55:39 PM | The Event Horizon is a threshold. Beyond that is the Killing Field. Together, the EH and KF make-up the Schwartzchild Radius. An object crossing the Event Horizon spends an instant in the Killing Field before going 'splat' into the Singularity. "Backwards in time" has nothing to do with escape from a Black Hole. In fact, there is no such thing as 'backwards in time.' The reason that escape is immpossible is because the curvature of the space beyond the Event Horizon. In other words, the Event Horizon is the threshold where space is so inwardly curved (collapsed) that nothing can escape.
On the matter of the Kerr vs. the Schwartchild Theories:
First: Both 'spin.' In "static" models things are distorted because we do not exist in a static Universe (or Multi-Verse, for that matter).
Second: Kerr's Theory matches better to what has been observed. From what I understand, these two models are not radically different or otherwise incompatible. Don't forget that Kerr's work was done years after Schwartzchild postulated his theories. | |
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| Black holes...help!
Posted: 1/28/2009 7:33:48 AM | So much theory,how is it known a black hole can suck in objects past the event horizon,is this pure theory or do we watch this with our own eyes via telescope.I have seen some very powerful telescopes in use by the scientific community but when seeing a pic of a black hole the pics I have seen are hardly even visible.
I once said at the start of this thread that why could it not be merely a gateway,such as one black hole pulls in and in perhaps another location pushes out as if they responded like currents of water or the breeze through ones home.One stated how immensely wrong I was and brought in worm holes to the conversation,which I wondered are they not also theory,why has one gone through one and came back with Polaroids .At times the debates remind me of peoples differences in major religions,meaning lots of debate but no proof.Why I remember when we all knew the world was flat,that was the consensus of the learned ,so are these black holes still pure theory,because just because we see a twinkle next to a black hole and then its gone also tells me its possible its merely behind it as if its blocked from our view.Just a humble thought,I come in peace. | |
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| Black holes...help!
Posted: 1/28/2009 8:29:59 AM | The whole reason they are called holes instead of spheres is simple once you read into what's Hawkin's explanation of how they form. Specifically the section describing the part where a star falls through it's own event horizon (center of gravity for all intents and purposes). So much mass builds up in such a unimaginably small point of space that it literally punches a hole in space (and as theorized time as well).
I never really followed well with the idea that black holes lead to white holes in another space/time (read as and or). I think they are a replication mechanism. A black hole forms and begins to take in matter/energy, but the point where that matter/energy is being collected is fixed in both spatial and chronological coordinate. Eventually the stream connecting our universe to that point is severed and it explodes into a new universe. Don't confuse that though with the stream being a tunnel backward in time, as all the matter in our universe would have moved past that point the instant it formed. This isn't to say it's an infinite cycle though, eventually the matter would be to dispersed to be collected by even ultra massive black holes. It could not even be exploding but instead be a universe at the core of the black hole, since the matter would be more tightly during the start of a universe it would make sense that more black holes could form during that time and thin it out enough for it to cool the point that our universe has. | |
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| Black holes...help!
Posted: 1/28/2009 3:43:12 PM |
The reason that escape is immpossible is because the curvature of the space beyond the Event Horizon. In other words, the Event Horizon is the threshold where space is so inwardly curved (collapsed) that nothing can escape.
Unless you are trying to say that the future pointing timelike trajectories inside the horizon all end on the singularity, then what you are saying makes no sense and contradicts your own use of the term Killing field. A Killing field preserves the isometries of the metric, which for an observer inside the horizon, means the singularity is in his future, since where the metric says it is. The singularity is NOT a location in space. It's all of space and it's located in the future of an observer who crosses the horizon. The horizon is in the past of an observer inside the horizon. You can easily see this just by looking at the interior Schwarzschild metric. Inside, the radial coordinate, r, is timelike and therefore r is the time coordinate, not a spatial coordinate.
First: Both 'spin.' In "static" models things are distorted because we do not exist in a static Universe (or Multi-Verse, for that matter).
Both do not spin. The schwarzschild black hole is the solution for spherically symmetric matter distribution in a static spacetime. (i.e., the spacetime is eternal and nothing ever changes.) Hence, schwarzschild black holes do not exist in this universe, despite being useful approximations. If you want to dispute that, write down the Schwarzschild metric and point out the term(s) containing the angular momentum.
Second: Kerr's Theory matches better to what has been observed. From what I understand, these two models are not radically different or otherwise incompatible. Don't forget that Kerr's work was done years after Schwartzchild postulated his theories.
