I Was the Universe Really Dark and Quiet After the Big Bang?

[Wondermine]

It is postulated that there was a "Dark Age" subsequent to the so called Big Bang.
The "matter" subsequent to the Big Bang would be composed of Quarks,if there was no light postulated for that time.
This would indicate that the forces present would be only the Strong Force.
The Strong Force of Quarks has an extremely small/short "reach". The smallest "reach" of any known force.
If the energy ,as postulate from observation, was accelerating at an exponential rate in the form of Quarks how then could the strong force possibly enforce a coalescence of quarks to form atoms thereby allowing subsequent electromagnetic forces to allow light? If the distances between Quarks accelerated exponentially ,would that not lead to an increasing improbability of nucleus formations?

 

[PeterDonis]

It is postulated that there was a "Dark Age" subsequent to the so called Big Bang.

Please give a specific reference. You appear to have mistaken information about what this actually is.

The "matter" subsequent to the Big Bang would be composed of Quarks,if there was no light postulated for that time.

I don't know where you are getting this from. There was always radiation in the universe.

This would indicate that the forces present would be only the Strong Force.

This is not correct.

Your post appears to be based on mistaken premises. I suggest starting with this for a better understanding:

https://en.wikipedia.org/wiki/Chronology_of_the_universe#Dark_Ages

Note that the time frame of the "Dark Ages" given here is from around 380,000 years after the Big Bang to somewhere between 150 million and 1 billion years after the Big Bang. The conditions of the universe during that period were very different from what you appear to think based on your post.

 

[Wondermine]

Clarification: It is my understanding that the intrinsic energies in the singularity associated with the "cause" of the universal matter would be such that no atoms would exists. That potential atoms would exist in the form of quarks which would then form atoms, subsequent to diminished energy levels which expansion would facilitate.
So my comment suggested that "radiation" would be exclusive to the Strong Force, since lower energies in the form of "light" would not yet exist.
How is that an erroneous and would be pleased with contrary or additive views.

 

[PeterDonis]

It is my understanding that the intrinsic energies in the singularity associated with the "cause" of the universal matter would be such that no atoms would exists. That potential atoms would exist in the form of quarks which would then form atoms, subsequent to diminished energy levels which expansion would facilitate.

First, this has nothing to do with the "Dark Ages" in the history of the universe (by that time atoms existed), so what does it have to do with the topic of this thread?

Second, I have no idea what you mean by "the intrinsic energies in the singularity associated with the cause of universal matter". Can you give a reference (textbook or peer-reviewed paper) for where you are getting this from?

Third, it is true that atoms were not present in the very early universe--not until a few hundred thousand years after the Big Bang. But what was present before that time was not just quarks.

my comment suggested that "radiation" would be exclusive to the Strong Force, since lower energies in the form of "light" would not yet exist.
How is that an erroneous

First, quarks aren't "radiation". Second, "light" (EM radiation/photons) was always present; there was never a time when it wasn't.

 

[Orodruin]

How is that an erroneous and would be pleased with contrary or additive views.

It is simply wrong. The current cosmological models do not say this. That the early Universe contained a quark-gluon plasma in no way states that there was no photons.

The ”dark ages” refer to a cosmological period before reionization but after recombination during which essentially no new light was emitted. This does not mean that there was no light in the Universe.

 

[Wondermine]

Correct. My query is concerned with events prior to the formations of atoms.Wiki: Hydrogen and helium atoms begin to form as the density of the universe falls. This is thought to have occurred about 377,000 years after the Big Bang.[21]

That is what I stated. The expansion indicates falling density.

In the extreme density of a singularity a form of Bose-Einstein state would dominate therefore this state would be extreme whereby nucleii would be gluons and quarks. These frequencies are not in the order of light frequencies.
So my postulate (are postulates allowed?) is that radiant energy would be in the form of the Strong Force exclusively in that environment.

My question is therefore,how would atoms form if the distances at an ever increasing expanding exponential rate allow strong forces(which act over extremely small distances) to form nucleii of helium and hydrogen?I did not state that quarks are radiation.Quite the opposite in fact. More like confined radiation since everything is a wave form.

"Radiation" in the conventional sense is form A to B at a distance greater than the wavelength of the energy. The current model does not exclude photons from the original singularity. To have photons means that there must be a source of appropriate vibration to an object for it to emit photons. Quarks would emit energy at extremely high frequencies.So high that the radiation would be termed the Strong Force,not photons. How is that in error?

 

[Orodruin]

So my postulate (are postulates allowed?) is that radiant energy would be in the form of the Strong Force exclusively in that environment.

