What is the Entropy Equation for the Universe?

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SUMMARY

The entropy of the universe can be calculated using the classical entropy equation for a spherical universe containing an ideal gas. The equation is defined as ΔS_u = K_b (ln(T_f/T_i) + ln((r_f/r_i)^3)), where T_i is 3000 K (Cosmic Background Radiation photo-transparency temperature), T_f is 2.725 K (Cosmic Background Radiation temperature), r_i is 7*10^5 Ly (photo-transparency range), and r_f is 1.761*10^{10} Ly (universe range). The calculated entropy value is ΔS_u = 3.230*10^{-22} J*K^{-1}. This discussion highlights the need for accurate values and further exploration of black hole entropy equations.

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Does anyone have an equation for the Entropy of the Universe?

Barring my computation, please provide your best equation for cross-verification with a numerical entropic solution in (J*K^-1) SI units.

I attempted to locate a solution on the internet, however only located entropy for various particles and black holes.

Anyone interested in examining some black hole entropy equations may click the reference provided.

These equations represent my classical approach.

T_i = 3000 K CBR photo-transparency temperature
T_f = 2.725 K CBR temperature
r_i = 7*10^5 Ly CBR photo-transparency range
r_f = \frac{c}{H_o} = 1.761*10^{10} Ly Universe range

Classical entropy equation for spherical universe containing an ideal gas:
\Delta S_u = K_b \left( ln \frac{T_f}{T_i} + ln \left( \frac{r_f}{r_i} \right)^3 \right) = K_b \left( ln \frac{T_f}{T_i} + ln \left( \frac{c}{H_o r_i} \right)^3 \right)

Ho = Hubble Constant

\Delta S_u = 3.230*10^{-22} J*K^{-1}

Does anyone have more accurate values?

Reference:
http://www.aeiveos.com/~bradbury/Authors/Computing/Frautschi-S/EiaEU.html
http://scienceworld.wolfram.com/physics/CosmicBackgroundRadiation.html
http://map.gsfc.nasa.gov/m_uni/uni_101Flucts.html
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"We cannot order men to see the truth or prohibit them from indulging in error." - Max Planck, Philosophy of Physics, 1936
 
Last edited:
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Originally posted by Orion1


Does anyone have an equation for the Entropy of the Universe?

Barring my computation, please provide your best equation for cross-verification with a numerical entropic solution in (J*K^-1) SI units.

I attempted to locate a solution on the internet, however only located entropy for various particles and black holes.

Anyone interested in examining some black hole entropy equations may click the reference provided.

Reference:
http://www.aeiveos.com/~bradbury/Authors/Computing/Frautschi-S/EiaEU.html


Firstly how does count?..something that is forever moving?

You would have to accommodate every instant..instanton.. and every Futurama?, if only just to get some approximation of what you are counting!.
 
Originally posted by Orion1
Does anyone have an equation for the Entropy of the Universe?
Well, let's see, if there is no alternative but that a universe exist, then the probability that the universe should exist is 1, and there is never any change in the total information contained in the universe. So the total entropy of the universe is always zero, right?
 

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