quiet

By the state that now it is, I think the best place for this thread is trash can ...

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

Thanks swansont pot the post. Also you have exposed reasonable objections, which deserve to be visible at the conclusion of the thread.

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47 minutes ago, Strange said:

I am disappointed that you are not willing to either support your claims or admit that you made them up.

Dear strange, you know that I dislike the fray. It is very easy to write citation needed. The hard part is to retrieve the titles of the publications inside a repository of old papers, search for those titles on the internet, find the exact paragraph within the extension of the publication and bring it here. They are many hours of work to serve on a tray plus gunpowder, which will be used to prolong the war.

It really is good that post yours that I have praised. And I admit that I have omitted those appointments. Then, as we are in speculations, I give you my affirmation that all these are speculative ideas of mine, that you will never be able to read in sources related to those authors. I solemnly affirm that I have invented all that whimsically. I solemnly affirm that the important thing is not to dialogue calmly. The important thing is to cut sentences and show them isolated from the context, where the sentences are paralyzed and we can easily charge the gun and shoot. This, advantageously, takes seconds. What the other forum member wrote has taken good fractions of hours. And adding up everything he wrote, he has taken many hours in more than a day.

In seconds we managed to get something from the legitimate discussion to the trash can, without doing anything other than putting empirical data as "proofs" apt to refute a methodological analysis. It is like trying to refute Herodotus about the existence of Atlantis, saying that if Atlantis had ever existed, the ruins would have been found, as were the ruins of other ancient civilizations. And in seconds write: ruins needed. Very easy and very profitable to explode in the middle of the room something that tries to be shown as an objection, without the least care to analyze the context to do it in a legitimate way.

I solemnly declare that I am capitulating in the war that you have created, dear strange. I sign the surrender and I put it into a golden tray. And I repeat, that post of yours that I have praised is good.

Thank you strange for your post. The way in which you have criticized each concept has been precise and, for that reason, I have been able to follow your thought.

You have exposed reasonable objections, which are a nice summary of what has been discussed. I think it's a good idea to leave your post as a thread closure.

11 hours ago, swansont said:

People were doing calculation based on the concept, for many years before GR, so clearly it is not.

Einstein included it in GR, but that does not mean the idea was new.

 

What you say is true. The word alien is not the best way to express the concept.

I only try to remark that in newtonian physics, only for convenience, was used the setup corresponding to equality of the values of both terms. This, like you say, works perfectly in applications.

When the point under discussion is the structure of the foundations of the physics, the convenience have nothing to do. The main issue is the recognition of what is postulated, and what is choosed conventionally.

Like I have pointed out in a previous post, you can measure the action and the angular mentum, both, in [math]joule.second[/math], this is, you can choose the same dimensions for both. What you can't do is believe that both are the same kind of physical property. In analog way, you can choose for the gravitatory property and for the inertial property the same dimensions and, if you wish, can too choose the same value. But you can not believe, without well proved reasons, that both have the same nature, both comes from the same intimate phenomenon, both are subject to the same influence, etc.

You have mentioned the satellital orbit. In this case, gravitatory mass is independent respect the tangential velocity. The inertial mass is dependent, like Lorentz transformation shows. Intentionally I say Lorentz transformation and not SR, because the increasing of the mass with the velocity was known and formulated in 19th century, before the publication of SR.

Back to the main point. The satellital orbit is a nice example of the natural difference between both terms.

Know you that the astronomers have finded EM waves with wavelength of astronomical size? When this kind of detection begins, a wavelength compatible with Earth-Moon distance was detected. What if an electromagnetic phenomenon is responsible for gravity? Oh!!! No!!! This is impossible because GR stablish spacetime warping!!! But, if the equality of both types of "masses" is not impossed by the physics previous to GR, and for create GR you stablish the equality like a new postulate, then, GR is just the thing under discussion, and we can not invoke GR to reject the possibility of an EM origin of the gravitation. 

There is somthing that here, in speculations, is not misplaced. Assuming an enough reasonable hipothesys, you can start a development that reaches various interesting results. One is to obtain, like a first aproximation, a formula for gravitatory force with the same format of Newton's formula. This fact is more or less obvious, because EM field vary with [math]r^2[/math].

Other result exhibit the intimate form of G in EM terms. Other shows that G is a fuction, not a constant. In special conditions G varies in very little proportion, in a way that allow take a little error if G is treated like a constant.