Postulates are allowed as long as they are in accordance with observations. Your "postulates" are not.

 

[JMz]

To be clear about at least one thing: After the first 3 minutes, and before 370K years, there were all the ordinary particles, just (a) no un-ionized atoms (though maybe singly ionized He for some of that time), and no nuclei heavier than He except for trace amounts of Li. But in no sense was the universe a quark-gluon plasma, or anything remotely so exotic. That era was over long. long before 370K years.

 

[Wondermine]

Postulates are allowed as long as they are in accordance with observations. Your "postulates" are not.

The current model does not have observations concerning the content of the singularity and science does not prohibit speculation (hypotheses). In fact hypotheses that pose relevant questions, in my view, create an atmosphere of inquisitiveness that provokes analysis. Analysis often produces unexpected observations that the mathematics, in this case,can peruse. Just a thought.

 

[Orodruin]

The current model does not have observations concerning the content of the singularity and science does not prohibit speculation (hypotheses).

I am sorry, but why do you keep referring to a singularity? It has nothing to do with the standard Big Bang model, which describes the expansion of the Universe from a hot dense state.

 

[berkeman]

The current model does not have observations concerning the content of the singularity and science does not prohibit speculation (hypotheses). In fact hypotheses that pose relevant questions, in my view, create an atmosphere of inquisitiveness that provokes analysis. Analysis often produces unexpected observations that the mathematics, in this case,can peruse.

You *have* read the part of the PF rules that prohibits speculation, right?

 

[PeterDonis]

My query is concerned with events prior to the formations of atoms

Ok, but the temperature of the universe at the time of recombination (when atoms first formed) was a few thousand degrees Kelvin. You seem to be talking about a much earlier time, when the temperature was many, many orders of magnitude larger.

In the extreme density of a singularity a form of Bose-Einstein state would dominate

As @Orodruin has pointed out, there is no singularity in our current best fit model of the actual universe. The "initial singularity" is an artifact of a particular set of idealized models; it's not a feature of the one we actually use.

Also, why would you expect a Bose-Einstein condensate to dominate at very high temperatures? A Bose-Einstein condensate is a low temperature state; it only forms when thermal degrees of freedom are sufficiently "frozen out".

my postulate (are postulates allowed?) is that radiant energy would be in the form of the Strong Force exclusively in that environment

I have no idea why you would think this. The fact that the temperature is high enough for a quark-gluon plasma does not mean photons are no longer present. Even in a quark-gluon plasma the quarks are still electrically charged, and it's going to be as easy to make photons of a particular energy as to make gluons of the same energy.

 

[Wondermine]

Thanks for the direction. The reason I used the word singularity is that there was only one event referred to (the "bang") and that the degrees for freedom would be minimal as in a singularity. It is a description I found convenient although I am somewhat aware there are differences.

The reason I thought that there would be no photons is that under extremely (most extreme) confined degrees of freedom there would not be room enough for a whole photon wavelength. Meaning the wavelengths and frequencies being so tiny they would more properly be forces,not photon waves. I then imagined that only force fields would be present and the candidate being the Strong Force as being the smallest and tightest form of atomic energy.

This then lead to the question about how atoms could be formed if rapid expansion occurred given the Strong Force acts over a tiny distance only.

I am not ignoring those suggestions that I am "wrong". Wrong is a word I avoid. Less aware or more aware is a more helpful and guiding principle . Finite judgments are dictatorial and do not nurture inquiry.

 

[berkeman]

This then lead to the question about how atoms could be formed if rapid expansion occurred given the Strong Force acts over a tiny distance only.

I am not ignoring those suggestions that I am "wrong". Wrong is a word I avoid. Less aware or more aware is a more helpful and guiding principle . Finite judgments are dictatorial and do not nurture inquiry.

Asking questions is generally a good thing. That is how you learn. In this case, you are getting help from @PeterDonis and others to help you see why the mental models you have learned from popular science so far are not correct. Keep asking good questions, and please be open to learning.

 

[PeterDonis]

The reason I used the word singularity is that there was only one event referred to (the "bang") and that the degrees for freedom would be minimal as in a singularity.

The term "Big Bang", properly interpreted (i.e., as cosmologists actually use it, as opposed to pop science usage), does not refer to any "initial singularity". It refers to the hot, dense, rapidly expanding state that is the earliest state for which we have good evidence. The current majority belief appears to be that this state occurred at the end of an inflation epoch, but that is still, strictly speaking, an open question.

