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| Black holes...help!
Posted: 4/20/2007 1:03:37 PM | | Right, gravity or gravity's "force" do not "equal" the speed of light, but the speed of the expansion of a gravitational field or the transmission of changes within that field happen at the speed of light. | |
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| Black holes...help!
Posted: 4/20/2007 1:21:26 PM | | ^^ what does this have to do with the Black hole? | |
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| Black holes...help!
Posted: 4/20/2007 1:51:28 PM | | ^^ The same principles apply to a black hole's gravitational field. Where I said "star" earlier, I could just as easily have said "black hole". | |
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| Black holes...help!
Posted: 4/20/2007 8:57:32 PM | The current explanation of a black hole is that it is a collpased something with such gravitational pul that even light cannot escape.
Just a theory.
Consider a different one. Light is relative in range. We define light but we see properties of a range of strings, that display the properties of light to us, what we have defined.
It doesn't get pulled IN. Black holes are pretty much the same as suns and stars, with one difference... the properties displayed to us are a different range.. the 'dark' range' unlike the range that is displayed to us by our sun, they have a range that displays darkness and just like around every star, planet or sun, the interacting 'matter' or better yet, the properties form new balances which result in different properties. That part of the light seemingly pulled inward is just a matter of being in range of reacting with other strings around the 'black hole' and that reaction results in the appearance of light being pulled in. | |
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| Black holes...help!
Posted: 4/20/2007 11:12:56 PM | Someone on the first page pretty much nailed it with that long description about the Schwarzschild solution to the Einstein equation. The Schwarzschild solution is one of the only known exact solutions to the 10 nonlinear partial differential equations in the Einstein equation (10 because the stress-energy and Einstein tensors are symmetric in four dimensions).
Someone said black holes were first theorized back in the "1700s or 1800s" or something to that effect. This is partially true, although I can't quite remember the approximate date, but they did not accurately know the speed of light until Maxwell predicted it and experimentalists like Michelson measured it in the mid- to late-1800s. The term black hole was actually invented by John Archibald Wheeler in, I believe, 1967 or 68. He's the same guy who came up with the term 'wormhole' and the phrase, "black holes have no hair" in regards to the three and only three properties black holes have: mass, charge, and temperature.
Stephen Hawking on the other hand, is more concerned with things like black-hole thermodynamics (this is where temperature and thus entropy come in) and black hole evaporation. This is the theory someone mentioned he changed or changed his mind about. Hawking predicted that black holes can evaporate, over a time about a billion trillion times longer than the current age of the universe, for a solar mass black hole, but did not say that they themselves emit radiation. Instead, 'Hawking radiation' is caused by quantum mechanical effects in the vaccuum near the event horizon. As virtual particle-antiparticle pairs pop in and out of existence in the vaccuum (yes, it is allowed by Heisenberg's uncertainty relation), one of them occasionally crosses the event horizon and falls into the black hole. The mechanism of mass loss in the black hole is the capture of this now real virtual particle with negative energy, which causes the other particle which escapes to become real, thus creating the appearance of mass loss and its associated radiation. The smaller the black hole, the faster it evaporates.
Black holes are well-accepted scientifically now. They are not some plot device concoted by Hollywood. There is a growing body of observational evidence for these objects in binary systems with companion stars and in the centres of almost every galaxy we look at, including our own. When matter falls into a black hole, it releases gravitational potential energy equivalent to roughly 40-50% of it's mass-energy. By comparison, Hiroshima was obliterated by the conversion of ~1% of 30kg or so of uranium mas to energy, so this is a very energetic phenomenon. This is the most reasonable explanation of active galaxies and quasars, supergiant stars orbiting unseen companions which give off large amounts of x-rays, and the incredibly rapid proper motions of stars in the galactic nucleus which suggest a mass of several million suns packed into a very small region.