The reason they aren't incompatible is that a Schwarzschild black hole is the limiting case of a Kerr black hole in the limit that the angular momentum goes to zero. Neither are ``theories.'' Both are the exact solutions to the field equations in general relativity for two specific matter distributions. The theory is the General Theory of Relativity. Black holes are merel a specific result. | |
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| Black holes...help!
Posted: 1/28/2009 4:34:00 PM | Still sounds like alot of differing theories, as if any of you could possibly prove your correct and since the closet believed to be a black hole from observations of strong X-ray emission is Cygnus X-1, located about 8000 light years away. Cyg X-1 being an ordinary star that is believed to be orbiting a black hole. There are other nearby candidates for black holes which include : GRO J0422+32 =V518 also A0620-00 = V616 Mon and also XTE J1118+480
So much of science and even anthropology is theories yet still the strong arguments exist,each scholar ready to disprove the other with a theory.
Mine and others opinion is no better or worse than any of yours, yet mine and other are quickly discounted as you try to prove to me using more theories and until you send something through, if there even is a through ,if there even is a hole,then the theory is nothing more than that,ones opinion,that is all.
The emission of strong X-rays could be from some other source,as if you have concrete proof on the only way to get strong X-ray emissions is ...........?
So many theories in recent history are proven as inaccurate as soon as new data disproves the former theory,I can think of dozens of examples off the top of my head.I can remember so many things taught to me as fact that actually turned out merely theory,and on some of the examples I have in the last 30 years ,ones I had been graded on only to have had modern discovery proving the theory incorrect,whether it was the nothing could exist in 800 degree water or cold fusion was absolutely impossible(progress is being made on the latter) I have found many a brilliant scholars throughout history has been shown his theory was incorrect thus making it hard to fight to passionately here.
Reminds me of when two multiple degree d doctors are put into a debate,each one author to many books,each one a leader in the same field,yet there conclusions are polar opposites.
Nonetheless theories are fascinating and its wonderful when one becomes proven and true.Think whats learned about theories is not to take them to seriously ! Even my hero Hawkins is under attack by some pretty good new theories. | |
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| Black holes...help!
Posted: 1/28/2009 5:21:51 PM | there's a few that hang out at Rosedale and Renfro
I feel their gravity for time to time ~ when I start reaching critical mass , is when their pull seems the strongest. It get so strong at times, it actually affects my automobile!
The car wants to circle the block several times, like it wanting to be sucked in!
It 's a wonder I escaped, ~ there's one in particular I have to watch out for.
Powerful stuff!
and "yes" ~ I believe you stated it well ~ I really do ~ always been an interesting topic.
This new space telescope that in the works ~ will offer many answers and I fear even more questions. I doubt if I'll be alive ~ if not ~ I'll flash you a message if I can.
Dance | |
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| Black holes...help!
Posted: 2/18/2009 1:46:08 AM | I don't think they exist. Here is why:
In order for no light to escape the total energy required for anything to escape must be infinite. Since there are no known infinite masses in the universe, light can always escape.
Relative escape velocity = sqr(2GM/r + (GM/rc)^2)/(1 + GM/(rc^2))
Where G = gravitational constant
c = the speed of light
r = is the distence from the center of M
M = mass from which to escape.
E = energy
Where E= GMm/r. The energy of two masses at distance of r between centers of gravity.
And kinetic Energy of an object to escape = mc^2/(1 - (v/c)^2) - 1.
If you think this is in error show the proof that it is wrong. | |
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| Black holes...help!
Posted: 2/18/2009 10:20:42 AM | If you think this is in error show the proof that it is wrong.
I've already done that. In addition, since the photon is massless, you can't apply an expression like, F = GMm/r^2. That expression is only suitable for a Galilean universe in which the only way to have a massless particle is for it to propagate at an infinite velocity. Your reasoning is based on hacking and patching parts of incompatible theories together. I gave you a reference to for this already. Photons propagate along null rays. Take the metric for the interior, consider rays with ds^2 = 0 and you'll discover that all future pointing null and timelike trajectories have decreasing r. That means that when you are inside the black hole, the horizon is in your past and the singularity is in your future. Unless you know how to turn around in time, your future awaits you at the singularity. | |
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| Black holes...help!
Posted: 2/18/2009 12:40:37 PM | If you think this is in error show the proof that it is wrong. I've already done that. In addition, since the photon is massless, you can't apply an expression like, F = GMm/r^2. That expression is only suitable for a Galilean universe in which the only way to have a massless particle is for it to propagate at an infinite velocity. Your reasoning is based on hacking and patching parts of incompatible theories together. I gave you a reference to for this already. Photons propagate along null rays. Take the metric for the interior, consider rays with ds^2 = 0 and you'll discover that all future pointing null and timelike trajectories have decreasing r. That means that when you are inside the black hole, the horizon is in your past and the singularity is in your future. Unless you know how to turn around in time, your future awaits you at the singularity.
