Shift Definition and 614 Threads

Hello, I am well and truly stumped on Doppler shift. The complete expression is f'=f \gamma (1-\beta cos(\theta)) where: \beta=v/c v=source\ velocity \gamma=\frac{1}{\sqrt{1-\beta^{2}}} \theta is the angle between received photons (lab frame) and the direction of motion of...

Bacteria Make Major Evolutionary Shift in the Lab This is pretty cool.

I hardly understand anything about relativity (as would be evident from my threads and posts), and thus, this dumb question. If there is only length contraction, and not length expansion, why do we have two shifts, namely redshift and blue shift? should not only there be only blue shift due to...

If I use the following code in Mathematica f1[t_] := Cos[w t + d1]; f2[t_] := Cos[w t + d2]; data1 = Table[f1[t], {t,1,10000}]; data2 = Table[f2[t], {t,1,10000}]; ft1 = Fourier[data1]; ft2 = Fourier[data2]; To take the Fourier transform of two data sets, how can I use the resulting data...

Homework Statement A distant star at rest with respect to an observer on Earth emits light of frequency 6.690 x 10^14 Hz. The star breaks up into two remnants of equal mass, which are observed to emit light of frequency 7.135 x 10^14 Hz and 4.282 x 10^14 Hz Find the velocities of the...

Homework Statement The full expression for the relativitic Doppler Shift is v' = v \gamma [1- \beta cos \theta] where v' and v are the frequencies of the light source in its own rest frame and and in the laboraty respectivley. \theta is the (laboratory) anglebetween the direction of...

This is a cool little video about statistics. I know some are right, most I haven't bothered to verify yet. Anyone that has any statistics that agree or disagree would be welcomed. Of course the part about the supercomputer's capacity and processing doesn't mean it has the ability to think...

Wiki If speed susceptible to Doppler's effect. Why shouldn't field since we're so determine they have a speed?

Hello everybody. I'm trying to build a sound direction localising subsystem for a robot. I have two microphones placed a distance apart. I'm not worried about sounds behind or the distance, just the direction. I see two choices. Phase shift detection or a neural sim of interaural time...

Consider a charge oscillating along the Y axis. EM waves are emitted around it and hits an observer further down the X axis. The charge then gains speed along the X axis, moving towards the observer. He notes a blueshift in the measured EM wave, ie the Doppler effect. My question is... Will...

First of all - please don't give me warnings if I write something that is not correct here. I'm just trying to understand the Big Bang theory, and I have some problems with it. OK, the red shift. What does it indicate? I don't believe it indicates velocity and distance, because there are...

What's the difference between Phase, Phase Difference and Phase Shift in terms of waves? I've taken a look to Wikipedia and a few other sites already, so please do not forward me to them...

[SOLVED] Doppler Shift and Beats Homework Statement A car horn sounds a pure tone as the car approaches a wall. A stationary listener behind the car hears an average frequency of 250Hz, which pulsates (beats) at 12 Hz. What is the speed of the car? The speed of sound is assumed to be 331...

[SOLVED] Le Chatelier's Principle - What is an equilibrium shift? When my chemistry textbook says, "the equilibrium shifts to the right", what does it mean? Is it increasing the rate of the forward reaction to accomplish this? If a shift in equilibrium is not a change in the rate of...

I've been trying this for 3 hours and I'm getting nowhere. These are the graphs I made for Hydrogen Intensity vs Frequency for a radio telescope that transits the sun and galactic arms of the galaxy. http://img220.imageshack.us/img220/5904/helpgraphia6.jpg...

Homework Statement The Doppler shift was first tested in 1845 by the French scientist B. Ballot. He had a trumpet player sound an A 440 Hz while riding on a flatcar pulled by a locomotive. At the same time, a stationary trumpeter played the same note. Ballot heard 3.0 beats per second. How...

Can anyone tell me what the doppler wavelength shift equation is? thanks

I have some issues with the current understanding of the cosmological red shifts and their interpretation using the spatial variation in the metric with time.To make the argument clear, I'm also posting pictures. The universe is depicted as the surface of a sphere but that doesn't affect the...

Hi! How can I time shift (ts) a real signal (N samples, T time period, dt sample rate, Fs sampling frequency) using matlab: Timeshift signal = ifft (fft(signal)*exp(2*i*pi*Fs*ts)) ? I am trying to do it this way and it is not working? For example how would you shift a Cos signal to...

I am working on the following problem. http://img244.imageshack.us/img244/9777/homeworkun4.jpg The Attempt at a Solution I realize that the relative phase shift between ray 1 and ray 2 will be \frac{4L}{\lambda} Next, I let \frac{4L}{\lambda_a}=1 and \frac{4L}{\lambda_b}=1.5 I did this...

Has anyone ever considered the possibility that the perceived Doppler effect of light from distant stars/galaxies is not caused by movement of the emitting bodies, but rather a side effect of light traveling extraordinarily long distances under the week gravitational force of the entire...

Folks, I've got a question. Is this definition correct? \delta _i = \frac{2\pi}{\lambda_i} * n_i * \cos \, \theta _i where \delta _i is the optical thickness of medium i \lambda _i is the wavelength in medium i (i.e. not \lambda _0, the vacuum wavelength) n_i is the refractive...

A distant galaxy is moving away from us at a speed of 1.85x10^7m/s. Starting from the formula for the doppler shifted frequency, derive a formula for the change in wavelength and hence calculate the fractional redshift (λ'-λ₀)/λ₀ in the light from the galaxy. I'm pretty confused at the moment...

Over a period of several years could the red shift of some ideal body be used to confirm the Hubble flow?

Homework Statement A source and an observer are each traveling at 0.52 times the speed of sound. The source emits sound waves at 1.2 kHz. (a) Find the observed frequency (in kHz) if the source and observer are moving toward each other. (b) Find the observed frequency (in Hz) if the...