Also, why would it not be reasonable to assume these objects exist? There is clearly evidence for white dwarf stars, the hot ash remnants of small- to medium-mass stars, which are supported by electron degeneracy pressure (it was called fermionic exclusion pressure in this thread - electrons are fermions (spin +/- 1/2)). Also, since the discovery of pulsars (rotating neutron stars), there has been evidence of objects formed in more dramatic events called supernovae, which are supported by neutron degeneracy pressure (neutrons are also fermions). What then comes after neutron degeneracy? Some though quark degenracy at one point, as quarks are fermions (which is why neutrons are too), but this idea has lost favour in the scientific community. So what is to stop an object from collapsing if there is no outward radiation pressure, like in a main-sequence star? There seems to be nothing, and so the object collapses forever. String theory would have us believe it collapses to the size of a string but we'll have to wait to see on that one.
This is where the term singularity comes from. Essentially, it's like having a plot of something like 1/r^2 and as you approach zero it shoots up faster and faster. When you "get" to zero, you have a singularity there because, as we like to say in physics, the function "blows up" when you divide by zero. The singularity of a black hole is where time ends for all observers. The event horizon is where all futures in spacetime end at the singularity. The photon sphere is where the star's last light was emitted as it collapsed (you could actually see the back of your head here if you looked horizontally). Since photons go the speed of light in any frame of reference, they're still happily chugging away, though in incredibly warped spacetime. An observer would see the black hole (only by the backround light it blocked and bent around itself) rushing at them at almost the speed of light.
Anyways, it's late and I'm sure I've made some spelling errors, but I thought I would add my bit to this discussion. In cause you were wondering, I'm just finishing my third year of my undergrad degree in physics and I'm particularly interested in classical and quantum field theory and general relativity.
Graeme | |
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| Black holes...help!
Posted: 4/21/2007 10:44:13 AM |
The speed of light is NOT constant. It is dependant upon the medium through which it passes. For most purposes, it SEEMS constant. The actual claims are "the speed of light is constant in a vacuum" and "the speed of light is not varied relative to the speed of the observer".
If light is the fastest known speed, does the universe expand at the speed of light, can light leave the universe, or is light bound within it regardless of speed?" c isn't simply the fastest known speed, it's the fastest possible speed. Time actually slows down to keep c a constant.
No, light cannot leave the universe because light exists inside the universe. You seem to have an erronious view of what the universe actually is.
To this last question, I would argue that the universe is defined by the presence of light/electromagnetism, and space/time does not exist until illuminated. Spacetime is full and always has been. It's also expanding.
Simply, light travels faster than matter, and nothingness does not become vacuum until it is part of the universe. This means that the size of the universe could be calculated as a sphere with a radius of C times the age of the universe. This also means we could never leave the universe by travelling less than the speed of light, unless there's a back door to bypass space/time. You seem to think of the universe as this three-dimentional spehere existing in a larger three-dimensional space. This is an entirely false belief.
The universe has no edge. The universe has no center. The universe does not exist in a bigger piece of timespace (though for dimensions >n we can only speculate).
To understand how timespace exists within nth dimentional space, it might help to imagine a two-dimentional space within a three dimensional space.
Think of the universe as the surface of a ball. The ball has a limited surface area, but it has no beginning, no end, and no middle. The ball is inflating, causing the surface area to expand (timespace is expanding). No matter how fast something moved across the surface of the ball, it would never reach the "edge", nor leave the ball.. The ball has no boundries.
This is a bit off topic, but it leads me to wonder about the speed [and general nature] of electromagnetism outside of the normal vacuum of space, in environments such as singularities or black holes. We don't know what happens within the event horizon of a black hole. We don't know that there is anything outside the nth dimentional universe or not.
Can you maybe briefly explain that because I'm not sure I'm getting your drift here. You did mention that light speed is constant ....right?. But with gravity , we have to take into account that there is an acceleration that must take place for something to move faster. You are confusing the accelleration of a mass caused by the influence of gtravity with gravity itself.
The current explanation of a black hole is that it is a collpased something with such gravitational pul that even light cannot escape.
Just a theory. Theories are proven... lith the theory of bouyancy, theory of gravity, lightwave theory and theory of evolution.
It doesn't get pulled IN. Black holes are pretty much the same as suns and stars, with one difference... the properties displayed to us are a different range.. the 'dark' range' unlike the range that is displayed to us by our sun, they have a range that displays darkness and just like around every star, planet or sun, the interacting 'matter' or better yet, the properties form new balances which result in different properties. That hypothesis fails to meet obervable fact. Among other things, the fact that the force of gravity meets "c" at the event horizon (the last point electromagnetic energy can make it through) and allows us to determine the mass of the black hole in question.
