Picture Definition and 416 Threads

Hi, I'm trying to learn stuff for my relativity module, and it goes on about spacetime and the 4-dimensional continuum and four-vectors and all that business. I am having trouble imagining whatever it is I am supposed to picture when people talk about this. Take this thing, i believe its...

I go to Iowa State University, which is a decent college for engineering, not great. My GPA is not good right now (3.3, about to be 3.6ish after finals next week). I will try to ace every single college class for my next 2.5-3 years in college. I will tackle heavy courseloads, and still work in...

can anyone tell me please what is the light spot in these picture ?

Homework Statement µ Q.4 An incompressible fluid of density ρ flows steadily through a two-dimensional infinite row of fixed vanes, a few of which are shown below. The vane spacing is a. The velocities V1 and V2 and pressures p1 and p2 are all constant along their respective stations, (1) and...

Hi Is it me, or is the polarity on the voltmeter wrong for this mutual induction example. http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indmut.html In particular the 2nd and 3rd images of the first page Coupled Inductors. I agree with the change in B field and induced current...

Hi, I'm just trying to convince myself that the field in the interaction picture (IP) \phi_I(x,t)=e^{iH_0t}\phi(x,0)e^{-iH_0t} satisfies the Klein Gordan equation: (\tfrac{\partial^2}{\partial t^2}-\nabla^2+m^2)\phi_I(x,t)=0 . I have so far worked out that the time derivative is...

The purpose of this thread is to collect information from various users on projects that will be applied by the end of the decade. Information/Computation Internet via Satellite may be more cheaply available and more reliable making internet access anywhere possible. Contact lenses with...

I was shooting some macro pix in the park today. Actually I was targetting this lichen in that pic: and this one: But it's more about the new life: Feel free to share your spring pictures.

hey, When people say you should form a mental image when doing physics, does that mean forming a picture(snapshot)in your head or an actual movie of what's happening in your head?

Is the Heisenberg's picture really equivalent to Schrodinger's ? It may seem so at a first glance & both produce the same results.But space & time are treated equally in Heisenberg's formulation : the operators are time dependent.In Schrodinger's formulation, states are...

How was we able to take the pictures of galaxies?

I know that the classical picture of QED is Coulomb interaction, magnetic interaction etc. But what does the classical phi^4 theory look like? In particular, do particles attract or repel each other in this theory? P.S. I'm surprised that my field theory books never discuss this. (At least in...

Homework Statement I was given these two questions to answer regarding TV: 1) Explain why there is a need for two sound carrier frequencies. 2)Explain why you still get good sound quality reception during a thunderstorm but picture quality declines. Homework Equations I was given...

can anyone write a program that can steganograph a picture (BMP)? or any seggestion?

Homework Statement A wheel with spokes rolls without slipping on the ground. You take a picture with a stationary camera from the side of the wheel. Because the wheel is moving and the camera has a nonzero exposure time, the spokes are usually blurred. At what points in the picture do the...

Homework Statement An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 25,000 V. It then passes between two horizontal plates 6.5 cm long and 1.3 cm apart that have a potential difference of 250 V, as shown below. At what angle θ will the...

Homework Statement What current flows through the resistors R(1) = 1Ω, R(2) = 2 Ω and R(3) = 3 Ω, if the driving voltages are V(1) = 1V and V(2) = 2V? Picture: http://item.slide.com/r/1/151/i/lvtwIwH-0j8A8o-XAKDtPRQO1eHAb4Ik/ Homework Equations V= RI → I= V/ R The Attempt at a...

Hello everybody! I wonder what is the latest developments in nano level photography. It was about four years ago when I heard picture were taken in atto second. It was a great achievment for mankind. It was like a challenge to catch speed of light. Did we go further down to zepto(10^-21m) level...

I know there have been debates on the roles of punctuated equilibrium, phyletic gradualism, and punctuated gradualism. It would seem to me intuitively that evolution would be a dynamic process combining mechanisms, but of course intuition can be misleading. Is there a mainstream...

Homework Statement An amusement park ride consists of a rotating circular platform 8.07m in diameter from which 10kg seats are suspended at the end of 2.87m massless chains. When the system rotates, it makes an angle of 37.3° with the vertical. a) What is the speed of each seat? b)...

Homework Statement I have a picture in the pictures folder, saved as pic.gif and i want to put this into my latex text, how do i do this? Homework Equations The Attempt at a Solution To be honest i have no idea.

1. In case a in the figure block A is accelerated across a frictionless table by a hanging a 10N weight (1.02kg). In case b, block A is accelerated across a frictionless table by a steady 10N tension in the string. The string is massless, and the pulley is massless and frictionless. Is A's...

Hey guys, Working on a program. My program mostly takes place on a Picture Box where a user can click the picture in different areas and different images and sentences and words come up. Hence, I used the following often... g = PictureBox1.CreateGraphics() g.DrawString("Hello...

Homework Statement It's a part of a bigger problem, but what I need help with is finding the commutator between x(t) and x(t) at a different time. So basically I need [x(t1),x(t2)] Homework Equations A(t)=e^{iHt/\hbar}Ae^{-iHt/\hbar} The Attempt at a Solution The farthest I can...

Hello everyone, I have an assignemnt where I have to use various transformed equations to draw a picture. I will be doing things like restricting the domain to control lengths. I was wondering if there were any computer programs that would plot equations and give me equations for lines so i...

Homework Statement A picture frame hung against a wall is suspended by two wires attached to its upper corners. If the two wires make the same angle with the vertical, what must this angle be if the tension in each wire is equal to 0.75 of the weight of the frame? (Neglect any friction...

