A Space & astronomy forum. SpaceBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Research
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Cosmic Energy Budget, vs time



 
 
Thread Tools Display Modes
  #1  
Old February 13th 17, 09:30 PM posted to sci.astro.research
[email protected]
external usenet poster
 
Posts: 35
Default Cosmic Energy Budget, vs time

Questions (below) relate to total energy (sum of terms) in this paper:

In the paper, "The Cosmic Energy Inventory" Fukugita / Peebles, They
created a list of all known forms of energy within the universe today.

(They said, "We present.............at the present epoch".........which
I take to mean, correct me if wrong, they are listing all forms of
energy that exist within the entire modern (co moving with us)
universe.)

For this question I ignore all "Dark" forms of energy and focus only on
the 5% that is in forms we have detected such as neutrinos, baryons, EM
radiation.

Ignoring Dark mass and Dark energy, the total universe energy inventory
is:

1.00 - 0.954 = 0.046 and the primary 4 constituents a

Neutrinos = 0.00126
Baryon Rest Mass
Warm Intergalactic plasma = 0.045
Intracluster plasma = 0.0018
Main Sequence Stars spheroids and bulges, disks and irregulars
0.0015 + 0.00055 = 0.00205

These 4 components combined constitute 0.05011.
(This is greater than 4.6%, so error bars must be the culprit
unless I did the addition wrong.)

At any rate, this 100% of known stuff (5% if we were to include dark
stuff) must total to the same value no matter what age of the universe I
consider, right?

In other words, section 7 is post stellar radiation. section 6 is post
stellar nuclear binding energy.

And the energy associated with those two categories must have originally
been associated with the section 3, baryon rest mass.

ie, fusion energy release reduced baryon mass and increased radiation
and nuclear binding energy. But the total energy (if I sum all of the
forms in addition to these 3) at previous epochs of our universe would
be the same as the total today, Right?

In other words, 100% of this 5% of stuff we know about, has always been
and always will be, 100%. The quantity of energy in each category may
shuffle around a little, but the total will remain unchanged.

So if I want to make a plot of this inventory as a function of age of
the universe, then I should make certain to track the sum of the
individual components to make sure they always sum to 100% of what 100%
is today, Right?

Thanks,

rt

Ads
  #2  
Old February 14th 17, 05:18 AM posted to sci.astro.research
Phillip Helbig (undress to reply)[_2_]
external usenet poster
 
Posts: 188
Default Cosmic Energy Budget, vs time

In article ,
writes:

Questions (below) relate to total energy (sum of terms) in this paper:

In the paper, "The Cosmic Energy Inventory" Fukugita / Peebles, They
created a list of all known forms of energy within the universe today.


Always good to mention the date, or a full reference.

(They said, "We present.............at the present epoch".........which
I take to mean, correct me if wrong, they are listing all forms of
energy that exist within the entire modern (co moving with us)
universe.)


Newer papers might have better data. (There is an old joke to plot the
Hubble constant as a function of time, seeing it decline from 600 in
1930 to 100 in 1980, then extrapolating that it would become negative
before 1990. The joke doesn't work anymore, because the decline has
levelled off and the current value is probably close to the true value.)

Neutrinos = 0.00126
Baryon Rest Mass
Warm Intergalactic plasma = 0.045
Intracluster plasma = 0.0018
Main Sequence Stars spheroids and bulges, disks and irregulars
0.0015 + 0.00055 = 0.00205

These 4 components combined constitute 0.05011.


At any rate, this 100% of known stuff (5% if we were to include dark
stuff) must total to the same value no matter what age of the universe I
consider, right?


To the extent that mass is conserved. Of course, they are talking about
mass fractions, not absolute numbers.

In other words, section 7 is post stellar radiation. section 6 is post
stellar nuclear binding energy.


Yes, but how much energy is released by fusion during the lifetime of a
star? 1% of the rest mass or something like that. Negligible at the
precision you have here. Ditto for radiation from starlight. (Almost
all photons are CMB photons, by the way.)

And the energy associated with those two categories must have originally
been associated with the section 3, baryon rest mass.

ie, fusion energy release reduced baryon mass and increased radiation
and nuclear binding energy. But the total energy (if I sum all of the
forms in addition to these 3) at previous epochs of our universe would
be the same as the total today, Right?


