how does matter get to singularity???

[elpenmaster]

how does matter ever get to the singularity at the center of a black hole? since time slows down for it, wouldnt it take it trillions of decillions of googleplexians of years for the matter to ever get to the very very very center of the hole? wouldnt it take infinity for the stuff to get to the very center of the black hole? and since the univers is finite old, has anything ever gotten to the center of a black hole yet? :?

[Aale de Winkel]

I'm not up to speed with current black hole theory, so I don't know wheter ther is supposed to be a singularity at the center, but probably I think you are right nothing goes there. Probably it just shoots past to be spitten out by the white hole at the other end (as some ancient speculations suggest the black and white holes connect).

[mightymrbob]

What a fantastic number.

trillions of decillions of googleplexians of years

May "god" strike me down for saying this, but what exactly is a "white hole"? :?

[Keiji]

A white hole is sometimes believed to be the place where stuff that goes into a black hole comes out. I don't believe in white holes; rather I believe in wormholes, which are two-way.

[mightymrbob]

I see. Here's a theory. It's probably all wrong, but there you go.

If we think about black holes or singularitys as 4D, then wouldn't there be more direction for the matter to move around the singularity. Or if a singularity was 1D (i.e. just a dot) then the matter could move ana/ kata round it, or just straight through it even, to be spat out at the other end through the white hole/ other end of the wormhole... Maybe...

[RQ]

The whole idea of a white hole (given the definition) is ridiculous. A white hole is supposedly in another universe, where it's the exact opposite of ours, or at least in the respect of heat where a cold objects transfers heat to a hotter one, and not the other way around. This is supposedly the way a white hole works, since otherwise it would violate all of the laws of our universe. Instead of pulling, it infinitely pushes, and nothing can get to it, but that defies the whole idea of an object being in it, since it is there, where it supposedly cannot get, so I don't think there are white holes.
As for worm holes, they supposedly saw another galaxy M7, or something like that through a wormhole, but I don't believe in that either.

[jinydu]

how does matter ever get to the singularity at the center of a black hole? since time slows down for it, wouldnt it take it trillions of decillions of googleplexians of years for the matter to ever get to the very very very center of the hole? wouldnt it take infinity for the stuff to get to the very center of the black hole? and since the univers is finite old, has anything ever gotten to the center of a black hole yet? :?

Remember that in relativity, time is relative. That is, different observers will make different measurments of time. According to General Relativity (GR), gravity affects time.

Let's say that I am falling into a black hole (after making funeral arrangements, of course), and you are watching me fall in from a safe distance (using a sufficiently powerful telescope). To keep track of time, both of us send out pulses of light at 1 second intervals. We can analyze the situation from two reference frames:

From your point of view, as I fall towards the black hole, strange things start happening to me. The photons I send out lose energy as they escape the gravitational field. Thus, their frequency decreases according to Planck's Equation: E = hf. Also, since the frequency of light works as a kind of clock (according to Einstein), clocks on my ship will run slowly compared to your clocks. These effects become more and more extreme as I fall further and further into the black hole. In fact, there is (by definition) a (relatively) small sphere around any black hole, called the event horizon. Inside the event horizon, the gravitational field is so strong that nothing, not even light, can escape outside of the event horizon from inside. As I approach the event horizon, the redshift factor approaches infinity. That is, the (let's say) blue light I send to you, gets redsifted into red, infrared, microwave and finally radio "light". More surprisingly, I would appear to slow down almost to a stop as I approached the event horizon. For quite some time (by your clocks), you would see an almost frozen (very low frequency) image of my ship. Eventually, that image would disappear because photons would bounce off my ship so infrequently that you would not receive enough photons to build up a picture at all in a reasonable time.

However, from my own frame of reference, everything is going on normally in my ship. I don't feel at all like I'm hurtling towards my certain death (the same way you wouldn't feel anything if you jumped off a cliff and closed your eyes (assuming there was no air resistance). However, the outside universe would look very strange indeed. Everything would be blueshifted (higher frequency), as the photons from outside gained energy while falling into the black hole. Morever, your clocks would appear to run fast compared to mine (which are still running normally). As I approach the event horizon, these effects become increasingly extreme. The outside universe would appear to race forwards in time at an ever increasing pace. As I passed the event horizon (if I was still alive), I would observe all of eternity passing for the outside universe. However, by crossing the event horizon, I would seal my own fate. Once inside, the gravitational field would be so extreme that it would be impossible for me to escape. As I approached the singularity, the gravitational field on the side of my body closer to the singularity would eventually become stronger than the gravitational field on the farther side of my body. Frantically, I would curl into a ball, but this would only delay my fate. Eventually, the difference would exceed the tensile strength of my body, tearing it in half. This ripping process would continue until I had been reduced to a stream of atoms. But what lies at the actual singularity itself? Nobody knows (yet).

YES! I'm now a Realmspace Citizen! Now I'm back in my 3D home!

