Do redshifts really indicate expansion of the universe?

Thread starter Lino
Start date Feb 10, 2011
Tags

Expansion Universe

In summary: OK. There would be no need for inflation, no need for the Big Bang, and no need for dark matter.In summary, the article suggests that there is a relationship between distance and redshift, but that the relationship is not always linear. The author suggests that this relationship may be explained by the concept of rotation, which is a component of General Relativity.

Mar 26, 2011

Chalnoth

Science Advisor

Lino said:

Am I correct in saying that every item of mass sits at the bottom of it's own gravity well

No, not at all. If that were the case, then all masses would be concentrated to a single point, and nothing would orbit anything else.

Now, what you have written here swings sort of kinda close to the truth, in that every mass is the center of the gravity well that it produces. But that well may be quite shallow compared to other nearby masses.

<h2>1. What is redshift and how does it indicate expansion of the universe?</h2><p>Redshift is a phenomenon in which the light from an object appears to have a longer wavelength, shifting towards the red end of the electromagnetic spectrum. This is caused by the Doppler effect, where the object is moving away from the observer. In the context of the universe, redshift is used to measure the expansion of the universe. The further away an object is, the faster it appears to be moving away from us, indicating that the universe is expanding.</p><h2>2. Is redshift the only evidence for the expansion of the universe?</h2><p>No, redshift is not the only evidence for the expansion of the universe. Other evidence includes the cosmic microwave background radiation, the abundance of light elements in the universe, and the observed distribution of galaxies and clusters.</p><h2>3. Can redshift be caused by factors other than the expansion of the universe?</h2><p>Yes, redshift can also be caused by other factors such as gravitational redshift, where the light is shifted towards the red end of the spectrum due to the gravitational pull of a massive object. However, in the context of the universe, redshift is primarily caused by the expansion of space.</p><h2>4. How do scientists measure redshift and determine the rate of expansion of the universe?</h2><p>Scientists use a tool called a spectrograph to measure the redshift of light from distant objects. This measures the amount of stretching or compression of the light waves, which can then be used to calculate the object's velocity and distance. By measuring the redshift of multiple objects at different distances, scientists can determine the rate of expansion of the universe.</p><h2>5. Does redshift always indicate expansion of the universe?</h2><p>No, there are cases where redshift can indicate contraction of the universe. This is known as blueshift, where the light from an object appears to have a shorter wavelength, shifting towards the blue end of the spectrum. However, the majority of observations and evidence suggest that the universe is indeed expanding.</p>

Related to Do redshifts really indicate expansion of the universe?

1. What is redshift and how does it indicate expansion of the universe?

Redshift is a phenomenon in which the light from an object appears to have a longer wavelength, shifting towards the red end of the electromagnetic spectrum. This is caused by the Doppler effect, where the object is moving away from the observer. In the context of the universe, redshift is used to measure the expansion of the universe. The further away an object is, the faster it appears to be moving away from us, indicating that the universe is expanding.

2. Is redshift the only evidence for the expansion of the universe?

No, redshift is not the only evidence for the expansion of the universe. Other evidence includes the cosmic microwave background radiation, the abundance of light elements in the universe, and the observed distribution of galaxies and clusters.

3. Can redshift be caused by factors other than the expansion of the universe?

Yes, redshift can also be caused by other factors such as gravitational redshift, where the light is shifted towards the red end of the spectrum due to the gravitational pull of a massive object. However, in the context of the universe, redshift is primarily caused by the expansion of space.

4. How do scientists measure redshift and determine the rate of expansion of the universe?

Scientists use a tool called a spectrograph to measure the redshift of light from distant objects. This measures the amount of stretching or compression of the light waves, which can then be used to calculate the object's velocity and distance. By measuring the redshift of multiple objects at different distances, scientists can determine the rate of expansion of the universe.

5. Does redshift always indicate expansion of the universe?

No, there are cases where redshift can indicate contraction of the universe. This is known as blueshift, where the light from an object appears to have a shorter wavelength, shifting towards the blue end of the spectrum. However, the majority of observations and evidence suggest that the universe is indeed expanding.