How is the speed of galaxies determined?

Question

Violet Adams · Accepted Answer

This can be explained by The Hubble Law

The farthest galaxies are moving away from us at rates proportionate to their distances, according to Edwin Hubble. This phenomenon is known as redshift, and it can be defined as the galaxy's speed of separation from us times its distance. #v = cz# where, Redshift can be computed by comparing laboratory values with the star or galaxy's spectrum, which can be obtained through a telescope. Redshift formula. #(lambda(o) - lambda(l))/(lambda(l))# where,

Audrey Adams · Answer

undefined The speed of galaxies is determined primarily through two methods:

1. Doppler Shift: By measuring the redshift or blueshift of light emitted by galaxies, astronomers can determine their radial velocity relative to Earth. This is based on the Doppler effect, which causes the wavelengths of light to shift as the source of light moves toward or away from the observer.

2. Hubble's Law: Edwin Hubble discovered that the farther a galaxy is from Earth, the faster it appears to be moving away from us. This relationship is described by Hubble's Law, which states that the velocity of a galaxy is proportional to its distance from Earth. By measuring the redshift of galaxies and their distances, astronomers can use Hubble's Law to determine their speeds.