Oh!!! GR assumes that G is  true constant!!! I don't believe how someone can think that G is a function!!! 

Newton's formula have an error compatible with not taking in account the cotribution of the electrons to the gravitational action, and, only take in account the contribution of nucleons. The chaotic behavior of electrons cloud gives a little net contribution, because the cloud don't align in a preferent direction, like nuclons do. The error calculated using the EM model is in the order measured by Eotvos experiments, and subsequent experiments of that kind.

Eotvos have find too that chemical composition intervenes in little proportion. The EM model just implies such fact.

Remember the astronomers, today, are not sure respect to accuracy of GR in all cases. The worst thing we can do, into this theme, is to held rigidly that equality of both types of "masses" is an undoubtable natural law.

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If both properties are not the same, then, we can't replace [math]m^2[/math] in equation (2) of the initial post. So, absurd is impossible. And if we, like Einstein, postulate the equality, the absurd is unavoidable.

Hi, studiot.

Since the gravitational equation and the second law are applied together, the military can, unfortunately, accurately calculate ballistic missile launches. And long before the cannon shots. In those cases the vertical component of the ballistic movement works like a vertical shot, which reaches its apogee and initiates the free fall.

In order not to result in verbal arguments I have put the same development that the texts present to teach that the equality of both types of masses is conventional. Einstein himself emphasizes that in the physics of Newton nothing does impose equality. And he emphasizes that, since equality is not the consequence of principles or of physical laws prior to GR, the hypothesis of equality is a new element introduced to give a basis to GR. Einstein calls it a principle, as befits a new element that is introduced as the basis of a theory. You do not need me to name it, but I will do it to avoid verbal scuffles because of the name. He called it the equivalence principle of the gravitational and inertial masses.

This principle is alien to Newtonian physics, to the theories of Lagrange and Hamilton, to thermodynamics, to statistical mechanics, to electrodynamics, to special relativity and to quantum theory. Only GR is based on that kind of hypothesis.

If I, with seriousness, take the task of accompanying my statements with mathematical developments and demonstrate that I affirm something coherent and in accordance with physical laws, it is only fair that my affirmations are refuted in the same way. In the last mathematical post I presented there are no terms in absurd places of some equation. It is only a free fall, because thus the texts teach that the equality of both types of mass is not a consequence of the well-known physical laws, nor of the principles that are the basis of all that is not GR.

Tired of the sterile verbal scuffle, in another post I put, ironically, that many people saying the same thing made me want to join them and think the same. I had really decided to leave the thread served to those who prefer the verbal fray, without writing me any new post. When swansont calmly resumed the dialogue, I thought: nobility obliges. That's why I wrote again and showed the corresponding mathematics. The tranquility was short lived. Now again the thread was thrown into empty verbality. What I do ? I follow ? I give up?

They say that I must notice this, that, the other, take into account this and that detail and many more etceteras. Discounting me, did someone take paper and pencil, to see how the subject remains mathematically, before filling a post with phrases? I have patience, all the patience that a teacher exercises in the classroom, but that patience is finite. And it has reached the end.

Let me go step by step. I have read all the posts, but first I analyze the main point of all this, to submit it to your criticism.

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- Free fall.

[math][/math]

[math]m_{g_1} \ \rightarrow[/math] gravitational mass of the planet

[math]m_{g_2} \ \rightarrow[/math] gravitational mass of the falling object

With this symbols, we write the force as:

[math]F = G \ \dfrac{m_{g_1} \ m_{g_2}}{r^2} \ \ \ \ \ \ \ \ \ (A)[/math]

The falling object is accelerating, and we write Newton's second law:

[math]F = m_{i_2} \ a \ \ \ \ \ \ \ \ \ (B)[/math]

[math]m_{i_2} \ \rightarrow[/math] inertial mass of the falling object

We equal (A) and (B).

[math]G \ \dfrac{m_{g_1} \ m_{g_2}}{r^2}= m_{i_2} \ a [/math]

We clear [math]m_{i_2}[/math]

[math]G \ \dfrac{m_{g_1} \ m_{g_2}}{a \ r^2}= m_{i_2} \ \ \ \ \ \ \ \ \ (C)[/math]

- Acceleration and distance are measurables with rule and clock. 

- Both gravitatory masses, of the planet and of the object, have the same physical nature and are measured and expressed in the same way.

