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The Doppler Effect See related link
Due to the Doppler effect, the faster a body moves away from you the larger its wavelength - meaning it tends to get more red. It was discovered that the further away a galaxy is from us, it is moving faster. So large redshift means a galaxy that is very far away.
It refers to an increase in frequency (and decrease in wavelength) of light or other electromagnetic waves, if the object that emits the waves is moving towards us. The opposite is REDSHIFT, which happens when the object moves away from us.
When wavelength increases, frequency decreases.
without energy there cannot be a wavelength.
It's not that a particular color has the longest wavelength. The wavelength BECOMES longer when a star moves away from us. Red light has a longer wavelength than blue, for example.
Astronomers determine whether a star is moving toward or away from the Earth via the Doppler effect. Imagine a motorcycle moving past you. As it drives towards you, it has a higher frequency, and a lower frequency when it drives away. The same thing happens with light. As an object moves towards us, its light has a higher frequency and lower wavelength - this is called blueshift. As an object moves away from us, its light has a lower frequency and higher wavelength - this is called redshift.
Astronomers determine whether a star is moving toward or away from the Earth via the Doppler effect. Imagine a motorcycle moving past you. As it drives towards you, it has a higher frequency, and a lower frequency when it drives away. The same thing happens with light. As an object moves towards us, its light has a higher frequency and lower wavelength - this is called blueshift. As an object moves away from us, its light has a lower frequency and higher wavelength - this is called redshift.
By examining its spectrum, and identifying absorption lines in it. Lines are shifted toward shorter wavelength if the object is moving towards us. They're shifted toward longer wavelength if the object is moving away from us.
Stars in the universe are all moving away from us, so their wavelength will be red shifted. When the source of a sound is moving away from us, the wavelength of the sound will increase, i.e. the frequency will lower. In both cases, this is known as Doppler shift.
The "doppler effect" (see link below) describes what happens to an observer who is moving toward or away for the source of any type of propagation wave such as light or sound.If we are moving rapidly toward any object which is transmitting an electromagnetic wave - or if it is moving toward us - the waves are "compressed" and we perceive them to be of a higher frequency than was originally emitted. With light, "higher frequency" means "more bluish", while "lower frequency" means "more reddish".So scientists refer to the increasing wave frequency as a "blue shift", while a decreasing frequency, meaning movement away from us, is a "red shift".
The Doppler Effect.
Light had properties of frequency that related to colour. It is apparently contract in the direction moving toward the observer (higher frequency-short wavelength) and apparently elongated in the direction moving away from observer (lower frequency-high wavelength). What moving toward us is tend to be look more blue than usual (blue shift) and what away from us is redder than usual (red shift).
The Doppler Effect See related link
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 an object is moving away from you and there are no forces acting on it,then it continues moving in a straight line at constant speed.
The star is moving away from us. Therefore, the Doppler effect must be considered. The Doppler effect is waves (in this case light) will be compressed in front of a moving object and stretched behind the object. This stretching creates a long wavelength. Red light has a long wavelength (the longest of visible light), so we call this stretching red shift.