The radiance of a star is not directl related to its mass... further, there's no such thing as "dark". | |
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| Black holes...help!
Posted: 4/21/2007 11:13:13 AM | Couldn't have said it better Jerry.
Can you maybe briefly explain that because I'm not sure I'm getting your drift here. You did mention that light speed is constant ....right?. But with gravity , we have to take into account that there is an acceleration that must take place for something to move faster.
No matter how you look at light, in the classical or quantum sense, it always goes the speed of light. There is no acceleration. Classically, light is an electromagnetic effect caused by accelerating charges. No matter how you accelerate the charges, they will have time-varying electric fields. Faraday's Law (one of Maxwell's equations) says that a changing electric field induces a magnetic field. But if there is a rate of change OF the rate of change of the electric field, this creates a magnetic field which also varies in time. The process continues ad infinitum and this is what we call an electromagnetic wave. The constants of the wave equation for an electromagnetic wave dictate how fast this goes. This speed is
1/(root(mu_0*epsilon_0)) where mu_0 is the permeability of free space and epsilon_0 is the permitivitty of free space. This fraction comes out to be the speed of light in a vacuum.
In the quantum case, a photon is a masless boson which is created by the electromagnetic interatcion. It makes sense that a massless particle would automatically travel at the speed of light.
Also, the equivalence principle in general relativity says that depending on your frame of reference, you could view gravity as an acceleration in one frame or vice versa. Say you jump out of a plane and neglect air resistance. You will, in your frame of reference, be weightless. In the frame of the ground, you are accelerating towards the Earth (or the Earth towards you) at 9.81 m/s/s. The same goes for astronauts on the space shuttle. They are in a gravitational field and are constantly plummeting towards the Earth, but since they revolve so quickly around the Earth, their altitude does not change and they appear weightless in their frame of reference. | |
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Posted: 4/21/2007 7:12:46 PM | And just to add to that, weightless is not the same as massless. Just making sure nobody gets confused and thinks those astronauts could instantly accelerate to the speed of light.  | |
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| Black holes...help!
Posted: 4/21/2007 8:27:22 PM | Wouldn't c be exceeded if 2 objects were moving away from each other on a straight line at anything faster than .5 c each
That is to say when viewed from each other? Or relative to each other?
Wouldn't the other object dissappear, relatively speaking?
What if three objects were moving away @ 120* to each other, or 4 @ 90*, or 5 @ 72* or even in 3d etc, speeds less than c would be needed to produce the same effect would they not?
How much does time slow down @ .5c?
How much does it slow down @ .99c?
What if the objects were travelling toward each other?
What would the doppler effect do to light waves @ speeds approaching 2 c | |
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| Black holes...help!
Posted: 4/21/2007 9:47:00 PM | All good questions.
Here, you have to look at it from the frame of one ship. If they are moving directly away from each other, which ship you consider doesn't matter. In one frame, the other ship will appear to be moving away at high speed, but no matter how fast either ships go, this speed will never exceed c. This comes out of the Lorentz velocity transformations which tell you how one velocity looks in another frame. I'd say this is where special relativity gets the most confusing, mathematically speaking.
If the ships move apart on an angle, you can redfine your coordinate system so things move in only one dimension of space. That's the great thing about special reltivity. Remember, no one frame of reference is more right than another. We could say they move apart at 120 degrees in one frame, or redefine the coodinates such that they only move apart along the line of sight of either ship. In this case, the new speeds can be calculated and then used in the Lorentz transform equations to find the relative speeds. No matter how many ships you consider, you have to find the "lay of the land" so to speak from each one, because each frame of reference has a different point of view. This is true whether ships are going towards or away from each other.
Another important thing to consider, and this is a fundamental postulate of relativity, is that the speed of light is the same in ALL frames of reference. If a ship is going 0.9999999c and send out a pulse of light in all directions, that sphere of influence will be a sphere for ANY observer.