- Inertial mass of the object is the term under discussion. We can stablish conventionally the value of G, without destroy the equality of the forces neither alter the equation (C).

- We can, conventionally, choose a value of G that makes [math]m_{g_2}= m_{i_2}[/math]. This simplify many calculus, but there is no physical law, nor physical principle, that necessarily requires [math]m_{g_2}= m_{i2}[/math].

40 minutes ago, swansont said:

There are other tests, though. If M>>m, you can look at e.g. a circular orbit. m will cancel, leaving a result that works. i.e. the cancellation was valid. So we have confirmation that inertial and gravitational mass are the same. 

It works for elliptical orbits, and works (with some more effort) even when you don’t have M>>m

Hello swansont. I liked the argument. And I would like it to stay firm. I'm thinking of a kind of chess between gentlemen. A is your argument and B is mine. I will try to look for a weak point in A and you can, if you decide to play, do the same with B.

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In the case of the satellite orbit you mentioned, as in all applications of Newton's gravitational equation, G is calibrated precisely so that it is possible to use the same term [math]m[/math], with the same value, in the gravitation and inertia. This is a conventional decision, it is not a physical law. The number of convetional decisions that could be proposed is unlimited and all would work without contradiction. So the satellite case does not show that the same physical property is responsible for gravity and inertia.

1. I say that: The equation (3) is absurde into the physical context.

2. I say that: Absurde comes only from replace [math]m^2[/math] in Newton's equation of gravitatory force.

3. I say that: If we reject the idea of gravity and inertia caused by the same physical property, then, we can not put the same symbol ([math]m[/math]) in force equation and in the second law equation.

4. I say thay: We can't to put the same symbol without suppossing the same cause in gravity an in inertia.

5. I say that: The absurdity of eqution (3) requires reject the idea of the same cause.

6. I say that: You can call it: idea of the same cause. Or can choose other name. The name choosed not diminish the physical absurde. There isn't a mathematical absurde. There is an unavoidable physical absurde.

7. I say that: If someone still have doubts, try perform a proof of the items 1 to 6 are false. With one item really false, the proof is done. Remember that a proof must be not only logically valid. Must be too physically valid and referred only to well known physical principles and laws.

8. I say that: I will receive with happyness such a proof and I will be greatful.

With many people saying the same thing, I tend to think the same as those people. I apologize for my ramblings. Best regards.

2 hours ago, J.C.MacSwell said:

...it is simply incorrect

Agree. And more, I have pointed out, in the first post of the thread, that is incorrect. The main question is where come from the incorrection? Have I made a wrong use of algebra? Have I altered Newton's equations? Have I commited an abuse?

Respect to an abuse, there is one. Wich? To  suppose that the same physical property is responsible for both, inertia and gravitation. This is simply incorrect. And this is the cause for what the same term [math]m[/math] appears in gravity formula and in the second law formula. This double appearing cause the absurde. And this double appearing come from the equivalence principle.

22 minutes ago, swansont said:

If you take GR in the weak gravity limit, you end up with Newton. How can that be, if they are in conflict?

In the limit you get Newton's gravitational formula. And that formula is incompatible with the principle of equivalence. Then GR is completely self-contradictory, since it contains a limit incompatible with its basic hypothesis.

2 hours ago, Strange said:

As Ghideon has pointed out, your formatting was completely ambiguous...

Hi, strange.

The equation written with LaTex shows the main line of division at the height of the sign equal and slightly longer than the other line, belonging to the numerator. Keeping this in mind, the notation looks unambiguous.
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The principle of equivalence assumes that physical property itself intervenes in inertia and gravitation. The physics of Newton does not allow to suppose that, because in case of supposing it you arrive at the equation (3), obtained in the initial post of this thread. In Newtonian physics you can not put the same m in the gravitational equation and in the formula of the second law, because by doing that you get to (3) irremediably.

I repeat what was expressed in a previous post. Two magnitudes that have very different physical natures can have the same dimensions. You can measure in Kg both physical properties, one that intervenes in inertia and another that intervenes in gravitation. That does not mean that the same physical property intervenes in both phenomena. Newton's physics requires accepting that they are different properties, because when you assume that it is the same property you inevitably arrive at (3).

A theory that demands to distinguish sharply between the property that intervenes in gravitation and the property that intervenes in the inertia, does not allow to accept the principle of equivalence. You must choose between Newton and Einstein regarding inertia and gravitation. You can not have both of them in the same kind of physics.

