Shift Definition and 614 Threads

This is a question on fluorescence spectroscopy so physics/chemistry. What causes a large Stokes shift in the spectra? I know what causes the shift in wavelength, i.e., a relaxation of vibrational states before de-excitation to the ground state, but what actually causes a (very) large Stokes...

I am new here and I have a question. Is it possible to shift between Everett's parallel universes in the form of your consciousness?

Find the function with the given derivative whose graph passes through point P. $$r'\left(\theta\right) =6+\sec^2 \left({\theta}\right), P\left(\frac{\pi}{4},0\right)$$ 6+sec^2(x) The phase shift appears to be 1 but not sure how to get that How do add another equation to desmos?

Hi, So when you over-excite the rotor of a synchronous motor, or under-excite the rotor of a synchronous generator, how is the flux actually changing the power factor of the armature to leading? (something to do with the magnitude of the armature reaction flux vector?) That is to ask: by what...

I know there is a pi phase shift when going from an area of lower index of refraction to higher. Is this phase shift still pi when going from a non-conducting dielectric with index of refraction n and reflection off a "good" conductor?

We see from wikipidea that EGSY8p7 z=8.68 13.2 is only a fraction away from the time of the BIG EVENT how close will a galaxy be to disprove the LCDM.

Homework Statement X-rays with wavelength 55pm are scattered from a graphite target. Consider an x-ray which is scattered from a valence electron at an angle of 180 degrees (back towards the x-ray source). a. Is the wavelength of the X-ray greater or less than before the collision? b. What is...

Is it theoretically/mathematically possible for light waves to be red-shifted so much that it's amplitude is equal to zero?

in the Haber process (N2 + 3H2 ⇔ 2NH3), if there are 2mol of N2, 3mol of H2 and 1mol of NH3, how do I know that the system is not in equilibrium and which direction will it shift?

My area of specialty has been geophysics for the last fifteen years, but I have been increasingly drawn toward mathematics, not the pure sort but the sort inspired by physics. Things like investigating the mathematical structure of physical theories and looking for connections between them...

Homework Statement Good Day, On an oscilloscope, when two incoming signals are out of phase, in an XY setting, an ellipse appears on the oscilloscope screen. The phase shift between the two incoming signals can be found by the formula: sin^{-1}((Y_{max})/(Y_{int})) where Y max is the...

I know we can shift the fermi level by doping the material with other elements. In case of semiconductors doping with the pentavalent or trivalent will change the fermi level. But my question is ''can we shift the fermi level, without altering the position of valence band and conduction band?"...

Capacitor-start induction motors use a capacitor in series with the start winding to create torque to start the motor. After the motor gets nearly up to full speed, a switch takes the capacitor out of the circuit. I understand the torque is caused by the phase shift created by having the...

hello, I'm a Phd student my Phd subject is about surface enhanced spectroscopy (SERS). i need a reference for the Raman Shifts of metals (ex: Gold (colloid or film), titan tungesten..). Plz if anyone can help me. thank you in advance Nicolas

Good day to you all, I wanted to share a struggle with you all that I can't seem to get out of. It's about calculating, in the case of sound, the decrease or increase in frequency (thus increase or decrease in wavelength) when a sound source is respectively moving away or towards an observer...

Hello, I'using Matlab to simulate phase shift in frequency domain (FD). I have got real and imaginary parts of the signal after FFT. I'd like to use phase shift in FD. This works: Y=fft(y); YY=Y.exp(-i*2*pi*nk/N*samples_delay); result=ifft(YY); But in my DSP I can't use the formula above and...

This is a question that I've had for years but because astrophysics and cosmology are down in the list of my interests, I constantly forget and remember the question. My question is, how do we know there is shift(red or blue) in the spectrum of the light coming from a star? Because for...

Homework Statement http://postimage.org/][/PLAIN] free picture upload Homework EquationsThe Attempt at a Solution I consider that if the fan is swinging, the source of sound (fan) will have an speed that lead to doppler's shift. but i can't calculate for this. i think speed of source will be...

What will you suggest someone for books which provide discussion on the Lamb shift (QED correction) of atomic energy levels?

i need thee the derivation of relativistic doppler shift. i found its derivation in the book of Serway, but it is not in detail and step by step. in the book there is given that: can anyone give me the step after eq#1.13? how eq#1.13 converted in the form of eq#1.14?

I have been studying the "fallen" photon experiment, in which the frequency of a photon changes as it falls through a height H. f'=f_0(1+\frac{gH}{c^2}) It is often stated that this is a huge factor in the application of GPS. However, I do not understand why. I understand that the photon will...

Homework Statement Prove that for any three vectors ##\hat a, \hat b ## and ## \hat c##, ##\hat a \cdot (\hat b \times \hat c)## = ##(\hat a \times \hat b) \cdot \hat c ## Homework Equations [/B] ## \hat i \cdot \hat i = \hat j \cdot \hat j = \hat k \cdot \hat k = (1)(1)\cos(0) = 1 ## ##...

hello, I have 3 signals in the form of sampled values. When I plot them using plot (t,vPa,t,vPb,t,vPc) where vPa, vPb, vPc contains the values and t contains the sampling istants I get this: when I calculate phase shift using fft I get phase angle = 0. I have tried using my own code ( which...

