Reference Definition and 1000 Threads

Where can one find a general and detailed exposition of Penrose diagrams? What I have seen so far, in the books, are relatively brief general comments and a couple of specific examples. Usually Minkowski and Schwarzschild metrics, sometimes one or two more.

If all frames of reference are taken as equally valid. when a car moves, to the passengers in the car the world is moving in the opposite direction. Moving the whole world should take a lot more chemical energy than was contained in the gas that was burnt... I know the passengers in the car...

Quick question: Is Planck time the same in all reference frames? Is it different at, say, half the speed of light than at a relatively stationary point? What about in a severe gravitational field, like a black hole?

Homework Statement [PLAIN]http://www.antonine-education.co.uk/Physics%20A%20level/Options/Module_8/Topic_6/cars_4.gif What is the speed of sound, relative to: A - B - C - Homework Equations None. The Attempt at a Solution For B, since B is a stationary reference point...

Consider two point charges in space: one positive(+Q) and other negative(-Q), lying on the y-axis and separated by distance 'r'. In frame A, both charges are at rest so, only attractive electrostatic force (F_elec) acts on both the charges which is defined by coulombs formula. In another frame...

Please help, I am confused with part c and d. 1. Doug in a lab on Earth observes a π-meson is created 2.8 km from the surface of the Earth. It has a rest decay time is 9.0 x 10-6 s and it travels straight down to the Earth at 0.95c. a) What distance would the π-meson measure to the lab...

Homework Statement If you are on the merry-go-round going in a circle at constant speed, are you looking at the world in an inertial, or non-inertial frame of reference? How do we tell whether from one's viewpoint, they are looking at something from an interial or non-inertial frame of reference?

Hi folks, I'm looking for a derivation of the following statement (formula 76) http://img845.imageshack.us/img845/1550/screenshot4op.png Do you know any reference, where I can find a bit more detailed description? I reckon, you can find it in Jackson's electrodynamic book, but I couldn't find...

What is a non-inertial reference frame? how is it defined?

Dear all, I'm trying to understand better why gravity makes impossible to physically define an inertial reference frame. Firstly, we must have an operational procedure that allows us to physically define an inertial reference frame. Secondly, we must show that gravity makes this procedure fail...

So apparently SR can handle non-inertial reference frames, and there are supposedly some interesting effects that come about, like non-constancy of the speed of light. I was wondering if anyone knew where I could find a treatment of accelerating frames in SR (like a textbook)?

Are galaxies, quazars inertial reference frame? I think they are at rest or moving at constant velocity relative to the expanding space. But what is the coordinate system to the scale of the whole universe that can describe these inertial reference frames appropriately? Is the coordinate...

I am not able to understand how a bandgap voltage reference works. The simplest ckt I found was here - (figure 2) - http://www.national.com/rap/Application/0,1570,24,00.html You have 2 branches of diodes, in one branch rich (high) current flows and in the other lean (small) current flows...

Fairly straight forward question. If you have a set of three vectors specifying a frame of reference and a second set of 3 vectors stating another frame of reference. How do you get the Euler angles associated with that rotation? More generally I am considering the relative orientation of one...

If a solid object rotates at constant angular velocity, is it possible to chose an inertial reference frame in which the object will not rotate?

I'm not always on the same computer, often times I'm using my phone to look for answers when doing physics on the go. Does anyone know a good, correct resource for ALL of the tree level feynman rules for QED+EW+QCD? Feynman gauge would be preferred, or ungauged. I can find most for the...

I am confused about the twin paradox. Let's imagine Mike and Angela are twins. Mike stays on Earth, and Angela rockets off, away from Earth at close to the speed of light, with the intention of making a round trip back to Earth at the end of her voyage. My question is this: why wouldn't...

Well I've just been learning about special relativity, and I think I understand everything I need to know, except frames of reference (for A level). I need to know where you are allowed to take frames of reference from, and where you are not. I understand that you can't take a frame of...

Hi all, I'm looking at the http://en.wikipedia.org/wiki/Gamma_function#General" for the gamma function, and it lists equations for the gamma function of half-integer orders (i.e. gamma(0.5+n) and gamma(0.5-n)). But, it doesn't list a reference as to where this equation comes from. Does...

I want to find a good reference in GR about the application of tetrad. Is there any good suggestions?

The Earth is an approximately inertial reference frame since it's acceleration with respect to the stars is very small. But if a group of stars is accelerating with respect to another group of stars which group is the inertial frame? Or thinking on an even larger scale, if a universe is...

A very important idea in General Relativity is, same laws in all reference frames. How does that work in rotating reference frames? Jonny

(feel free to move this post if it doesn't belong here) I've been searching around the internet and here for the past few days and can't find anything relating to this. Does anyone keep a personal notebook wherein they have complied useful formulas and such for reference? If so I would...

So I was pondering long distance space travel. As I understand it, if you can accelerate a vessel, say over the course of a year, to near light speeds, you can cover very very long distances in a very short period of time(as measured on your on space ship) due to the effects of relativity...

"suppose there is an instruction to copy one register contents to another... now, without paging only 1 memory reference is required to fetch the instruction...but with paging..we need 3 memory reference (as page tables are to be accesed)..." please explain why 3...?