You can calculate time dilation effects quite simply on any decent calculator. The equation is
t = (1/(root(1-(v/c)^2)))*t_0 ,
where v is the ships speed relative to you, c is the speed of light, and t_0 is the "proper time" or the time in your rest frame. The bracketed term (1/(root(1-(v/c)^2))) is usually called gamma to make calculations less messy. This is the fraction which determines time dilation and length contraction effects.
You asked what the time dilation would be for a ship going 0.5c past you was. Say the you measure 10 seconds on your watch. To the guy on the ship, that same 10 seconds actually takes t = (1/(root(1-(0.5)^2)))*10s = 11.5 seconds.
The effect is more drastic at higher speeds. In the same scenario, t = (1/(root(1-(0.99)^2)))*10s = 70.9 seconds. Relative to the observer on the ship, it takes over a minute of his time for your watch to read 10 seconds!
As for the doppler effect, I'm pretty sure that if you put in speeds of 2c, you would get a complex (imaginary) shift in wavelength. When calculating reletivistic doppler shifting, use the relative speed of the source, which you can again find using the Lorentz transformations. In general, the faster the source moves toward you, the bluer its light appears. The faster it moves away, the redder it's light appears.
One last note. It is perfectly acceptable for you to be at rest and observe two ships moving away from each other at high speeds. Say there is a space station some ways away in your rest frame and two ships leave, each going 0.75c. Relative to YOU, the ships are moving apart at 1.5c. When you consider the frame of one ship or another, you again have to consider relativistic effects. | |
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| Black holes...help!
Posted: 4/22/2007 12:28:57 AM | To specifically address this:
"Wouldn't c be exceeded if 2 objects were moving away from each other on a straight line at anything faster than .5 c each
That is to say when viewed from each other? Or relative to each other?
Wouldn't the other object dissappear, relatively speaking?"
The objects would not disappear from view from either viewpoint. Light coming from an object moving away from you inherits none of that object's momentum, so it doesn't have to "overcome" that .5c, though it would be red shifted. Also, let's say there is a lighted dot moving from side to side on that object. It seems to me that it would appear to move more slowly than if the object were not moving away from you. | |
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Posted: 4/22/2007 5:36:38 AM | Ah touché.
That's what I was alluding to when I mentioned the sphere-shaped pulse of light coming from a ship. No matter how you look at it, you'll always see light coming from it. You said it better though lol.
And yes, you can't give momentum to something which doesn't have momentum based on its mass and speed, like light. Light does have momentum from quantum mechanical effects though. | |
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| Black holes...help!
Posted: 4/23/2007 12:37:28 PM | | It is a spherical hole, think of it as the void in the center of a block of swiss cheese, the same in all directons, as opposed to a hole through a slice of swiss cheese. | |
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Posted: 4/23/2007 4:15:20 PM | | That's essentially true, except that most black holes should be expected to rotate (I left angular momentum out of the list of properties, oops :P) and so their event horizons bulge outwards, like the Earth does as it rotates. I don't know much about this but there is another event horizon for rotating black holes. Just outside the outer event horizon is a redshift surface. Apparently, if you fire particles through this region correctly, there is a way to steal energy, thus mass, from the black hole. | |
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Posted: 4/27/2007 4:27:39 PM |
http://www.cbc.ca/health/story/2000/07/20/speedlight000720.html
Scientists have finally exceeded the speed of light, causing a light pulse to travel hundreds of times faster than normal.
It raced so fast the pulse exited a specially-prepared chamber before it even finished entering it.
The experiment is the first-ever evidence of faster-than-light motion.
The result appears to be at odds with one of the basic principles of Albert Einstein's theory of relativity, that nothing can go faster than the speed of light in a vacuum, about 186,000 miles per second.
However, Lijun Wang, one of the scientists from the NEC Research Institute in Princeton, N.J., says their findings are not at odds with Einstein.
She says their experiment only disproves the general misconception that nothing can move faster than the speed of light.
The scientific statement "nothing with mass can travel faster than the speed of light" is an entirely different belief, one that has yet to be proven wrong. The NEC experiment caused a pulse of light, a group of waves with no mass, to go faster than light.