According to QFT, how do two masses attract? Is the action instantaneous? How is momentum/energy conserved? Is the action non-local?

Introductory Vector Equation Illustrated by a Moving River -- Picture Included Homework Statement A swimmer wants to cross a river, from point A to point B, as shown in the figure. The distance (from A to C) is 100 , the distance (from C to B) is 75 , and the speed of the current in the...

Homework Statement The problems asks: According to the above sketch, find accelartion (a1) of mass1? Note that the cables and pulleys are ideal (massless and frictionless). Everything started at rest until the pulleys lock were realsed. m1, m2, m3 have all different masses...

Homework Statement dB = 12mm (0.012m), dC = 20mm (0.02m), E = 140GPa and the coefficient of thermal expansion, α = 12e-6/°C. Homework Equations δ = (R*L)/(E*A) The Attempt at a Solution Please see picture for my attempt. I don't know how the thermal expansion, which...

Homework Statement The stress-strain curve of the steel bars may be idealized as elastoplastic with yield stress σy. Each bar has cross sectional area A. Determine the yield load PY and the plastic load Pp. Homework Equations σ = F/A The Attempt at a Solution See picture with my...

Hello, I need to calculate diffraction picture produced by source generating partially coherent illumination. I read Born and Wolf, Goodman and still I do not have complete understanding. Suppose we have source with size d, simple object (let's take opaque rectangle) and detector. According...

How have we taken the picture of our own galaxy? All the milkyway pictures look like taken from outside the galaxy.

I was trying to explain the origin of spin-orbit coupling to a beginning student and I used the following naive analogy: An electron orbiting around the nucleus "sees" the nucleus rotating about itself (the electron) in its own (electron's) reference frame, thus this is like a current loop...

Homework Statement http://classes.uleth.ca/200503/phys2000a/private/ass02sol_files/image002.gif With \theta = 27 degrees, d = .015m, q2 = 6.4 *10^-19, q3 = q4 = -4.8 *10^-19. Problem states: Find the distance D between the origin and particle 2 if the net force on 1 due to the others is...

Homework Statement I have this solution as domain of f,wheref(x,y)=1/(x+y2) Please describe this picture in words for me...PLZ Homework Equations The Attempt at a Solution I can't figure it out..

http://img216.imageshack.us/img216/3503/philosoraptor7.png thoughts?

please do not laugh. i am only curious and want to learn. I read article about entanglement in scientific American for the first time just a few months ago. it was called "lights, camera, entanglement". then i read something about electron spin and how counterparts spin in exact opposite...

Hello I'm a visual artist and I'm trying to make a project were I need to add a sound to a photograph hang to a wall in a picture frame.The source of the sound it will be a ipod (unless someone has a better idea)I need to build a device to make the music from the ipod place in the narrow place...

I think it's quite an accomplishment to obtain a picture (from LiveScience) of a new viral infection. I can tell the virus has a set of "arms" attached all around it's outer coat. I assume this is for gaining entry into the cell membrane. Not sure though. Can someone explain what the purpose...

http://i662.photobucket.com/albums/uu347/TwinGemini14/showme5.gif Consider a triangular wave pulse shown traveling to the right on a rope with a speed v. Its height is h. The total length of the pulse is 3L, as shown in the figure. The vertical displacement is much exaggerated. The solid line...

http://i662.photobucket.com/albums/uu347/TwinGemini14/showme3.gif The top picture to the right is the picture of the rope before the wave pulse arrives, and the bottom picture to the right is a picture of the rope after the wave pulse has arrived. Notice that the rope has to stretch in...

Homework Statement Esperanza uses a 35-mm camera with a standard lens of focal length 50.0 mm to take a photo of her son Carlos, who is 1.3 m tall and standing 4.0 m away. What must be the distance between the lens and the film to get a properly focused picture? this answer is 50.6 mm...

Hello everyone, Right now I'm working on an inclined plane problem. "a) The worker exerts a force(F) of 86 N. How much work does he do? (b) How much work is done by gravity? (Be careful with the signs you use.) (c) The coefficient of friction is µ = 0.20. How much work is done by...

Homework Statement A large painting is 5m in height. The painting is hung on a wall so that its lower edge is 1m above the eye level of an observer. How far from the wall should the observer stand to get the best view? (Assume that the best view means that the angle subtended by the painting...

Homework Statement I'm supposed to quantify the picture below and show how to find D and the angle theta. http://img10.imageshack.us/img10/7079/labg.jpg Homework Equations none i can think of The Attempt at a Solution I guess S and H are the same. I really can't think of a...

I don’t understand why the arrangement of electrons around an atom (the electron cloud) orientates itself around the nucleus in different shapes i.e, spherical, dumbbell shape, etc? I know electrons have wavelike properties but I can’t picture in my head why, after two electrons, why they...

Hi, Am I right when I say that the cosmic microwave background is a picture of the radiation left from recombination but that the picture (from COBE or WMAP) that we see today is not exactly the same as it was then due to the redshifting of the radiation particles. The flucuations that we see...

I am a philosopher with little bakcground knowledge in physics. The GRB news brought me here. Thanks to the help from Marcus and DaleSwanson, now I know much better about the universe expansion. I am not as good at math as most of you here are, but my hobby is drawing a big picture whenever I...

Homework Statement http://img4.imageshack.us/img4/898/integerqj5.jpg Homework Equations The Attempt at a Solution It does appear to be a Riemann sum, I figured the 1/n is probably the width of the intervals and the sum in brackets is related to the sums of the heights of the rectangles. But my...