Shift Definition and 653 Threads

Hi all, I understand the concept of red shift, and how it helped to explain how the universe was expanding and that most of the observable universe is moving away from us. It happens due to the wavelength of light increasing due to the expansion of space. As I understand it, it's not know how...

Dear Experts, When an electromagnetic wave moves from a rarer to a denser medium or gets reflected by a mirror, it encounters a phase shift of pi or (lambda/2), in that case, the reflected wave will be out of phase with the incident wave. I have a very basic (maybe non intuitive or even...

Hi, I'm trying to figure out exactly what colors a white light (i.e. the Sun) would look like to an observer traveling at varying relativistic velocities. Yes, moving away from it - red shift. Moving towards it - blue shift. In more detail, the human eye has a limited varying-amplitude...

Hello Forum, I understand how fluorescence works: there is an absorption spectrum and an emission spectrum. The two spectra are shifted relative to each other in the sense that the absorption peak wavelength is different from the emission peak wavelength (Stokes shift). That said, fluorescent...

Just some conceptual ideas that I don't understand A spaceship starts falling under gravity with an acceleration g as measured by an observer Barry at rest on Earth. At the instant that the ship starts to fall, an astronaut Harry at the base of the rocket ship sends a light signal of frequency...

Problem: In my class, we have been assigned a project where we must implement a shift and add algorithm to a set of xray images. There are 16 xray images of a finger joint taken with a 5 angle increment using a C-arm xray system. The xray images we will be given is from the second citation that...

How do scientists know if something is traveling away from us at any given moment, yes, it might be red, but it could be just a red dwarf star? How do they know it is the Doppler Effect in action, not just its natural colour?

Hi, I'm a medical student who is using ultrasound to measure cardiac strain. I'm trying to read up a bit on the physics behind doppler imaging (I did AP physics in high school), and I have a question for some genius out there. I keep reading that in pulsed wave doppler measurements, one does...

I am learning about transformers and from everything I've read I can see how its possible to create a 180 degree phase shift by winding the primary and the secondary in opposite directions. What I wanted to know was if it's possible to make a 90 degree phase shift with a transformer.

Hello all, so I've always wondered about the expansion of the universe as indicated by the observed doppler (red) shift... i get the observed spectrum change and how this can be credited to the stretching of electromagnetic waves... what doesn't make sense to me is that if this is due to a...

Would one expect the emission and absorption spectral lines for Hydrogen to be at slightly different frequencies ? So if electrons are excited to higher energy levels on absorption of photons and then fall back down again emitting photons, would there be any difference in frequency. Assuming...

1. Homework Statement You are standing on side of road and ambulance drives by. Smallest distance between you and ambulance is 4m. Ambulance v=10m/s^2. You have 2.2 GHz radar. Ambulance travels 100m with center of straight line directly across from you. Compute exact doppler shift by taking...

When a photon loses a little bit of energy, its frequency lows a little. That is, it suffers a slight redshift. So, why to interpret the redshift as being only due to the expansion of the Universe?

Homework Statement The Sun rotates with a period of 24.7 days and has a radius of 7.00 x 108 m. For a terrestrial observer, Calculate the resultant Doppler shift of light of wavelength 500 nm which is emitted from the solar equator at : i)each side of the disc, ii)the center of the solar disc...

I have come to learn that the Doppler shift equation is asymmetric. That is, the Doppler shift is not the same when source is moving towards the observer or when the observer is moving towards the observer (both with same speed). I have looked at the derivation of the Doppler shift equation...

For a school project I need to be able to shift the phase of a 100 kHz sine wave by 90 degrees (either positive or negative). I have tried several passive integrators and differentiators, both with poor results. I have also tried using an op-amp integrator and differentiator, but in both cases...

Relativistic frequency shift of satellite signal Homework Statement An Earth satellite used in the Global Positioning System moves in a circular orbit with period 11 h 58 min. (a) Determine the radius of its orbit. (b) Determine its speed. (c) The satellite contains an oscillator producing...

