Connection Definition and 520 Threads

I have read several books on relativity and find the subject fascinating. But there are a couple of things that I hope someone can help me understand. The big question on my mind is "why is light always associated with time"? It seems to my simple mind that light just portrays a visual...

I currently have 2 computers (laptop running ubuntu, desktop running vista) connected to the internet, through a "Linksys 5-port workgroup switch", which my cable modem is also plugged into (my internet gives me 2 IP's, so I don't need an additional router). This arrangement works perfectly, no...

Hi everyone -- I have a question about the relation between the spin connection and the Christoffel connection. The spin connection comes from the local (gauge) Lorentz symmetry of how we orient vielbeins at each point in space, it contains a manifold index and two tangent space indices. The...

Dear PF, What does this mean? .. Bayonet connection. It is used in cryostats..If anyone have some experience with such things..please explain me in details.. how does it work? etc... thanks

It seems to be true, that if some eigenvalue of a Hamilton's operator is an isolated eigenvalue (part of discrete spectrum, not of continuous spectrum), then the corresponding eigenstate is normalizable, and on the other hand, if some eigenvalue of a Hamilton's operator is not isolated, then the...

Could anyone tell me about the covariant derivative with respect to the connection?

hallo, i now spent an hour looking for a formula connecting the modified bessel functions I_n and K_n to the hypergeometrical series F(a,b;c;z). has somedoby an idea? thank you

I quote http://en.wikipedia.org/wiki/Torsion_tensor#Affine_developments": I try to apply this to the natural connection on the tangent bundle of M = S2 (or more intuitively, of the surface of the Earth) I mean here natural connection the connection which defines the parallel transport so...

I'm building a tank circuit and I need to know if a ground connection is needed.

Hi I've just started a new Electrical Course and have been working through an old exam paper but i got a bit lost when doing the star connection question - see attached for question and work done would just like someone to tell me if any of what I've done is correct and where I've gone...

Is there some mathematician who knows the "core reason" why exp() is connected with cos()? I mean I'm confident with "advanced maths for physicists", but maybe some abstract theory gives an answer to this. I was think of something like: |e^{i\phi}|=1 therefore it's a unit circle. But also...

Im sorry to bother you, but I am trying to understand one thing about embedding. Consider you have sphere embedded in the R^3, so you have a flat metrik. Otherwise you could describe the same sphere without embedding but with an induced metric. My problem is to make clear that the Lie-Brackets...

Homework Statement I have to prove in a conservation of energy question T-W =(mv^2)/L mgL(1-cosO)=(mv^2)/2 mg=W T=W(3-2Cos0) How could I go about starting this?

I have to prove in a conservation of energy question T-W =(mv^2)/L mgL(1-cosO)=(mv^2)/2 mg=W T=W(3-2Cos0) How could I go about starting this?

Stock market - no connection company/share - money isn't lost?!? I've spoken to some hobby stock market "users" but none of them could convincingly explain the basic share system without ending up in circular arguments. 1) My impression is that there is no logical connection at all between...

I thought this 'd be interesting http://www.sciencedaily.com/releases/2008/10/081010081650.htm Mathematicians Illuminate Deep Connection Between Classical And Quantum Physics ScienceDaily (Oct. 17, 2008) — In a seminar co-organized by Stanford University and the American Institute of...

Hi guys! Today I remembered that I used to have a fantastic image (like a flow chart) about different parts of mathematics and how they are connected. In the final stage (at the top), they were connected to QFT and GR. It's down->top, at the lower end were basic mathematics (sets, boolian...

How do I obtain the Levi-Civita connection from the concept of parallel transport? So Do Carmo asks to prove that for vector fields X, Y on M, and for c(t) an integral curve of X, i.e. c(t_0) = p and X(c(t)) = dc/dt, the covariant derivative of Y along X is the derivative of the parallel...

I am trying to set up remote desktop. I have only one account with user name "FirstName LastName" with no password. I followed all instructions, and have "username" for accessing my computer. But, it doesn't work! I have used 3rd party software (I forgot it's name but it's pretty...

http://www.annomundi.com/history/trojan_london.htm The early inhabitants of Britain, who arrived more than a thousand years before the Roman invasion, were the scattered remnants of the fallen city of Troy. They founded a city on the Thames and called it "Troia Newydd" (New Troy) which later...

Hi Is there any connection between creativity and level of order? wikipedia - Creativity (or "creativeness") is a mental process involving the generation of new ideas or concepts, or new associations of the creative mind between existing ideas or concepts. so, will it create chaos -...

Hey all, This question stems from Scorpan, "The Wild World of 4-Manifolds", pg 302 (and all through that chapter). He states that a random homogeneous polynomial of degree d in CP^2 with coordinates [z_0:z_1:z_2] defines a complex curve C, with homology class [C]=d[CP^1]. So I understand...

I have a photodiode/amplifier module, which has a D-sub connection for the power supply. The manufacturer sells a power supply, but it is out of my budget range, and the lab only has standard laboratory PSU's (+V,-V, gnd). Is there any connections so that I can use this module with my power...

Hey Everyone, I'm reading a paper by Claude LeBrun about exotic smoothness on manifolds and he is talking about a connection between polynomials and groups that I am not familiar with (or at least I think that's what he's talking about). He's creating a line bundle (which happens to be...

I am trying to include salt water in my Rube Goldberg project. Instead of the wires that connect a motor simply being continuous, I want to bridge a connection through salt water. Meaning, but one wire, put both ends in the solution so that the connection still works. But its not working. Are...

