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Where Does Space End? It Must End Somewhere!


Edisonian

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Based on what data do you claim that the density is decreasing?

Would you kindly present this evidence?

 

 

Primarily the CMB, but all the other evidence as well.

http://www.astronomynotes.com/cosmolgy/s7.htm

Actually, if the Universe is infinite, while the mass is finite then by now the density of our universe should be zero or close to zero.

 

What calculations do you base that on?

Somehow, our universe maintains the density even with its infinity size (and I assume also infinity age).

 

 

It clearly does not maintain its density. It used to be denser and hotter.

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The CMB itself is only possible in a cooling universe. Secondly temperature history shows a decreasing value. At time of the CMB it was 3000 kelvin today 2.7 kelvin. Density and temperature both drop due to expansion.

 

You already know these details. They have been mentioned numerous times to you in past threads

 

We have to distinguish between evidence and theory.

It was agreed to keep a clear table for only real evidences.

 

The CMB as it is today (2.7) is evidence.

The idea of 3000 K is part of the current theory.

So please, based on what real CMB measurements, do you claim that the density is decreasing?

Edited by David Levy
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Both you always have to account for redshift. However BAO baryon accoustic oscillation rate is also affected by density. So redshift aside the BAO dynamics alone support a higher density past.

 

The particle (element composition) of the CMB is only possible via BB nucleosynthesis, the percentages of hydrogen, lithium etc of that time era is completely different than today. This is also an effect due to expansion.

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I believe thats already detailed in this thread. Lets play connect the dots.

 

1) Cosmological redshift is caused by ?

 

2) A change in volume causes a change in temperature/ pressure and ?

Edited by Mordred
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Thanks

 

Would you explain why redshift support a higher density in the past?

 

If possible, please highlight an article about this issue.

 

 

This is getting painful. And repetitive.

 

Originally, there was a theory that predicted increasing red shift and a universe that was cooling and becoming less dense. It was not widely accepted. (Maybe not even widely known.)

 

Then Hubble published his famous red-shift vs distance law.

 

Lots of scientists came up with different possible explanations. Lots of them were quickly shown to be wrong (not fitting all the data).

 

Several survived for quite a long time (because they could explain all the data available at the time).

 

Then the CMB was observed. It matched predictions of one theory perfectly, and all the other theories were unable to explain it.

 

So we were left with just one good, working theory: the "big bang" model.

 

As more data has been collected it has all found to be consistent with that model.

 

Because this is science (and not dogma) people still try other models to see if they work. So far, none have been able to match all the data as well as the "big bang" or Lambda-CDM model.

 

OK?

 

I know you don't like it and you don't understand it. But that doesn't make it wrong. It is currently the best (only) theory we have. It isn't going to be overturned by you saying "yeah, bit what if..." It will only be overturned by evidence.

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I believe thats already detailed in this thread. Lets play connect the dots.

1) Cosmological redshift is caused by ?

 

Thanks

 

So if I understand you correctly:

With regards to the Cosmological redshift - that by itself isn't a proof that the density of the Universe is decreasing.

However, it is related to our current theory.

 

 

2) A change in volume causes a change in temperature/ pressure and ?

 

 

This also related to our current theory.

 

In other words, the science estimates that if there is a change in volume (due to the expansion) then the outcome should be a change in temperature/pressure/density.

However, this is the current understanding for what we see. It doesn't mean that there is a proof that the density is decreasing.

Therefore, The redshift by itself or the change in the volume can't be use as evidences for density decreasing.

Actually, we both look at the same evidence and we get different conclusions.

We all agree that the volume is increasing due to the expansion.

 

1. Science - Based on the current approach – the science has decided that there is no new mass creation. Hence, if there is a change in volume without new mass creation – then there must be density decreasing. That is logical.

 

2. Me – I claim that as the Universe is infinite in its size and (even in its age) it must be at its stable state. This stable state means that even in the next 100 Billion years or infinite time from now the Universe should look the same. The only solution for that is that the density must be stable.

 

Therefore, if the volume is changing while the density is stable, then the only solution is mass creation.

 

So, based on the current science approach as the density is decreasing we should see less and less galaxies. If we come back to our universe in the next 100 billion years it should surly be less dense.

If we will come after the infinity, we might not see even one galaxy in our observable universe.

