you don't, we ar ethe ones moving not the stars.
Only if you know your location (the coordinate on the distance scale and the time scale) where "you" are can you infer if the object is moving towards you (the absolute distance to the object is decreasing) or away from you (the distance is increasing).
Astronomers can determine the rotation of a galaxy by measuring the Doppler shift of the light emitted by stars and gas within the galaxy. The rotation speed can be calculated by observing the difference in wavelengths of light from objects moving towards or away from us. This information allows scientists to create maps of how the galaxy's stars and gas are moving.
blue shifted
Not nessicarily. Stars do move u know, cause the earth rotates.
Yes, the Doppler effect can be applied to light. Any wave function can be subject to the Doppler effect if there is relative motion between the source and an observer. That's how we know that the Universe is expanding.
Yes. Every star has a "proper motion", which is their motion relative to the solar system. Some stars are moving toward us, while others are moving away. Nothing is standing still. Of course, the Earth is moving around the Sun, and the Sun is orbiting the center of the galaxy, and the Milky Way galaxy itself is moving - but we can't know where. Every other galaxy is moving too, and there isn't a way to identify where the Big Bang started.
If you mean something like "crash into us", no, that isn't likely; it is far away for practical purposes, and as far as I know, it isn't moving exactly towards us.
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.
email her, talk to her on the phone and tell how you feel about her moving away
The apparent redshift is caused by the Doppler Effect; the frequency of waves is increased by an approaching source and decreased by a leaving source. Since the fgrequencies we see from stars are slightly lower than they should be, we know that the stars and other objects are moving away. The Doppler Effect causes changes of light emanating from distant stars and galaxies.
When a sound-source moves toward you, its pitch gets higher and the sound gets louder. When it moves away, the pitch lowers and it gets quieter. The frequency change is called the Doppler shift.
You've probably heard the old classical description of the Doppler effect; if you're standing still near a train track, you can hear the sound of the moving train shifted to a higher frequency as the train is coming toward you, and as the train passes by, you can hear the sound shift down in pitch. The sound waves are bunched up a bit as the train is coming toward you, and you hear the train at an increased tone; when the train passes by and moves away from you, the sound waves are stretched out so you hear the sound at a lower pitch. By measuring the change in the sound, you can calculate quite accurately how fast the train was moving when it passed by. For stars, we're not listening to a tone; we're measuring the light spectrum, but the principle is the same. We know what the "normal" frequencies in the starlight would be, for a star not moving towards us or away from us. We measure specific spectrum patterns called "absorption lines". We can detect shifts in these patterns. So, we can measure whether the star is coming toward us (spectral lines at higher frequencies than normal) or is headed away from us (spectrum showing lower frequencies than normal). When we measure the light - and the Doppler shift - of other stars in our Galaxy, we see a mix of stars moving toward us, and stars moving away from us. This is perfectly normal. But when we measure the Doppler shift of the light from other galaxies, we see that most of the other galaxies are moving away from us, and that the farther away they are, the faster they are moving! Note: For those who like a bit of extra detail: The change in the light from distant galaxies is not a true Doppler shift. It's similar, but is caused by the expansion if space itself.