Reference Definition and 1000 Threads

quantum optics is a reference to a "c-number" Hi In my lecture notes on quantum optics is a reference to a "c-number" electric field, and it is stated that, since it is a c-number, there is no corresponding Hamiltonian. As far as I have understood, a c-number is a classical value of some...

Hello All, The following may be a simple problem. But, your thoughts will be very much appreciated. Homework Statement Let's use a gun with mass m1 and a bullet m2. The bullet is fired in the positive direction with speed v2, and the gun recoils in the negative direction with speed v1...

If we have light, any particle, and maybe car, the particles travel at 0.98c and car let say 50m/s. Let them start moving at the same time to the given point let say 300 metres away. The difference between times of arrival of light and particle will be small compared to that between light and...

Hi, Anybody used TI's SN74LV132 'NAND Gate with schmitt trigger i/p' in their design or any other similar part ? If so, please send me any Reference schematics or application notes.

Hey guys, I am having some problems with the concept of inertial/non-inertial frames of reference and their applications in engineering dynamics. So I've learned that a given frame of reference is defined to be non-inertial when something in the studied system can only be explained through...

Homework Statement A 20g ball of clay is shot to the right at 12m/s toward a 40g ball of clay at rest. The two balls of clay collide and stick together. Call this reference frame S. Homework Equations What is the velocity of a reference frame S' in which the total momentum is zero...

This thought experiment involves two people named Person-A and Person-B. Person-A fires a gun from a car which is traveling at 60mph. Imagine that the bullet travels at a constant speed of 300mph for some time, assuming that the air friction is ignored. Person-B is stationary observing the...

Hello, I am having difficulty understanding the concept of Newton's first law only applying in an inertial reference frame, or a frame that is at constant velocity, however, apparently the 1st law no longer applies if the reference frame is accelerating. Can anyone give me some sort of concrete...

is the question

Hi, I'm looking for a QM mechanics book, which I could use for review and reference. I've took 3 QM courses, the first two was based on Cohen-tannoudji and Sakurai, and the third was about atoms and molecules etc. , although I haven't studied scattering theory and relativistic QM/QFT. (I took...

According to this, if someone spins around at 2 revs per second when the moon is in the horizon, the moon seems to move at 4 times the speed of light. And this implies the moon is not in our local reference frame. And per this, local inertial frame applies to "small regions of a gravitational...

How to choose an adequate reference electrode and what is the principal mechanism?

Hello. I am new to the idea of Special Relativity. From what I have read, based on what speed something is traveling it experiences an increase in mass. Let's say I am standing on the earth. I am experiencing a gravitational force of (me(m))/r^2. Now let's say I am the same person that somehow...

Homework Statement I a little lost on how to use the relativistic velocity addition formula to determine the increase in speed "v" over a short time interval in the Earths frame of reference, for a rocket having left Earth at rest and traveling through space accelerating at constant acc. of...

Homework Statement The electron is traveling at a speed of β=.9999999, γ=1957, with mass mc^2=.51099 MeV. The Proton is traveling at a speed of β=.9, γ=2.29, with mass mc^2=938.27 MeV. They are heading in opposite directions, directly towards each other on the x-axis Find the reference...

The initial presentation of Newton’s Laws of Motion (NLM) to students often proceeds as follow: 1. The 3 laws are presented, 2. The caveat that the laws are only valid in Inertial Reference Frames (IRFs) is (sheepishly) mentioned, 3. An attempt is made to define an IRF, and 4. Some examples...

If you a mass being accelerated by a force which is acting upon a spring attached to the mass it will exhibit harmonic motion. However unlike a fixed harmonic oscillator there is no explicit solution to the equation which describes the motion of the mass in a reference frame outside of the...

As I understand in SR light is always c in it's local reference frame regardless of a present gravitational field. Light would appear to be traveling slightly less than c in a gravitational field otherwise known as the Sharpio Delay in all non-local reference frames. Now, light must be traveling...

reference in "the origin of species" I've been reading Darwin's "The Origin of Species". It turns out the benefit isn't so much seeing a familiar theory in original form, although there is a fascination in seeing evolution described without knowing Mendellian inheritance. The best benefit is...

Homework Statement Do objects same kinetic energy in all inertial reference frames? For objects interacting, is energy conserved in all inertial reference frames? Homework Equations None The Attempt at a Solution I think the answers are No for the first one, and Yes for the...

Can someone give me a clue/hint to finish this question? "In a reference frame S, the electric and magnetic fields of an electromagnetic wave E and B are perpendicular to each other. Determine the velocity of a reference frame S' in which (a) E' = 0 and (b) B' = 0"

Hello all :smile: I am trying to sort out how to use pass by reference properly and I am getting a Build error related to my pass by reference function. Perhaps someone could help me out here. I thought I was doing this correctly by reading my text, but apparently not. Maybe someone can...

I am re-posting this question here in a new thread as Humber mistakenly posted it in a two year old thread.

Is it possible for a particle to exist according to one reference frame and simultaneously not exist according to another? If energy is relative, can a collision between two particles have enough energy to produce new particles according to its own reference frame but not have said amount of...

I found out that Proxima Centauri is 4.2 light years away from earth. If someone was on a voyage to this star via space ship, would this person measure the time to be shorter than 4.2 years if their spaceship was traveling 99.99999 percent the speed of light, assuming that the 4.2 years is...

