[Bill S]

a paragraph could be proposed and tested among those in the scientific community with the intent of finding a consensus on "how the model addresses the issue of the beginning".

Sadly, what we often seem to need is an explanation as to whether the "author" thinks "nothing" is "nothing" or "something" 

[PmbPhy]

What is nothingness?

The cause of my stomach making funny sounds??

[Bill S]

Nice one Pete. Promise I'll credit you if I ever use it. 

[Bogie_smiles (OP)]

The cause of my stomach making funny sounds??

Are you suggesting that I modify the definition of nothingness in the OP, perhaps to:
No space, no time, no energy, and no hunger sounds,  and no potential for space, time, or energy

I don't see it as an improvement.

[Bogie_smiles (OP)]

Reply #24

Sadly, what we often seem to need is an explanation as to whether the "author" thinks "nothing" is "nothing" or "something" 

That would be nice to know.

[Colin2B]

@PmbPhy makes a good point

There is the same amount of energy before the big bang as there is now. The total amount of energy in the universe is zero. That's how energy remain conserved as it was created. There's two kinds of energy; positive and negative. Negative energy comes from gravitational potential energy and positive energy comes from particles. You can read about it in The Inflationary Universe by Alan Guth. I can make those pages available to you if you'd like?

So even if the energy pre-whatever is zero, it doesn’t imply nothing.

[PmbPhy]

Are you suggesting that I modify the definition of nothingness in the OP, perhaps to:
No space, no time, no energy, and no hunger sounds,  and no potential for space, time, or energy

If that's what you do with responses meant to give people a reason to smile then sure, why not.

[PmbPhy]

So even if the energy pre-whatever is zero, it doesn’t imply nothing.

I don't know. I have no physical example to base a reliable response on.

[Bogie_smiles (OP)]

Reply #28

Sadly, what we often seem to need is an explanation as to whether the "author" thinks "nothing" is "nothing" or "something" 

Agreed, and in fact what modern cosmology is doing is exploring what isn’t nothing, i.e., what is “Somethingness”; what are the alternatives to Nothingness as defined in the OP.

As pointed by Colin2B, the alternatives don’t generally state that they are intentionally invoking the “Something from nothing” explanation, and so they are likely to ignore the issue. Taking a practical look at the development of modern cosmology, we could start with the definition of the Cosmological Principle:

https://en.wikipedia.org/wiki/Cosmological_principle
In modern physical cosmology, the cosmological principle is the notion that the spatial distribution of matter in the universe is homogeneous and isotropic when viewed on a large enough scale, since the forces are expected to act uniformly throughout the universe, and should, therefore, produce no observable irregularities in the large-scale structuring over the course of evolution of the matter field that was initially laid down by the Big Bang.

That explanation points to a Cosmological Constant or Omega value of 1.

The Friemann equations address the expansion of space within the context of Einstein’s General Relativity:
https://en.wikipedia.org/wiki/Friedmann_equations
The Friedmann equations are a set of equations in physical cosmology that govern the expansion of space in homogeneous and isotropic models of the universe within the context of general relativity. They were first derived by Alexander Friedmann in 1922^[1] from Einstein's field equations of gravitation for the Friedmann–Lemaître–Robertson–Walker metric and a perfect fluid with a given mass density

Note the reference to a perfect fluid with a given mass density:
https://en.wikipedia.org/wiki/Perfect_fluid
In physics, a perfect fluid is a fluid that can be completely characterized by its rest frame mass density
ρ, m; and isotropicpressurep.
Real fluids are "sticky" and contain (and conduct) heat. Perfect fluids are idealized models in which these possibilities are neglected. Specifically, perfect fluids have no shear stresses, viscosity, or heat conduction.


Alan Guth, mentioned above in Colin2B’s link, didn’t see the observational results of a perfect fluid and set out to understand the formation of large scale structure in the universe.That is why the field of modern cosmology leads to Alan Guth
https://en.wikipedia.org/wiki/Alan_Guth
See the section on Inflationary theory.

[Colin2B]

So even if the energy pre-whatever is zero, it doesn’t imply nothing.

I don't know. I have no physical example to base a reliable response on.

I think that’s the conclusion this thread is coming to. There are many unknowns and no reliable examples, but I think @Bogie_smiles is just trying to clarify that many of the interpretations of something from nothing are not based on clear definitions of what is truly nothing - or isn’t? 

