Dimensions Definition and 1000 Threads

Hi everybody, I've a started a little a game, it is based on the nokia game snake, where you have to guide the snake and eat the food. I wrote a little script in python, and a C++ version of the game but in 4 spatial dimension. The snake moves through a euclidean 4 space. what do you...

Hello all, I understand that the taylor expansion for a multidimensional function can be written as f(\overline{X} + \overline{P}) = f(\overline{X}) + \nabla f(\overline{X}+t\overline{P})(\overline{P}) where t is on (0,1). Although I haven't seen that form before, it makes sense...

What are the dimensions of tension? What are the dimensions of linear mass density? Thank you!

I would really appreciate some help with this! h= (L) r=(L) p=(ML-3) g=(LT-2) I just don't know what to do with the directly proportional sign. Should I isolate the surface tension before or after adding the constant?

Hi. I am lost in this problem. Could someone tell me what to do. How to start with the problem?

Ship A is located at 4 km north and 2.5 km east of ship B. Ship A has a velocity of 22 km/h toward the south, and ship B has a velocity of 40 km/h in a direction 37 degrees north of east. (a) What is the velocity of A relative to B in unit-vector notation with i toward the east? (b) Write an...

Let us consider the metric given by the following line element: {ds}^{2}{=}{dr}^{2}{+}{r}^{2}{(}{d}{\theta}^{2}{+}{Sin}^{2}{(}{\theta}{)}{d}{\phi}^{2}{)} For a particular value of r we have two independent coordinates in the embedded surface--and the surface has been embedded in a 3D space.For...

Hi guys, this is my first post/thread, so I'd like to start with an easy one:rolleyes: I've searched the web and I wasn't able to find a satisfying proof of the fact that Lorentz contraction is NOT applied to the dimensions, that are not parallel to the direction of motion (e.g...

In the book Applied Physics by P.K.Mittal, on page#25 under the heading of "Bravais lattice in two dimensions", a paragraph says, "The number of point groups in two dimensions is 10." My 1st question is, Then how many in three dimensions? Paragraph further says, "10 groups in two...

Homework Statement A cylinder of height 45mm and radius 12mm is placed inside a circular cone. What are the dimensions of the cone with the smallest volume to enclose this cylinder Homework Equations v=1/3(pi)r^2h v=(pi)r^2h SA=2(pi)rh The Attempt at a Solution I substuted values...

Introduction The premise that our universe might have more spatial dimensions than the three that are immediately apparent is so widespread and popular that it is nearly accepted already as a fact despite the absence of evidence. This is primarily the result of two separate influences: the...

What is the study of higher dimensions called? What I'm referring to are hyper cubes and such. I finished basic math this past year (calc123, ode and linear alg) and I really want to learn the calculus of higher dimensions. Does a field like this exist?

Homework Statement Find 2 more orthonormal polynomials on the interval [-2,1] up to degree 2 given that the first polynomial p(x) = 1/√3. ( Note: Take the highest coefficient to be positive and enter your answer as a decimal.) Homework Equations This is a web assign equation so the answer...

General relativity states that our universe is four dimensional curved space so time dimension is not separated from space dimensions .Why then is the time dimension different from the 3 space dimensions ? and why there must be 3 space dimensions and not 4 for example ?

"Kaluza-Klein theories in twelve dimensions" ... and F-theory This is a separate thread to discuss another idea by arivero, originally https://www.physicsforums.com/showthread.php?t=485247&page=4#63". Some references: http://www.sciencedirect.com/science/article/pii/0550321385902329" )...

what do dimensions physically signifies? how does they affect the space/time?

https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=ySBaYMESb8o How can they predict anything after dimension 7? Especially the part where they go from dimension 8 to 9. Isn't everything in that dimension supposed to be in-explainable by the our science and minds? And isn't...

So I'm sure everyone here knows of the basic spatial dimensions. 1D is a line, 2D a plane and 3D a cube. There is even a 4th dimension (theoretical), the tesseract. And an infinite number of dimensions beyond, represented by various hypercubes. Finding the space taken up by one of these objects...

I would like to know which calculations to use to determine the dimensions, including the thickness of square tubing that needs to carry a load of 6 bicycles each weighing 18kg. The bicycles are vertically suspended from the tubing and the support is in the middle of the tubing so the ends are free.

Hi, I am a sculptor working with glass. I have come to this forum for some information. Several years ago I read an article on sting/M-theory that gave a description of one of the possible shapes the the 7 compact extra dimensions of m-theory. I have been unable to find the article again. I...

I have a question, and I hope I can word it correctly. Say I have a round pipe of length 5 feet (actually, the length is irrelevant). I want to bend it at a certain radius in the horizontal direction, and also a certain radius in the vertical direction. Let's say I bend it at 20' horizontal...

I really like it, but haven't seen any good, simple descriptions of it! Is there any place to get just the overall gist of it?

Is it correct to say that the three space dimensions are no more physically (as in materially) real than the time dimension, but that only the mass that exists in the dimensions are real in a material sense? I have a suspicion that why som people insist that time (and spacetime) does not exist...

A ball is kicked from 12 m high traveling horizontally at 1.3 m/s. How would the horizontal motion affect the vertical motion and why?

Hi how, in my master project I am working on extra dimensions and I am asking my self why is it common to start most of the theories with a space time symmetry given by SO(n,1) (n>4) and then compactify the obtained spectrum to SO(3,1)xG (where G is an abitrary symmetry group). Because...

"Most physicists do not recognize temperature, Θ, as a fundamental dimension of physical quantity since it essentially expresses the energy per particle per degree of freedom, which can be expressed in terms of energy (or mass, length, and time). Still others do not recognize electric charge, Q...

