The Doppler Effect: Near and Far Galaxies

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    Doppler Doppler effect
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Discussion Overview

The discussion centers around the Doppler Effect and its application to understanding the differences between nearby and distant galaxies, particularly in relation to redshift and distance measurement. Participants explore the implications of the Doppler Effect in astrophysics and cosmology.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant describes their understanding of the Doppler Effect and its relation to the motion of wave sources, seeking clarification on how distance affects the observed phenomenon.
  • Another participant suggests researching "Hubble expansion" as a means to understand the relationship between redshift and distance.
  • A later reply indicates that the redshift value of receding galaxies is proportional to their distance from Earth, reflecting a connection between redshift and distance.
  • Another participant questions how distances to galaxies are determined using the redshift acquired velocity, given the proportional relationship mentioned.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the relationship between redshift and distance, with some seeking clarification and others providing insights. The discussion does not reach a consensus on the specifics of how distances are measured using redshift.

Contextual Notes

The discussion involves assumptions about the nature of redshift and its implications for distance measurement, which may depend on various definitions and models in cosmology. Specific mathematical steps or methodologies for measuring distances are not resolved.

jerome951000
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I found a question in a Maltese physics past paper dealing with the doppler effect. I managed to figure out the part dealing with the effect of motion of the wave source, but i was asked this:

How does The Doppler Effect show us the difference between galaxies that are near and those that are far away?

I was familiar with the doppler effect and the motion of the source causing it, but i never knew that the distance could make a difference. Any help would be much appreciated.
 
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Try a Google search on "Hubble expansion".
 
thanks that was really helpful. it said that the redshift acquired value of the velocity of the receding galaxies is proportional to their distance from earth. thanks again :-)
 
how are the distances between the Earth and other galaxies deciphered using the redshift acquired velocity since these two are proportional?
 
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