PS hunger sounds implies a hungry tum, that’s probably because there’s ‘nothing’ in it

[Bogie_smiles (OP)]

Reply #30

So even if the energy pre-whatever is zero, it doesn’t imply nothing.

I think that’s the conclusion this thread is coming to. There are many unknowns and no reliable examples, but I think @Bogie_smiles is just trying to clarify that many of the interpretations of something from nothing are not based on clear definitions of what is truly nothing - or isn’t? 

Correct. That is why I include the phrase, “and no potential for space, time, or energy” in the definition.

If there was nothingness, and no potential for anything, then you can refer to that as zero energy if you want because there is zero energy, but you cannot call it a pre-energy state; a pre-zero energy state is somethingness and cannot come from nothingness.

[Bogie_smiles (OP)]

Reply #31



In reply #28, re. taking a practical look at the development of modern cosmology, it doesn’t take long to get to General Relativity and Inflationary theory.

Here is a cut and paste of the section in the Guth Wiki that addresses Inflationary theory, if you want to take a quick read:

Guth’s first step to developing his theory of inflation occurred at Cornell in 1978, when he attended a lecture by Robert Dicke about the flatness problem of the universe.^[7] Dicke explained how the flatness problem showed that something significant was missing from the Big Bang theory at the time. The fate of the universe depended on its density. If the density of the universe was large enough, it would collapse into a singularity, and if the actual density of the matter in the cosmos was lower than the critical density, the universe would increasingly get much bigger.
The next part in Guth's path came when he heard a lecture by Steven Weinberg in early 1979.^[8] Weinberg talked in two lectures about the Grand Unified Theory (GUT) that had been developed since 1974, and how it could explain the huge amount of matter in the universe compared to the amount of antimatter. The GUT explained all the fundamental forces known in science except for gravity. It established that in very hot conditions, such as those after the Big Bang, electromagnetism, the strong nuclear force, and the weak nuclear force were united to form one force. Weinberg also was the one who emphasized the idea that the universe goes through phase transitions, similar to the phases of matter, when going from high energy to low energy. Weinberg’s discussion of why matter is so dominant over anti-matter showed Guth how precise calculations about particles could be obtained by studying the first few seconds of the universe.
Guth decided to solve this problem by suggesting a supercooling during a delayed phase transition. This seemed very promising for solving the magnetic monopole problem. By the time they came up with that, Guth had gone to the Stanford Linear Accelerator Center (SLAC) for a year, but Guth had been talking to Henry Tye back and forth. Tye suggested that they check that the expansion of the universe would not be affected by the supercooling. In the supercooled state, a false vacuum is produced. The false vacuum is a vacuum in the sense that it is the state of the lowest possible density of energy; it is false in the sense that it is not a permanent state of being. False vacuums decay, and Guth was to find that the decay of the false vacuum at the beginning of the universe would produce amazing results, namely the exponential expansion of space. This solved the monopole problem, since the expansion dilutes the monopole density.
Guth realized from his theory that the reason the universe appears to be flat was that it was fantastically big, just the same way the spherical Earth appears flat to those on its surface. The observable universe was actually only a very small part of the actual universe. Traditional Big Bang theory found values of omega near one to be puzzling, because any deviations from one would quickly become much, much larger. In inflation theory, no matter where omega starts, it would be driven towards equal to one, because the universe becomes so huge. In fact, a major prediction of inflationary theory is that omega will be found to be one.
Two weeks later, Guth heard colleagues discussing something called the horizon problem. The microwave background radiation discovered by Arno Penzias and Robert Woodrow Wilson appeared extremely uniform, with almost no variance. This seemed very paradoxical because, when the radiation was released about 300,000 years after the Big Bang, the observable universe had a diameter of 90 million light-years. There was no time for one end of the cosmos to communicate with the other end, because energy can not move faster than the speed of light. The paradox was resolved, as Guth soon realized, by the inflation theory. Since inflation started with a far smaller amount of matter than the Big Bang had presupposed, an amount so small that all parts would have been in touch with each other. The universe then inflated at billion times the speed of light so the homogeneity remained unbroken. The universe after inflation would have been very uniform even though the parts were not still in touch with each other.
Guth first made public his ideas on inflation in a seminar at SLAC in January 1980. He ignored magnetic monopoles because they were based on assumptions of GUT, which was outside the scope of the speech. In August, he submitted his paper, entitled "Inflationary universe: A possible solution to the horizon and flatness problems" to the journal Physical Review.^[9] In this paper Guth postulated that the inflation of the universe could be explained if the universe were supercooled 28 orders of magnitude below the critical temperatures required for a phase change.
In December 1981, Guth read a paper from Moscow physicist Andrei Linde saying that the whole universe is within just one bubble, so nothing is destroyed by wall collisions. This conclusion was made using a Higgs field with an energy graph that was originally proposed by Sidney Coleman and Erick Weinberg. Guth discussed this with Linde, who had independently been working on bubble inflation, but without considering the flatness problem. Linde and Guth eventually exchanged papers on the subject.
By 1983 Guth had published a paper describing how his supercooled-universe scenario was not ideal, as the "triggering mechanism" to exit such a state would require "extreme fine tuning of parameters" and felt a more natural solution was required.^[1][10][11] However, this did not deter him from the belief that the universe expanded exponentially in a vacuum in its early lifetime.^[12]
[End of Wiki cut and paste]

