Why Does Andromeda's Wavelength Calculation Differ from Hubble's Law?

Click For Summary
SUMMARY

The discussion centers on the calculation of the wavelength of light from the Andromeda galaxy, highlighting the differences between observed values and those predicted by Hubble's Law. The formula used for calculating redshift, z = ∆λ/λ0 and z = v/c, reveals that Andromeda exhibits a blue shift, resulting in a wavelength value smaller than λ0. In contrast, applying Hubble's Law yields a greater wavelength value, illustrating the impact of gravitational interactions within local galaxy groups that prevent adherence to Hubble's predictions.

PREREQUISITES
  • Understanding of redshift and blueshift in astrophysics
  • Familiarity with Hubble's Law and its implications
  • Knowledge of the formula z = ∆λ/λ0 and z = v/c
  • Basic concepts of gravitational interactions between galaxies
NEXT STEPS
  • Research the implications of gravitational interactions on galaxy velocities
  • Study the effects of blueshift and redshift on astronomical observations
  • Explore advanced calculations involving redshift in cosmology
  • Learn about the limitations of Hubble's Law in local group dynamics
USEFUL FOR

Astronomers, astrophysics students, and anyone interested in the dynamics of galaxy movements and the implications of redshift and blueshift in observational astronomy.

Orion78
Messages
25
Reaction score
0
I have calculated the wavelength of a line that would be observed in a spectrum from Andromeda where speed and λ0 were known, using the formula z =∆λ/λ0 and z=v/c. I obtained a value smaller than λ0 because Andromeda display a blue shift. After I calculated the same wavelength pretending that Andromeda obeyed the Hubble relationship and I found a different value, greater than λ0. his is because the blueshift indicates a decrease in wavelengths while the redshift an increase in wavelengths? Thanks!
 
Physics news on Phys.org
Yes, that sounds right. We cannot expect relative velocities of galaxies withing a local group to obey Hubble's law because of the mutual gravitational attraction between the galaxies.
 

Similar threads

Undergrad Is the light from Andromeda truly blue shifted?
  • · Replies 33 ·
2
Replies
33
Views
6K
Wavelength of Sound: Solve Using X & Y
  • · Replies 6 ·
Replies
6
Views
2K
Doppler shift of object in expanding universe
  • · Replies 4 ·
Replies
4
Views
2K
What Visible Wavelengths Cause Maximum Constructive Interference in a Thin Film?
  • · Replies 1 ·
Replies
1
Views
3K
Relativity - wavelength differences for two observers?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Physics Error in Larry Niven's "Neutron Star
  • · Replies 28 ·
Replies
28
Views
3K
Undergrad Challenges to the Redshift Method and Hubble's Law
  • · Replies 5 ·
Replies
5
Views
3K
Graduate Lightcone 1.0 basic redshift article development
  • · Replies 14 ·
Replies
14
Views
4K
Undergrad How can I identify the appropriate spectral line for Doppler calculation?
  • · Replies 6 ·
Replies
6
Views
3K
Graduate Why Is My Calculation of Doppler Shift Different from the Standard Formula?
  • · Replies 24 ·
Replies
24
Views
3K