What do red shifts and blue shifts mean?

Question

when dealing with space

Answer 1

This is something related to what is called the Doppler effect. You can experience it first hand when a police car is approaching and then going away: the sound of the siren is higher pitched when it is getting closer, and lower pitched when it goes away.
The same effect occurs with light. A light emitter -- a star of a whole galaxy -- will seem to be bluer (higher frequency) if it is getting closer, or redder if it is moving away. How much bluer or redder is called blue (or red) shift. If one knows what should be the neutral color of the light (and we do, thanks to the spectroscopic lines of emission) then the speed of the object can be derived by said amount of blue or red shift. This is what allowed Edwin Hubble to deduct that the universe was in expansion, as most galaxies have a redshift that is greater the further they are.

Answer 2

Red Shift & Blue Shift
A light source moving away from the listener (v is positive) would provide an fL that is less than fS. In the visible light spectrum, this causes a shift toward the red end of the light spectrum, so it is called a red shift. When the light source is moving toward the listener (v is negative), then fL is greater than fS. In the visible light spectrum, this causes a shift toward the high-frequency end of the light spectrum. For some reason, violet got the short end of the stick and such frequency shift is actually called a blue shift. Obviously, in the area of the electromagnetic spectrum outside of the visible light spectrum, these shifts might not actually be toward red and blue. If you're in the infrared, for example, you're ironically shifting away from red when you experience a "red shift."

Answer 3

Hi. Star light (and Sun light too) contains lines of brightness (emission lines) and lines of darkness (absorption lines). These lines happen at very particular frequencies. It is the relative motion of these lines that get shifted by the Doppler effect. Stars moving away from us, mostly in distant galaxies, have the lines shifted toward the red end of the spectrum.

Answer 4

This refers to how other stellar objects are either moving toward, or away from us. It is similar to the effect you get when a car or a train is approaching your location, then passes you by and starts heading away from you. The noise it makes goes from a higher pitch to a lower pitch as it passes you. So it is with stars, galaxies, etc. If we are receiving light from them that is shifted toward the blue end of the light spectrum, they are moving toward us. If the light we receive from them is shifted toward the Red end of the spectrum, then they are moving away. Scientists can determine how fast they are moving by howm much of a blue shift or red shift exists.

Answer 5

A red shift is when a star is moving closer to earth, and a blue shift is for stars moving away from earth.

Answer 6

Republicans are red and Democrats are blue. Every few years we have elections and the reds and blues shift.

Answer 7

It is the doppler effect with respects to light waves in lieu of sound waves

Answer 8

soething coming closer and nearer to something