Hubble and the Law of Redshifts

In summary, the conversation discusses Hubble, Red shifts, and the measurement of the universe's expansion. One theory proposes a stationary universe with consistent red shift from all light sources, while the other suggests galaxies are receding and have a 13% dimmer light source. The issue arises with the understanding that red shift is a measure of a light source's recession speed. The concept of a "linear relation" is also mentioned. Hubble's observation supports the theory of receding galaxies, as the law of red shifts is no longer linear when taking into account the dimming factors of distant nebulae.
  • #1
pulsexx
7
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I've just started learning about Hubble, Red shifts, and how we measure the universe's expansion.

It seems that he had two theories, that there is a stationary universe where the red shift from all light sources would be consistent or a theory in which the galaxies would be receding (and have a 13% dimmer light source?)

The problem I have is that isn't red shift a measure of how fast a light source is receding from you?

How can there be stationary galaxies that have the same red shift with a "linear relation"(whatever that means?) ?
 
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  • #2
Here's hubble:
"Since the corresponding velocity of recession is the same fraction of the velocity of light, the nebulae in the most distant cluster observed, if they are actually receding, will appear 13 per cent fainter than they would appear if they were stationary. The difference is small but, fortunately, the measures can be made with fair accuracy. The results may be stated simply. If the nebulae are stationary, the law of red shifts is sensibly linear; red shifts are a constant multiple of distances. In other words, each unit of light path contributes the same amount of red shift. On the other hand, if the nebulae are receding, and the dimming factors are applied, the scale of distances is altered, and the law of red shifts is no longer linear"
 

1. What is the Hubble Law of Redshifts?

The Hubble Law of Redshifts, also known as Hubble's Law, states that the farther away a galaxy is from Earth, the faster it is moving away from us. This is based on the observation that galaxies show a redshift in their light spectra, indicating that they are moving away from us.

2. How was the Hubble Law of Redshifts discovered?

The Hubble Law of Redshifts was discovered by astronomer Edwin Hubble in the 1920s. He observed that the light from distant galaxies showed a redshift, indicating that they were moving away from us. He then plotted the distance of these galaxies against their redshift and found a linear relationship, which became known as Hubble's Law.

3. What is the significance of the Hubble Law of Redshifts?

The Hubble Law of Redshifts is significant because it provides evidence for the expansion of the universe. It also supports the Big Bang theory, which states that the universe began with a single, massive explosion and has been expanding ever since.

4. How does the Hubble Law of Redshifts help us understand the age of the universe?

By using the Hubble Law of Redshifts to measure the distance and speed of galaxies, scientists can estimate the age of the universe. This is because the rate of expansion of the universe can be used to calculate how long it has taken for galaxies to reach their current distances from each other.

5. Can the Hubble Law of Redshifts be used to measure the age of individual galaxies?

No, the Hubble Law of Redshifts cannot be used to measure the age of individual galaxies. This is because the law only applies to the overall expansion of the universe and does not take into account other factors that may affect the motion of a specific galaxy, such as its gravitational interactions with other galaxies.

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