Is this correct? There are two clocks on Earth that are synchronized. One clock goes out on a spaceship at .8c. Now according to the stationary or Earth FOR one year goes by for its clock but he sees that only .6 of a year has gone by on the clock of the spaceship. Now the spaceship...

i came over the terms 'inertial' and 'non-inertial' frames during the study of rotational motion...pls clarify the difference...! plus can anyone give me a link from where i can practice numericals of angular momentum, moment of inertia, torque..

So what will it see it self as?? At rest or moving a velocity c? Either way it seems to be a contradiction, so does that mean a photon can't be reference frame?

Last thread that I initiated was titled `Simultaneity is directional while Time Dilation is not', which presented a scenario for the Non-directional property of Time Dilation in STR. Which I think, needs to be reconsidered. And I believe this is the reason why `STR can only be worked out when we...

Post any thoughts or ideas here.

The speed of light, the term "light year", and reference frames. Hi everyone. This is my first post, and I post out of desperation. A friend of mine and I were casually discussing Time Dilation, interstellar travel, etc. when we came to a point we fundamentally disagreed upon. Neither of us...

Homework Statement A particle moves in a rotating reference frame along the x-axis as x(t) = xo eat (xo and a are positive constants). The frame rotates with a time-dependant angular frequency ω(t) about the x-axis. The true physical force is in the x-direction of the rotating frame. Break up...

Please excuse my ignorance - I am a biologist by training - but this is one of those questions that just keeps bothering me and I can't find the answer with Google/Wikipedia. Take as our example the ocean currents on the Earth caused by the Coriolis Effect of the Earth turning. When I read up...

I have been reading Einsteins Relativity and a simple concept in special relativity is tripping me up. I have heard that an object can never reach the speed of light. To which observer is this speed limit seen by. I know your answer will be "By all observers" but that is what I don't get...

The first law of motion says that it takes force to accelerate something. The second law of motion says that F=ma. So now my teacher says that the first law is for inertial reference frames, while the second is for non-inertial reference frames. This really annoys me because I don't...

If one wants to calculate the elapsed time from the perspective of an object A moving at velocity, v, for time, t, relative to a stationary object B, all you have to do is calculate: \int_{t_o}^{t_f}\frac{t}{\gamma} Of course, \gamma has no dependence on t because v is constant, so we get...

Hi, Currently, I need to read some reference about Integrable System, but I am stuck in Riemann Surface, genus, divisors, and Riemann Theta Functions. This makes me anxious. Is there introduction or pedagogical reference on this topic? I think I can spend some time read it during winter...

Hi, I've been listening to a Professor Jim Al-Khalil's scipod on time travel. I think this guy is bloody excellent by the way. http://reader.mac.com/mobile/v1/http%3A%2F%2Fwww.jimal-khalili.com%2Fpodcast%2Fjim.rss Anyway, He said to an observer on the Earth a clock on a...

a frame of reference is moving with a constant velocity with respect to a inertial frame of reference,then moving frame will be inertial itself?

Hello; I'am asking about the best textbook or refrence in particle & high energy physics ?

The experts say the age of the universe is known with considerable accuracy. What frame of reference are they using and why doesn't it violate the idea of relativity to claim to have a preferred frame?

Hello there I have 2 questions: 1. Can one change the coordinate system of torque vectors through a homogeneous transformation matrix with both rotation and displacement? 2. What's the procedure to add two torque vectors about different axes? Thanks in advance, João

An inertial frame is one which is not accelerating. i.e if I'm sitting in an accelerating bus or plane I'm not an inertial observer however if I am in a bus or train traveling at a constant velocity i.e zero acceleration then I am an inertial observer. One thing Id like to ask here is that...

- http://www.physicsinsights.org/glossary.html I'm often unsure whether people are using "frame" to mean a chart, or a basis field of tangent vectors, or a basis for an individual tangent space. Have I got this (more or less) right? (1) A MCRF of a pointlike object is a function that...

Is there really an absolute reference frame?? According to mechanics as we understand today, all reference frames are equally valid in analysing in the universe, whether measurements are taken relative to the earth/sun... However if all reference frames are equal, why can't we take...

Hi All! I found discussions on this here while researching the subject to see if anyone else has attempted to explore the subject. I saw that several people asked questions pertaining to this, but the question was never really answered. It seemed unanswerable. While many discussions of...

Hey all! For awhile, I have been looking for a .pdf version of a math notation sheet, similar to these sites: http://www.rapidtables.com/math/symbols/Basic_Math_Symbols.htm http://en.wikipedia.org/wiki/List_of_mathematical_symbols I like the way they have the notation in LaTeX, have a meaning...

Homework Statement Challenge: a rather eccentric group of astronomy students wanted to celebrate the impact of the Shoemaker-Levy comet on Jupiter by holding a party of sufficiently long duration that their celebrations were simultaneous with the impact of the comet in all inertial reference...

Homework Statement A frame is accelerating uniformly along the x-axis relative to an inertial frame (x,y,z) with acceleration a.Find the transformation between the frames given that the origins concide at t=0. Homework Equations The lorentz transformations cannot apply here ,but what...

Hi friends, I need the average speed of sound in some common solids, such as Si, Cu and Al, over temperature ranges from 100K to 500K. After 5 hours of surveying acoustic and physical properties handbooks and googling the web, what I find is almost nothing. Does anybody know a...