Note "Henry Tye suggested that they check that the expansion of the universe would not be affected by the supercooling. In the supercooled state, a false vacuum is produced. The false vacuum is a vacuum in the sense that it is the state of the lowest possible density of energy; it is false in the sense that it is not a permanent state of being. False vacuums decay, and Guth was to find that the decay of the false vacuum at the beginning of the universe would produce amazing results, namely the exponential expansion of space".

That is not a perfect vacuum of course, and it is not nothingness.

To be continued ...

[Bogie_smiles (OP)]

Reply #32

The Wiki information is saying that the findings of Alan Guth were that the decay of the false vacuum at the beginning of the universe would produce exponential expansion of space. Have you given Guth’s papers a good read to understand the particulars of Inflationary theory? I’m wondering about the mechanics of the decay of the false vacuum and the resulting exponential expansion of space.

@Bogie_smiles , “Do you think that would fly?”
It would certainly help. It is very clear in Alan Guth’s papers as he states that he is not dealing with what happens before inflation.

...

Does he say what causes a false vacuum in the first place? Does he say there was a hot dense plasma at the beginning of the expansion? Where does that come from?

[Bogie_smiles (OP)]

Reply #33


Here are a few links that I have searched that begin to shed some light on the false vacuum, and the theories where it applies.

I find it helps my thought process if I cut and paste content from the links. See my discussion below the linked content:
vvvvvvvvvvvvvvvvvvvvvvvv
https://en.m.wikipedia.org/wiki/False_vacuum

In quantum field theory, a false vacuum is a hypothetical vacuum that is somewhat, but not entirely, stable. It may last for a very long time in that state, and might eventually move to a more stable state. The most common suggestion of how such a change might happen is called bubble nucleation - if a small region of the universe by chance reached a more stable vacuum, this 'bubble' would spread.
A false vacuum may only exist at a local minimum of energy and is therefore not stable, in contrast to a true vacuum, which exists at a global minimum and is stable. A false vacuum may be very long-lived, or metastable.


bubble nucleation

In the theoretical physics of the false vacuum, the system moves to a lower energy state – either the true vacuum, or another, lower energy vacuum – through a process known as bubble nucleation.[4][5][24][25][26][27] In this, instanton (https://en.m.wikipedia.org/wiki/Instanton) effects cause a bubble to appear in which fields have their true vacuum values inside. Therefore, the interior of the bubble has a lower energy. The walls of the bubble (or domain walls) have a surface tension, as energy is expended as the fields roll over the potential barrier to the lower energy vacuum. The most likely size of the bubble is determined in the semi-classical approximation to be such that the bubble has zero total change in the energy: the decrease in energy by the true vacuum in the interior is compensated by the tension of the walls.
Joseph Lykken has said that study of the exact properties of the Higgs boson could shed light on the possibility of vacuum collapse.[28]
__________

Instanton: An instanton[1] (or pseudoparticle[2][3]) is a notion appearing in theoretical and mathematical physics. An instanton is a classical solution to equations of motion[note 1] with a finite, non-zero action, either in quantum mechanics or in quantum field theory. More precisely, it is a solution to the equations of motion of the classical field theory on a Euclidean spacetime.
In such quantum theories, solutions to the equations of motion may be thought of as critical points of the action. The critical points of the action may be local maxima of the action, local minima, or saddle points. Instantons are important in quantum field theory because:
they appear in the path integral as the leading quantum corrections to the classical behavior of a system, and
they can be used to study the tunneling behavior in various systems such as a Yang–Mills theory.
In dynamics, instantons are families of deterministic solutions that connect, e.g., different critical points of equations of motion. From the physical point of view, instantons are particularly important because the condensation of instantons (and noise-induced anti-instantons) is believed to be the theoretical essence of the noise-induced chaotic phase known also as self-organized criticality.