Thinking of the correct "Big Bang" state as having minimal degrees of freedom is not a good way to think of it. Because of the extremely high temperature, that state actually had many more degrees of freedom excited (i.e., containing significant energy density) than our universe today does.

The reason I thought that there would be no photons is that under extremely (most extreme) confined degrees of freedom there would not be room enough for a whole photon wavelength.

Wavelength depends on energy; the higher the energy the shorter the wavelength. At high temperature most of the photons will be very high energy and therefore very short wavelength.

Also, this argument, if it were correct, would prove too much: it would prove that there could be no particles at all at high temperature, since they all work the same as photons do as far as wavelength is concerned.

the wavelengths and frequencies being so tiny they would more properly be forces,not photon waves. I then imagined that only force fields would be present and the candidate being the Strong Force as being the smallest and tightest form of atomic energy

This is not a good way to think of it. The distinction between "force fields" and "waves" is not a matter of how small the wavelengths get (btw, small wavelength means very high frequency, not low). In fact, if anything, smaller wavelengths (and higher frequencies) are more likely to have "wavelike" behavior than "force field like" behavior; what we usually think of in everyday life as "force fields" are manifestations of quantum fields at long wavelengths and low frequencies and therefore low energies (and also off the mass shell as opposed to on shell, but that's a whole separate can of worms). When wavelengths get very small (and frequencies/energies get very high), the behavior gets more "particle-like", e.g., what is seen in high energy experiments like the LHC. Those experiments have no useful features in common with "force fields"; the best quick layman's description is that they're very high energy particles hitting each other and breaking into various pieces.

This then lead to the question about how atoms could be formed if rapid expansion occurred given the Strong Force acts over a tiny distance only.

As you should be aware by now, this question is based on a number of misunderstandings. When the misunderstandings are cleared up, the question vanishes. To quickly recap: when atoms were formed, the universe was at a much lower temperature than a quark-gluon plasma would be, and the dominant forces were gravity (governing the large scale expansion of the universe) and electromagnetism (which is what attracted electrons to nuclei to form the atoms). The strong force had already done its major job a long time before, by driving nucleosynthesis in the first few minutes of the universe--and even that was well after the quark-gluon plasma stage. When the strongly interacting portion of the universe's energy density was a quark-gluon plasma, the temperature was much too high for any higher level structures at all to form--not even protons or neutrons, much less nuclei or atoms. And even at that time, the quark-gluon plasma was not the only significant component of the universe: others included electrons and positrons, neutrinos and antineutrinos, W and Z bosons, and photons.

 

[mfb]

To be clear about at least one thing: After the first 3 minutes, and before 370K years, there were all the ordinary particles, just (a) no un-ionized atoms (though maybe singly ionized He for some of that time), and no nuclei heavier than He except for trace amounts of Li. But in no sense was the universe a quark-gluon plasma, or anything remotely so exotic. That era was over long. long before 370K years.

There were always some neutral atoms, but they didn't stay together long before getting ionized again.
Most helium was neutral before most hydrogen became neutral as it has a larger ionization energy.

 

[JMz]

There were always some neutral atoms, but they didn't stay together long before getting ionized again.

We-l-l-l, "always some" is literally true but probably obscures more than it clarifies, for the early part of that interval, when the temperature was >> 10⁶K.

Most helium was neutral before most hydrogen became neutral as it has a larger ionization energy.

Quite right, and why He was an ionized "atom" (i.e., not just a bare nucleus, Wondermine's apparent focus) for a while before recombination.

 

[Wondermine]

Thanks for the insight to all. I remain skeptical about the possibility of nucleii existing before expansion . Oh,by the way I never have and don't read popular science. Never have,never will.

For casual reading I quite like Dirac. He postulated a monopole. No one shouted from the room Wrong! I will only say that the character and energies a moment in advance of the "big bang" had energies many times higher than CERN or anything we can imagine. If some say nucleii can exist there then I will take that on advisement and peruse this view further.

Thanks for the comment that there would be many species of particles at the extreme high energies. Is there not implied a conundrum here?
That being if the energy/matter before expansion is compressed to an unprecedented degree in what is described as a "singularity" like region, then how could there be more degrees of freedom.

The particles you describe that are seen from collisions are post collision here on earth.

In other words after the extreme compression of collision of a couple of particles with vectors. Residue of the compressed state in effect with their specific qualities.

If extreme compression or closeness of all matter in the form of energy at the locus of the so called "big bang" were to have limited degrees of freedom then where would the energy come from to cause an expansion, given that confinement limits degrees of freedom and therefore net excitation.

You mentioned that extreme compression produces more degrees of freedom.
Is that not a conundrum?

