# Dimension and blackhole

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From the point of view of an external observer far from a blackhole, spacetime look like streached. I readed that the time dimension is dilated and at the event horizon it is infinetly dilated. I concluded that the spaces dimensions must be infinitely contracted to conserve the canstancy of the speed of light. Am i correct ?

Also I readed that the time dimension become spacelike passed the event horizon so the spaces dimension should become timelike and there are 3 spaces dimensions so there are timelike dimension pass the event horizon. What do you think about that reasonning?

I also found that paper that speak of 3D time http://arxiv.org/PS_cache/quant-ph/pdf/0510/0510010v1.pdf

Edited by Jacques
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From the point of view of an external observer far from a blackhole, spacetime look like streached. I readed that the time dimension is dilated and at the event horizon it is infinetly dilated. I concluded that the spaces dimensions must be infinitely contracted to conserve the canstancy of the speed of light. Am i correct ?

I might have misunderstood, but I don't think what you said makes sense. The event horizon has a definitive size, and a definitive, non-zero area.

If I may correct your English, the verb "read" is irregular and the past tense is written the same as the present, but it is pronounced differently:

* "I read a book now"

* "I read a book yesterday".

Yes, English is a stupid language In the first example "read" sounds like /rid/ while in the past tense, "read" sounds like /red/.

Also I readed that the time dimension become spacelike passed the event horizon so the spaces dimension should become timelike and there are 3 spaces dimensions so there are timelike dimension pass the event horizon. What do you think about that reasonning?

I wouldn't make this sort of logical jump without at least seeing the exact text that you read. The word "timelike" means that the time+distance between two events is such that something travelling at less than the speed of light could go between these events, and "spacelike" is the opposite.

When you say that the time dimension becomes spacelike, what do you mean? When you say that the space dimensions become timelike, what do you mean?

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• 3 weeks later...

sorry i am new here, in fact a rookie in astronomy but anyway i tried to understand the 3d time but i couldnt understand how can time have 3 dimensions if it is a dimension itself in the 4d universe ? another thing how can we explain time is an event that is already here in space and we discover through living from past to present to future or is it defined by the speed of light and the distance it is traveling or in other words if we are in a place in the cosmos where there is no light (black holes) does time exist ?

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sorry i am new here, in fact a rookie in astronomy but anyway i tried to understand the 3d time but i couldnt understand how can time have 3 dimensions if it is a dimension itself in the 4d universe ?

Time does not have 3 dimensions. It never does.

another thing how can we explain time is an event that is already here in space and we discover through living from past to present to future or is it defined by the speed of light and the distance it is traveling or in other words if we are in a place in the cosmos where there is no light (black holes) does time exist ?

If there is no light, time continues to exist. I don't think I understood your first question.

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Time does have three dimensions does it not, past, present and future?

I do not know much about the theories of phyiscs (yet, i hope to though) but if i am correct about want i do know some theories need time to exist to make them work and some theories do not need time to exist to make them work. So to answer your question is hard.

Agian i do not know much so do not go by me, but i suggest opening a new thread?

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Time does have three dimensions does it not, past, present and future?

That is not usually what one means by a dimension. For example, let us take the real line and pick a coordinate system. This really just amounts to stating where "zero" is. All points to the right (stuff > 0) is positive and everything to the left is (stuff < 0) is negative. This is analogous to your past, present and future.

Note that although we can separate the real line into three parts it is still considered a one dimensional. It takes only one coordinate to describe any point.

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That is not usually what one means by a dimension. For example, let us take the real line and pick a coordinate system. This really just amounts to stating where "zero" is. All points to the right (stuff > 0) is positive and everything to the left is (stuff < 0) is negative. This is analogous to your past, present and future.

Note that although we can separate the real line into three parts it is still considered a one dimensional. It takes only one coordinate to describe any point.

Maybe what he means by past/present/future being dimensions is that the past exists as accrued change, future as range of all possible events accessible from the present, and the present as the actual energies and forces that contain the residues and potentialities of the past and future, respectively. This would be like the diagram of time that has two cones joined at their points where the present is the plane that intersects with the point between the two cones. I don't know if this model makes time any more multidimensional, but maybe it's worth thinking about.

Edited by lemur
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ajb,

You are right that is what i meant. But what i was thinking of is like the up and down part of the height dimension. Above the x axis on a graph would be positive or up and below the x axis would be negitive or down. The other two dimension of space are like this so i was thinking why can't time. On a graph above the x axis is positive or the future and below would be the past and on the x axis would be the present.

I think i may start a thread on this but what would i put this topic (time) under astronomy?

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From the point of view of an external observer far from a blackhole, spacetime look like streached. I readed that the time dimension is dilated and at the event horizon it is infinetly dilated. I concluded that the spaces dimensions must be infinitely contracted to conserve the canstancy of the speed of light. Am i correct ?

Also I readed that the time dimension become spacelike passed the event horizon so the spaces dimension should become timelike and there are 3 spaces dimensions so there are timelike dimension pass the event horizon. What do you think about that reasonning?

I also found that paper that speak of 3D time http://arxiv.org/PS_...0/0510010v1.pdf

http://www.einstein-online.info/spotlights/changing_places

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between3and26characterslon that is it! Thanks for the link

I also found that paper that speak of 3D time http://arxiv.org/PS_...0/0510010v1.pdf

In relation with that paper where the author discuss of 3D time, that the 2 extra time dimension are compact (some kind of loop) maybe inside a black hole the space dimension turn into compact dimension and the time dimension turn into an open dimension ...

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