For the experiment, the researchers manipulated a vapour of laser-irradiated atoms that boost the speed of light waves causing a pulse that shoots through the vapour about 300 times faster than it would take the pulse to go the same distance in a vacuum.
Light travels slower in any medium more dense than a vacuum, which has no density at all. For example, light travelling through glass slows to two-thirds its speed in a vacuum. If the glass is altered, the light can be slowed even further.
The NEC team produced the opposite effect. Inside a chamber, they changed the state of a vapour in a way that light travelling through it would travel faster than normal.
When the pulse of light travelled through the vapour, the pulse reconfigured as some component waves stretched and others compressed. As the waves approached the end of the chamber, they recombined, forming the original pulse.
The key to the experiment was that the pulse reformed before it could have gotten there by simply travelling through empty space. This means that, when the waves of the light distorted, the pulse traveled forward in time.
The NEC researchers published their results in this week's issue of the journal Nature.
I just love it when my whacky ideas once again get proven right! | |
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Macar
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Joined: 3/15/2007
Msg: 116 | |
| Black holes...help!
Posted: 5/2/2007 12:31:25 AM |
Okay I have nearly given up with this question, however you guys seem quite informative on here and maybe you can help me:
First of all, I want you to know I am familiar with the concept of a 'black' (HOLE.)
However I cannot get my head around the concept of a black hole in space..bear with me here...
I am led to believe when picturing a black hole..as a hole..a hole in space..sureley it should be a black sphere! Not hole!?
I shall try to explain:
If I am on earth...anywhere on earth, the gravitational pull would be the same.whether in China, Australia or the Americas.
And the same would be true if I was on a neutron star..?
when a neutron star collapses...it collapses on itself...yes? and the gravitational pull would be equal..Yes?
So when a black hole is produced regardless at which angle I or an object approached the black hole...the gravitational pull would be the same? thus it would be a black shpere not hole...?
Would be grateful for your thoughts on this
I suggest 2 excellent books on this subject, and very savy to the not so informed reader. First is 'Cosmos' by Carl Sagan. It is one of my favorite science readings of all times and Im sure you would agree. The other is 'A Brief History of Time' by Stephen Hawking which goes more into depth about black holes and the universe. He is one of the best physisists of all time. (sorry for my spelling) | |
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Posted: 5/7/2007 9:17:52 PM | Pale Rider...
You are an iron worker? After that post? You are putting us on, right?
Not that your occupation means you should not have your theory - but you don't have to be that good...:) I loved the part about mass falling back on itself - if indeed it came from one central point...
Damn. I wanted to think of that first....LOL
Snaps to you from NY...
Jane | |
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| Black holes...help!
Posted: 5/9/2007 5:20:19 AM | | why singularities? I understand you can have black holes without this bizarre extrapolation of maths. Is there any reason to believe that we can get infinite density (apart from in the math) when empirical evidence (-nature!) suggests no reason for infinity? Sorry, this is a bit off-topic. | |
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| Black holes...help!
Posted: 5/13/2007 2:30:33 PM | | simply put a black hole has no space so it is not a sphere or really a hole as in a place with dimensions that some thing can fall into. It is a thing in existence that is solid mass that has no dimensions thus has no "space". Because things are attracted to mass and the mass is infinite its gravity is strong. Do not confuse mass with weight. Weight changes with gravity but not mass, mass changes gravity. I am no physicist but that is what the basics physics type have told me that makes sense to me that us peons may understand. Please correct me if I am wrong. | |
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| Black holes...help!
Posted: 5/13/2007 4:16:23 PM | I had almost forgotten about this thread. We have had some good discussion I see. One of the problems with physics and science is that when a new theory or a different theory is introduced to the field, the theory is rarely able to stand on its own merit, but rather relies on how well the individual applies himself in the community of science.
This bring me back to Jerryintampa and our conversation about big bang.
And yet you think you grasp the concept when you don't know at even the layman level what happened in the big bang?
Please Jerry, enlighten us with your theory on big bang as it seems to differ from what I learned in high school and a few interesting books I have read. Since the only other way I can interpret what you have said is that I am an idiot and you know all the answers. Please solve it for us once and for all, won’t you Jerry? | |
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| Black holes...help!