Hey, I was playing around with Gamma and plotted it as shown in the attachments. I noticed that the area swept out was similar to phi (in spherical coordinates.) So I started wondering if this could have any really relevance. So I looked at it more closely and was able to find length...

According to this book I'm reading these groups are said to be equivalent and I am trying to better understand how this is so. The generators of SU(N) are N^2-1 traceless complex anti-hermitian matrices. The group is over the real numbers and is N^2-1 dimensional. On the other hand we have...

if F is any function and H is the hamiltonian, then the Poisson Bracket of F and H, is given by: [F,H] = dF/dt - \partialF/\partialt Can someone show me how the right side of this equation comes about? Also how can the normal derivative of F w.r.t t be different from the partial of F...

Dear all, i am possible to do experiment on the application of solar cell and i have run into several problems so i need to seek advice from all the experts in here. I have several DC loads include: 1 x Cooler fan (12V, 0.25A) 1 x cooler fan (12V, 0.2A) 2 x rechargable AA size battery...

According to the Correspondence Principle Discrete Quatum levels become Continous Classical levels when n goes to infinity, meaning that the difference between two adjacent level goes to zero. Questions; 1) What does infinity mean here? How for do we to go from the center of the atom...

Hi I'm looking for a simple definition fo the affine connection because I can't understand it's meanning , that meanning that givse the mathematical formula of the affine connection a life , You could call it the physiacl meanning . For your knowledge my friend , I'm very good with the...

Might there be a similarity between Dyson's equation and Heisenberg equation? (It's just a feeling, nothing based on arguments.) Both describe how a system (density matrix or Green's function) behaves in time. Both require knowledge of the intial system at time t=0 and the potential acting on...

just after cleaning its CPU fan because of its noise...when a open many sites and navigate and when i login to any site (it happenned 3 times while signing into yahoo), a security alert says "information you exchange with this site cannot be viewed or changed by others. However, there is a...

I have noticed an apparent correlation between two seemingly unconnected phenomena, but I do not have the mathematical ability to prove the connection. I was wondering what a rolling wheel would look like at relativistic speeds. To investigate this I created a java simulation that solves the...

Hello, I opened up an AC to DC power supply today to see where they connected the Earth ground wire and I found that it's connected to the negative side (labeled V-) of the DC output. V- is also connected to one side of the transformer's output. Why would they connect the Earth ground wire in...

[SOLVED] computing affine connection I've got a task of computing the components of the Riemann tensor, starting from the given Robertson-Walker metric g=-dt\otimes dt + a^2(t)\Big(\frac{dr\otimes dr}{1-kr^2} + r^2\big(d\theta\otimes d\theta + \sin^2\theta d\phi\otimes d\phi\big)\Big) When...

why torsion free metric compatible connection ? Why in conventional GR we choose a torsion free, metric compatible connection? Can that be derived from somewhere like physical principles/postulates or it's just a the simplest convenient choice (many terms drop from equations) that produces...

Hello, When is it OK to connect the shield wire of a loadcell to the 0V rail vs chassis ground? I have seen it connected to the 0V rail but other sources seem to indicate that it should be connected to chassis ground. Any thoughts/advise? Thanks

I am supposed to write a program using C++ that will take data collected by two separate DAQ cards and save them as either a text or spreadsheet file. Now, I'm still new at C++ and I do not even know where to begin. How am I even supposed to make a connection between Visual Basics and the DAQ...

Homework Statement Can someone explain what they mean at the bottom of the page "by swapping derivatives with respect to a and x' " and in general how they arrived at equation 3.17? Homework Equations The Attempt at a Solution

Can anyone tell me what the following circuit connection means? It's the arrow going from VEE to the 50k resistor. Thanks. http://img442.imageshack.us/img442/8861/picture1ry3.png

Homework Statement I am confused about this question and probably the connection in general. When we only have two independent coordinates here what do the three indices in \Gamma ^a_{bc} stand for? I found the metric for this space, but every formula for Gamma has indices a,b,c and I do...

Homework Statement I am trying to show that the connection \Gamma^a_{bc} is equal to 0 when the metric g_ab is diagonal. Will the formula \Gamma^a_{bc} = 1/2 g^{ad}(\partial_bg_{dc} + \partial_cg_{bd} - \partial_dg_{bc}) be of use? How can I manipulate that equation and use the fact that...

I know that if I want my muscles to grow stronger, I should eat lot of protein containing food, apart from only training hard. And taking protein precisely after the training and before sleeping is probably most effective. Does the way I eat also have an effect on my ability to learn new...

As usual, I don't know if this is the right place, but, I have been thinking, and if samarians ( if that's spelt right ) were right about planet x, then it should be near us soon in a few years or a few decades, now, if this is true, wouldn't that explain that if the ufo sightings are true...

What is the relationship between friction and heat?

Homework Statement Does a torsion module M imply M is cyclic? Or does it imply M is finitely generated? I think cyclic implies torsion module. What about the reverse? The Attempt at a Solution I think there is a connection but don't see it.

hi y'all after lurking a lot on this forum and searching for the answer I've got something to ask, if you get that all the non trivial zeros do lie on 1/2+ib then what? I've read a book on the riemann hypothesis but i really don't get the link between the zeros of zeta(s) and the prime counting...

I tried to obtain refraction of light by sun's gravity by substitution of sun's gravitational field by aether with different speeds of light. I do not get right result. Where I am wrong? For light which travel close to the sun by direct trajectory, I get the following speed of light in...

Is there a particular reason why the probability density distribution function of atomic orbitals bears a similarity to the modes on a circular membrane? Is this just a coincidence? Is it not actually that similar?