Any increase in size of the bubble will decrease its potential energy, as the energy of the wall increases as the surface area of a sphere
4
π
r
2
{\displaystyle 4\pi r^{2}}
<img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b81fcce302776a01dc66fc186a1ce0a616b4d772" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.338ex; width:4.597ex; height:2.676ex;" alt="4\pi r^{2}"> but the negative contribution of the interior increases more quickly, as the volume of a sphere
4
3
π
r
3
{\displaystyle \textstyle {\frac {4}{3}}\pi r^{3}}
<img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/d685ddd147c84e123fe4c01d6a7ee9813f7b04d3" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -1.338ex; width:5.093ex; height:3.676ex;" alt="\textstyle {\frac {4}{3}}\pi r^{3}">. Therefore, after the bubble is nucleated, it quickly begins expanding at very nearly the speed of light. The excess energy contributes to the very large kinetic energy of the walls. If two bubbles are nucleated and they eventually collide, it is thought that particle production would occur where the walls collide.
The tunnelling rate is increased by increasing the energy difference between the two vacua and decreased by increasing the height or width of the barrier.


The addition of gravity to the story leads to a considerably richer variety of phenomena. The key insight is that a false vacuum with positive potential energy density is a de Sitter vacuum, in which the potential energy acts as a cosmological constant and the Universe is undergoing the exponential expansion of de Sitter space. This leads to a number of interesting effects, first studied by Coleman and de Luccia.[3]


https://en.m.wikipedia.org/wiki/Maxima_and_minima

In mathematical analysis, the maxima and minima (the respective plurals of maximum and minimum) of a function, known collectively as extrema (the plural of extremum), are the largest and smallest value of the function, either within a given range (the local or relative extrema) or on the entire domain of a function (the global or absolute extrema).[1][2][3] Pierre de Fermat was one of the first mathematicians to propose a general technique, adequality, for finding the maxima and minima of functions.




If the Standard Model is correct, the particles and forces we observe in our universe exist as they do because of underlying quantum fields. Quantum fields can have states of differing stability, including 'stable', 'unstable', or 'metastable' (meaning very long-lived but not completely stable). If a more stable vacuum state were able to arise, then existing particles and forces would no longer arise as they do in the universe's present state. Different particles or forces would arise from (and be shaped by) whatever new quantum states arose. The world we know depends upon these particles and forces, so if this happened, everything around us, from subatomic particles to galaxies, and all fundamental forces, would be reconstituted into new fundamental particles and forces and structures. The universe would lose all of its present structures and become inhabited by new ones (depending upon the exact states involved) based upon the same quantum fields.



^^^^^^^^^^^^^^^^^^^^^^

Discussion; The false vacuum is not entirely stable, but by chance it may move to a more stable state:

“The most common suggestion of how such a change [to a more stable state] might happen is called bubble nucleation - if a small region of the universe by chance reached a more stable vacuum, this 'bubble' would spread.”

Note that the false vacuum is local minimum energy, and theoretically, can move to a more stable state, i.e., contain more potential energy  per volume of space than the false vacuum, by bubble nucleation. It becomes a smaller bubble within the false vacuum bubble and therefore has higher energy potential.

Bubbles can expand, and if they do, their potential energy decreases down toward the energy potential of the local false vacuum.

If two bubbles are nucleated within a false vacuum, and they eventually collide, it is thought that particle production would occur where the walls collide. Is that a potential source of the hot dense plasma that is consistent with Standard theory at 10^-43?


It would seem to be consistent with QFT, at least per the limited content of the above links.

[Bill S]

It never ceases to amaze me, how complex a discussion about "nothing" can become. 
Isn't a false vacuum "something".

I'm looking for a bit by Vilenkin on that subject, but I'll not have time to find it tonight.

[Bogie_smiles (OP)]

Reply #35

Perhaps you are seeing my point, that there is no chance of nothingness, since there is obviously something; many fine things all around us for that matter. None of which would be possible if at first there was nothing, at least under the definition I gave in the OP.