 

However, we are already after the infinity, but we still see a universe with billions over billions galaxies. Therefore, I estimate that the Universe is already in its stable state.

Edited by David Levy
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1. Science - Based on the current approach – the science has decided that there is no new mass creation. Hence, if there is a change in volume without new mass creation – then there must be density decreasing. That is logical.

 

2. Me – I claim that as the Universe is infinite in its size and (even in its age) it must be at its stable state. This stable state means that even in the next 100 Billion years or infinite time from now the Universe should look the same. The only solution for that is that the density must be stable.

 

 

Well, if is a choice between science based on evidence and the baseless and illogical guesses of a random guy on the Internet, I'll stick with science thanks.

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You claim in 2 that it must be in its stable state if it is infinite in extent. Why? I don't see how one follows from the other.

 

Well it's quite simple.

 

The asymptote of the infinity means stability.

 

Infinite universe in its size/age means that there is virtually no starting size or time.

 

As infinite means "limitless or endless in space, extent, or size; impossible to measure or calculate"

 

Therefore, if we could go through the universe, we should see that it is there at any direction to the infinity.

 

In the same token, if we could go in time forward or backward it should be there at any scale of time.

 

If it is there at any scale of size/time then it must be stable.

 

On the other hand,

 

Let's assume that the current approach/theory is correct (no new mass creation) and verify the outcome.

 

Today we see a universe full of galaxies.

 

Due to the expansion, we should see in the future less and less galaxies (in our observable Universe).

 

So, it is clear that in 100 billion years from now we should see significantly less galaxies.

 

If we go 1,000 BY from now, we might not see too many galaxies.

 

If we go 10,000 BY from now, we might not see any galaxies at all.

 

If we go to the infinity we might not see even one star.

 

But, we are already in the infinity and we still see a universe full of mass and galaxies and still in expansion.

 

Therefore, it must be in its stable state. Therefore it must keep its density.

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Well fortunately research and observations disagree with a stable density. Of course you would actually have to study the thermodynamic laws itself.

 

For one thing its incredibly possible to have an infinite universe whose average density decreases. In point of detail it is incredibly Unlikely to have a thermodynamic stable system.

 

Stellar formation itself lends to expansion. I would normally post the math showing that but I would be wasting my time

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Well, so far you didn't offer even one real evidence which contradicts the universe stability.

I do believe that by math you can prove it. However this isn't evidence.

There are plenty of tricks in math which can prove whatever we wish.

Evidence please.

Edited by David Levy
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I'm not about to waste my time. Particularly as you will just argue its just math. Did the thought ever occur to you that COBE, Planck and WMAP datasets literally provide the proof of an evolving density? I'm pretty positive the evidence is already posted in this 40 plus page thread. Considering that LCDM itself states an evolving density the burden of proof of a non evolving density is in your court. Every other poster that actually understands how this universe evolves according to the FLRW LCDM metric. Including the professional scientific community.

 

You should take that as a solid hint your wrong. As been mentioned numerous times You can't even have a CMB without a density change. Quite frankly I'm tired of repeating myself in this thread while you continuosly go in circles.

 

Here is a thought why would we even need the cosmological constant to explain the accelerating expansion, when initially our math showed no accelerating expansion?

 

 

Could it possibly be because our model was shown incomplete by observational evidence? that it took several decades of research before the cosmological constant became accepted and the equations were subsequently repaired?

 

But I suppose according to you none of this counts as evidence simply because a formula is involved right ? 😄.

 

Do you honestly believe science Doesn't spend billions of dollars and not test those formulas you ignore? Like I said I'm not about to waste my time proving what a 100 years of research and tests have shown. In case you try the " They just say that to make the math fit" conspiracy argument you will be wasting your time

Edited by Mordred
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[ignorant twaddle deleted]

 

 

Maybe you should learn about some of the scientific theories about the possibilities for an infinite universe, instead of just repeating the same nonsense that you been told is incompatible with the evidence.

 

One very simple example, that even you might be able to understand, is the idea that the universe undergoes continuous cycles of expansion and contraction. (Currently, the accelerating expansion makes that seem unlikely.) Combining quantum theory and gravitation will probably create other possibilities.

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How is it stable if, only 13.4 Bil yrs ago the universe was hot and dense enough that electrons could not stick to protons so as to form atoms ?

That IS the source of the CMB.

