Grid Definition and 206 Threads

Wanted: video by Wilczek on "The Grid" Does anyone know of a video lecture on the WWW by Prof Wilczek describing his theory of the Grid? (Suitable for someone with a basic science knowledge.) Thanks.

Homework Statement What is the resistance between A i B if resistance is proportional to length, and the resistance of a side of the largest square is R? Homework Equations This is nothing more than a bunch of serial (parallel) resistors. The Attempt at a Solution n=1 => R=1 n=2...

Hi, Not sure if this is the correct sub-forum or not. Perhaps, general math is better. Anyways.. In the following, a simple reference covering what I am after would be very helpful. Let's say you have a 4x4 grid of cells each cell contains either a 1 or 0. Let's say it is this...

1) What's the voltage in the overhead power lines in residential areas? Basically how many volts is it before it gets stepped down to 120 for your house? 2) What's the typical primary inductance of a distribution transformer that does the stepping down?

Hi, I'm a newbie here, i joined just now purely to ask this question that's been on my mind recently. Now i apologise if this question is fundamentally wrong (which it probably is), but I'm only the average person with an amateur interest in physics :P So don't laugh. Firstly, as you know, we...

can anyone tell me if it is possible to run a asynchronous generator from a capacitor bank and what it may entail.

What would happen if I hooked up a generator at my house (voltage and frequency identical) to the power grid and it was 180 degrees out of phase?

Hey all, Well for my senior project my class has to construct a mini grid. It will be connected to 3 renewable energy sources. My team is in charge of the connections to the grid and the energy sources. My team has decided to use a PIC micro controller to interface to the other groups. I am...

Hello. I want to build an electron accelerator grid in vacuum. The grid, which has the purpose of accelerating or decelerating electrons produced by a nearby filament has to be electrically charged at +500V or -500V. The switching frequency between the voltages +500V to -500V has to be...

All about smart grid, New ideas and news about what's happening now in this area. Including Smart meters, Renewable Energy (Solar and Wind), Green Cars and Green IT. Lets start from the beginning What is the definition of Smart Grid?

How many possible games of "go" are there? I realize this is a ridiculous question, but what strategies would you take to solve it? A sure-fire but incredibly tedious one would be to create a giant tree diagram. And before anyone says it, the answer is not just the factorial of (19*19)...

Hi, I have a problem (1) where I need to compute the ratio of probabilities of hitting and stopping at a positive vertical barrier x vs hitting and stopping at a negative horizontal barrier y after starting from (0,0). I feel that by symmetry, the answer to this would be the same as...

I want a projection of Earth where distances are undistorted. i.e. 10 degrees of latitude at the equator is exactly the same map distance as 10 degrees of latitude at the Arctic Circle. As a disqualified example, the Mercator Projection has map distance increasing with increasing latitude...

Hi, I'm here for help and hope somebody could give a hand on this because I'm noob in this. I'm now constructing a MATLAB program to find Electrical field and potential within a square grid mesh with square cavity inside. like the picture above. I only manage up to this...

I am trying to find out how many possible puzzles can be created out of the standard 9x9 grid. I was never very good at permutations and combinations, so I won't get very far here... All I can think of at the moment is that while there are 9^{81} ways to fill all the boxes with numbers from...

Guys, I have a Lister generator that is capable of producing approx 5KW of power from an attached ST alternator. I am in australia so our standard power is 240v at 50hz I have a grid tie inverter for my solar panels - this unit accepts between 150v dc into 500vdc It has a single input...

I'm doing some classic research into the possibility of replacing copper core power transmission lines in the United States power grid with tubes designed to contain low temperature plasma. The idea is that one would be able to transmit power more efficiently and effectively in plasma opposed...

Through our research we discover that an AC induction motor can act as a DC amplifier, as long as there is torque making it turns. Applying the process we are able to build RPM independent grid tie induction generator. Tested with variable US grid at consumer configuration. Similar to PMA...

"Evolving grid" simulation? I'm not quite sure what to call this problem, but basically, I am trying to solve a puzzle. It works as follows: There is a 9x9 grid Each square can either be "on" or "off" At the beginning of the puzzle, the 9 squares dead center of the grid are "on", the...

Place the letters A, B, C, D, E, F, G, H and I into a 3x3 square grid with each square containing a different letter, using the following information: (i) I is in the same column as E which is not in the center column. (ii) D is in the row below the row which contains F. (iii) A is in...

I'm working in matlab, and looking for help on how to do the following. (answers in any language or pseudocode will be fine) I have an nxn matrix, with each cell containing a 1 or a 0. The border cells are all 1's. Is there an efficient algorithm to determine if there are any "islands" of 1's...

Hello everyone: I am a C++ newbie; I am interesting in using C++ in my work on coupled fluid flow-chemical reaction problems. I apologize in advance for what is probably a very simple question. I would very much appreciate any help to get me on the right track! My goal is to come up with...

The Grid, dark energy not created at BB ? In his book “The lightness of being” page 105, Frank Wilczek says: “The concept of Grid density is essentially the same as Einstein’s cosmological term, which is essentially the same as “dark energy” “. Dark energy, contrary to the other energy...

http://www.xkcd.com/356/ Thoughts on the problem?

Homework Statement Microwave oven I. The glass window isn't important to the microwave oven's operation, but the metal grid associated with that window certainly is. The grid forms the sixth side of the metal box that traps the microwaves so they cook food effectively. What is the approximate...

Hey iam trying to place some text in each grid in a grid field and also to fill each one with different color can anyone please help me out...