It never ceases to amaze me, how complex a discussion about "nothing" can become. 
Isn't a false vacuum “something".

Yes indeed. Though it is only theoretical, as you can see, following two theories, BBT with Inflation, and QFT at the barest level of investigation, both are consistent with the formation of matter out of “bubble convergences”.

[Bill S]

Perhaps you are seeing my point, that there is no chance of nothingness

And you mine (?)

There never was nothing.

What do they say about great minds?

BBT with Inflation, and QFT at the barest level of investigation, both are consistent with the formation of matter out of “bubble convergences”.

That's fine, as long as you interpret "bubbles" as "something".

[Bill S]

I’ve found the Vilenkin reference, but before looking at it I would like an opinion as to the accuracy, at a non-technical level, of my understanding of the idea of representing the vacuum as a “landscape”.

In trying to establish a non-technical image of the vacuum, and its energy, it may be helpful to visualise it as an irregular surface of waves and troughs which represent this energy, and to consider this as a “landscape”. 

The bottom of the lowest valley would be considered to be the “true vacuum”, that in which our Universe exists.  Crests of waves, and the slopes linking them to the valleys, represent “false “vacuum” states in which the vacuum energy is higher than that of the true vacuum.  Essentially, these are very unstable states.  Some stability may be achieved by a false vacuum state, and this would be represented on the vacuum landscape by a valley at a higher level than the true vacuum. 

Obviously, this gives some stability to the false vacuum state, and to see why, it is necessary to look at the “inhabitants” of the vacuum landscape.  It appears that these inhabitants are scalar fields.  Popular science books usually depict these scalar fields as spheres that can roll about on the hilly landscape.  Their energy is dictated by the vertical position they occupy, at any given instant, on the landscape.  A scalar field that is at, or near, the top of a hill will equate to a false vacuum state.  It will be unstable, so will have a tendency to “roll down” to a lower level if an opportunity presents itself.  Energy would be needed to "lift" the scalar field out of the valley so that it could progress to a lower level.

[Bogie_smiles (OP)]

Reply #38

And you mine (?)


What do they say about great minds?

They are something, right

That's fine, as long as you interpret "bubbles" as "something".

Two bubbles nucleated within a false vacuum in QFT are something, as is Guth's supercooled vacuum at the start of Inflationary theory, and certainly BBT's hot dense ball of energy, all are something.

I’ve found the Vilenkin reference, but before looking at it I would like an opinion as to the accuracy, at a non-technical level, of my understanding of the idea of representing the vacuum as a “landscape”.


In trying to establish a non-technical image of the vacuum, and its energy, it may be helpful to visualise it as an irregular surface of waves and troughs which represent this energy, and to consider this as a “landscape”. 


The bottom of the lowest valley would be considered to be the “true vacuum”, that in which our Universe exists.  Crests of waves, and the slopes linking them to the valleys, represent “false “vacuum” states in which the vacuum energy is higher than that of the true vacuum.  Essentially, these are very unstable states.  Some stability may be achieved by a false vacuum state, and this would be represented on the vacuum landscape by a valley at a higher level than the true vacuum. 


Obviously, this gives some stability to the false vacuum state, and to see why, it is necessary to look at the “inhabitants” of the vacuum landscape.  It appears that these inhabitants are scalar fields.  Popular science books usually depict these scalar fields as spheres that can roll about on the hilly landscape.  Their energy is dictated by the vertical position they occupy, at any given instant, on the landscape.  A scalar field that is at, or near, the top of a hill will equate to a false vacuum state.  It will be unstable, so will have a tendency to “roll down” to a lower level if an opportunity presents itself.  Energy would be needed to "lift" the scalar field out of the valley so that it could progress to a lower level.

That would be something, with some emphasis.


QFT seems to be a work in progress, and like string theory, got traction from the shortcomings of BBT, especially the infinitely dense, zero volume conclusion reached by backtracking the observed expansion to its limit.


If I could weigh in on your non technical understanding of the landscape of the greater universe, in regard to visualizing it from the QFT perspective, it would seem permissible to discuss the nucleating bubbles across the true vacuum as a landscape. Is this an infinite landscape that would fill all space? If not, I suspect nothingness would want to pop up in the "what lies beyond".


Let's see the Vilenkin link.

[Bill S]

Let's see the Vilenkin link.

It's not a link, I'm afraid; just some notes from a good-old-fashioned book.

With any luck I might have a half-hour to sort the notes out now.