 

If it has changed so much in 13.4 Bil yrs, how can you say that it will look the same in 10000 Bil yrs because it is 'stable' ?

And expect us to take you seriously ???

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How is it stable if, only 13.4 Bil yrs ago the universe was hot and dense enough that electrons could not stick to protons so as to form atoms ?

That IS the source of the CMB.

 

If it has changed so much in 13.4 Bil yrs, how can you say that it will look the same in 10000 Bil yrs because it is 'stable' ?

And expect us to take you seriously ???

 

Yes and No

Yes - Based on the BBT 13.4 BY ago the universe was hot and dense.

Please also see the following explanation about the Big Bang:

https://en.wikipedia.org/wiki/Big_Bang

"Detailed measurements of the expansion rate of the universe place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe"

"Extrapolation of the expansion of the universe backwards in time using general relativity yields an infinite density and temperature at a finite time in the past."

"The Big Bang theory offers a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background, large scale structure, and Hubble's Law.[6]"

That's could be a nice explanation for finite universe.

No - The BBT can't explain an infinite Universe. Even if the space expansion will be in the speed of light, the evolvement after 13.8 BY can only get to finite universe.

Therefore, the science adds just one single word "Infinite".

Therefore, instead of:

"13.4 Bil yrs ago the universe was hot and dense"

It is stated that:

"13.4 Bil yrs ago the universe was infinite hot and dense"

Small change - big difference.

The science can't explain the source for this Infinite hot dense.

 

When it was finite hot dense, we could understand that somehow something came out of nothing. But now, how can we explain that the infinity came almost out of nothing.

I'm sure that the science should surly find a solution also for this "small" question.

In any case, I think that if the Universe was infinite hot dense, then we really don't need the whole BBT.

They can just say – Yes the Infinite Universe was always there – don't ask us why. We can tell you only about the evolvement.

 

 

 

I'm not about to waste my time. Particularly as you will just argue its just math. Did the thought ever occur to you that COBE, Planck and WMAP datasets literally provide the proof of an evolving density? I'm pretty positive the evidence is already posted in this 40 plus page thread. Considering that LCDM itself states an evolving density the burden of proof of a non evolving density is in your court. Every other poster that actually understands how this universe evolves according to the FLRW LCDM metric. Including the professional scientific community.

You should take that as a solid hint your wrong. As been mentioned numerous times You can't even have a CMB without a density change. Quite frankly I'm tired of repeating myself in this thread while you continuosly go in circles.

 

 

I really don't want to waste your time or even my time.

Unfortunately, I couldn't find any correlation between all of those examples to density decreasing.

I'm not asking for several evidences. One is enough for me.

 

Please offer one solid evidence for density decreasing.

 

 

Here is a thought why would we even need the cosmological constant to explain the accelerating expansion, when initially our math showed no accelerating expansion?

Could it possibly be because our model was shown incomplete by observational evidence? that it took several decades of research before the cosmological constant became accepted and the equations were subsequently repaired?

But I suppose according to you none of this counts as evidence simply because a formula is involved right ?

Do you honestly believe science Doesn't spend billions of dollars and not test those formulas you ignore? Like I said I'm not about to waste my time proving what a 100 years of research and tests have shown. In case you try the " They just say that to make the math fit" conspiracy argument you will be wasting your time

 

The cosmological constant is part of the BBT.

If there is an error in the BBT there might be also an error in that issue.

In any case, this isn't an evidence.

 

I had the impression that we have agreed to pile all the evidences on a clear table.

You set on this table also the current theory - BBT, and try to see all the evidences through the narrow prism of the BBT.

As long as you insist to hold the BBT on the table - then we might not get to any real conclusion.

You and Strange are base of knowledge about all the evidences and theories.

You both surly know to distinguish between evidences and theory.

Please - only evidences.

 

If I recall it correctly:

Sir Fred Hoyle which was an English astronomer, have stated that we only need few atoms per year per cube in order to maintain the stability of the Universe.

Edited by David Levy
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No - The BBT can't explain an infinite Universe.

 

 

It doesn't matter how often you repeat that, it still won't be true. The big bang model works equally well whether the universe is infinite or finite.

 

 

I'm not asking for several evidences. One is enough for me.

 

Apparently not. You have had the evidence explained to you in minute detail many times over many years. You stiller fuse to accept it. I don't know if this is because you are monumentally stupid or you just wish the universe behaved in a different way. Either way, we are all wasting our time.