 

[Orodruin]

I remain skeptical about the possibility of nucleii existing before expansion .

This statement clearly shows that you do not grasp the theory.

I quite like Dirac. He postulated a monopole. No one shouted from the room Wrong!

Dirac was very well versed in the current theories as well as the front-line experimental results. He knew what he was doing and what could be assumed without anybody shouting "Wrong!" at face value.

That being if the energy/matter before expansion is compressed to an unprecedented degree in what is described as a "singularity" like region

Please stop talking about the singularity or singularity like. It is quite clear that you do not have a grasp of what this means.

given that confinement limits degrees of freedom and therefore net excitation

This statement shows that you do not understand what is meant by a degree of freedom in cosmology.

I am sorry, but the level of ignorance of what current theories state and the nomenclature that you are using makes it rather unsurmountable to give you an answer that gets you where you want to go. If you really want to know about this stuff, I recommend a basic textbook in cosmology (and if you do not understand that, go back in level until you reach the level you are comfortable with and start from there to work your way up).

 

[mfb]

You are jumping around between completely different periods of the big bang and between completely different questions about the existence of particles from post to post. In addition you misrepresent the answers given by others. That makes a discussion very difficult.

 

[Wondermine]

O.K. Fine. I see what you are saying. I was referring to the time before the "Dark Ages". This is clear from what was queried.
Secondly that period and locus is directly related to the "Dark" period and is related. Therefore the "jumping around" critique is a mute point.

Thirdly I described that period as a "singularity". This was unacceptable.
What would it be termed as then since this general description offended.

Fourthly I was asking the questions about the density of energy at that time and the character of energy/mass as related to the existence or not of particles as they are described in the current model. Again no jumping around.

Fifthly my questions were specifically centered on the degrees of freedom associated with energy preceding the so called "Dark Age" in the conventional description of that period when all "matter" was located in a extremely small loci.
This is clear from the question I asked which was,if there were limited degrees of freedom,via the extremely confined nature of the situation a moment-isimal before the BB and the vibration energy very confined and therefore low and hence cold,
where did the energy come from to create an expansion and when that occurred how would the strong forces be local enough to create atoms?

This seems a very straight forward question that does not involve "jumping around".
It is contingent with the topic as well.

I see no problem asking this question nor its relevance.
If it is a problem then I won't trouble you more or provoke your criticism of what I may know or not know,which is perhaps another matter entirely.

Forgetting about what I may know or not,do limited degrees of freedom produce heightened net energy or reduced net energy?
I will leave it at that one question since nomenclature here leads to confusion.

 

[Wondermine]

You are jumping around between completely different periods of the big bang and between completely different questions about the existence of particles from post to post. In addition you misrepresent the answers given by others. That makes a discussion very difficult.

Thanks.
There was an event termed the BB.
Subsequent to that there were effects and states of matter.
They are contingent so one cannot escape referring to both.
If this is called jumping around,which I perceive as a derogatory comment,then there is nothing I could add nor no amount of knowledge which could affect that view.

 

[JMz]

You mentioned that extreme compression produces more degrees of freedom.
Is that not a conundrum?

To address just this one point: Degrees of freedom (in this thermodynamic sense) consists of position and momentum, among other things. Confining something adiabatically reduces the former (as you recognize) but increases the latter.

Moreover, many d.f. are "frozen out" at low temp's. (That's the "among other things".) For instance, hydrogen and oxygen molecules at low temp. do not participate in chemical reactions, even if mixed. Compressing them enough, OTOH, raises the temp. to the point where they can rearrange electrons across molecules when they collide. (Bang!) The rearrangement corresponds to additional d.f. that were effectively absent at low temp. So also cosmologically.

 

[mfb]

I was referring to the time before the "Dark Ages".

That time spans at least 40 orders of magnitude in time and at least 30 in energy, with several huge changes in the composition of the universe. You are jumping around between different points in time in this giant range of different conditions.

Therefore the "jumping around" critique is a mute point.

At least three physicists working on topics connected to the big bang told you that it is unclear which time you are referring to where. You might reconsider if what you write was really as clear as you think.

do limited degrees of freedom produce heightened net energy or reduced net energy?

What do you mean by that? Degrees of freedom are not physical objects, they cannot cause something.
Net energy of what?

