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When hearing to a sound from a moving source, we notice a change in pitch (frequency) as that source moves towards us, and then passes us and moves away, eg. think of the difference in sound frequency of fast moving cars if you've ever seen a formula 1 grand prix. This difference in pitch is due to the Doppler effect.
The Doppler effect can also be observed in light waves. To understand this, we first need to explore what is meant by a spectrum and how it is observed.
When white light passes through a prism, it is dispersed, in other words, split into its component colours (red, orange, yellow, green, blue, indigo, violet - the colours of the rainbow). This is known as the visible spectrum of light. The colours of the spectrum always appear in this order, and its important to remember that the colour of light depends on its frequency. Blue light has a high frequency, and red light a low frequency. Now, when we observe the spectrum of light from a hot glowing gas (such as hydrogen or helium as in a star), we won't see all the colours, but only certain lines (this is due to the change in energy levels of electrons within the H or He atoms). The resulting spectrum is known as a line emission spectrum. Since all stars are made of the same gases, when we look at their line emission spectra, the lines of colour should all be the same compared compared to each other.
However, we notice that the line spectra of distant stars are shifted closer to the red end of the spectrum, (the colours will be "redder") meaning that the light reaching us is at a lowerfrequency than we expect. This means that the source of the light, the star, "must" be moving, just as in the Doppler effect applied to sound, a car moving away from us would have a lower pitch.
If the moving object was approaching us, we would see light as a higher frequency, and therefore the lines in the emission spectra would shift toward the blue end of the spectrum.
The key to understanding the red shift is to remember the Doppler effect in terms of the moving car, and to remember that colour is the frequency ("pitch") of a light wave.
First: sound Doppler is not quite Relativistic Doppler.
Second: a shift towards the red end of the spectrum means the light has lost energy. Could be lost to movement, a Doppler shift, or could be lost due to gravity, a gravity-hole effect.
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Does the velocity of a star toward or away from earth determine measuring the shift of its spectral lines?
Yes. If the star is moving away from the Earth, its spectral lines will shift towards the red end of the spectrum. If it is moving towards the Earth, its spectral lines will shift towards the violet end of the spectrum. This is due to Doppler effect.
What does it mean when an astronomers observing starlight wa spectrograph notices shift at off lines to the red end of spectrum?
The star is moving away fro where it is. ~Justine... :))
What is the difference between the red shift and the blue shift?
A "redshift" is a change in the light observed from a source to longer wavelengths. That's a change from the blue end of the spectrum to the red end of the spectrum. A "blueshift" is the opposite. It's a change towards shorter wavelengths.
What does a blue shift of the light from a star indicate?
When light shifts toward the blue end of the spectrum, it is shifting in the direction of shorter wavelengths. This happens when a luminous object, such as a star, is moving toward you. This motion tends to compress the waves which it emits. Stars that are moving away from the observer will instead exhibit a red shift. The waves are stretching out, because of the motion. And because the universe is expanding, red shifts are by far the most common.
What does a blue shift of light from a star indicate?
When light shifts toward the blue end of the spectrum, it is shifting in the direction of shorter wavelengths. This happens when a luminous object, such as a star, is moving toward you. This motion tends to compress the waves which it emits. Stars that are moving away from the observer will instead exhibit a red shift. The waves are stretching out, because of the motion. And because the universe is expanding, red shifts are by far the most common.
Does the velocity of a star toward or away from earth determine measuring the shift of its spectral lines?
Yes. If the star is moving away from the Earth, its spectral lines will shift towards the red end of the spectrum. If it is moving towards the Earth, its spectral lines will shift towards the violet end of the spectrum. This is due to Doppler effect.
What does the blue shift mean in regard to stars and galaxies?
Light is a spectrum. On one end it is red and the other blue. We see light in this spectrum as waves and if it is blue, the object is coming toward us. If the waves are red than it is moving away. The frequency of these waves tell us how fast and object is moving toward or away from us.
When the wavelength of a spectral line emitted from an object increases which end of the visible light spectrum does not move toward and what is the objects motion relative to earth?
Increasing wavelength is an indication of a Doppler shift caused by an object moving away from the viewer. Longer wavelengths (of the visible spectrum) are redder, shorter wavelengths are bluer. Objects moving away from you have a red shift, objects moving toward you have a blue shift.
When the absorption line of a galaxy shift toward the blue end of the spectrum it means that the galaxy is?
It means the heading towards us, red means it is moving away from us.
What does it mean if a star is experiencing a red shift?
redshift is what happens when visible light gets longer in wavelength, thus shifting toward the red end of the spectrum of visible light. This is a phenomenon that occurs when the light source is moving away from the observer.
If light experiences the Doppler effect what will happen to its color?
If light is subject to the Doppler effect, it will change color. The light changes color toward the lower (red) end of the spectrum or the upper (blue) end of the spectrum. Which way the color shifts depends on whether the distance between the source and the observer is increasing or decreasing. Should we find the distance is increasing, the light will be shifted toward the red end of the spectrum. This is called redshift (one word), and astronomers know this well because most all galaxies are speeding away from the Milky Way and have their light shifted toward the red end of the spectrum. If the distance between a source and observer is decreasing, the color of the light will be shifted toward the blue end of the spectrum. In either case, the amount the color is shifted will be determined by the rate the distance between the source and observer is changing. If a galaxy is moving away from the Milky Way, we'll see a shift toward red, and if another galaxy is moving away faster, will see a greater shift in the color of the light from it.
What does it mean when an astronomers observing starlight wa spectrograph notices shift at off lines to the red end of spectrum?
The star is moving away fro where it is. ~Justine... :))
What is the difference between the red shift and the blue shift?
A "redshift" is a change in the light observed from a source to longer wavelengths. That's a change from the blue end of the spectrum to the red end of the spectrum. A "blueshift" is the opposite. It's a change towards shorter wavelengths.
What happen to the spectrum of a star moving toward the earth away from the earth?
If a star is moving towards Earth. The light is seen as 'blue shifted'. As we look at our sun, on the colour spectrum, black lines appear. When looking at distant stars, we can tell if they are moving away from us (Red shift) or getting closer to us (Blue shift). This is because the black lines shift to the red or blue end of the spectrum depending on which direction the star is travelling.
What did humble conclude when he noted that light emitted from stars is shifiting toward the red end of the electromagnectic spectrum?
This discovery led to the conclusion that the "red shift" is a property of stars moving away from us; i.e the galaxy is expanding.
What is a redshifted light called?
You may want to refine the question. Red shift is the systematic shift of spectral lines from very distant cosmic sources toward the red end of the spectrum. It seems to derive primarily from the Doppler effect, so one might say that it is Dopplered toward the red. I can think of no other specific name for it, so am not certain what you are asking.
What did hubble conclude when he noted that light emitted from stars is shifting toward the red end of the electromagnet spectrum?
Hubble, after some time, released that the Red Shift he was seeing meant that these stars were hurtling away from the Earth at a large velocity.
