Use this tag for dimensions of a manifold, typically the space-time. DO NOT USE THIS TAG for dimension of a physical quantity.

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How does a black hole's gravity affect other dimensions? [closed]

Given the extreme gravitational force of a black hole, can it have affects on other higher dimensions? Does it continue to warp space-time regardless of the number of dimensions? In fact, can a ...
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0answers
21 views

How to determine the size of other galaxy's/The dark matter problem

From what i understand there are two methods (well as far as i know) to determine how much mass there is in a distant galaxy. First, Luminosity. By measuring the amount of light produced from a ...
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4answers
239 views

How many legs (minimum) would a chair need in 4 spatial dimensions for you not to fall?

I was reading another post in physics.SE about chairs when this question arose. My guess is we would need more than in 3 dimensions as in 2 dimensions you would just need 2 (I think). I've been trying ...
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1answer
64 views

Theoretical implications of multidimensional Time [duplicate]

While the idea of extra spatial dimensions has been around for quite a while now, is there a possibility or any theory which proposes extra time dimensions? If so, what could be theoretical ...
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0answers
41 views

How do quantum effects scale to a 4 dimensional being?

I just finished High School a couple of weeks ago (Brazilian schedule) and my grandfather gave me a couple of books on quantum mechanics as a gift. I was reading on Heisenberg's Uncertainty ...
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5answers
88 views

Could there be a -1 dimension? [duplicate]

This might be a silly question as it just doesn't make sense to me - but could we have a dimension lower than one? Could we have a 0th dimension? Could we have a -1th dimension? Are we supporting the ...
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0answers
40 views

How confident are we that we live in a universe that has at least a 4th spatial dimension?

Modern pop culture would have us believe that there is such a thing as the 4th spatial dimension. And yes it's easily shown that $n$ dimensions is possible using math alone and 3 just happens to be ...
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3answers
98 views

Is time created by movement through a higher dimensional object? [closed]

In a comment I read on this page, someone mentions a theory where time is created by moving through and slicing "moments" of a higher dimensional object. For analogy, a 2-D creature living on a plane ...
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2answers
104 views

What is the basic concept of four-dimensions in physics?

I have been reading a few books lately and browsing the internet for an explanation on the concept of "four-dimensional" space (or, space-time, as some of them have been calling it). But, what those ...
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0answers
52 views

In Newton's gravity, is the inverse square law related to the fact that our Universe has (apparently) 3 dimensions? [duplicate]

I read, long ago, a book, whose title I can't remember but I think the author was Carl Sagan. In the book was saying that gravity follows the inverse square law because of our Universe was 3 ...
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1answer
95 views

do we live in 3.5 dimension? [closed]

After watching interstellar movie i came to know that time is 4th dimension and watch some videos and read articles which says there is there is around 10 dimension(11 also). As x,y,z are 3 dimension ...
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1answer
40 views

Nahm's theorem and related with SYM ;other theories

To study $S$-duality in more detail, i tried to read, Electric-magnetic duality and the Geometric Langlands Program. In section 2.1, there is a comment about 10d SYM. Excerpt from the paper above, ...
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2answers
232 views

Dimensional Paradox Demonstrated by Light Moving Between Parallel Mirrors

In a thought experiment, there are two parallel mirrors which are very long which also face each other. One has a hole in it and one flash from a strobe light shines into that hole. One observer in ...
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1answer
101 views

Are atoms unstable in 4+1 dimensions when quantum mechanics is taken into account?

I understand that in 3+1 dimensions according to classical physics atoms should be unstable however atoms are stable in 3+1 dimensions because the behavior of atoms is governed by quantum physics ...
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0answers
26 views

Does current understanding of EM theory provide any evidence of additional physical dimensions?