 

[Chronos]

The term 'dark ages' was coined because it is believed the universe was largely devoid of stars until it was about 400 million years old. The universe was obviously not devoid of photons because cmb photons, referred to as the oldest photons in the univese, were being emitted by the time the universe was only a few hundred thousand years old

 

[nikkkom]

The term 'dark ages' was coined because it is believed the universe was largely devoid of stars until it was about 400 million years old. The universe was obviously not devoid of photons because cmb photons, referred to as the oldest photons in the univese, were being emitted by the time the universe was only a few hundred thousand years old

I think it's referred as "Dark" because it would look literally as darkness to a human eye, IOW: no visible light radiation was present. CMB photons were infrared at that point, and no other sources of light existed yet.

 

[phinds]

I think it's referred as "Dark" because it would look literally as darkness to a human eye, IOW: no visible light radiation was present. CMB photons were infrared at that point, and no other sources of light existed yet.

That's interesting. Chronos just told you EXACTLY why the term "dark ages" was coined and yet you have decided to create your own definition. Good luck with that.

 

[nikkkom]

It is postulated that there was a "Dark Age" subsequent to the so called Big Bang.

There are quite a number of steps in between. The "Chronology of the universe" wiki article:
https://en.wikipedia.org/wiki/Chronology_of_the_universe
is a good introductory explanation.
It has a nice table which describes temperatures, energies, "time since BB" and what was happening.

In particular:

...
Big Bang nucleosynthesis, 10..1000 seconds - Protons and neutrons are bound into primordial atomic nuclei, hydrogen and helium-4. Small amounts of deuterium, helium-3, and lithium-7 are also synthesized.

Photon epoch, 10sec..380000years - The universe consists of a plasma of nuclei, electrons and photons; temperatures remain too high for the binding of electrons to nuclei.

Recombination, 380k years - Electrons and atomic nuclei first become bound to form neutral atoms. Photons are no longer in thermal equilibrium with matter and the Universe first becomes transparent. Recombination lasts for about 100 ka, during which Universe is becoming more and more transparent to photons. The photons of the cosmic microwave background radiation originate at this time. The spherical volume of space which will become the observable universe is 42 million light-years in radius at this time.

Dark Ages, 380k...150M years - The time between recombination and the formation of the first stars. During this time, the only source of photons was hydrogen emitting radio waves at hydrogen line. Freely propagating CMB photons quickly (within ~500 ka) red-shifted to infrared, and Universe was devoid of visible light.
...

For me, this is fairly well written and understandable.

 

[JMz]

Astronomers do not generally consider infrared light, or even radio waves, to be "darkness". Who specifically coined this term in this context, and what s/he was thinking at the time, I do not know, but that's a question of psychology, not of physics.

 

[nikkkom]

"The age without sources of visible light" just does not roll off my tongue as easily as "Dark Age".

 

[russ_watters]

Astronomers do not generally consider infrared light, or even radio waves, to be "darkness".

Agreed. And as such, the term "dark ages" - per the definition Chronos provided - isn't meant to refer only to visible light. If it did, the timeline would be missing an epoch!

Who specifically coined this term in this context, and what s/he was thinking at the time, I do not know, but that's a question of psychology, not of physics.

I think the term makes a lot of sense from an astronomical point of view. It means that we can't "see" what happened during that time because there was no new "light" created then. Telescopes are windows into the past, and that time is "dark" to us, at all wavelengths.

 

[russ_watters]

There are quite a number of steps in between. The "Chronology of the universe" wiki article:
https://en.wikipedia.org/wiki/Chronology_of_the_universe
is a good introductory explanation.
It has a nice table which describes temperatures, energies, "time since BB" and what was happening.

In particular:
...
Recombination, 380k years...

Dark Ages, 380k...150M years - The time between recombination and the formation of the first stars. During this time, the only source of photons was hydrogen emitting radio waves at hydrogen line. Freely propagating CMB photons quickly (within ~500 ka) red-shifted to infrared, and Universe was devoid of visible light.
...

For me, this is fairly well written and understandable.

"The age without sources of visible light" just does not roll off my tongue as easily as "Dark Age".

I feel like you're still suggesting "dark ages" is referring specifically to visible light. Please note that if that were true, the timeline would be in error and there would be an epoch missing; from 380ka-880ka, with the "dark ages" starting at 880ka.

 

[mfb]

At 380,000 years the CMB had a temperature of 3000 K and z=1100. Things glow visibly to the naked eye down to ~800 K, or z=290, corresponding to about 3.2 million years. That is quite a significant range where the light would have been visible to human eyes.

 

[Wondermine]

You are jumping around between completely different periods of the big bang and between completely different questions about the existence of particles from post to post. In addition you misrepresent the answers given by others. That makes a discussion very difficult.