[RQ]

I've kinda had this interesting thought for a while:
Just suppose, that ur ship was traveling at a speed just so that u are still because it cancels out the pull of gravity. Suppose you put ur hand throught the event horizon (assuming ur right next to it).

[jinydu]

I think that would cause a gravitational amputation.

[RQ]

Lol, yeah I suppose, it would either get chopped off, but most probably you would get pulled in because I don't think most people have the courage to cut his/her hand before it's too late.

[mghtymoop]

it is common theory that nothing can ever move beyond the event horison for this is the point where infinate energy is required to escape the gravity and therefore the point at which gravity bends time in such a manner that time itself stops.
therefore it is probably possible to retain your hand but it would be impossible to ever remove it from within the horison without amputating it. however in a small black hole your hand would also be spaghettfied, but you could never feel it because the nervous signals would never be able to reach your brain because the gravity would stop the flow of the sodium ions, quite an interesting concept really.

[elpenmaster]

but all the matter in the event horizons going toward singularity right now would think that they had entered black hole a minute ago, even if they entered it billions of years ago. so if the universe is only finite in time, the universe would end before the matter actually ever got to the singularity, wouldnt it? :?

[jinydu]

As I mentioned in the previous post, time is relative!

In this case, an outside observer would never see an object reach the event horizon. However, an observer falling into the black hole would see himself cross the event horizon without detecting anything strange going on with his clock. On the other hand, he would also see an infinite amount of time pass in the outside universe. So yes, in some sense, it does take an infinite amount of time for objects to reach the event horizon (let alone the singularity), but time passes infinitely quickly for these objects!

[RQ]

Quite true moop. At least you will have the experience without pain! Well if you really have nothing to do with your left hand (assuming you're right handed), this would be quite interesting.

Hawking mentions that before an observer even has a chance to glimpse beyond the event horizon, he would be spaghetti. However the astronaut could pass the event horizon without noticing it if the radius of the star was very big (don't get confused that bigger radius means more gravity, it's just less mass per inch of space so less gravity for a bigger radius).

[elpenmaster]

so is it true that all the matter that ever entered a black hole, assuming that the univers is finite old, no matter has ever actually reached a singularity? is all that matter still falling toward the singularity, never to get there until the universe ends? :wink:

[jinydu]

so is it true that all the matter that ever entered a black hole, assuming that the univers is finite old, no matter has ever actually reached a singularity? is all that matter still falling toward the singularity, never to get there until the universe ends? :wink:

Basically, yes! All observers agree that matter will not reach the singularity before 100000000000000000000000000000000 (add as many zeroes as you like, so long as the number is finite) years pass in the outside universe. In fact, not only has the matter not reached the singularity, it hasn't even reached the event horizon!

For us, on Earth and far away from any black hole, this is because the matter is moving too slowly. For unfortunate people who are falling into a black hole, its because our clocks are moving too fast.

[mightymrbob]

Didn't Mr. Hawking just say recently that he thinks matter can actually get out of a Black Hole over time? :? If it can get out, then it must be able to get in!

[jinydu]

I think we should wait until he's published his ideas and they've been reviewed. I've analyzed things using a "classical" (ie, non-quantum) approach, the way Einstein originally formulated the theory. Things get quite a bit more complicated if you add quantum effects in, and in fact, they are not yet fully understood.

[mightymrbob]

Ah...

Well then, lets just wait!

----

<Some time later>

I have a theory. Again, it may be all wrong, but there you go.

Right. Singularities = nothingness. So if a singularity was 0D or 1D (most probably 0D) then... (continued later on in post)

Right. Alkaline has established the fact that "stuff" ina higher dimension can pass through "stuff" in a lower dimension without an entrance or exit hole, right?

So, imagine a man falling into a black hole. Time slows down for matter at this point, right? The man travels through the black hole over a MASSIVE period of time, as we've already said. The man (who is 3D) passes straight through the singularity and comes out through the white hole at the other side... :?

I don't know how valid any of this is...

Anyway, there we go.

[jinydu]

I've found an article with a bit more information about Hawking's new work. Apparently, it hasn't been fully accepted yet:

http://story.news.yahoo.com/news?tmpl=s ... lack_holes

[RQ]

Elpenmaster, I should try to clear up your questions about the black hole.
To an observer, falling in a black hole will take a finite amount of time to get to the center. Now to an outside observer, the time for him to go there is infinite, because it is as if he is gone, although we know that it will take a finite amount of time for him to get there, that last second that the astronaut who fell in the black hole will be a "hole" eternity.

By the way, quite interesting story. I hope it's true (real big fan of Hawking). I'm not gonna say I told you so about the universes, because you can't really trust what yahoo says.

[Geosphere]

Hawkings new work has the much more reasonable "stuff gets crushed and spat out" conclusion, rather than universes being created.

But no matter what happens, nothing will survive. Particularly not fleshy matter.

[RQ]

Of course, everything would be plasma, if not more broken down.

