Tagged Questions

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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Is this possible to create a 1D or 2D thing in real?

We are living in the fourth dimension(time).So we can now travel through the third dimension. Now just imagine to make a 1 dimension thing, A line in real world. If I draw a line in paper with a ...
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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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What would a universe with 2 time dimensions be like? [duplicate]

In a universe with 2 dimensions of time, and 3 spatial dimensions, the equation for finding the change in time is: $\Delta T= \sqrt{(\Delta \alpha_1)^2+(\Delta \alpha_2)^2} \geq 0$ Where $T$ is the ...
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Could it be theorically posible “cut off” a piece of space-time? [closed]

I know I may not have an accurate idea of what are the properties of space-time, but here is the idea: By doing an analogy with moving from 2 to 3 dimensions, I have been wondering if in theory it ...
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How can dimensional regularization “analytically continue” from a discrete set?

The procedure of dimensional regularization for UV-divergent integrals is generally described as first evaluating the integral in dimensions low enough for it to converge, then "analytically ...
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Is most of what everything is made from in another dimension?

If there are eleven dimensions as M-Theory asserts would that mean that the majority of what we are made from exists in the seven other dimensions?
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What is the relationship between potential energy and electrical potential?

I actually always thought this was trivial, now I am not so sure. For a potential $\phi$ the potential energy is $V=q\phi$ where q is a test charge. Now I am thinking this may work differently in two ...
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2 space and 1 time dimensions [closed]

I know it is impossible to visualise a 3 space and 1 time dimensions. But what about 2 space and 1 time dimensions? Will it be like similar to 3 space dimensions or different? If different will it be ...
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Compare a normal spring and a torsion spring

Consider a torsion spring with a known spring constant $K_c$. I would like to calculate the required $K_l$ for an equivalent linear spring, which would store the same amount of energy when compressed. ...
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How exactly do superstrings reduce the number of dimensions in bosonic string theory from 26 to 10 and remove the tachyons?

In bosonic string theory, to obtain the photon as the first excited state, the ground state must have a negative mass (tachyon). By applying $1 + 2 + 3 + \cdots = -1/12$, it can be shown (in a ...
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Number of supercharges in $N\ge 1$ SUSY in $d\ge4$ dimensions

I have a couple of questions concerning supercharges and superalgebras: 1, In four-dimensions, the minimal spinor representations are Weyl spinors. These have 4 real degrees of freedom (dof). This ...
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Can quantum entanglement be a proof of a 4th spatial dimension?

What I know about quantum entanglement is almost nothing. What I know can be resumed to: "two particles created together have a correlated behaviour no matter the distance between them". This is ...
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Nanotech - zero dimensional fullerene

Not really a physics junkie, and I think this is a chemistry question, but since there's no chemistry.stackexchange.com (yet) I think here is the best place. I was just reading up on nanotech and ...
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Why time is considered a dimension?

Why is time considered to be a dimension? And the other 7 (except the 3 dimensions of space, and the dimension of time) dimensions that string theory suggests, why can't they be realized?
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Center of mass/centroid changes between 2d and 3d?

Unless I completely botched the calculation, I noticed something strange: if you find the centroid of a 2d curve, and then revolve the curve around its axis then find the center of mass, the CM is ...
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Time. Is it really a dimension? [duplicate]

I have trouble accepting that time is a dimension, in the same way that space has three dimensions. Wherever there is space and matter, it has spatial properties. You can move back and forwards in ...
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Magnetic monopole in arbitrary dimension

Assume we have D-dimensional space-time in spherical coordinates $(t, r, \theta_1, ..., \theta_k)$. We have Maxwell equations for $k$-form $F^{\alpha_1, ..., \alpha_k}$ \partial_{\mu} F^{\mu \...
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Could a 3+1 space be embedded in a 4+1 space and retain its 3+1 characteristics? [closed]

I'm confused because I can conceptualize this embedding scenario in two seemingly incompatible ways. Which of the following scenarios are possible?: 1) 4+1 space automatically enforces 4 dimensions ...
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Is there a limit in dimension?

According to wikipedia Dimension In physics and mathematics, the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any ...
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Is there an underlying reason why some forces are inversely proportional to the square of the distance? [duplicate]

This is the first time I'm studying those subjects (I'm still in high school) and my teacher couldn't give me an answer. I'm referring specially to Newton's law of gravitation and Coulomb's law of ...
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Black hole's singularity: Does it has to be multi-dimensional?

We assume that there is an infinite density at the center of a black hole. But we also know that if it was really infinite, it would apply an infinite gravitational force to masses even if they were ...
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Are path integrals integrals with countable or uncountable infinite dimensions?

Path integrals are integrals with infinite dimensions. But I recently became confused about if the number of dimensions are discrete/countable or continuous/uncountable. I always thought it should be ...
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In what ways is four dimension relevant to modern physics?

In what fields can the consideration of four perpendicular vectors be useful to making theories and models in physics? Is the concept of four dimension restricted to spatial dimensions?
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Connecting the diffusion coefficient in 2-dimensions and 3-dimensions?

Say the diffusion coefficient of the concentration of a particle in a fluid in 3-dimensions is $D_{3\textrm{d}}$. Can we estimate the diffusion coefficient of the same particle in the same fluid, in a ...
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On the c-theorem

I have been reading a few papers on CFT and AdS/CFT regarding the c-theorem and I have a few questions regarding c-theorems: a) Why is it that the c-theorem is usually considered for only unitary ...
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General Relativity, Curvature, and extra dimensions

Setup of idea I had somewhat of a thought question regarding general relativity. Consider a simple situation of a sphere and arrow. You hold the arrow and walk from the equator to the north pole. ...
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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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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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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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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 ...