Dealing with CMB, people sometimes refer to the shift parameter; R = \sqrt{\frac{\Omega^0_m}{\Omega^0_k}}sinh(\sqrt{\Omega^0_k}\int^{z_{dec}}_{0}{\frac{dz}{E(z)}}) I know that it is related to the position of the first acoustic peak, however, the amount is around 1.7. What does this mean?! does...

Does anybody know a good read/primer that compares the observed cosmological redshift values to predictions made by the relativistic (gravitational) redshift? Thank you!

In contemplation and research regarding another thread's question about the asymmetry of doppler shift wrt the medium, I find myself trying to imagine two people talking... or perhaps better yet matching pitch. In still air with both people facing each other at ten paces of course they would...

Its always said that a reflected light ray acquires a phase shift equal to ## \pi ## if ## n_1 < n_2 ##. But considering the Fresnel coefficients, its revealed that its only for the s-polarization reflection coefficient that ## n_1 < n_2 ## causes the coefficient become negative. The...

Does light get red shifted during lensing, when it passes by an object with great mass such as a galaxy or cluster? If so then what are the effects on measurements of the CMBR and most distant red shifted galaxies? If true then presumably some light would be red shifted more than others...

Homework Statement In an NMR spectrum a CH2 group has a peak centred at 9.81 ppm. What is the shift in Larmor frequency of the protons from that of an unshielded proton if the spectrometer magnetic field is 9.4 T? The magnetogyric ratio of an unshielded proton is γH = 26.75 × 107 rad s-1T-1 2...

I am trying to derive the gravitational red shift effect but I think I am going about it all wrong. Specifically, I want to derive the change in frequency/ wavelength when a photon moves away from the surface of a star mass M and radius R. So I tried to use relativistic mass of the photon and I...

I am looking at derivations of the Doppler effect for sound and light, and I am very confused about what stays the same when it comes to sound. In this video, at 5:10, it is said that the wavelength will be the same. I'm not sure I agree with this because I'm pretty sure both the observed...

Hello to everyone! First I would like to go through one simple example: We have two bodies. One is wave source, other is wave receiver. In this example they are positioned like this: (source) O=====> (receiver) O=====> Distance between them is always 1000 m. Let's say that the waves are...

I understand that because galaxies are receding from us due to the expanding universe, that we see a red shift in the light from these galaxies. If there is a red shift, the light loses energy, but where does this lost energy go? Is it that in the photon's reference frame there is no change in...

Homework Statement As you stand by a railroad track a train passes with its whistle blowing. As it passes, you hear a frequency shift equal to 21 % of the frequency of the whistle. How fast is the train moving. Express your answer in km/hr.(Speed of sound is 331.4 m/s) Homework Equations f’ = f...

My basic understanding is that no matter how you observe light, it always a constant, it always travels at the speed of light. So even traveling at near the speed of light you will always measure light traveling at the speed of light. If this is the case? Why do we observe red shift?

Hello all I know that the step response of a second order underdamped system is : y(t) = 1 – (e^(-ζωn*t) / sin(θ))*sin(ωd*t + θ) Where sin(θ)= sqrt(1-ζ^2) , ωd = sqrt(ωn^2 – ωn^2 * ζ^2 ) my question is: I can see on the simulation ωd and I can calculate it , but I want also to see the...

So I saw this a moment ago: How can the second and third terms yield (n+1)+(n-1)=2n and not (n+1)+n=2n+1? PS: I solved the problem by using [a,a(+)]=1. Sorry, this is very simple but I cannot figure out what I did wrong.

Hi guys long time no see, I'm having a small difficulty here in understanding the process. Looking at the equation and the derivation of it, it seems clear that the shift in wavelength can only be caused by the target mass. If we are talking about electron being hit by x-ray, then I take it...

Does the expansion of space cause cosmological red-shift or does EM red-shift cause space to expand?

Many websites gives the results of Dew Point but not the reason. What is going on at the dew point? Not the result (at a certain VSP vapour becomes liquid if it can find nuclei to coat) but the reason for the result. I have been reading up on this – just out of curiosity – and would like...

Hi Folks, I have a function x {e^{-x}} and if i shift it one unit to the right on the x-axis we have (x-1) {e^{-(x-1)}} How do I show this mathematically? Even consider the simple case of x^2, if we shift by 1 unit to the right it becomes (x-1)^2 What is the method mathematically? Regards

If an observer and a visible light source are in relative motion such that the visible light source is blueshifted to ultraviolet frequencies, then would this visible-light-turned-ultraviolet-light being received by the observer have the same properties as that of actual ultraviolet light i.e...

I am trying to figure out when electrons are subject to an Aharonov-Bohm apparatus (the pick up a phase of +/- e(magnetic_flux)/(h_bar), how the interference fringes are shifted. I know de Broglie wavelength is given by lambda = h/p and that the fringe spacing without the vector potential is...

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?