What is Spiral: Definition and 192 Discussions

Spiral galaxies are usually taken to be structured lenticular objects with spiral arms depending from a bulging star-dense central hub. The whole arrangement is essentially planar. Since our view of these objects is projected upon our fixed celestial sphere, their shape has to be inferred from...

If an observer on the Andromeda galaxy looked back at us, how would the Milky Way galaxy look to him? Edge-on, spiral face on, or in between?

Hi All, I am at present working on coil design for RFID tag, i want to know how you add capacitance in spiral coil i.e. how you join two ends in spiral structure with capacitance in between, i have already calculated capacitance value needed to resonant at particular frequency. Any help is...

basically need to look up and use this formula but i can't remember the name. i know it has uses in other fields apart from super lattice structures. basically it forms an outward spiral until it reaches an equilibrium point and forms a circle. i think it has a double barrel name and is named...

Hi Pf, I've searched through the forums for an answer to this question and have found bits and pieces but not a full answer. Why are spiral galaxies planar (I know there are exceptions to the rule, I'm just trying to understand the why). From what I understand, it is a bit of a battle between...

I met this old nerd wearing a tie with a certain spiral, which does not look like a Bernoulli spiral to me. He actually told me, what it was, but I seem to have lost the note and time made me forget it. I wouldn´t be able to describe properly, so I have a photograph of the tie on my flickr...

Hi there. I have a current I running throught a tesla spiral coil, and I have to compute the magnetic field at the center of it. The tesla coil has N turns, and an inner radius a, and outer radius b. This is the tesla spiral coil: The courrent enters through the outer cable, and goes out...

A bee goes from its hive in a spiral path given in plane polar coordinates by r = b*ekt , θ = ct, where b, k, c are positive constants. Show that the angle between the velocity vector and the acceleration vector remains constant as the bee moves outward. (Hint: Find v · a/va.) attempts...

why most of the galaxies are having two spiral arms only?

Homework Statement This is an example taken from the textbook lesson and there's one part I don't understand: Find the area of the region bounded above by the spiral r = pi/(3θ) and below by the polar axis, between r = 1 and r = 2. SOLUTION: Double integral of r(dθ)(dr) with boundaries...

Hello, It has been said if a photon crosses the event horizon of a black hole it will have a spiral orbit; The spiral is Archimedes r = r_{i}+r_{0}\theta^2 There is one such example in "Introduction to tensor calculus, relativity and cosmology" by D F Lawden on page 165 Is it possible...

So I was watching this: which talks about the winding paradox of spiral galaxies, e.g. the stars all move at the same relative speed however that shape is maintained. However, we still have those shapes. The video talks about density waves of some sort. I don't really understand. This...

"multiplying equations" - spiral coil heat transfer Hi, I was wondering if anyone could explain to me what is meant in this article by "Multiplying equations 8 & 9". I have both equation 8 and equation 9 however I cannot seem to work out how to get equation 10...not sure if it's something...

Longo, "Detection of a Dipole in the Handedness of Spiral Galaxies with Redshifts z ~ 0.04," 2011, http://arxiv.org/abs/1104.2815 If this is right, then I guess it would be the first possible hint of a nonzero rate of rotation for the universe. He doesn't attempt to state his results in terms...

I want to write a Visual Basic Program that draws a golden spiral. Can anyone please direct me to the forumula to use to draw this spiral? thanks

Hello all, My first post here. I do CG animations, and am working on a project where two galaxies collide. It is important to note up front that my simulation will NOT be physically accurate - I don't have the tools, knowledge, or processing power for that, but I AM interested in getting...

Hi, have worked out the formula for a hyperbolic spiral space curve to be r(t)=1/t X cos(alpha)+1/t X sine(alpha) + t and obtained the tangent vector T, normal vector N, and curvature (kappa) with the z axis being the central axis of the spiral. Am having trouble finding the formula for the...

I was wondering what shape a (1/r^2)sin(theta) force would produce between two bodies. theta = angle between the distance between the two bodies and the velocity vector (90 degrees for a circular orbit).

Hello, I need help for this problem on my calculus chapter curves and motion on curves Homework Statement a) for the spiral cornu defined by the parametric equations x=\intcos(pi*u^{2}/2)du and y=\int sin(pi*u^{2}/2)du obtain the length of the curve s(t) from 0 to t and hence reparametrize...

... Obviously we can't fly out and look down on it, so what observations are made to deduce the structure of the galaxy?

Lol :) http://www.herkesebendencay.com/2011/01/fibonacci-spiral.html

. Is this possible? Or is it photoshopped? [PLAIN]http://img153.imageshack.us/img153/8440/fibonacci.jpg

Why do the spiral arms of galaxies split or bifurcate? Is this due to a previous merger or some kind of current?

Homework Statement Hi guys. Electrical engineering student here trying to get some real physics under his skin. I'm trying to derive the field and ultimately the inductance of a finite solenoid based on the spiral shape of the windings (because I assume - for no good reason - that the exact...

If disk galaxies redshifts don't fit normal rotational curves, why do we still think they are spinning? What is the physical basis of that inference? Just because they have the form of a disk?

Is there a model for determining the self resonant frequency of a flat spiral inductor? I can determine the inductance but the capacitance is escaping me. Thanks for any help.

Propose a parametric representation of a spiral. Hint: Use the parametric representation of a circle. This is the parametric representation of a circle we are given : x = r * Cos(Theta) y = r * Sin (Theta) 0 <= Theta <= 2 Pi Nope, we are not given anything background on spirals...

