Redshift & Blueshift: Is There a Consensus?

In summary, there is evidence of at least two other galaxies approaching the Milky Way besides the Andromeda galaxy. The Milky Way is also already colliding with another galaxy and there are more collisions to come. This is due to the fact that galaxies tend to be found in clusters, which are not expanding away from each other.
  • #1
LocktnLoaded
32
0
Since we have been taken readings of redshift, blueshift for sometime now, is there a consensus on a percentage of each?
 
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  • #2
You need to be a LOT more specific. If you mean measurements of cosmological expansion, all measurements are redshifted. If you mean the local volume, then they are dependent on local motions and I don't know the mix.

What are you asking?
 
  • #3
novice at astronomy

In short I guess what I'm trying to ask is , besides the Andromeda galaxy, are there any other large bodies coming our way, or are they all expanding outward from us?
 
  • #4
I believe there are at least another two galaxies approahing us.
They are fairly local.
You could try NASA site or NED, to ask your question.
 
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  • #5
http://nedwww.ipac.caltech.edu/cgi-bin/nph-allsky?ra_constraint=Unconstrained&ra_1=&ra_2=&dec_constraint=Unconstrained&dec_1=&dec_2=&glon_constraint=Unconstrained&glon_1=&glon_2=&glat_constraint=Unconstrained&glat_1=&glat_2=&z_constraint=Less+Than&z_value1=0&z_value2=&z_unit=km%2Fs&ot_include=ANY&ex_objtypes1=Clusters&ex_objtypes1=Supernovae&ex_objtypes1=QSO&ex_objtypes2=AbsLineSys&ex_objtypes2=GravLens&ex_objtypes2=Radio&ex_objtypes2=Infrared&ex_objtypes3=EmissnLine&ex_objtypes3=UVExcess&ex_objtypes3=Xray&ex_objtypes3=GammaRay&nmp_op=ANY&out_csys=Equatorial&out_equinox=B1950.0&obj_sort=RA+or+Longitude&zv_breaker=30000.0" lists 2189 blue-shifted objects.
 
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  • #6
LocktnLoaded said:
In short I guess what I'm trying to ask is , besides the Andromeda galaxy, are there any other large bodies coming our way, or are they all expanding outward from us?

Seems that the Milky Way is already colliding with another galaxy and there are a few more on the way.
http://curious.astro.cornell.edu/question.php?number=386

The Andromeda galaxy collision will just be much more significant.

The Milky Way is part of a "Local Group" of galaxies which are not expanding away from each other (galaxies tend to be found in clusters).
http://www.seds.org/messier/more/local.html
 
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Related to Redshift & Blueshift: Is There a Consensus?

1. What is redshift and blueshift?

Redshift and blueshift are phenomena observed in the light emitted by objects in space. Redshift is the shift towards longer, redder wavelengths, while blueshift is the shift towards shorter, bluer wavelengths. These shifts are caused by the motion of the object relative to the observer.

2. How do redshift and blueshift provide evidence for the expansion of the universe?

The redshift and blueshift of light from distant objects, such as galaxies, can be used to measure their velocity. It was observed that the further away a galaxy is, the greater its redshift, indicating that the universe is expanding and the galaxies are moving away from each other.

3. Is there a consensus among scientists about the cause of redshift and blueshift?

Yes, there is a consensus among scientists that the cause of redshift and blueshift is the Doppler effect, which is the change in frequency and wavelength of a wave due to the relative motion between the source and observer.

4. Can redshift and blueshift be used to determine the age of the universe?

Yes, redshift and blueshift can be used to determine the age of the universe through the Hubble's Law, which states that the velocity of a galaxy is proportional to its distance from us. By measuring the redshift of distant galaxies and using Hubble's constant, scientists can estimate the age of the universe.

5. Are there other factors that can cause redshift and blueshift?

Yes, there are other factors that can cause redshift and blueshift, such as gravitational redshift, which occurs when light is emitted from an object with a strong gravitational field, and cosmological redshift, which is caused by the expansion of the universe. However, the majority of redshift and blueshift observed in galaxies is due to the Doppler effect.

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