I need help developing a theory of a general "shift function sequence transform" I'm new here and this is my first post. In 1999 I read part of "The Book of Numbers" by John Conway and Richard Guy and came across a section titled "Jackson's difference fans". In their book, there's no mention...

When the source is moving with respect to the observer, the emitted wave undergoes this well-known frequency shift (Doppler shift). But isn't there also a power shift? Let a source emit a signal (sound or light) with constant power, say P_0, and moves towards the observer with constant speed...

I've a gearbox from a 250 cc Honda engine. The pattern in one down and four up. This engine will be integrated into a car, so the changing of gears will be difficult with the foot pedal. wouldn't it ? :) . So i decided to integrate a small motor to the gear shift pedal so that it can change...

Homework Statement You are standing by the roadside as a truck approaches, and you measure the dominant frequency of the truck noise at 1100 Hz. As the truck passes, the frequency drops to 950 Hz. What is the truck's speed? Homework Equations f'= f (vsound)...

Energy of Photon/Red-shift, inflation, acceleration I have a few questions (following a short premise) below. I have been reading medieval philospohy recently and also some about the "Big Bang." What I am struck by is number of assumptions made in both fields. There is a large amount of...

BACKGROND: Myself and a number of others are doing a thing called Dynamic Soaring with our special purpose built radio controlled gliders. We are getting them going very fast; in the range of 300-320mph. We have verified a top speed of 309mph using radar guns but that is the highest that...

Is there a relationship between red shift of galxies and zero point energy? Has the zero point energy changed over time?

Hello friends! Would a star (O-Type) with max output peaking in the UV range, which was subject to (at distance) redshift 8 end up in the IR spectrum when its light approached earth? Would this be taking into consideration the doppler effect? BTW, yes this is somewhat an extension of my...

Question about phase shift SHM The displacement of an object is given by x(t)=x_mcos(\omega t+\phi) If the inital displacement is 0 and the initial v is in the negative x direction, then the phase constant must be ___rads I know that if x=o then the cosine of the phase must be 0...

What I want to do is apply a frequency-independent phase shift to a Gaussian Noise signal. Obviously I can just invert it to get a pi shift. Also I can take the Hilbert transform to get a pi/2 shift and I can invert that to give myself in effect a 3/2pi shift. BUT... what I want to do is to be...

We have measures that define the volt, amp, kilo, pressure, etc, etc, compared to these measures how accurate are red shift figures? i know that tolerances are only guaranteed in a machine shop if the temperature is within limits, and all the above can be tested time and time again, but how...

Can gravity be red-shifted? I've never seen this addressed directly, but I don't see how it couldn't be. If gravity isn't affected by the expansion of the universe, why isn't it? If it is red shifted, would this dimunition of gravity be like a repulsive force?

a Concept Question. Is there a Doppler Shift if the source and observer move in the same direction with the same velocity? Explain . Can someone drop their comments and ideas ..? please and thanks you.

I just accepted a job offer for a position stocking shelves in a grocery store... at night. I originally asked for a shipper/receiver position but eh, I wanted the job anyways. Anyways, I had my interview at 1pm and I start today for my first 8.5 hour shift at 11pm, in 2 hours. Ahh I am...

I have a single phase mains supply which I need to split it into two phases, then shift one of them by 90 degrees relative to the other (with peak values of both waveforms having the same magnitude). I know this is generally done by two branches in parallel, with a series capacitor in one...

help me guys... i reall need the answer ASAP...:cry: Thanx in advance..

I have a quick relativity question. Say an observer is moving at a relativistic velocity with respect to some light source that emits light at one particular frequency (the observer's path does not intersect the emitter). At the point of closest approach, will light from the emitter be Doppler...

Einstein in his "On the electrodynamics of moving bodies" (1905) starts the derivation of the Doppler shift formula by stating: In the system K, very far from the origin of coordinates let there be a sourcce of electromagnetic waves..." . Taking into account his advise "never stop thinking" we...

Hi. I get a signal from an acclereometer that I integrate using an op-amp to get the velocity. But the problem is that this signal is phase shiftet 90 degree. Because I'm supposed to compare this signal with a reference signal that is 180 degree phase shiftet, and now I'm getting wrong...

Hello, this is my first post. I am a programmer from Regina, SK Canada who likes to learn about Physics when I have spare time. My question: Does anyone know the name of the following solution for the perihelion shift? I do not know who to attribute it to. Thank you for your time. For...

Homework Statement A resistor of 362 Ohms is connected in series with a capacitor of 50.0 µF capacitance. A sinusoidal signal of f = 11.7 Hz experiences an impedance of 452.836 Ohms. Find the phase shift between the current and voltage at f = 11.7 Hz. Homework Equations I tried using...

I know that in spectroscopic Binaries, you can observe wavelength shifts in each star. But how do you determine the total radial velocity of this system alltogether, and how do you find each star's radial velocity?

I was playing around with a thought experiment where an observer is moving towards a light source at a speed infinitesimally less than C and it seems like, for any given wavelength, the maximum possible Doppler shift is 1/2. for example near infrared light with a wavelength of 800 nm would be...

I know that the variation of cosmological red shift with the distance is given by z= H_0 l (1+\frac{1}{2} (1+q_0) H_0 l) Where l is the luminosity distance, H_0 is the Hubble parameter at the corrent epoch and q_0 is the deceleration parameter. I would like to know how does z...

Ok, these are the general facts... - NASA states that the sun has gone through a polar shift on the year 2001 and will go through another one on 2012. http://www.gvnr.com/74/3.htm - For people who don't know, the Mayans had the most precise calendar of their time. The calendar states...