Some theories (such as variants of the String Theory) postulate the existence of additional dimensions beyond the 3 spatial dimensions. So I was thinking that if such dimensions exist, perhaps some ...
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1answer
332 views

Do multiple dimensions exist? [duplicate]

I came up with this line somewhere: To properly experience $n$ dimensions the retina of the organism should be at least of $n-1$ dimensions. And human eye has $2$ dimensional retina, so we ...
2
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0answers
47 views

What is the relation between dimension and Quantum Field Theory? How does different dimensions change QFT? [closed]

Does the quantisation rules & field operators for scalar or Dirac fields change with dimension? Most books wrote about 3 spatial dimensions, and then upgraded it to 4 spacetime dimensions, keeping ...
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0answers
62 views

Two dimensional spacetime and the Gauss Bonnet theorem

Generally two dimensional spacetimes are deemed to be static, as the Gauss Bonnet theorem implies that the Einstein Hilbert action would be a constant independent of $g$. But as far as I can tell, ...
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2answers
54 views

What is the criterion for a vector field (dim > 1) to be conservative?

We know that if the curl vanishes: $$ \nabla \times \vec{v} = 0$$ then the field is irrotational and is conservative, but what about in higher dimensions than 1? The cross product is not defined ...
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0answers
38 views

QFT decay rates in lower dimensions

My starting point is the decay of a Higgs particle into two fermions, with decay rate proportional to \begin{equation} \Gamma \propto g_\psi^2 N m, \end{equation} where $g_\psi$ is the coupling, $N$ ...
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3answers
347 views

The size of extra dimensions

Supposing we have a model, like the String one, which predicts (or requires) $N$ spacetimes dimensions, for the precision let's talk only about space dimensions. What is the process, the rule or the ...
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2answers
93 views

Is it possible to calculate the shape of extra dimensions?

According to Brian Greene it is possible to calculate the physical constants from the shape of the extra dimensions. Is it possible to do the inverse, so predict the shape of these dimensions from the ...
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0answers
64 views

can extra dimensions explain the non locality of entanglement? [closed]

This is the question of layman fascinated by quantum theory. Entanglement of particles far apart from each other (relative to the speed of light) has been addressed in some other questions where the ...
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5answers
604 views

Perception of Depths and Stereovision [closed]

I watched a video on Youtube and read a few articles which say that human beings see 3D because we have two eyes. But does that mean when I close one of my eyes, I should see 2D? It doesn't happen so. ...
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2answers
92 views

Could time have tertiary directions?

This is a late night thought, but it seems interesting enough to ask: Has anyone considered the possibility that time might have more directions that forward and backward? Could time go sideways?
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2answers
84 views

Are fundamental particles just a trajectory in spacetime? [closed]

Long time ago Wheeler proposed an idea that there is only one electron, some kind of a closed(?) four dimensional knot in spacetime, and in one particular time we slice this knot with a plane and ...
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1answer
79 views

Is each succeeding dimension time? [closed]

I have been researching but I have found nothing on this topic (at least after basic google searching and some deeper searching on this site), I'm not sure if this is a common sense thing or it is ...
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0answers
34 views

Higher dimensions and energy conservation [closed]

In popular descriptions of the the fourth dimension, e.g. this one, the following explanation is usually given: A hyperbeing can effortlessly remove things before your very eyes, giving you the ...
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2answers
91 views

How can some theories claim the existence of higher dimensions?

Note: The following question is probably demonstrating a complete misunderstanding of higher dimensions. I am by no means an expert in string theory and higher dimensions. I'm a 7th grader who ...
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2answers
73 views

How many dimensions our universe consists of?

Omnibus science convinces us in that we live within three-dimensional space. The coordinate measuring units XYZ. Quite controversial, but there are some legitimate theories clarifying why we live in ...
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0answers
41 views

What is the importance of $2d$ supersymmetric gauge theory? [closed]

I have been working $2d$ $N=(2,2)$ theories focused on checking duality like, Seiberg duality (2d version: named "Hori-Tong" duality) and its extension. During the study i got $2d$ $N=(2,2)$ ...
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1answer
31 views

What is the 'dimensionality' in solid state materials?

In the context of condensed matter physics, when it is referred to a '1D', '2D' or '3D' material, what context is this dimensionality understood in? Real space? momentum space? or something else? We ...
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2answers
98 views

Schwarzschild metric in lower-dimensional spaces

I was trying to explain the consequences of the Schwarzschild metric to someone last night and obviously it's pretty difficult to conceptualize in four-dimensional spacetime. Elementary googling has ...
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2answers
125 views

How do we know we live in 3 dimensions?

