Blackholes

[Paradox]

So how can a blackhole be in space? I've seen the drawings of how it's supposed to be like a tunnel, and that it has that event horizon, which is like the edge of the blackhole. But if it is like a tunnel, then could you see it from the side, sort of like the side of a pipe? I know you can make a hole in the ground, but that's just the earth's 2 dimensional surface. How does a blackhole, or any hole or tunnel exist in 3 dimensional space without you being able to move along the side of the tunnel? Can you only be pulled into a blackhole by going past it's event horizon? Sorry if I'm not making much sense, but I'm a bit confused.

[Zingu]

A black hole is not actually "black" ;) .


To think about black holes and our universe, think that you are an intelligent, blind ant on a flat elastic surface. This surface is your whole universe. Now suppose there is a rock place on this sheet. You are a blind ant, so you cannot know that there is this rock that warps the sheet.
So, you set out and explore the sheet, you find this indentation in the sheet, and are puzzled, you walk around the circular edge of this indentation, measureing that the circumfrence is 30 meters. Now according to Euclidian geometery. You predict a diameter of 10 meters.

Now you realize that your 2-d space is warped, extremely warped.

This is a good explination of black holes, applied to 2-d enviroments instead of 3-d, since it is impossible for us to visiualize 4 dimensions, but we still can understand them. We can think of the 3-d space inside and around the "black hole" warping this 3-d space into higher-dimensional flat space (called "Hyperspace").

The odd thing is, if you fell into a black hole, there is no way to get back out or send signals to the people outside.

The "Horizon" is the point when it is no longer possible to send signals back, the horizon, according to Einstein's equations, the flow of time slows down near the hole itself at this horizon/edge. Time gets so warped at this point that it starts to flow in a direction that would regullary be spatial; meaning the future flow of time is being pulled towards the hole's center itself, meaning nothing can move backwards in (space-)time.

So if I fall down this hole, all my signals sent would be dragged down with me with the flow of time, because if it would try to go back out the black hole, it would be going backwards in time; get it?

There is an other property of this black hole, other than bending of space-time and the slowing down and adverting the flow of time; there is one more thing black holes do to space-time.
A hurricane whirl of space-time around the hole's horizon. Like a tornado almost, expect much slower, the closer to the core, the faster. But, near the horizon, the whirl of space-time is so fast that it drags all objects that come near the whirling motion, no matter how hard to fire your engines, once you are near the horizon, you cannot escape,

why? Simple; the flow of time is warped to go in that direction towards the black hole's gaping singularity.

I think thats enough for now.... I'll write more later once I think about it.

[Paradox]

This is a good explination of black holes, applied to 2-d enviroments instead of 3-d, since it is impossible for us to visiualize 4 dimensions, but we still can understand them. We can think of the 3-d space inside and around the "black hole" warping this 3-d space into higher-dimensional flat space (called "Hyperspace").

So then a "black" hole is 4 dimensional? It's not like a tunnel that you get sucked into?

Let's compare a black hole to a pipe (don't know if this is a good comparison, but it's all I can come up with). Let's say that the hole at the end of the pipe is it's event horizon. If we are standing alongside of the pipe, we cannot get into the pipe. If we want to get into the pipe, we have to walk alongside the pipe to it's end and go inside the hole, in other words, the event horizon. What I was asking was if this is possible with a black hole. Can we travel alongside the tunnel (like the side of the pipe) of the black hole til we reach the end where the hole (event horizon) is? But if a black hole is 4 dimensional, then I guess that wouldn't be possible.


the flow of time is warped to go in that direction towards the black hole's gaping singularity.

Doesn't time end at the singularity? Isn't it like the opposite of the Big Bang?


A hurricane whirl of space-time around the hole's horizon. Like a tornado almost, expect much slower, the closer to the core, the faster. But, near the horizon, the whirl of space-time is so fast that it drags all objects that come near the whirling motion

Is that the thing they call the ergosphere? And it sucks up gases from nearby stars, and so you can see the gases whirling?

If it sounds like I have some knowledge on this topic it's cuz I got a book from the library. :D It's called Black Holes, Wormholes, and Time Machines, have you read it? Pretty interesting stuff.

[Dyst]

it is impossible for us to visiualize 4 dimensions
Hardly. Look out the window. Time is also considered a dimension, therefore, we know of four dimensions.

[Zingu]

Originally posted by [email protected] 10 2005, 05:37 PM

Hardly. Look out the window. Time is also considered a dimension, therefore, we know of four dimensions.
If you were able to see 4th dimensional, you would be able to visualize what this object is judging by its shadow a 4th dimensional "hypercube".

http://home.wlu.edu/~whaleyt/classes/parallel/topics/dmnet/hypercube.jpg

Well, can you?

[Se7en]

you people are making my head spin! space and all it encompasses is just simply amazing. i would love to read a basic intro book to such things as i've never really studied it. any suggestions?

[Zingu]

"The Future of Spacetime" or "Hyperspace" are good starting books.