Universe Expansion

[David Levy]

David you cannot directly take the mass density of the full universe and directly convert it to Joules then state that it will be the energy density in the past .

What do you mean by: "mass density of the full universe"? Do you mean: mass/energy of the full universe?

 

I have used the mass/energy of the full visible Universe, which is already given in Joules. (So I didn't have to convert it to joules by myself)

 

In the following article:

http://www.physicsoftheuniverse.com/numbers.html

It is stated that:

3 × 10^{52 -} Estimated mass (in kilograms) of the observable universe.

4 × 10^{69 -} Estimated total mass-energy (in Joules) of the observable universe.

 

Why do you claim that the total mass/energy in the early Universe should be different from the current Universe?

 

Based on the BBT, no new energy or mass could be created after the BBT.

So if it is different, than in the past the mass/energy must be higher than our current time.

That actually gives even higher confidence to my calculations.

 

Please - if you think that in the past it was different (I assume that you want to prove that it was lower...), than please prove it by showing your calculations.

How could it be that new mass/energy had been created after the BBT?

 

Shrink the universe enough and all particles become relativistic hence radiation.

 

This is a key message.

 

However, radiation is energy by definition.

Therefore, it doesn't matter if we measure the energy of the particles or the energy of radiation which creates the particles.

Energy is Energy.

However, I would expect that during the conversion from radiation to particles, some energy will be lost.

Please also be aware that those particles represents less than 5% of the total Universe mass...

Therefore, In the past, the total Mass/energy must be higher than the current Mass/energy.

Hence, do you agree now that my calculation is fully correct?

Edited February 12, 2016 by David Levy

[Mordred]

Your still missing the key detail. Please look at how matter and radiation scales down.

 

Your using values today and expecting the % to be the same in the past.

This figure for example is the rest mass of the observable universe TODAY.

 

3 × 10^52 - Estimated mass (in kilograms) of the observable universe.

 

The problem is in the past particles are more energetic (higher temperatures). There is fewer atoms then than today and more radiation then than today. So the rest mass then will be different than today.

 

then you took this value without looking at which portion is matter which portion is radiation

 

4 × 10^69 - Estimated total mass-energy (in Joules) of the observable universe and tried scaling them back as a function of volume.

 

However the % of matter and the % of radiation is different in the past than it is today.

[latex]H_z=H_o\sqrt{\Omega_m(1+z)^3+\Omega_{rad}(1+z)^4+\Omega_{\Lambda}}[/latex]

 

Notice the density parameter for matter changes as a function of z different than radiation.

 

[latex]\Omega_m(1+z)^3[/latex]

[latex]\Omega_{rad}(1+z)^4[/latex]

 

However the cosmological constant doesn't scale back it's average density remains constant. It's total energy changes as the volume changes. So today you have more total energy contribution from the cosmological constant today than you will in the past.

 

[latex]\Omega_{\Lambda}[/latex]

 

This is why the method your using is giving you the wrong answers.

Edited February 13, 2016 by Mordred

[David Levy]

The problem is in the past particles are more energetic (higher temperatures). There is fewer atoms then than today and more radiation then than today. So the rest mass then will be different than today.

 

This is very clear to me.

 

 

then you took this value without looking at which portion is matter which portion is radiation

4 × 10^69 - Estimated total mass-energy (in Joules) of the observable universe and tried scaling them back as a function of volume

 

That is correct.

I do not even try to distinguish between Energy from matter to the Energy from radiation.

Energy is Energy. It should be clear to all of us.

At least we both agree that the Estimated total mass-energy (in Joules) of the observable universe is 4 × 10^69

 

 

However the % of matter and the % of radiation is different in the past than it is today.

 

[latex]H_z=H_o\sqrt{\Omega_m(1+z)^3+\Omega_{rad}(1+z)^4+\Omega_{\Lambda}}[/latex]

 

Notice the density parameter for matter changes as a function of z different than radiation.

 

[latex]\Omega_m(1+z)^3[/latex]

[latex]\Omega_{rad}(1+z)^4[/latex]

 

However the cosmological constant doesn't scale back it's average density remains constant. It's total energy changes as the volume changes. So today you have more total energy contribution from the cosmological constant today than you will in the past.

 

[latex]\Omega_{\Lambda}[/latex]

 

 

Yes, I fully agree with you.

The % of matter and the % of radiation is different in the past than it is today

I also agree that the density parameter for matter changes as a function of z different than radiation.

 

So, please go ahead and set the calculation.

Do you know for sure the % of matter and the % of radiation at the early Universe (when its temp was 3000K)?

 

If you do, than it should be easy to calculate the equivalent density of early universe.

Somehow, I do believe that no one really know this percentage.

So, it is quite clear to me that it is an impossible mission - You are welcome to prove the opposite if you wish!

 

However, your explanation (about the % of matter and the % of radiation is different in the past than it is today) has no real effect on my calculations.

