Inflation & the Hubble Length in cm

In summary, the Hubble length is approximately 1.3 x 10^26 meters, or about 14 billion lightyears. It is defined as the speed of light divided by the Hubble constant, which can be calculated using Google's calculator. It would not make sense to describe the Hubble length in centimeters.
  • #1
Golfer
18
0
I am presently reading a paper on Inflation. It uses the term Hubble length. Can someone provide the Hubble length in cm.
 
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  • #2
Golfer said:
I am presently reading a paper on Inflation. It uses the term Hubble length. Can someone provide the Hubble length in cm.

The Hubble time is about 14 billion years. That means the Hubble length is about 14 billion lightyears. 13.8 might be better.

definitions: the hub time is 1/H0
the hub length is c/H0

just use google calculator. type this into the google search window verbatim
71 km/s/megaparsec
and press "search"

you will get an inverse time in Hertz

now type c divided by that, verbatim, in other words
c/(71 km/s/megaparsec)
and say search again

you will get 1.3 x 1026 meters

that is the Hubble length in meters
google calculator will just calculate it for you automatically and tell you that
 
Last edited:
  • #3
Can someone provide the Hubble length in cm.
marcus said:
about 14 billion lightyears.
Thus, it is probably silly to describe it in centimeters.
 
  • #4
Google calculator also does automatic unit conversion, you can say things like

c/(71 km/s/megaparsec) in centimeters

It is a great tool.
 

FAQ: Inflation & the Hubble Length in cm

1. What is inflation in terms of the Hubble length?

Inflation is a period of rapid expansion in the early universe, where the Hubble length (the distance over which objects are receding due to the expansion of the universe) increased dramatically. This expansion is thought to have occurred in the first fraction of a second after the Big Bang.

2. How does inflation affect the Hubble length?

During inflation, the Hubble length increased exponentially, meaning that objects that were once close together became much further apart. This rapid expansion is thought to be responsible for the large-scale homogeneity and isotropy of the universe that we observe today.

3. What is the relationship between the Hubble length and the size of the observable universe?

The Hubble length sets a limit on the size of the observable universe, as objects that are further away than the Hubble length are receding faster than the speed of light and therefore cannot be seen. However, the observable universe is much larger than the Hubble length, as the expansion of the universe has allowed us to see objects that were once within the Hubble length but are now much further away.

4. Can the Hubble length change over time?

Yes, the Hubble length is not a constant value and can change over time as the universe continues to expand. However, the rate of change is not constant and can vary depending on factors such as the amount of matter and energy in the universe.

5. How is the Hubble length related to the speed of light?

The Hubble length is not a physical length, but rather a measure of the distance over which objects are receding due to the expansion of the universe. It is not directly related to the speed of light, but the expansion of the universe is often described in terms of the Hubble constant, which has units of velocity (km/s) per megaparsec and gives the rate at which objects are receding due to the expansion of the universe.

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