A red shift indicates an object that is moving away from the observer, and a blue shift indicates an object that is moving toward the observer. Both of these are called Doppler shifts.
If you were on a plant looking into the stars the sun would be blue shifted. When looking up at the sky we see the sun moving towards us making it look smaller.
If a star is moving toward Earth, it will experience a redshift in its light spectrum due to the Doppler effect. This means that the wavelengths of light will be stretched and appear more red. This effect allows astronomers to measure the speed and direction of a star's movement.
The relative motion between the observer and wave source causes an apparent change in frequency which is known as Doppler Effect. On combination with identification of spectra, it can also be used to find if the start is moving away or towards the earth, When there is shift in lines of spectra towards the red end of visible spectrum the star is said to be travelling away from the earth.
blue shifted
They are not actually, moving, they just appear to be moving because we are. Consider that if you are on a train moving forward, objects that you pass by appear to move toward the read of the train.
blue shifted
blue shifted
If you were on a plant looking into the stars the sun would be blue shifted. When looking up at the sky we see the sun moving towards us making it look smaller.
If a star is moving toward Earth, it will experience a redshift in its light spectrum due to the Doppler effect. This means that the wavelengths of light will be stretched and appear more red. This effect allows astronomers to measure the speed and direction of a star's movement.
Distant stars appear red shifted because they are travelling away from Earth. It just happens that more distant stars are moving faster, so there is a greater red-shift the further a star is from the Earth.
No, an object not moving relative to Earth is not a blue shifted object. With no relative motion, an object will not be subject to Doppler effect and will not red or blue shift. For an object to be blue shifted, the distance between the object and Earth must be decreasing. The object must be closing on Earth or vice versa.
The clouds appear to move across the sky because of the Earth's rotation.
Because of Earth's rotation.
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.
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.
If a galaxy is moving towards the Earth, its spectrum will be blueshifted. This means that the wavelengths of its emitted light are compressed, resulting in a shift towards the blue end of the spectrum.
If the Universe was shrinking the galaxies would appear to be moving towards the Earth, and look more blue than they should. This is the opposite to the universe expanding where galaxies would appear to be moving away from the Earth, which we know due to "red shift". Andromeda would be the exception since it's directly moving towards the Milky Way.