I disagree with your criticisms entirely. The questions referred to the nature and form of energy preceding the BB.
Subsequent time periods are related to that and contiguous with that energy environment. So called "jumping around" is simply referring to consequences of one state and time leading to another.

Secondly, mentor ship is the act of commenting, not criticism of what one may know or not.
You have failed in your role as mentor to comment on specifics in a lighthearted way (all mentor comments have done this in fact).
Mentoring is not proving how much more you know at the expense of others. It is unbecoming for you to exhibit impatience when there is ample time for replies that do not require burdensome lengths of time.
Thirdly, the need to comment on how much I may know or not know dominated all of your replies. My questions remain unanswered.
Valid questions as to the density of the "singularity" before the BB were not answered. Many astrophysicists refer to the period before the BB as a singularity therefore it is a waste of your time focusing on critic.ism of my comment using this term.
I asked how you would define this period and what name you would like to assign to it in terms of structure. This question was not answered.
I asked what the consequences would be on the net energy of that system and whether you felt the net energy would rise with decreased degrees of freedom or fall with decreased degrees of freedom(before the BB).
This question was not answered.
Both questions relate to the BB and subsequent time line in the terms of energy states.

 

[berkeman]

I disagree with your criticisms entirely. The questions referred to the nature and form of energy preceding the BB.
Subsequent time periods are related to that and contiguous with that energy environment. So called "jumping around" is simply referring to consequences of one state and time leading to another.

Secondly, mentor ship is the act of commenting, not criticism of what one may know or not.
You have failed in your role as mentor to comment on specifics in a lighthearted way (all mentor comments have done this in fact).
Mentoring is not proving how much more you know at the expense of others. It is unbecoming for you to exhibit impatience when there is ample time for replies that do not require burdensome lengths of time.

Well, we are indeed trying to help you. If it's not working so well so far, then ...

For example, you just referred again to the time "before the Big Bang". Did you read the links that I sent you that explained why we cannot say much about that period?

 

[Wondermine]

That time spans at least 40 orders of magnitude in time and at least 30 in energy, with several huge changes in the composition of the universe. You are jumping around between different points in time in this giant range of different conditions.At least three physicists working on topics connected to the big bang told you that it is unclear which time you are referring to where. You might reconsider if what you write was really as clear as you think.What do you mean by that? Degrees of freedom are not physical objects, they cannot cause something.
Net energy of what?

The net energy of the system immediately preceding the BB and what form(s) that energy is in. What states(particles) survive that extreme compression that is widely postulated and termed a "singularity).

Well, we are indeed trying to help you. If it's not working so well so far, then ...

For example, you just referred again to the time "before the Big Bang". Did you read the links that I sent you that explained why we cannot say much about that period?

There is an ample supply of mathematical models describing the "singularity" states associated with Black Holes. Why would it be assumed the "singularity" before the BB would be anything different in character? What reason would be presented to justify the difference.

Well, we are indeed trying to help you. If it's not working so well so far, then ...

For example, you just referred again to the time "before the Big Bang". Did you read the links that I sent you that explained why we cannot say much about that period?

Yes. Extreme and accelerated expansion infers extreme contraction.
Therefore questions about extreme densities and "before the BB" are entirely acceptable paths of inquiry in a general sense.

 

[russ_watters]

There is an ample supply of mathematical models describing the "singularity" states associated with Black Holes. Why would it be assumed the "singularity" before the BB would be anything different in character? What reason would be presented to justify the difference.

I can think of one obvious one: the Big Bang banged and black holes don't. So it is very likely that the vastly different results are the result of vastly different conditions.

 

[berkeman]

For example, you just referred again to the time "before the Big Bang". Did you read the links that I sent you that explained why we cannot say much about that period?

Therefore questions about extreme densities and "before the BB" are entirely acceptable paths of inquiry in a general sense.

It sounds like either you didn't read the links that I suggested, or are not happy with what you found there...

From the INSIGHTS article: https://www.physicsforums.com/insights/big-bang-happen/

According to standard cosmological models, which are based on general relativity and are found to agree well with observations, time and space did not exist before the Big Bang — or even at the time of the Big Bang, which is a point where the theory breaks down because various quantities (such as temperature and spacetime curvature) are infinite. Therefore these models do not describe the Big Bang as an explosion that happened at a particular point in a preexisting landscape of time and space.

These are only statements about a particular kind of model. The model incorporates various assumptions, and as we get closer and closer to the Big Bang, these assumptions become more and more uncertain. For example, it is possible that under conditions of very high density and temperature, matter has exotic behavior that causes gravity to become repulsive. If this happens, then it’s possible that the Big Bang was not a bang but a bounce, and then time could be extended farther back into the past.