How do we know that we are really living in 3 dimensional world? We can draw 3D in a paper that is one dimension. So, maybe the world around us just looks 3D! how can we prove that we're living in 3 ...
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0answers
77 views

How do these 3D paintings work ? (See the images)

I know that our brain perceives two images from two eyes and combine them to see 3 dimensions and the 3D stuff uses this. But how this works and how can there be two images ? Thanks in advance :)
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4answers
104 views

Why do not the ripples on a pond form a 3 dimensional wave?

I can see that that the expansion of the the circles happens in a two dimensional plane. Therefore, we say that a two dimensional wave is formed. But, why cannot we count the vertical disturbance so ...
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1answer
52 views

How does the holographic principle apply to the $n$ dimensional space of String Theory?

The holographic principle is a property of string theories and a supposed property of quantum gravity that states that the description of a volume of space can be thought of as encoded on a ...
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2answers
123 views

Do physicists have idea about medium that would be required to perceive other dimensions? [closed]

For example, to sense the existence of any object, we have eyes as receiver and photons as the medium. Similarly we have ear and sound-waves to hear, nose and air to smell and skin to receive the ...
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1answer
140 views

What would be gravity in one spatial dimension? [duplicate]

First of all, I should say that I understand if this is put on hold for being unclear... but I'll try my best to make it as clear as it can get. For all the time I spent learning Newtonian Gravity ...
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2answers
187 views

Gravity in 2d space and inverse linear law

In our three-dimensional universe, gravity obeys the inverse square law. In a four-dimensional universe, gravity would be expected to obey the inverse cube law et cetera. In a two-dimensional ...
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1answer
79 views

Infinite dimensional manifolds in general relativity [closed]

In GR the concept of a manifold is very useful. However, all of these manifolds are of finite dimension. Is it possible to define a manifold with infinite dimension (ie much like Hilbert space in QM) ...
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2answers
1k views

Is it possible to generalize the Maxwell equations to higher dimensions?

The usual Maxwell equations are for 3 spatial dimensions, right? Is it possible to generalize them to 2 spatial dimensions or 4 spatial dimensions?
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3answers
1k views

How many dimensions does a singularity have?

my understanding of a singularity is that it is a 'point' in the universe with an infinite energy density. I have also read on the internet that a singularity is one-dimensional. This is a concept ...
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0answers
28 views

Does dimensionality determine the net effects of randomly oriented forces on an object?

My question relates to the orthogonality of random vectors in high dimensional space, and the relationship of random vectors as a function of dimensionality. My question can be formulated as a ...
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4answers
366 views

Speed as the fifth dimension

In spacetime there are four general dimensions, three of space and one of time. Why is it that other dimensioned qualities seem to be rarely considered as part of spacetime? For example, why isn't ...
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2answers
635 views

Circle becomes Sphere in 3d? [closed]

I was watching a movie Interstellar when it came out. Its been months but now I cant keep it inside and I must ask this question. So a guy was talking about wormhole in movie and ask the other guy ...
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1answer
126 views

How to extract depth of a pixel from an image?

I'll have a few pictures that show the same scene, but only a few things move around a little bit. Now I don't have an information about any size in real life but I'd like to extract a scaling factor ...
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1answer
184 views

Are there topological non-trivial states in zero dimension?

The periodic table of topological insulators and superconductors suggests that there can be topological non-trivial phases in zero dimension in non-interacting system with certain symmetries. A 0D ...
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1answer
87 views

Why are we not able to visualize Dimensions beyond 3 (or maximum 4 including time)?

We consciously know and feel the first three dimensions and with some thinking time as well. But according to literature like String theory etc., we have many many more dimensions. We can readily ...
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5answers
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What exactly is a dimension?

How do you exactly define what is and isn't a dimension? I heard somewhere that it is "anything you can move through" but if that is right, why wasn't time and space considered a dimension before ...