No you did not. You have argued. But shown no proofs here or there.
A photon has a mass as per fh/c^2. Photons have no rest mass - the're photons. If photons didn't have mass they would not be affected by gravity. Space is bent? We think that space is bent because the path of light is bent in gravity. Are you arguing that the bending of light is not according to GMm/r^2? Again, photons have no rest mass, but do have frequency shift in garvity. Suffering a change in mass energy.
f' = f / ( 1 + GM /(rc^2)). Where if escape velocity is v, f' = f x sqr(1 - (v/c)^2)
So the mass energy of a photon changes but the speed of light remains the same.
Wave length l. l' = l x (1 + GM /*rc^2)) or l' = l / sqr(1 - (v/c)^2)
c = fl and c = f'l'
A high energy photon (gamma ray) in passing through other matter can turn into a electron (which has a rest mass) and a positron (which has a rest mass) pair. Photons have mass - but not a rest mass. | |
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| Black holes...help!
Posted: 2/18/2009 5:23:46 PM | No you did not. You have argued. But shown no proofs here or there.
Yes, I have. In fact, the post you inclded in your reply has all the information you need. Write down the schwarzschild metric and do a little arithmetic. If you're up to disputing general relativity, you ought to at least be able to understand it enough to know what the metric tells you.
A photon has a mass as per fh/c^2.
That is not a mass. That is a momentum and you cannot use it as a mass the way you are trying to use it.
A high energy photon (gamma ray) in passing through other matter can turn into a electron (which has a rest mass) and a positron (which has a rest mass) pair. Photons have mass - but not a rest mass.
If you do the calculation, you'll discover that a photon cannot turn into an e+e- pair. It requires 2 photons. I've built a gamma ray detector that performs such a conversion, so I'm very familiar with how it works. The second photon is the virtual photon from the field of a heavy nucleus, like Pb.
If you think you can get pair production from a single photon try calculating it and you'll discover you cannot conserve energy and momentum precisely because the photon is massless. | |
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| Black holes...help!
Posted: 2/18/2009 7:52:23 PM | Black holes are called in more modern terms dark stars.
A dark star is a collapsed collection of matter which has such gravitational pull that an event horizon forms. The event horizon, due to the phenomenon that gravity's strength increase exponentially based on the distance between two given objects, is the point in which the very small mass photon or light particles cannot travel past the escape velocity required to break the gravitational pull of the black hole. Hidden behind the event horizon is the singularity. As matter becomes more and more dense and warps the fabric of space and time the singularity is an estimated point of infinite curvature. Science has not yet merged the world of quantum mechanics, or the science of the nature of the universe on a sub atom scale, with the classical modern of physics. Since classical modern physics is accurate for objects with extremely large amounts of mass and quantum mechanics is very accurate for studying objects very small a merging of the two schools of physics is required in order to have a more complete understanding of what actually goes on behind the event horizon.
Black holes have been proven and detected by gamma ray bursts. This is the last sign of matter passing the event horizon. According to modern physics theories using quantum mechanics we can also detect the existence of black holes by detecting hawking radiation. Since "virtual particles" as predicted by quantum mechanics are created and annhiliate each other so quickly so as not to violate the laws of conservation of mass or conservation of energy are so common when a black hole pulls one of these "virtual particles" beyond the event horizon but the other anti particle can escape we can detect energy the anti particle's wave like function as it decays into electromagnetic radiation. Thus hawking radiation. It's quite a bit to understand and anyone that says they have an incredibly firm grasp on it is a fool. | |
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| Black holes...help!
Posted: 2/18/2009 9:03:13 PM | You know, it's amazing the half-heard facts that people take to be the whole story and get repeated in these discussions. So here's a little black hole physics from an enthusiastic amateur astronomer.
First of all, they exist and their effect has been observed. They represent a stellar evolutionary end-point in that the mass of a star has contracted to virtually infinite density and the gravity well has become so steep as to be unscalable even by electromagnetic forces - photons.
Either that, or in the case of galactic black holes, have the mass of millions of stars, again contracted to infinite density.
Stellar-mass black holes have been observed and one of the most famous ones is Cygnus X-1, a source of X rays. A star was observed spectroscopically to be orbiting another stellar mass object but that second object couldn't be observed. Two stars orbiting one another can be discerned by their individual spectra so it had to be orbiting something invisible. It was also eating mass from the visible star and emitting xrays. The original term for it was "black star" but, after Einstein, black hole came to be preferred term.