Right. Again, energy density. And in comoving coordinates. Everything
gets thinner as the universe expands (except the cosmological constant,
which is why it is called the cosmological constant).

In other words, 100% of this 5% of stuff we know about, has always been
and always will be, 100%. The quantity of energy in each category may
shuffle around a little, but the total will remain unchanged.


Right.

So if I want to make a plot of this inventory as a function of age of
the universe, then I should make certain to track the sum of the
individual components to make sure they always sum to 100% of what 100%
is today, Right?


Right.

However, to a very good approximation, the energy density in radiation
and neutrinos is negligible and always has been, except in the very
early universe, and will be even more negligible in the future.
  #3  
Old February 20th 17, 07:50 PM posted to sci.astro.research
[email protected]
external usenet poster
 
Posts: 35
Default Cosmic Energy Budget, vs time

On Monday, February 13, 2017 at 9:18:20 PM UTC-8, Phillip Helbig (undress t=
o reply) wrote:
In article ,
writes:

Questions (below) relate to total energy (sum of terms) in this paper:

In the paper, "The Cosmic Energy Inventory" Fukugita / Peebles, They


At any rate, this 100% of known stuff (5% if we were to include dark
stuff) must total to the same value no matter what age of the universe I
consider, right?


To the extent that mass is conserved. Of course, they are talking about
mass fractions, not absolute numbers.

In other words, section 7 is post stellar radiation. section 6 is post
stellar nuclear binding energy.


Yes, but how much energy is released by fusion during the lifetime of a
star? 1% of the rest mass or something like that. Negligible at the
precision you have here. Ditto for radiation from starlight. (Almost
all photons are CMB photons, by the way.)


OK, sure, I get the 1% conversion factor. But we can independently
measure the photons (energy) produced. And we know the mass to energy
conversion ratio. So, we can estimate the mass that disappeared, and
appeared as energy (radiation).

We can also guess at volume of universe with age, via creating models.

So, we can estimate the ratio (dE/dt from stellar etc. processes) vs
(dV/dt of universe) to get an energy density of the universe as a
function of age of the universe.

Same as dM/dt vs dV/dt by the way since a reduction in M is what drives
an increase in E radiation (from stellar processes) cosmically speaking.

Similarly, we can guess at dark energy as being proportional to V_universe.

BUT, *if* we find that dE/dt is linarly related to universe volume, and,
dark energy is supposed to be linearly related to universe volume, that
would essentially mean that mass to energy conversion is linear to dark
energy creation.

Right?

In other words, could the cosmological constant just be the conversion
ratio for mass that disappears due to E=mc^2 processes, and space that
appears (currently ascribed to expansion of the universe (more space
today than yesterday due to Hubble expansion)).

These are treated as separate things today, but is there any observation
that requires they actually be unrelated? I mean, if they are both
linear with expansion of the universe, might they be interelated?

We know of things like water evaporating where a small volume of one
form of a thing is converted into a large volume of a different form of
that same thing (condensed matter water to vapor water). Why can't it
be that what we call empty space is just the "vapor" form of what we
call "matter"?

rt

  #4  
Old February 22nd 17, 08:04 PM posted to sci.astro.research
Phillip Helbig (undress to reply)[_2_]
external usenet poster
 
Posts: 188
Default Cosmic Energy Budget, vs time

In article ,
writes:

Questions (below) relate to total energy (sum of terms) in this paper:

In the paper, "The Cosmic Energy Inventory" Fukugita / Peebles, They


At any rate, this 100% of known stuff (5% if we were to include dark
stuff) must total to the same value no matter what age of the universe I
consider, right?


To the extent that mass is conserved. Of course, they are talking about
mass fractions, not absolute numbers.

In other words, section 7 is post stellar radiation. section 6 is post
stellar nuclear binding energy.


Yes, but how much energy is released by fusion during the lifetime of a
star? 1% of the rest mass or something like that. Negligible at the
precision you have here. Ditto for radiation from starlight. (Almost
all photons are CMB photons, by the way.)