Posted: 5/13/2007 5:04:30 PM | Leif, look at it this way. (and this is only one way of looking at it.) One of the ways black holes come into existence is though the collapse of a giant star. The nuclear reactions in a star break down as the star gets old and it loses its fuel, hydrogen. This has been what keeps the star from falling in on itself in the first place, so when the fuel runs out, all of the remaining matter falls in on itself. If the star was large enough and there is enough material in the star it continues to fall in on itself until a black hole is formed.
Look at it on a smaller scale. If you were able to look at the atoms that make up your desk on a small enough scale, you would see a very large amount of space between the atomic structure. The electrons, protons and neutrons in one atom has a lot of space in it, not to mention the space between the atoms themselves, this is all held together with electromagnetism. If you were able to remove all that space between the atomic parts, push all that stuff together so there is no space between any of it, guess what, your desk would disappear. It would become so small you would not be able to see it. This is what occurs in a singularity at the heart of a black hole. All of those little guys are bunching together so there is no space between them.
Ah, but I don’t know anything... | |
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| Black holes...help!
Posted: 5/13/2007 9:02:23 PM | "No, light cannot leave the universe because light exists inside the universe. You seem to have an erronious(try spell check OK) view of what the universe actually is."
Actually your theories are valid and well thought but are just that, theories. You can't prove what is out of our sphere to detect. They have a picture of what they can detect and they think the universe is in the shape of an egg. But what is out of what telescope can detect can only be speculated. Mathematically you may find things work but that does not prove it exists. Mathematically for instance a line goes on in one direction forever. But that does not mean that it actually does.
There could be an edge to that egg of a universe they have mapped out with telescope. Beyond that quiet simple may be nothing. No depth width or height not to mention energy/mass, substance.
Take all mass and energy out of a space many might think that the complete vacuum has nothing in it but they would be wrong. There is height width and length so there is something there. Just because we can not detect anything there besides measuring its dimensions does not mean nothing is there. First something is there because we can measure the space. Also perhaps there is a substance to space that we have not found a way to detect besides measuring its dimensions.
Perhaps what the man said about light going out of the universe is not as off as it may seem to appear at first. Let’s say that out side the egg shape universe we detect, there is nothing. Not space, time, matter or energy. Now let’s say that light goes into that nothing what would happen. Perhaps as the light traveled into the nothing it created space as it went into the nothing, so that the nothing now has dimensions and becomes something. Since it has dimensions it becomes something. Then that would mean that there could conceivably be a way to make something out of nothing.
Carry it further, if it is an ever expanding universe perhaps something is being made out of nothing all the time. The universe would not be infinite but finitely growing into an infinite size. We do not know what space is really because we can not detect its substance one way or the other, empty space or substance. Because at this point we are not aware of all the aspects of empty space we could not know what effects that this new space being created by an ever expanding universe could be. Bottom line, if space could be create from nothing, then perhaps there is a way for energy/matter to be created from nothing that has not been considered.
In conclusion one could reasonably say that it is a fact that one plus one equals two. Philosophers could argue that point but let’s not get into the obscure. But so often scientist can't distinguish one plus one equals two and there are twelve Tera sand grains on the Santa Cruz beach. So often scientist want their theories to be true so they fool others and often themselves into believing it has been proven to be as true as one plus one equals two when in fact it has not and often is disproved latter. Theories lead into us finding facts but believing theories are facts suppresses others from finding facts by closing minds to new theories. | |
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| Black holes...help!
Posted: 5/15/2007 11:26:18 AM | | Just wondering....what does it mean to be "on the edge" of the Universe, or to "leave the universe" what does that mean? where is the edge of the universe? Also if light leaves the universe....where would it go?? | |
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| Black holes...help!
Posted: 5/15/2007 4:05:11 PM | Mrpalerider thank you for the explanation that us peons can understand.
“what does it mean to be "on the edge" of the Universe”
There may not be an edge to the universe. Many believe it is infinite. Long ago I heard about the paradox of the infinite. In our mind everything must have an end. But if you go in one direction and you meet an end what is on the other side. There must be something right. So it must go on for ever. But how can there be no end. Neither concept can be fully grasped. Perhaps it just ends and there is nothing. Perhaps the universe goes on forever. Also some believe if you go one step beyond the infinite thus infinite plus one, you go to the beginning.