I want to know that ,I have read in many books regarding compton's effect that a photon collides with an electron and this collision is a head-on collision,but if this is a head-on collision then why both these particles are deflected by making a respective angle,don't they should move forward...

Homework Statement An RLC circuit has a resistance of 2.0 kΩ, a capacitance of 8.0 µF, and an inductance of 9.0 H. If the frequency of the alternating current is 4.0/π kHz, what is the phase shift between the current and the voltage? A) -1.6 rad B) -1.5 rad C) 36 rad D)...

So, I'm trying to study phase shift in an unbalanced rotating system (where "phase shift" means the resulting response of orbital motion lags behind in time/position relative to the force that's causing it) I know that conservation of angular momentum applies ideally in a closed system...

I apologize if this is a dumb question, or if I am not remembering things correctly, but ... ... wasn't one of the earliert objects (a Cepheid?) Hubble detected as red-shifted located within the Andromeda Galaxy? If so, and since we're on a "collision course" with the Andromeda, why didn't...

Homework Statement I need some help understanding how the phase shift was calculated in the following solved problem: So how did they work out the phase shift to be π? The Attempt at a Solution What formula have they used to find the phase shift? :confused: I couldn't find any notes in...

Homework Statement Part (a):Find the first order shift in energy Part(b): What is the degeneracy after perturbation? Find Show average shift in energy is zero. Homework Equations The Attempt at a Solution I've shown part (a), the troubling part is part (b). Part (b) With the perturbation...

Find the equation of a sine function with its first positive maximum point at (pi/5,8) and its next minimum point at (7pi/10,-2). With the sin form as y=a*sin[b*(x-c)] + d I found: a=[max-min]/2 = 5 b= 2pi/period= 2pi/(2*[max-min])=2 d=max+min/2=3 I am having troubles determining...

I have a short question which I have been discussing with a fellow student and a professor. The question (which is not a homework question!), is as follows: If you shift all the energies E_i \to E_i + E_0 (thus also shifting the mean energy U \to U + E_0), does the entropy of the system remain...

If we consider a point on the central part of a contracting object as observed from earth, the point is continuously moving away from us as the object contracts. Moreover, light emerges from a deeper gravitational well as the object contracts. So, shouldn't contracting objects show a red shift...

I'm learning about properties of Fourier transforms at the moment, and I've come across 2 terms "time-scaling" and frequency shift. A quick google search of time-scaling suggests that it is when I make the period of my signal longer (i.e a sine wave would take longer to finish 1 cycle) but...

Definition: ##f(x+k) = \exp(k \frac{d}{dx}) f(x)## So I thought, how take advantage this definition? Maybe it be usefull in integration like is the laplace transform. So I tried to integrate the expression ##\int f(x+k) dx = \int \exp(k \frac{d}{dx}) f(x) dx ## that is an integration by parts...

Homework Statement Space probes communicate with controllers on Earth using radio waves. Suppose a probe has a radio-transmitter that operates at a frequency of 516.0 MHz when at rest relative to the observer. This probe is now wandering the solar system. The signal you pick up from the probe...

Hi there, Let S denote the shift operator on the Hardy space on the unit disc H^2, that is (Sf)(z)=zf(z). My question is to show the following identity (1-\lambda S^*)^{-1}S^*f (z)=\frac{f(z)-f(\lambda)}{z-\lambda}, where \lambda,z\in\mathbb{D} Thanks in advance

I have a 13x16 led screen I'm making(leds are put together), but now I'm trying to set up 4x 74hc595's. I've looked online and lots of the site seam similar but don't work and I do not know/understand how I can get my arduino to send (for example have the shift registers do "1010101010101010").

phasor diagrams: what happens @ R=0? when R=0 and there is only the inductive impedance, what's the angle?

I understand mathematically etc how light can doppler shift when looked at as a wave but can it be understood how light doppler shifts as a photon i.e. could just one photon be doppler shifted? For example; Say there is an atom with energy levels 1 and 2. One observer, stationary relative to...