I've had a good search through the archives and haven't found an answer to this question. Many apologies if this is old ground. . . Having read the threads on the Pioneer Anomaly a quick question to which I'm sure there is very simple answer (I just don't know what it is !): When...

Homework Statement I have been looking at one of my review sheets, and do not know how the professor got the equations. Here is the relevant paragraph: Consider two particles of mass m1 and m2 isolated within a box, with respect to which they have velocities u1 and u2. The box is moving at a...

Homework Statement the acceleration of a particle as seen from 2 frames s1 and s2 is 4 , what can be the value of acceleration between s1 and s2 Homework Equations The Attempt at a Solution the answer to this question is anything between 0 to 8 , but i do not know the reason , pl...

Can someone explain to me what is this sequence referred in the page? http://oeis.org/A004730"

Homework Statement A particle as observed in a certain reference frame has energy 5GeV and momentum 3GeV. what is the energy in a frame in which its momentum is equal to 4GeV/c? what is its rest mass? what is the relative velocity of the two reference frames? Homework Equations The Attempt at a...

Einstein's theory of relativity is based on the fact that all motion is relative, which precludes the existence of a universally defined state of rest (priviledged reference frame). Einstein also recognises the existence of rest mass. If an object were at its rest mass, wouldn't it be perfectly...

[FONT="Arial"][SIZE="2"]Hi. Let's suppose to have a car with a reference system called Body-NED with its origin in the center of gravity of the car, Xb-axis (called North) pointing towards the front of the car, Yb-axis (called East) pointing towards the right door and Zb-axis (called Down)...

Okay, so I know what inertial and non-inertial frames of reference are: 1. Inertial is when Newton's laws of motion hold. 2. Noninertial is when they do not hold (the object is accelerating without a force). And I have a few examples as well, such as when you are is in a car and the car is...

Human body is mass having energy. thanks to Joule it is proved. Newton explained First, Second and Third laws. Now, 1. Two equal amount of forces in opposite direction at a given time may not move the OBJECT as per third law of Newton. This is horizontal pull like Tug-of-War. Here 'x'...

I am not a chemist, so I have a feeling I'm going about searching for the wrong key words or something. What I want is a table of Fe+2 and Fe+3 compounds in solution (ie. different ligands like CO, CN-, etc.), listing each compound as paramagnetic or diamagnetic. I've searched for a nice...

I'm reading a research paper and they bring up the term "natal kick". And google didn't turn up a great explanation immediately so I thought I'd check here. Can anyone help me? Thanks.

I accept that the FAQ section is there to cut down on repetitive questions, but this arises out of an answer in the FAQs. Would this line of reasoning not lead to the conclusion that, even without an inertial frame of its own, a photon would not be able to be stationary relative to itself?

I have been doing some study on the theory of relativity and it has got me thinking. We say that the Earth revolves around the Sun but from what reference frame? From the reference frame of Earch, we are stationery and the Sun simply spins. Why is any reference frame more accurate than another...

Homework Statement Find the reference angle of - \frac{7\pi}{6} Homework Equations - The Attempt at a Solution I can tell you right now, that the answer is pi / 6. My method would be to sketch the angle, find out at which point the appropriate x axis-coordinate will be used...

Homework Statement Is it possible to reference Lemmas inside another Lemma? That is, while you are trying to prove a lemma, you refer to another lemma you have just proven. Is this accepted? Homework Equations None. The Attempt at a Solution None.

Hi... Can anyone one give me a good reference for the decomposition of perturbations into independent scalar, vector and tensor parts, with all the gory details?

My thinking has been that a photon, in its own F of R, in a vacuum, travels through space, but not through time. This seems to have been "confirmed" in various things I have read. However, I recently came across the assertion that "...in physics, there is no theory that defines the frame...

Does special relativity hold between two inertial reference frames that are undergoing relative acceleration? For example, consider two spaceships traveling toward each other on parallel (but not collinear) trajectories. They would pass each other at some non-zero distance, and thus their...

I'm working on 3.19 from Schaum's Outlines: Basic Circuit Analysis (not homework). The problem can be found at this...

Hello.. Am working for my FYP concerning prosthetic arm, so i have to take data from EMG sensors which are on the surface of the body. The first step of my project is signal conditioning and filtering, so i was searching for circuits concerning signal conditioning and i got the circuit in the...

***not homework for any class*** Title: "Preserving Magnetic Polarity in a Revolving Reference Frame" Problem: How can a revolving reference frame (assuming an uncharged observer with negligible mass) observe the same polarity for a magnet in the case where the rotational speed is great enough...

So I was studying some physics, and I keep encountering how many things depend on the frame of reference. For example, kinetic energy and momentum. My question is if there is an absolute frame of reference? Can we define one? I remember reading somewhere that the absolute reference...

Hi, I have a simple question in my mind, I could not find the answer anywhere so I came here. Here is my question, Assume a source of light and observer are five light seconds apart, and are travling parllel to each other at a constant speed of say 200 meters per second. Now if the source of...

Homework Statement Not really a homework/coursework problem, I'm just trying to make sense of some class notes from our chapter on special relativity. I'm trying to find the expression for electromagnetic wave propagation in a reference frame S' that is moving at a constant velocity with...

This is what my teacher told me, but I still don't really see how it works. Say a person is in a car traveling at constant velocity, and it crashes into a tree, from an inertial frame of reference (the road), the person in the car continues traveling at the constant velocity of the car until...