Years ago NASA used telescopes and computers to map out the sky and everything it knows about how to detect what is stars and galaxies and how far away they are. They came up with a picture of an egg shaped known universe.
"push all that stuff together so there is no space between any of it, guess what, your desk would disappear. It would become so small you would not be able to see it."
Now I have heard similar explanation, and I am not disagreeing with you but I think for years I had a misunderstanding as a result of such explanations. When I hear singularity I get a picture of a dot on a piece of paper which actually does have dimension. Statement like so small seem to indicate that it does have some size.
Some explain it is packed together which would also indicate dimension. When people explain there is no space between the stuff in an atom they explain it like there is no empty space in an atom and that all space in the atom is occupied by stuff. Basically this gets explain as if it is a very small sphere. Even if there was a way to measure it this explanation indicates it has say .000000000000000000000000000001 micro millimeters radius sphere to pop a number off the top of my head.
But that is not what the top physicist say happens in a Black Hole. They say it is a singularity. The first dimension is length as in a line. The second dimension is length and width as in a plane. The third dimension is length width and height as in a cube. Some will say we are in the third dimension and some will say we are in the fourth dimension because time is a dimension but here we are just arguing semantics. But what is said by the top physicist is a Black Hole is a singularity which means it has no dimension.
I think this is the top misunderstanding I am reading on this thread. I keep hearing the Black Hole explained as an infinitely dense sphere. Maybe true, I guess, but if it was it would not be a singularity, it would have three very small dimensions.
So I think I get it. What I don’t get is it a infinitely dense mass that it would occupy a space, a dimension. So all dimensions, space is pushed aside to put it simply. So since it this infinitely dense mass, has no dimension/space but must have dimension that it punches a hole in dimension/space. I think I get that.
So I understand why Einstein would think that this mass would have to go some where. So I can understand why he came up with the white hole theory for the mass to come out of back into our dimension/ space in an instance. That is not that it would happen quickly but just would happen period. But why would it have to be a white hole is what I don’t get. Why could not any number of other things happen to the mass like say it get absorbed into what ever empty space is? Einstein was a very rational and logical man so there is a reason why he came up with this as what would happen but am clueless why, peon little me.
The other possibility is that every thing that makes up an atom is without dimensions. So when it collapses there is no space between it so it is without dimension. I am sure I am just ignorant but I do wonder which it is.
From what I under stand they have not found white holes so perhaps Einstein was wrong about that. Then again I hear top physicist talking about small and big black holes and I go huh. First you tell me it has no dimension thus no size and then you describe it with a word that indicates size. So I ask what do they really mean or are they just pseudo intellectuals that are brilliant at pushing numbers around but don’t really understand what those numbers really mean. I suspect when they talk about small and big they really mean greater or less effect on the world of dimensions.
But like I said I am just a peon just starting on this path of becoming a low level physicist. I have some questions from our grad students and such on this thread. I hear you talking about gravity going the speed of light. My question is what is gravity? Yeah I know it is the force that two masses cause on each other to attract. But that does not explain what it is. That just explains what it does. If it moves at the speed of light and is not just instantaneous then it is something. So once again, I ask what is it? Also what is magnetism? I hear explanations about what it does and about molecules lining up and all but what is it to cause attraction. Any how thanks for thinking you all and please never stop searching and think you got it. Because I assure you that you don’t. That goes for you also mister Hawking.
I would like to clarify a slightly miss worded concept on my last post. I described the universe as possibly being finitely growing into an infinite size”. What I meant is the universe could be finitely growing infinitely. In other words the universe would always be finite but there would be no limit on how far the ever expanding universe can expand. Just a theory like so many more. | |
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| Black holes...help!
Posted: 5/16/2007 1:42:27 PM | | Some good thoughts! Just to possibly clarify things a bit, there seem to be two different things people mean when they say "black hole". To some it is the singularity at the center, but I believe the correct definition would be "the area beyond the event horizon, including the singularity AND the space around it from which nothing can escape". | |
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