I've been trying to locate an algorithm to model the distribution of stars in a spiral galaxy. Simple, I thought, I'll just Google it. However I quickly disappeared up my own black hole! What I'm looking for is a simplified algorithm I can use to model n stars in a galaxy of size x (for...

[b]1. First off i am not a student per say, this is related to my hobby I am repairing an old clock and need to replace the balance spring which is completely missing. I have located ONE source that may carry suitable springs but I cannot figure out which spring to order. The spring...

Just looking at a spiral galaxy made me wonder if there was an external resistance causing the spiral arms to fold in on the structure or if the gravity at the centre of the galaxy was pulling the arms back in on itself. Please let me know!

This is a significant discovery that something is fundamentally controlling and ordering the properties of spiral and disk gaseous galaxies. Elliptical galaxies have no gas and no star formation. The question is not only what but how is the unknown parameter controlling spiral and disk galaxy...

Homework Statement I'm trying to figure out what exactly this equation (the one inside the red box) means for this article. The whole article is the attached PDF. Homework Equations The Attempt at a Solution I've been looking at this article for 2 days now and I'm doing OK for the...

Here's something simple but also a bit puzzling, let me know if you have any ideas... For clarity, I'll describe three cases before asking the final question (skip ahead if you like). 1. Mounted on a disk are two curved fences, just a few centimetres apart from each other. Between the fences...

Homework Statement Calcualte the value of \int\limits_L \sqrt{x^2+y^2}dl, where L is an arc of a logarithmic spiral r=ae^{m\phi} between points A(0,a) and B(-\infty,0). Problem: I can't find a value of \phi where x=-\infty or y=a. Homework Equations We parametrise and get...

I am trying to use the 'Regression Wizard' in SigmaPlot to obtain a best-fit curve to a data set of ~15 data points that map out a spiral. None of the equation categories given in the regression wizard seem to work (i.e. polynomial, exponential, logarithm, hyperbola etc. etc.) and I am unsure...

Homework Statement Given L, find the V(r) that leads to a spiral path of the form r = r0(theta)k. Choose E to be zero. The Attempt at a Solution I know that I need to find r' as a function WITHOUT theta, but I'm not sure how to do that. I know how to find r' as a function of...

Homework Statement A particle is moving down a spiral path parameterized by: x = cos(au), y = sin(au), z = -u, where 0 \leq u \leq b (a,b real, >0). Starting from rest, the particle moves down the spiral under the influence of gravity and free from friction. Let g be the positive...

Hello This is my first post and excuse me I'm a bit dim (hence my username). So, I've had this question rattling around in my head for a while... There are a lot of pictures of so called "Spiral Galaxies" and according to Wikipedia the taxonomy of galaxy shapes was described by Edwin...

I was browsing sites on the galaxies in response to another thread, and I encountered a rather unusual picture of ESO 510-G13 Hubble Photographs Warped Galaxy as Camera Passes Milestone http://hubblesite.org/newscenter/archive/releases/2001/23/...

Hi All, I have written a paper showing that the spirals over Norway could not have been caused by a missile. I posted the paper to my blog: http://bringthefunk.blogspot.com/2009/12/on-norway-spirals-and-their-physically.html I would really love feedback from whoever is willing. Thanks.

Could be an asteroid or comet - the spiral thing is pretty cool.

I am looking for the formula to describe a spiral formed around a conical shape. If any particular details are needed, please make them variables and define them. Thanks to all for the help!

I'm a sci-fi writer and would like some help, if you would please. My story is simple: monopoles arising in spin-ice can be charged with enough magnetricity to deflect spin 2 gravitons, freeing manking from the tyranny of a lone world, and propelling us into a vast new tyranny. I heard...

I was wandering what the general belief of why barred spiral galaxies, contain 'bars' as straight lines in nature are pretty rare. To my untrained and unqualified eye, it clearly looks - on all the photographs that I've seen - as if there are two 'bars' being emitted from the opposite sides of...

I want a shirt with a spiral galaxy on both sides. On the front, it's slightly blue, and on the back, it's slightly red. So, when I'm walking toward/away from people.. get it? No one steal it and make a million dollars please.

Homework Statement Let S be the spiral surface parametrized by {(x,y,z) | x=ucosv, y=usinv, z=v} where 0<u<1 and 0<v<Pi/2. Let F(x,y,z) = (z,x,y) and compute \oint F \cdot t dS. Homework Equations The Attempt at a Solution Let me explain where I'm not certain. I can compute the...

Both Riemann hypothesis and Ulam's spiral (and http://en.wikipedia.org/wiki/Sacks_spiral" ) show some patterns emerge from the prime numbers. I was wondering if there is some know relation between them, for example, if the RH is proven true does that imply something on Ulam's spiral?

If there was a stick the length of the diameter of Earth spinning in space for the same amount of time at the same rate as earth, would it appear as a spiral?

I'm sorry if this is the wrong place to post this but I can't find the answer anywhere. Does a spiral pulley offer any mechanical adavntage if it is wrapped once around like in the drawing?

Homework Statement Given L (angular momentum), find the form of V (r) so that the path of a particle is given by the spiral r = C(theta)k, where C and k are constants Homework Equations L = mr2(theta)'The Attempt at a Solution I know I have to find a expression for r' using no theta's and...