Could hidden dimensions help "hidden variable theories"? Could extra unobserved dimensions be of use in finding a hidden variable type theory that also satisfied Quantum Theory? Thanks for any help!

I'm doing some work with neural networks lately and I'm having trouble with this seemingly simple equation. The equation describing the network is: y = \psi(W3 x \psi(W2 x \psi(W1 x I))) Where: y (scalar) is the output value W1 (2x2 matrix) are the 1st layer weights W2 (2x2 matrix) are...

I am not a scientist just an observer and enthusiast. We have 3 spatial dimensions and one dimension of time. What I have been wondering is... could time have more than one dimension? I mean we percieve time as a continuous line, but can time move in other ways that we cannot percieve, like...

Dear all, I feel this should be a simple problem but I can't solve it. Could you give me a hand? Imagine if an arc is bounded by a rectangle of dimensions width and height. The arc starts in the bottom left corner of the rectangle, and ends in the bottom right corner. The apex of the...

Hi all, I've got this problem (which is attached as q1.jpg). I've tried to solve it, but I'm stuck... my solution is also attached (my_sol1.jpg). PLS help me :-( Thnx TED

Why is it that things appear smaller the farther they are away and bigger the closer they are away? It is almost as if the magnitude of their dimensions (length, width, and height)changes. But in reality it is still the same object. My cup x distance closer to me than the door may appear 1/6th...

Alrighty, I'm working on a three dimensional physics simulator that does every operation in spherical coordinates and vectors, and I'm stuck on figuring out elastic collisions. are elastic collisions essentially trading momentum between the two colliding bodies? I'm assuming not, but i can't...

Sorry for the trivial question. But I'm not a physics student by training and I think I running into problems due to interchanging metrical systems. S = E \times H E \equiv \frac{N}{C} H \equiv \frac{N}{A \cdot m} Also, is there any standard operator for denoted dimensions...

obviously in one coordinate neighborhood it can't.. I'm thinking of a line which smoothly develops into a surface : -----<< what particular properties would this object have.. Thanks :)

Homework Statement Calculate basic dimensions of power using MLT notation. 2. Given information: E= P*t E= .5*mass*velocity^2 The Attempt at a Solution Rearranging E=Pt to P=E/t a) P = (.5 mass * velocity^2) / seconds * seconds^2 b) P = (.5 kg * metres^2) / seconds^3 c) moving to one line...

When physicists talk about 4+ dimensional space are these real spatial/temporal/something dimensions or just mathematical constructs that are the only known way to accurately describe the observed behavior? Take the flatland example... We live on a 2D Plane and see a 3D Object (say a sphere)...

Homework Statement A charge q1 = 5uC is placed at (x,y,z):(1,2,-1). A charge q2 = -2uC is placed at (x2,y2,z2):(-2,1,3). Determine the electric force (vectorized form) exerted on q1. Homework Equations F12= kQ1Q2 / r2 The Attempt at a Solution At first I tried finding the distance between...

According to M-Theory there are 11 dimensions including time. 10 of these dimensions are spatial, so objects can move and therefore have velocity? Correct? According to Einstein's General Relativity whenever an object is not in motion in the three spatial dimensions, velocity is conserved...

Homework Statement Suppose the river is moving east at 5 km/h and the boat is traveling 45 degrees south of east with respect to earth. Find (a) the speed of the boat with respect to Earth and (b) the speed of the boat with respect to the river if the boat's heading in the water is 60...

When explaining the concept of spacetime curvature many popular science books (but I've also seen it mentioned in some textbooks) recur to the difference between intrinsic and extrinsic curvature, and how in a 2-D world with ants or bugs that are two dimensional, they would not be able to detect...

Why is it not possible to have Weyl spinors in odd dimensions?

If T:Mnxn ----> Mnxn then dim(T(Mnxn))+dim(ker(T))=dim(Mnxn) I chose matrices because I thought they would be hardest and I am looking to understand concepts here. Suppose n=2. The dim(Mnxn)=4. Now I need to be able to find the other two values. I also know dim(T(Mnxn))=RANK, well at least I...

Hi, Reading up on dimensions, like the m-theory's 11 dimension model, I'm unsure what is meant by this. Does it mean 7 more dimensions beyond space and time, or does it mean something akin to 11 universes in the multiverse (ours being 1 of the 11)? When relating this to string theory, does it...

How many dimensions are there. I can describe the first 3 spatial dimensions plus 1 of time, but all the others are a mystery. I also read that an equation predicted that there would be 10 or 11 dimensions, if this is true, what equation is that?

This may be way off base, but is there any support for the notion that virtual particles seem to appear and disappear because they move into and out of dimensions that we can't see? I kind of envision them appearing on arcs similar to solar prominences, where plasma follows the magnetic field...

Homework Statement A steel ball with a velocity of 2.7 m/s collides elastically with an identical stationary steel ball, and ends up going at a 40. degree angle with its original path. What is the direction of the other ball? What is the final velocity of each? Homework Equations...

Hello, my question is: A rectangular piece of sheet metal with area of 1200cm^2 is to be bent into a cylindrical pipe having a volume of 300cm^3. What are the dimensions of the sheet of metal ? Can someone please give me a pointer as to how to go about solving this. I struggle with math...

According to Wikipedia the formula for the field created by an aperture (the Kirchoff-Fresnel Integral) is: \Psi(r)\propto \int\!\!\!\int_\mathrm{aperture} E_{inc}(x',y')~ \frac{e^{ik | \bold r - \bold r'|}}{4 \pi | \bold r - \bold r' |} \,dx'\, dy'...

Is it true to say that most higher dimensional spacetimes have symmetries amongst their n extra dimensions? Thanks.