 

 

Please offer one solid evidence for density decreasing.

 

The CMB. (As you have been told already.)

 

 

 

Sir Fred Hoyle which was an English astronomer, have stated that we only need few atoms per year per cube in order to maintain the stability of the Universe.

 

And his theory COULD NOT EXPLAIN THE CMB.

 

So it was abandoned in favour of the only (current) theory that can explain ALL the evidence.

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The CMB. (As you have been told already.)

 

Sorry.

The current measurements of the CMB don't give any indication about density decreasing.

What I do understand is that today its value is 2.7K.

That's by itself can't give any negative or positive information about the density.

The value of 3000K had been calculated based on the BBT theory.

We don't have direct measurements of that value.

Therefore, it seems to me that CMB by itself can't be used as an indication for density decreasing.

 

However, it sounds to me like catch 21.

1. Based on the BBT you have calculated that the CMB value in the past was 3000K.

2. Based on the 3000K you prove that the density is decreasing.

3. Based on density decreasing you prove that the BBT is the only valid theory. (Go to 1.)

Did I miss something?

If so, please explain.

Edited by David Levy
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Then please explain the source of the CMB.

 

Thanks

 

Yes, I have full explanation for the CMB. I will do it in the near future.

 

However, before we continue our discussion it is vital to close this issue as follow:

Without the BBT theory - There is no evidence for density decreasing.

 

Once we agree on that we will move on to the next step.

Edited by David Levy
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Without the BBT theory - There is no evidence for density decreasing.

 

Once we agree on that we will move on to the next step.

BS the thermodynamic laws of physics alone state that expansion causes a density decrease. Which has been pointed out to you before Edited by Mordred
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"thermodynamics in an expanding universe."

 

A little on the math heavy side.

 

http://www.google.ca/url?sa=t&source=web&cd=2&ved=0ahUKEwjqvprFxr_QAhUQ_WMKHVRLDIQQFggcMAE&url=http%3A%2F%2Fwww.personal.psu.edu%2Fduj13%2FASTRO545%2Fnotes%2Fch4-ExpandingThermodanamics.pdf&usg=AFQjCNG9oF7OYmRjYL0n0Yl1j8eaEz2BXg

 

Your in luck though I found an open source full length lecture note on thermodynamics.

 

http://www.google.ca/url?sa=t&source=web&cd=1&ved=0ahUKEwi6hbf7zL_QAhXCgrwKHVAVAcsQFggdMAA&url=https%3A%2F%2Fwww3.nd.edu%2F~powers%2Fame.20231%2Fnotes.pdf&usg=AFQjCNED3Gx272wGY3Nfzwk2-_C1tC4iwA

 

 

"Local thermal equilibrium is then reached before the effect of the expansion becomes relevant. As the universe cools, the rate of interactions may decrease faster than the expansion rate. At

tc tH , the particles decouple from the thermal bath. Different particle species may have different interaction rates and so may decouple at different times."

 

From this link, this process creates the CMB itself.

 

http://www.google.ca/url?sa=t&source=web&cd=3&ved=0ahUKEwi6hbf7zL_QAhXCgrwKHVAVAcsQFggiMAI&url=http%3A%2F%2Fwww.damtp.cam.ac.uk%2Fuser%2Fdb275%2FCosmology%2FLectures.pdf&usg=AFQjCNGxvGWwx9QmCl2FyZLAUmB7lkZ7xQ

 

I am curious what exactly is your definition of Density?

 

Density. Density is the mass per unit volume. This means that the density of any solid, liquid or gas can be found by dividing its mass in kilograms by its volume in cubic metres.

 

So any volume change by definition and mathematical, results in a change in density.

 

You tried to state that expansion does not result in a density decrease but the very definition of density tells you otherwise.

 

It is the repetition of these mistakes which makes trying to teach you cosmology extremely fustrating. As the repetition indicates your not learning. Or you are missing key details in your posts.

 

Are you perhaps referring to the cosmological constant influence upon conservation of energy?

 

Side note: Recall an earlier statement I made to there being a cosmological redshift to temperature relationship?

 

see first link section 4.6.4

 

Please recall a change in mass density also changes temperature/pressure and entropy density (and vice versa in any change mentioned)

Edited by Mordred
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