I didn't try to distinguish between the different densities and then try to calculate the equivalent density. There is no need for that.

I have focused on the total mass/ energy of the universe.

Therefore, I have used the total Estimated mass-energy of the observable universe, as an indication for the total mass energy in the early universe.

I have assumed that there is no change in the total mass-energy between the current time and the early universe. Although it is quite clear that the Universe is losing energy over time - I will elaborate about it later on.

So actually, the total mass- energy of the early universe should be higher than our current universe.

But even if it is the same, I have proved that even this minimal total mass/ energy can't support the expansion.

If you estimate that the total mass/energy of the early universe should be lower than our Universe - than please go ahead and prove it.

Edited February 13, 2016 by David Levy

[Mordred]

You can believe whatever straw man argument you like or you can confirm what I'm stating by reading the link Strange provided. As well as pick up a cosmology textbook.

 

I personally don't care if you believe me or not. Neither do I care how foolish statements such as

 

"Therefore the early universe can't expand" when its obvious it did expand and evidence supports this expansion.

 

So go right on ahead make errors in your calculations by using the wrong formulas and drawing the wrong conclusions as a result.

 

The only person your affecting is yourself. Your doing so by not learning the correct methods.

I wasted enough time arguing with you in numerous other threads where you showed a lack in mathematical ability and drawing wrong conclusions as a result.

[David Levy]

Sorry if I have disappointed you.

I have full appreciation for your support!

You have actually opened the door for higher cosmology knowledge to me.

Edited February 13, 2016 by David Levy

[Mordred]

Ok David think of it this way the Cosmological constant is constant.

 

It's energy density per metre cubed stays the same. No matter when you measure it. So if you take the energy density of the cosmological constant multiply that by the volume of the observable universe TODAY.

 

Then do the same for the cosmological constant for the volume at the CMB.

 

Which is higher in total energy/mass?

 

Now do you understand why your method leads to error?

 

Why cosmological constant stays constant is one of the biggest mysteries in Cosmology. So don't ask me to solve that problem lol.

 

Here lets go over these relations again I assume your familiar with the scale factor a...

 

https://en.m.wikipedia.org/wiki/Scale_factor_(cosmology)

 

[latex]\rho_{radiation}\propto R^{-4}[/latex]

 

 

[latex]\rho_{matter}\propto R^{-3}[/latex]

 

 

[latex]\rho_{\Lambda}=constant[/latex]

 

[latex]a=\frac{R}{R_o}=\frac{1}{(1+z)}[/latex]

 

[latex]\rho=\frac{\rho_{r,o}}{a^4}+\frac{\rho_{m,o}}{a^3}+\rho_\Lambda[/latex]

Edited February 13, 2016 by Mordred

[David Levy]

Ok David think of it this way the Cosmological constant is constant.

It's energy density per metre cubed stays the same. No matter when you measure it. So if you take the energy density of the cosmological constant multiply that by the volume of the observable universe TODAY.

Then do the same for the cosmological constant for the volume at the CMB.

Which is higher in total energy/mass?

Now do you understand why your method leads to error?

 

Thanks

 

Now it is fully clear to me.

 

So you claim that the current cosmological constant is the same at any size of the universe.

 

Therefore, the energy density of the universe should be the same - today, 13 Billion years ago and in the next 100 billion years.

 

Based on this constant we can find that the total mass energy of the early universe is significantly lower than our time universe.

 

However, in the same token we can claim that in the future the total mass energy of the universe (let's say 10 billion years from now) should be significantly higher than our current total mass/energy.

 

So, what is the source for this new energy?

 

I had the impression that based on the BBT, no new mass/ energy can be generated.

 

Is it feasible?

 

[Mordred]

Like I stated cosmology hasn't solved that problem yet .. ordinarily energy is conserved. As we don't know the mechanism for the cosmological constant we can't determine how to maintain the conservation of energy with regards to the cosmological constant.

 

Quantum fluctuations was at one time the leading contender but produced too much energy. Now we're looking at the non zero vacuum of the Higgs field

 

Though we haven't completely ruled out quantum VP production

Edited February 13, 2016 by Mordred

[David Levy]

Like I stated cosmology hasn't solved that problem yet .. ordinarily energy is conserved. As we don't know the mechanism for the cosmological constant we can't determine how to maintain the conservation of energy with regards to the cosmological constant.

 

Quantum fluctuations was at one time the leading contender but produced too much energy. Now we're looking at the non zero vacuum of the Higgs field

 

Though we haven't completely ruled out quantum VP production

 

Thanks again

 

With regards to our visible universe;

Based on the redshift we know that further galaxies are moving away from us.

Therefore, theoretically, every day we are losing matter from our visible universe.

So, if we claim that the energy density of the visible universe should be the same in the future than we have to find the real answer for that new mass/energy ASAP.

Edited February 13, 2016 by David Levy

[swansont]

Energy is Energy. It should be clear to all of us.

But energy is not an invariant quantity.