[elpenmaster]

Elpenmaster, I should try to clear up your questions about the black hole.
To an observer, falling in a black hole will take a finite amount of time to get to the center. Now to an outside observer, the time for him to go there is infinite, because it is as if he is gone, although we know that it will take a finite amount of time for him to get there, that last second that the astronaut who fell in the black hole will be a "hole" eternity.

so, then, is the logical conclusion that nothing has ever reached the event horizon of a black hole yet?

maybe somebody could skim by event horizon and when they come back the universe has disintegrated into atoms by entropy

[Geosphere]

so, then, is the logical conclusion that nothing has ever reached the event horizon of a black hole yet?

Isn't that a neat idea...

[mghtymoop]

RQ, why do you count plasma as broken down, its just superheated matter, and by being superheated it is also super excited and expands at an incredible rate, this doesn't fit with the whole black hole environment at all

[Rkyeun]

It's not so much that time slows down as that the photons themselves are being pulled back more and more strongly, so they emerge more slowly and produce an increasingly delaying image. The last photon you emit as you fall through the horizon isn't moving, ever, because its speed is precisely what it needs to be to maintain its position.
A black hole is only a sphere in three dimensions. Viewed in four dimensions it is shaped more like a funnel. It extends forever kata with a shrinking length, width, and height, and is hollow at the center like the two-dimensional surface of a funnel.
As you fall kata you become increasingly stretched in height until your feet are pulled from your head, and increasingly compressed until your shoulders wrap around the width of the universe and crush into each other on the other side. Your front and back will pull the same stunt, until you are touching yourself all the way around. And then you squish further.
If the atomic bonds could stop the compression, the star would never have ignited. If the Electromagnetic bond could stop the compression, the star wouldn't have gone nova. If the nuclear bonds could stop the compression, it would have just been a neutron star. The only fundamental force left is gravity, and it's attract only.
You will not reach the center of the hole, because just like looking down the funnel, there IS no center in trispace. In tetraspace, the shape certainly has a central axis, but the surface volume of your trispace does not go there. Your path is an infinite kata of squishing.

Time is different inside the hole. Not really faster or slower. The time dimension is also bent by the gravity of the hole, so that the future points in the kata direction. You detect no change in your own time, but as you move at a further and further right angle to your old timeline in trispace, events from it seem to slow as your kata-pointed seconds move you less future. When your time is pointing directly kata, you will cease to observe any new information from outside, as no new seconds are occurring relative to you. This creates a new timeline inside the hole. Eventually in your original threespace, the hole will appear to shrink and evaporate due to Hawking radiation, until it finally explodes. This explosion heralds a big bang for your local threespace.
With the mouth of the hole cut, your trispace unwarps and forms a new sphere. The duration of the black hole's existance in the original trispace is a line segment running from past to future. Your new timeline is a ray running from the future endpoint of that segment forevermore kata. At this point, kata becomes your future, and there is no more tetraspace distortion to call kata until the universe cools sufficiently to allow particles and non-uniformity to occur that would distort the trispace again. And your entire timeline, being perpendicular to the original timeline, occurs in its entirity during the instant at which the hole explodes.

[Rkyeun]

Oh, a few other comments and a correction.

Plasma is not the end. Being matter, that can be squished down to quarks, and that can be squished down to furious gluons/EM interactions until well, it stops mattering. Eventually one field effect will saturate it all, growing in intensity as the available size diminishes.
Nothing survives crossing the horizon. Imagine if you had a rope tied to an anchor. Now we throw this anchor in. It is experiencing rather obscene acceleration, since not even the speed of light is sufficient escape velocity. The rope will fall in cleanly until it breaks, and it will break above the horizon, because its physical bonds aren't strong enough to hold up the anchor.
When the broken rope segement gets closer, its chemical bonds will give way and it will continue falling towards the horizon atom by atom. Those break too, and so on. Only the energy of the field effects they represent may penetrate the horizon. This also happens to the anchor, and your hand. Anything else will break as it approaches and fall in. You cannot stick your hand in the horizon, because your hand will disintegrate long before it gets there due to tidal forces.

I was mistaken in my previous post about the internal shape. It is not quite a sphere. Because the center of the fourspace is hollow, there must be a similar hole in the center to conserve topology, because the 'black hole' still is there. Eventually the hole will 'pop' and that empty spot in the middle of the funnel will lance back up from infinity kata and snap closed in the original trispace, leaving the new timeline in its wake in your new trispace.

[houserichichi]

Now that's all well and good for stationary black holes, but what about rotating ones? Isn't the three-dimensional "shape" that of a 3-torus (not a funnel)???

[jinydu]

You cannot stick your hand in the horizon, because your hand will disintegrate long before it gets there due to tidal forces.

Not exactly. If the black hole is sufficiently large, it may be possible to get inside the event horizon without getting ripped apart immediately. But of course, that doesn't matter because once you've crossed the event horizon, your fate is sealed...

But of course, if it was a very large black hole, you would probably get fried by infalling matter long before reaching the event horizon...