Doppler shift Definition and 141 Threads

Doppler shift with microwaves...i think... Homework Statement Microwaves, which travel at the speed of light, are reflected from a distant airplane approaching the microwave source. It is found that when the reflected waves are beat against the waves radiating from the source, the beat...

Homework Statement What sort of frequency shift does a rocket ship traveling along the x-axis as some speed close to c observe when it passes directly over a light source emitting photon on the y-axis (so when the angle between them is 90 degrees). At this angle, the rocket is neither...

I've heard it said that it is impossible to determine an objects absolute velocity, all one can do is find it relative to some other object... but, if the CMB is everywhere, why could you not just measure the doppler shift in all directions, and adjust your velocity so the CMB has no doppler...

Homework Statement Derive the doppler shift equation from the equation in terms of frequency to one in terms of wavelenght. Clues: frequency=c/lamda, use Taylor's expansion, velocity of source is much smaller than velocity of wave. c-velocity of wave v-velocity of source f-frequency...

Alice and Bob are each in their own spaceship, and are traveling radially, initially away from each other, and subsequently toward each other, at some highly relativistic relative speed, say 99c. Each ship emits light flashes toward the other. Alice observes the light from Bob's outbound...

I am trying to grasp how Maxwell's equations and energy/photons are related in a doppler shift problem. The way I stated it seems to have attracted non-serious hecklers; so I am trying to restate the problem for people who know Maxwell's equations and are familiar with engineering. In...

I chose to write an essay on the "interesting" question I stumbled upon For part of it I am trying to calculate the Doppler shift in light with the relative motion of C. I suppose in the effort to not drone on for days I will first limit it to small, more simple questions and later,if we...

Homework Statement How fast would a motorist have to be traveling for a yellow (l = 595 nm) traffic light to appear green (l = 550 nm) because of the Doppler shift? Homework Equations v=[(c)(f0/fs)2-c] / [(f0/fs)2+1] The Attempt at a Solution v= Speed of motorist c= Speed of light...

Presenting the aberration of light effect we consider that two observers at rest in I and I' in the standard configuration equipped with laser guns start to emit light when they are instantly located at the same point in space. The problem is to find out a relationsship between the directions...

The formula which accounts for the Doppler shift is derived from the invarainace of the phase of a plane wave. [1] The plane wave is a mathematical construction associated with an infinite source os oscillation or with a very high source-receiver distance. The same formula is derived...

Were there any experiments that proved doppler shift of light on a fast moving object - that it has higher frequency if the object is moving towards you and lower if the object is moving away?

If not Doppler, what type of transformation does Hubble's law utilize?

Random question that I thought of while trying to fall asleep last night. :) We all know that galaxies moving very fast away from us exhibit visual redshift. If gravity waves / gravitons are real, they must then have a frequency of some kind. Does the frequency of a gravity wave affect...

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...

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...

[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...

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...

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...

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...

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...

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 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...

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...

Homework Statement The hydrogen atoms in a star are also moving at high velocity because of the random motions caused by their high temperature. As a result, each atom is Doppler shifted a little bit differently, leading to a finite width of each spectral line, such as the 656.46-nm line we...

I have to calculate the suns period time, when given the following information; "The H_{alpha} line has the wavelength \lambda_0 = 656.1~nm . Measuring this spectrum from opposite sites of the suns equator, shows that there is a difference between that is \Delta \lambda=9\times 10^{-12}~m ...

Hi all. I was reading: http://www.astro.ucla.edu/~wright/doppler.htm but I'm failing to understand this part: My understanding is that a galaxy cannot move faster than c (the speed of light). Why then could a galaxy moving close to c have a recession velocity greater than the speed of light...

I am to measure the rotational velocity of Io relative to Jupiter, and will do so using a spectrograph. I will measure the frequency change of a specific mineral emmision band in the spectra, and then check how much it has shifted from its original wavelenght with a table. Then I use the...

do you get a doppler shift when your moving towards a light source? like, i know light gets redshifted with expanding space and gravity, but if light always approaches you at the same speed, how would frequency change there?

For the relativistic doppler shift: change in wavelength = (c - Vs) To / (1 - Vs ^2 /c^2)^1/2 where Vs is emitter velocity, c is speed of light and To is time. Suppose change in wavelength was equal to just 1 / (1 - Vs ^2 / c^2)^1/2 then (c - Vs) To = 1 c -Vs = 1 / To c = Vs + 1...

A train moving toward a detector at 31m/s blows a 305-Hz horn. What frequency is detected by a statiory train? Using the equation f´= f(V + Vd/ V - Vs) The answer is supposed to be 340-Hz but I don't understand how to get it. Mind helping me out?

What is "FOR"? doppler shift? What is "FOR"? I believe it an acronym having to do with the doppler shift? :confused:

Photon Doppler Shift? I am a practicing EE who has used the standard Doppler shift equation for thirty years in radar design; therefore, I am not disputing the correctness of the equation but the "explanation" that is so often given in textbooks. The general explanation always discusses...

relativistic doppler shift I'm trying to show that this equation for the doppler shift for light: f' = [&radic;(1+(v/c))/&radic;(1-(v/c))] * f reduces to &Delta;f/f = -v/c for v<<c So I expanded (1+v/c)^(1/2) = 1 + v/(2c) and (1-v/c)^(1/2) = 1 - v/(2c) dropping higher order terms on the...

My book derives two formulas for Doppler shift. One for when the source moves and one for when the observer moves. What about when both are moving? I tried deriving it myself... but I couldn't :( If you want, you could just give me a hint on how to derive it.

i've been having a tough time trying to solve the following problem. A pulsating star has a period of 3 sec as seen from the rest mass frame of the star. What is the period of the star as measured by an observer traveling 2.2e8 m/s with respect to the star? I assumed that it was simply...

Suppose we have a weightless light source that is moving. Its output light will therefore undergo a Doppler shift. Now, if the lightsource had weight but were static, its light would undergo a red shift. If the light source had weight and were moving, would it undergo both a red shift and a...

I’m on a train sitting next to an open window - it’s a bit stuffy - traveling towards a station. A siren is sounding at the station. As I travel toward the siren its pitch is higher that it would be if I were stood on the platform. Once I have passed the siren and I’m moving away, its pitch...