Can we estimate the volume of the observable universe?

[davidgow77]

Hi folks.... I wonder if anyone can help me.

I want to find out if there is a relationship between the amount of energy in the observable universe (including dark matter and dark energy), and the amout of space in the observable universe. Does anyone know how to calculate these values?

Also, can anyone tell me what the current rate of expansion, along with it's rate of acceleration???

Afew questions there, but any help would be greatly appreciated.

dg77

[JoeBachofen]

Hi folks.... I wonder if anyone can help me.

I want to find out if there is a relationship between the amount of energy in the observable universe (including dark matter and dark energy), and the amout of space in the observable universe. Does anyone know how to calculate these values?

Also, can anyone tell me what the current rate of expansion, along with it's rate of acceleration???

Afew questions there, but any help would be greatly appreciated.

dg77

Thanks davidgow77 for asking a question I've often wondered about.
From Wikipedia, the radius of the observable universe is about 46 billion light years.

So, the volume of the observable universe is
\frac{4}{3} \times \pi \times \mathrm{R}^3 = 4 \times 10^{32}\text{ ly}^3
with R = 46 billion light years according to Wikipedia and my own calculations.

The same Wikipedia article estimates the visible mass in that volume as
9 \times 10^{21} \ \textrm{solar masses}
or about
1.8 \times 10^{52}\ \textrm{kg} if one solar mass = 2 \times 10^{30}\ \textrm{kg}

Since visible matter is less than 5% of the total matter in the universe, I guess the total is
3.6 \times 10^{53}\ \textrm{kg}
or more.

Wikipedia gave me the dark matter estimate as 22% and the dark energy as 74%

No doubt you have much better answers by now, but this has been a good exercise for me. I suspect I have a bit to learn regarding this editor and how it handles tags.

Thanks

[mkirkpatrick]

Thanks davidgow77 for asking a question I've often wondered about.
From Wikipedia, the radius of the observable universe is about 46 billion light years.

So, the volume of the observable universe is
\frac{4}{3} \times \pi \times \mathrm{R}^3 = 4 \times 10^{32}\text{ ly}^3
with R = 46 billion light years according to Wikipedia and my own calculations.

The same Wikipedia article estimates the visible mass in that volume as
9 \times 10^{21} \ \textrm{solar masses}
or about
1.8 \times 10^{52}\ \textrm{kg} if one solar mass = 2 \times 10^{30}\ \textrm{kg}

Since visible matter is less than 5% of the total matter in the universe, I guess the total is
3.6 \times 10^{53}\ \textrm{kg}
or more.

Wikipedia gave me the dark matter estimate as 22% and the dark energy as 74%

No doubt you have much better answers by now, but this has been a good exercise for me. I suspect I have a bit to learn regarding this editor and how it handles tags.

Thanks

Thanks Joe for such a great response to this question,and welcome to the forum.

warm regards michael.

[Play_Dough]

edited...

I want to find out if there is a relationship between the amount of energy in the observable universe (including dark matter and dark energy), and the amout of space in the observable universe. Does anyone know how to calculate these values?

Afew questions there, but any help would be greatly appreciated.

dg77

One approach to this question is to employ the Hermetic axiom "As above, So below" (as a hypothesis).
The matter/space ratio of an atom is approximately 99% space to 1% matter. So, we can hypothesize that the universe (the 'above') mirrors the atom (the 'below' or microcosm).

Your question presumes that 'space' is 'non-energetic' because you draw a dichomonty between energy and space.
So, assuming that your approach is correct I would estimate that the ratio is 99:1.... or mirrors the ratio (space/matter) of a hydrogen atom.

The 'dark matter' item is a curve-ball in the analysis because we do not understand if 'dark matter' really exists or if our math has run out of validity.... the way that algebra ran out of explanations so Newton invented calculus and when calculus ran out of explanations Einstein introduced quantum mechanics (and much of the math is still missing).

Never-the-less... my conclusion is 99% space and 1% matter (energy).
Taking my analysis one step further..... if all matter in the universe was converted to energy then I would still state that the ratio (space:energy) remains as 99:1 as an 'unexpressed potential'.

.