OK, sure, I get the 1% conversion factor. But we can independently
measure the photons (energy) produced. And we know the mass to energy
conversion ratio. So, we can estimate the mass that disappeared, and
appeared as energy (radiation).


Except that most radiation doesn't come from fusion in stars.

We can also guess at volume of universe with age, via creating models.

So, we can estimate the ratio (dE/dt from stellar etc. processes) vs
(dV/dt of universe) to get an energy density of the universe as a
function of age of the universe.

Same as dM/dt vs dV/dt by the way since a reduction in M is what drives
an increase in E radiation (from stellar processes) cosmically speaking.

Similarly, we can guess at dark energy as being proportional to V_universe.


It is exactly proportional, if it is the cosmological constant.

BUT, *if* we find that dE/dt is linarly related to universe volume, and,
dark energy is supposed to be linearly related to universe volume, that
would essentially mean that mass to energy conversion is linear to dark
energy creation.

Right?


Wrong. First, you are almost assuming that that which you wish to prove
is true. Second, just because two things are linearly related doesn't
mean that they are the same thing, nor even that one causes the other.
There is a good anticorrelation between global warming and the number of
pirates, a good correlation between the number of stork pairs and the
birthrate.

In other words, could the cosmological constant just be the conversion
ratio for mass that disappears due to E=mc^2 processes, and space that
appears (currently ascribed to expansion of the universe (more space
today than yesterday due to Hubble expansion)).


No, because the cosmological constant has a different equation of state
than radiation.

These are treated as separate things today, but is there any observation
that requires they actually be unrelated? I mean, if they are both
linear with expansion of the universe, might they be interelated?


See above. You also have it backwards; you need an observation (or
theory) to prove that they are related.

We know of things like water evaporating where a small volume of one
form of a thing is converted into a large volume of a different form of
that same thing (condensed matter water to vapor water). Why can't it
be that what we call empty space is just the "vapor" form of what we
call "matter"?


Because it doesn't work quantitatively.
  #5  
Old February 26th 17, 04:45 AM posted to sci.astro.research
external usenet poster
 
Posts: n/a
Default Cosmic Energy Budget, vs time

Wrong. First, you are almost assuming that that which you wish to prove
is true. Second, just because two things are linearly related doesn't
mean that they are the same thing, nor even that one causes the other.
There is a good anticorrelation between global warming and the number of
pirates, a good correlation between the number of stork pairs and the
birthrate.


OK, sure, I know. The number of earthquakes has dramatically
increased over the past 100 years too. As has sale and installation
of seismometers.

correlation does not prove causality.

However, causality does come with correlation. And sometimes, the
answer is right in front of our face and we ignore it because it
is too (seems impossibly) simple.

I'm poking at whether we're overlooking something right in front
of our face.

Might exothermic processes be linked to the expansion of the universe?
If so, then the energy density of the vacuum would remain nearly
constant over time. but it has as best I can find.

Why can't it
be that what we call empty space is just the "vapor" form of what we
call "matter"?


Because it doesn't work quantitatively.


What do you mean? I read that the energy density of the vacuum has
remained constant...........ie, Dark Energy has had the same energy
density over time.

And at least today, the value for Dark Energy I've seen is close
to the value for all forms of energy (cbr, starlight, etc.) So
quantitatively dark energy is close to the energy density of other
forms of energy. I'm still working on assembling a plot for all
ages of the universe, lots of work, little time to do it.

Thanks,

rt
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Reionization Energy or Universe Mass Budget [email protected] Research 0 December 24th 16 10:14 AM
All Tha Cosmic ENERGY is in the Quantum Realm I'm even proof of that G=EMC^2TreBert Misc 4 June 29th 14 10:37 PM
Earth's Energy Budget Remained Out of Balance Despite Unusually LowSolar Activity Sam Wormley[_2_] Amateur Astronomy 18 February 10th 12 04:53 PM
Might be a bad time to mention this, but...Space/Sci Budget Should Be'ed Frank Robertson Policy 8 July 31st 10 01:25 PM
Black hole Time Universe Time Cosmic Time G=EMC^2 Glazier[_1_] Misc 5 July 1st 07 04:03 PM


All times are GMT +1. The time now is 09:06 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2004-2017 SpaceBanter.com.
The comments are property of their posters.