How to calculate the age of the universe with redshift

In summary, calculating the age of the universe with redshift involves finding the scale factor and using it to determine the "lookback time". For a flat universe, the formula is t_L = 0.337 t_H, where t_H is the Hubble time and H_0 is the Hubble constant. There may be other methods for solving this calculation, but the basic principles can be found in a cosmology textbook.
  • #1
b_o3
52
0
Hi i am confused as to how to calculate the age of the universe with redshift
say for example

The age of the universe now is 13.4 billion years old (and a critical universe).
How do i find the age of the universe if it was a redshift at say 0.6??

Do i have to find the scale factor first?
I am not very sure, please help!
 
Physics news on Phys.org
  • #2
someone help me with it please
 
  • #3
The scale factor is related to the red shift.

R(t) = 1/(1+z) ; where R(t) is the scale factor at time t. R(t_0) = 1, t-0 is today.

What we want is the "lookback time" (t_L)

For a flat Universe, this is:

t_L = t_H * (2/3) * (1 - (1+z)^(-3/2))

t_H is the Hubble time ( 1 /H_0 ); approx 13.8 Gyr.
H_0 is the Hubble constant.

t_L = 0.337 t_H

I don't know what values you have in your book and so on, but this one way to solve it, there is probably more. The way to deduce the forumulas is pretty straightforward, it should be stated in our course book in cosmolgy.
 

1. How does redshift help us calculate the age of the universe?

Redshift is a phenomenon observed in the light emitted from distant galaxies, where the wavelength of the light appears to be stretched or shifted towards the red end of the spectrum. This is caused by the expansion of the universe, and the amount of redshift can help us determine the distance of the galaxy. By measuring the distance and redshift of multiple galaxies, we can estimate the age of the universe.

2. What is the formula for calculating the age of the universe using redshift?

The formula for calculating the age of the universe using redshift is t = 1/H0 * (1/z - 1), where t is the age of the universe, H0 is the Hubble constant, and z is the redshift value. This formula is based on the expansion rate of the universe and the relationship between distance and redshift.

3. How accurate is the calculation of the age of the universe using redshift?

The calculation of the age of the universe using redshift is relatively accurate, but it is subject to some uncertainties and assumptions. The accuracy also depends on the precision of the measurements of distance and redshift. The current estimated age of the universe using redshift is around 13.8 billion years.

4. Can redshift be used to determine the age of the universe for all galaxies?

Redshift can only be used to determine the age of the universe for distant galaxies. This is because galaxies that are closer to us may have a different rate of expansion due to local factors. Therefore, the redshift value may not accurately reflect the distance and age of these nearby galaxies.

5. How has the calculation of the age of the universe with redshift changed over time?

The calculation of the age of the universe with redshift has changed over time as the technology and understanding of the universe has advanced. In the early 20th century, it was believed that the universe was static and eternal, but the discovery of redshift in the 1920s led to the realization that the universe is expanding. Since then, the Hubble constant and other factors used in the calculation have been refined, leading to more accurate estimates of the age of the universe.

Similar threads

I Universe is older than we think
    • Astronomy and Astrophysics
Replies
3
Views
666
Calculating Age of Universe Using Redshift: 0.6
    • Advanced Physics Homework Help
Replies
9
Views
2K
I Seeking reference for math related to the age of Recombination
    • Cosmology
Replies
3
Views
965
I An odd result from integrating to calculate the age of the Universe
    • Cosmology
Replies
21
Views
2K
B Size of universe - rewinding big bang versus "flat" universe
    • Cosmology
2
Replies
54
Views
3K
I New research puts age of the Universe at 26.7 billion years
    • Cosmology
Replies
6
Views
2K
Plotting Density Parameters as a Function of Redshift
    • Advanced Physics Homework Help
Replies
1
Views
2K
I Galaxy redshift and thermodynamics
    • Thermodynamics
Replies
10
Views
2K
Find the Age of the Universe when Matter and Radiation densities were equal
    • Advanced Physics Homework Help
Replies
14
Views
2K
B Age of Universe: 13.8 Billion Years
    • Cosmology
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top