Homework Statement I've done physics in a non-english medium and I want to know what is the technical term to call the incident where the image is flipped vertical through a mirror. I mean if we stand infront of a mirror and raise the right arm, the mirror image shows we're raising the left...

In automatics,one needs to press the brake (i.e the brake shift interlock switch) to shift the car out of park. What damage would happen if the brake shift-interlock wasn't present. Has it got something to do with the Fottinger fluid clutch? i.e with the automatic "creep" effect?

I've just begun to study spectroscopy, and I need a clarification about the Doppler Effect. Consider a cell containing Rubidium and enlight it with a laser. Connect the system with an oscilloscope and give a triangular wave as input (so you can know when the Rubidium is resonant). This is the...

Hi there, When it sounds like I am hearing the world from underwater for a few hours/few days after a very loud music concert, is that what is called temporary threshold shift? Or is TTS something that occurs only during the exposure to high dB? (Eg. at the loud concert itself). Thank...

Hi. In light of that ridiculous Ham / Nye debate I have someone trying to explain away the red shift of light from galaxies by suggesting it could be due to the photons interacting with electrons or other subatomic particles en-route, thereby loosing energy and increasing their wavelength...

Homework Statement Given that you have found the following transfer function for a circuit, H(jω), what is the phase at very low frequencies? (jωRC-ω2LC)/((1-ω2LC) + jωRC) a:∏ b:-∏/2 c:+∏/2 d:0 The Attempt at a Solution I understand that the phase angle is ψ=arc tan(img(ω)/real(ω))...

questions asks to write the piecewise function as a unit step function and then to find the laplace transform t(e^t) 0≤t≤5 0 t≥3 I know it should be along the lines of t(e^t) - t(e^t)u(t-5) which then goes to t(e^t) - (t-5)(e^(t-5))u(t-5) I know there should be more to...

I'm aware of the doppler effect for sound waves. But light waves are different, e.g., light travels through a vacuum but sound does not. Has there been any laboratory confirmation for red shift for LIGHT. I could find only ONE paper by Bélopolsky, A. in 1901 using rotating mirrors. But there...

I'm curious whether it is at all possible to rent a stick shift car in the US, or are they all automatic? I just received my driving license and I'd like to practice, so a road trip is on my list. I need a vacation anyway :biggrin: The problem is that in Europe (the countries I checked) I need...

Dear All, I have a question about the optical properties of light in a metal. I need to solve a problem. Homework Statement a] Why is the phase shift in a metal neither 0 or pi? b] And calculate the phase shift of gold with a wavelength of 514 nm? n_real=0,5 and n_imaginary=1,85...

What is phase shift of qpsk when symbol change occurs ? Can anybody explain please ?

Hi guys, I have been wondering if its possible to alter equilibrium concentrations without adding stress to the system? Thanks, Larry

How do Doppler shifts work for light if, according to special relativity, light is constant velocity for all observers? So if c is unchanged, then surely wavelength and frequency don't change. I appreciate that I must be misunderstanding something, because redshift on stars occurs, but I am...

After going on a ghost tour over Halloween, several people were able to take photos of ghosts seen through an old hotel window, a few stories above our position. This got me to wonder if this was a trick that relied on the way that the digital cameras may be able to detect non-visible...

I did an experiment with two solenoids, one inside the other. The inner solenoid was hooked up to an AC power source and ammeter. The outer coil had a voltmeter. This is a faraday's law experiment. Because the current is changing, we can find a formula for the emf. Here are my math steps: So...

1.What is the Goos-Hnanchen shift and how i can find some physical interpretation about this concept? 2.whats physically happens when light path throughout the second medium? 3.please introduce me some references to know more about this shift.

Hello, the internet. I am attempting to graph Doppler Shift as a function of time for a music project. The equation for observed frequency is: fo=fs(c)/vs(c) Where fo is observed frequency fs is the source frequency c is the speed of sound vs is the velocity of the source But...