But even if time existed before the Big Bang, there is still another reason not to imagine the Big Bang as happening at one point in a preexisting empty space. Observations of the universe show a nearly complete lack of structure on very large scales, and the cosmic microwave background is also extremely uniform (with fractional temperature differences on the order of 10-5). For this reason, realistic cosmological models must be almost exactly homogeneous, meaning that no point in space has properties that differ very much from those of any other point. Therefore the best evidence is that the Big Bang happened uniformly, everywhere at once.

Reference https://www.physicsforums.com/insights/big-bang-happen/

 

[PeterDonis]

The questions referred to the nature and form of energy preceding the BB.

And the short answer to that is: we don't know, but the primary current hypothesis appears to be that it was potential energy in the inflaton field.

Notice that this answer has nothing to do with any "singularity". Nor does it bear any resemblance to any of the suggestions you have been making. Nor does it have anything to do with the "Dark Age", which happened well after the Big Bang. So the reason you didn't get an answer earlier to the question quoted above is that you didn't ask that question; you've asked a bunch of other questions that are either not well posed at all or are not about "the nature and form of energy preceding the BB".

Many astrophysicists refer to the period before the BB as a singularity

Please give an actual valid reference--textbook or peer-reviewed paper--that says this. Many pop science sources say this, but that just shows you can't learn actual science from pop science sources. Some textbooks use this term in reference to a particular idealized model that is used for pedagogy, but nobody thinks it actually describes our actual universe.

What actual valid references say about our actual universe is that the period before the BB was a period of inflation, since, as noted above, that appears to be our best current hypothesis.

Mentoring is not proving how much more you know at the expense of others. It is unbecoming for you to exhibit impatience when there is ample time for replies that do not require burdensome lengths of time.

You need to stop complaining about the tone of people's replies and start reading the actual content of those replies. We are trying to explain to you why the mental model you appear to have of how the universe developed is wrong. This thread can't go anywhere until you understand why that is.

 

[Orodruin]

Mentoring is not proving how much more you know at the expense of others.

Learning is accepting that your preconceptions and imaginations may not be as solid as you imagined and listening to people who have actual experience with the topic.

As already stated, you have gotten advice from numerous people who work with related topics for a living, all saying that your preconceptions are false in one way or the other. Not accepting this is just making you appear stubborn and unwilling to learn by unlearning false premises.

 

[russ_watters]

[period before the BB is referred to as "singularity"]
Please give an actual valid reference--textbook or peer-reviewed paper--that says this. Many pop science sources say this, but that just shows you can't learn actual science from pop science sources. Some textbooks use this term in reference to a particular idealized model that is used for pedagogy, but nobody thinks it actually describes our actual universe.

I don't think this point is necessarily critical to the thread, but I think Steven Hawking is probably the source of many of the "popular" tellings we see. One of many examples, from a lecture (you didn't list qualified lectures as valid, but we generally consider them to be):

So the time of zero separation...

At this time, the Big Bang, all the matter in the universe, would have been on top of itself. The density would have been infinite. It would have been what is called, a singularity. At a singularity, all the laws of physics would have broken down.

http://www.hawking.org.uk/the-beginning-of-time.html

There are probably three items you would quibble with here:
1. That the singularity is being referred to at all.

2. For whatever reason people on PF don't like the zero volume/infinite density "feature" Hawking likes to say for a space-time singularity (in a black hole, too), but to me "infinity" and "approaches infinity" aren't far enough apart to be worth quibbling over. But perhaps more to the point, I think that given his his significant contribution to this exact issue, Hawking's wording should be considered acceptable (the inventor gets to decide the name of his invention).

3. It is common to cite the "Big Bang" as the earliest identifiable state after the singularity, not the singularity itself. But I'm not sure this is a distinction worth quibbling about either (the wiki article notes the slight differnece in usage). These slightly different labels are colloquial, not scientific, no matter where they are used; in a paper, a lecture a news article, or on PF.

[note: this lecture/link is not dated, so it is possible this is an obsolete position of his. The wiki article's section on the singularity cites a 1973 paper of his as the source for describing the initial state as a singularity.]

[edit]
This wiki article provides some history:

Hawking's singularity theorem is for the whole universe, and works backwards in time: in Hawking's original formulation, it guaranteed that the Big Bang has infinite density.[1] Hawking later revised his position in A Brief History of Time (1988) where he stated that "there was in fact no singularity at the beginning of the universe" (p. 50). This revision followed from quantum mechanics, in which general relativity must break down at times less than the Planck time. Hence general relativity cannot be used to show a singularity.

https://en.wikipedia.org/wiki/Penrose–Hawking_singularity_theorems

So it would appear the idea that the universe started with a singularity was a naive early view that has been superceded but still remains in popular literature and some wiki articles. Still, it is a little surprising it hasn't been taken out of the BBT wiki article.