And there's numerous instances of galactic black holes. Our own galaxy's center has been observed to have stars revolving around a central mass and speeds that should have them easily flying out of our galaxy. And we're talking a region of space no larger than a few times our own solar system. The speed of those stars tell of a mass millions of times that of our sun. That can only be one thing. A black hole.
Galaxy M87 at the centre of the Coma-Virgo cluster has something that is creating a massive jet. If a black hole is eating, it would create an disc of material that was being accreted into the black hole. Conservation of motion causes the material to revolve around the event horizon before falling in. This sets up tremendous friction which generate great heat and magnetic fields which twist, collimating a giant jet of material to be shot out of either poles of the system. Black hole environments are very dynamic places.
Then there's quasars - the active center of galaxies. The brightest one is 3c 273 in Virgo. It's dim but I have seen it in my telescope. Distance: about 2 billion light years.
Oh, by the way, someone mentioned gravity. No, you don't fall at the speed of light if you fall off a chair. However, gravity waves travel outward from objects in space rotating around one another at the speed of light. That's Relativity for you. Information is restricted to c. Darn that Einstein guy! | |
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| Black holes...help!
Posted: 2/19/2009 7:06:03 AM | | Speed of mass containing particles is restricted to c however when we take advantage of particles' tendency to behave like waves and transmit them through denser mediums we increase the speed c is capable of. | |
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| Black holes...help!
Posted: 2/19/2009 11:37:00 AM | Gravitation (gravity) varies everywhere.eg anywhere on earth...there will be many instances where it not entirely equal....disregarding height...or distance from centre. All quantised matter(fields interact) slightly differently - even in theory identical.
Neutron star is a collapsed star...it will not collapse any further.
Mass is blamed on the elusive higgs boson particle - allegedly the only elementary particle yet to be discovered ( they mean vague proof by that).
Space time is never truly circular/linear so gravitation always varies, even slightly dependent on ones coordinates.
Enough evidence currently to state to say there is a super massive black hole at the centre of each galaxy...one may conclude its formation is due to being the approx centre point of a large body with mass.
best am gonna do on this one the nite
tooters of for a wine
come to think of it where did my gravity thread go :( | |
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| Black holes...help!
Posted: 2/19/2009 6:56:14 PM | When mass consisting of neutrons and protons gets completely compressed does the whole mass become in effect one giant nucleus?
What then happens to all of the electrons which would normally "orbit" the nucleus. Would there be a sphere of "orbitting electrons" surrounding the huge nucleus.
What effect would a sphere of electons have on incoming matter crossing the event horizon?
Should the incoming protons not be expelled by the negative field? | |
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| Black holes...help!
Posted: 2/24/2009 4:55:04 AM | | Because the thing is in sub-space, and the thing is spinning, it makes a vortex which manifests as a 'hole' on either end of the 'space' that this thing is at. if you collide at the middle, between these disks, you get pulled to the disk of the vortex, most of the time, before going into it. A Pulsar or a Neutron Star is more like a 'black sphere.' | |
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| Black holes...help!
Posted: 2/24/2009 5:04:50 AM | | Not an infinite mass, but a mass sufficient to 'collapse' the time-space continuem! | |
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| Black holes...help!
Posted: 2/24/2009 5:25:47 AM |
Your metric is called a Gauge Scalar.
A metric corresponds to a spin 2. A scalar is a spin 0. | |
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| Black holes...help!
Posted: 2/25/2009 1:03:29 AM | I think of black holes as being more like stars than holes or spheres.
Put a enough matter together that gravity forms it into a round shape, and you get a planet that you can see if light from something else bounces off of it. Pile on some more mass so that fusion starts and you get a star that you can see because it generates it own light.
Keep piling on more mass and eventually its gravity becomes so strong that any light it produces or gets pointed toward it gets trapped. This has the effect of making it look like a hole in space but it's really more like a big spinning mass.
How do we know there are black holes?
Near the center of our galaxy we've observed several stars orbiting a single point -- really fast. Astronomers know the mass of the stars, and how fast they are moving, so they know how much mass the object that they are orbiting must have. We can't see anything at the point they are orbiting, but we know from the theory of gravity that putting that much mass in one place means that light can't escape, so we know it must be a black hole.
Black holes are a fact, though there are some things we don't understand such as what happens inside of one. | |
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| Black holes...help!
Posted: 2/27/2009 4:34:48 PM | How many black holes could fit on the head of a pin?
Discuss
A parody on a Jesuit Examination, University of Toledo c 1500 | |
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