Short Circuit Current Hi, I am reviewing a ground grid study of a substation for a wind farm that is being built. The ground grid will be for a substation with a low side of 34.5kV and two transformers that step the high side voltage up to 345kV. There are six distribution feeders on the...

By now we have heard of all of these fascinating new technologies "just around the corner" that will "remove our energy dependence on corporate and foreign resources." In nearly every cable news interview, researchers claim that this new technology is "only five to ten years away." As a nation...

Hi I'm trying to deepen my conceptual knowledge about electrical systems. I'm definitely a lay level, tradesman level user here. I'm lucky if I can do some simple algebra, so I don't want a lot of math (though I might get into that later if I want to get deeper into engineering). I have...

I have an interesting finding in spacetime diagram - The area of the square grid for the rest frame O, is the same as the area of the rhombus grid for the inertial frame O'. More specifically, the area of the square for frame O (0, 0), (0, 1), (1, 1) and (1, 0) is 1 The area for the...

Homework Statement Hi, I need to calculate the voltage drop in an n by m grid. There are resistors 4 resistors connected to a square; R1 for horizontals and R2 for verticals. There's a voltage applied at point B and point A is grounded. I need to create a MATLAB function that will solve for...

Frank Wilczek has presented a way of looking at the world which is curiously consonant with Lattice Quantum Gravity approaches a la Renate Loll, John Barrett, Lee Smolin, Carlo Rovelli and others. The world as lattice---what Wilczek calls the Grid. It is oddly reminiscent of spin networks...

I have made a Solar collector out of a 10' diameter satelight dish and lexan mirrors. I have a collector that converts water to steam ( 20lb propane tank) at a rather frightening rate I must add. Now i have a dilema. Where can I buy a turbine that i can bolt onto this scary steam source...

Is it possible to use an image as a background to a function graph in Geometer's Sketchpad, so that I could superimpose a grid over a map? Does anybody have an alternative suggestion if that's not possible in GSP? Thanks, -tubegeek

Homework Statement In a 6 x 4 grid (6 rows, 4 columns), 12 of the 24 squares are to be shaded so that there are two shaded squares in each row and three shaded squares in each column. Let be the number of shadings with this property. Find the remainder when is divided by 1000. There is a...

There is an infinite square grid with each side of every cell making up the grid of resistance r. What is the equivalent resistance between two adjacent points on the grid?

Homework Statement Consider the parametric surface r(u, v) = <vsin(u), vcos(u), v^2> The point (1, 1, 2) is on this surface. Find the grid curve with v constant that contains this point. And the grid curve with u constant that contains the point. Then find tangent vector to both...

I'm working on this subject. I'm trying to make a MATLAB emulation on this subject. In tha attached pdf I have the equations and the MATLAB code. You think that the graphs below are correct. You think that the current graph shouldn't be "negative". I will be glad to see your comments.

http://xkcd.com/356/ "I first saw this problem on the Google Labs Aptitude Test. A professor and I filled a blackboard without getting anywhere. Have fun." Discuss.

Consider a 3-by-3 square grid. Suppose you pick 5 of the squares at random. What is the probability that at least 1 line of 3 squares is formed? (3 diagonal squares is NOT a line). I do know that there are 6 combinations of lines that are possible. After that, I'm not sure how to follow along...

Ok, I have a teaser and I want to check with all of you on what's the most points. We have a 5x5 grid. That grid can be filled with numbers 1 thru 4. There are rules to placing these. Diagonal directions do not count as neighbours. 1 can be placed anywhere; 2 needs to have 1 as a neighbour; 3...

I was just curious, has there been any theories on how small of a movement is possible? For example, moving an atom a certain length, then moving it half that length, then again half, is there a point when you would get to the smallest movement possible (looking at it as the smallest unit of a...

Wouldn't an extraterrestrial looking at the sports clubs think that people must be working hard to supply electricity? That they are running on giant dynamos? But isn't the reverse true, that sports machines consume, not generate, electricity? Is it merely a symbol of affluence (that is...

Hi, I have created a program to generate grid points for a Joukowski airfoil. I was wondering if anyone knew of a 2D Sheared Parabolic Grid Generator that I could use to get a grid. If you are unfamiliar with this grid, it's basically a long rectangle that is "wrapped" around the airfoil so...

If you move a magnet towards a loop of wire it will generate a current in that wire. Could a reversal of the Earth's magnetic field be sudden enough to cause significant damage to the Earth's power grid?

Here's a problem that I need help figuring out... imagine a 9x9 grid filled with the numbers 1-81 starting in the upper left corner and progressing left to right, top to bottom; like so: /--------------------------------------------\ | 1, 2, 3 | 4, 5, 6 | 7, 8, 9 | |...

Can electricity be sent back into the UK national grid via a normal household plug socket?

Hi: I'm looking for an algorithm to fill a grid without repeating places. I have looking for Pseudorandom number lists (http://en.wikipedia.org/wiki/List_of_pseudorandom_number_generators#gsl_rng_minstd) but i do not get it clearly... Any help ? :)

Could not find a thread on this particular topic, but I want to verify my thoughts. I emailed my local Green Party rep in Canada here regarding his partys take on Nuclear Power. Our particular area of Canada is facing a bit of a situation where more megawatts NEEDS to be available in the...

I have a small technical problem in MATLAB. I am trying to use comet to make an animated path of this spirograph program I've made. I'd also like to add some grid lines however my problem is the following. If i run the comet command everything looks great and works fine, but if I then use a...