 

[PeterDonis]

There are probably three items you would quibble with here:

No, the item I am objecting to is that the idealized model Hawking is implicitly referring to, the one that has an "initial singularity" and no inflation, is not the model cosmologists actually use to describe our actual universe. It's an idealized model that is used for pedagogy, not physics.

It is common to cite the "Big Bang" as the earliest identifiable state after the singularity

No, it is common (in actual peer-reviewed literature) to use the term "Big Bang" to refer to the earliest identifiable state at the end of inflation. That is the current best-fit model: a hot, dense, rapidly expanding state that is modeled as arising from "reheating" when inflation ends and the energy stored in the inflaton field is transferred to the Standard Model fields. This model does not even have an "initial singularity" at all; it is agnostic about the question of whether such a thing exists, and does not use it, or even limits approaching it, to make any predictions at all.

Unfortunately, cosmologists do very little to clarify this point when pop science articles talk about an "initial singularity" and give the impression that the term "Big Bang" refers to it, or to some state "just after" it. What's more, cosmologists obfuscate the issue further by commonly quoting "times after the Big Bang" to label events, when what they are actually doing is: estimating the temperature of the universe at some event (such as the end of inflation) based on the actual best-fit model, which, as noted above, includes inflation and does not assume an "initial singularity" even exists; figuring out what the comoving coordinate time after the initial singularity would be for such a temperature in an idealized expanding FRW universe with no inflation; and quoting that idealized time as the "time after the Big Bang" of the event.

 

[Orodruin]

No, it is common (in actual peer-reviewed literature) to use the term "Big Bang" to refer to the earliest identifiable state at the end of inflation.

I just have a minor issue with this. Inflation is not really necessary for the standard Big Bang (even if it is useful to explain a series of issues that would otherwise arise). I would just call it the earliest identifiable state and be agnostic about what came before.

 

[PeterDonis]

Inflation is not really necessary for the standard Big Bang (even if it is useful to explain a series of issues that would otherwise arise). I would just call it the earliest identifiable state and be agnostic about what came before.

Yes, that's a fair point.

 

[russ_watters]

No, the item I am objecting to is that the idealized model Hawking is implicitly referring to, the one that has an "initial singularity" and no inflation, is not the model cosmologists actually use to describe our actual universe. It's an idealized model that is used for pedagogy, not physics.

I added some additional history I found, to my previous post, as you were posting this...

It appears from the history that Hawking's verbiage is just a very early view from a "first pass" at the issue some 45 years ago and was quickly supplanted. Suprising that it remains (with its 45 year old reference) in the wiki article...and undated lectures don't help.

Unfortunately, cosmologists do very little to clarify this point when pop science articles talk about an "initial singularity" and give the impression that the term "Big Bang" refers to it, or to some state "just after" it. What's more, cosmologists obfuscate the issue further by commonly quoting "times after the Big Bang" to label events, when what they are actually doing is: estimating the temperature of the universe at some event (such as the end of inflation)...

Well, colloquial labels are imprecise by nature, and depending on the context of the discusion, and event can be a process (think car crash or explosion). I suspect it doesn't cause any real problems in the research.

 

[PeterDonis]

I suspect it doesn't cause any real problems in the research.

I'm sure you're right, since in the actual research all of the cosmologists involved know what they actually mean. The problem is that lay people who read pop science articles by those cosmologists don't, and as a result many lay people get an incorrect understanding of what our current best cosmological models actually say. In other words, it's an issue of communication of research results to the public, not research itself.

 

[nikkkom]

Come to think of it, "Dark Age" was a rather unique period of time when Universe was a very quiet place.

There were practically no radioactive elements. BB nucleosynthesis may have produced radioactive Be-10 with half-life of 1.4 million years, but in extremely tiny concentration of ~10^-15 relative to hydrogen.

There were no sources of high-energy particles or any kind (be it gamma and X-rays, or lepton or hadron cosmic rays). If you'd magically teleport any current particle detector into the past into Dark Age, it would detect absolutely not a single cosmic ray for years on end. It would probably only detect particles from decays of its own radioactive impurities. :D

The only (known to us) relativistic species at that time were CMB photons, 21-cm radio from hydrogen, and relic neutrino background from neutrino decoupling.