To the same type of physics belong Newton's theory, the Lagrangian and Hamiltonian theories, thermodynamics, electrodynamics, special relativity and quantum theory, because none of these theories postulates the principle of equivalence. General relativity belongs to another type of physics, whose principle of equivalence is incompatible with the kind of physics mentioned previously.

The mathematics of the initial post of the thread is simple and brief, but it brings out an essential detail. If you say that General Relativity is a physical theory, then Newton's theory, Lagrangian and Hamiltonian theories, thermodynamics, electrodynamics, special relativity and quantum theory are not physical theories. And if you say that the latter are physical theories, then general relativity is not a physical theory. Like it or not, that's inevitably so. For that reason the hope of linking general relativity with quantum theory is futile. Union attempts suffer from the same type of incompatibility that we see in equation (3).

1 hour ago, Ghideon said:

I did not say there is an error. I said the formatting may look ambigous. I tried to show that by adding paranthesis without changing the mathematical meaning.

Oh, sorry. I had a confusion.

The format is fine. Both lines of division are well located and well sized.

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• There is something important that deserves to be elucidated.

When the principle of equivalence of Einstein is introduced in the physics of Newton, the result is absurd and self-contradictory. I do not see how to avoid that problem.

Are Newton's physics and the principle of equivalence mutually incompatible? This question needs a well-founded answer.

In case of being mutually incompatible, another question appears. Does Special Relativity remain valid if we reject Newton's physics?

If it does not remain valid, another question appears. Can GR be valid if SR is discarded?

47 minutes ago, Ghideon said:

Should we read...

There is no mathematical error in this equation. If you smplify respect to F remains F at the first power. Then you clear F and obtain the equation (3). 

Still doubts? Make a dimensional analisys and verfy that units are coherent.

@strange

Hello strange. In what kind of error are you thinking?

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I am thinking more in a methodological abuse than a mathematical error.

Is there some reason for suppose that the same physical property is responsible of the inertia and the gravitation?

If there is no reason, and if we anyway suppose yes, we are commiting a serious abuse. See. If you, instead [math]m[/math] use another symbol in the equation of gravitatory force, without suppossing the new symbol is the same that the mass, neither supposing that have the same physical meaning, then, in the gravitatory equation you can't apply the second Newton's law.

Something that requires to take much care in physics is to avoid confusions between different properties that have the same dimentions. 

Example. The action and the angular momentum are dimentionally identical. Can someone admit that these two terms have the same physical nature and the same physical meaning?

Like I see the problem, inertia and gravitation are not related with the same cause. For this reason, I guess that there is an abuse in to state that both, inertia and gravitation, are referred to the same property.

I know that, in case we can not stablish the Einstein's equivalence principle, we will have serious trobles with General Relativity.

Today, we prefer GR over Newton's physics. Anyway, the inertial mass is a property that rules moving objects, and the property with same dimentions used in gravitational formula, is someting capable to rule the force between objects in mutual relative rest.

1 hour ago, Strange said:

1 hour ago, Strange said:

There seems to be an error in the derivation of (3).

Hello strange. In what kind of error are you thinking?

59 minutes ago, uncool said:

You should understand it by ...

21 minutes ago, Sensei said:

You brought simplified version ...

20 minutes ago, uncool said:

...the math is what you provided...

19 minutes ago, swansont said:

Newton’s gravitational law does not ...

All the answers help, because in the classroom they stimulate reflection. Thanks for answering.

12 minutes ago, uncool said:

You should understand ...

I guess the explanation would be more obvious if you could include some math. Thanks in advance.

I bring to the forum the query made by a student at the school.

- Newtonian gravitation.
- Simple case of two equal spheres that gravitate to each other (equal masses).

Let's write the Newtonian equation of gravitational force.
[math]F = G \ \dfrac{m \ m}{r^2}[/math]
Both masses are the same. Then there is the following.
[math]F = G \ \dfrac{m^2}{r^2} \ \ \ \ \ \ \ \ \ (1)[/math]
We clear the mass in the equation of Newton's second law.
[math]m = \dfrac{F}{a}[/math]
We raise both members to the square.
[math]m^2 = \dfrac{F^2}{a^2} \ \ \ \ \ \ \ \ \ (2)[/math]
In (1) we replace [math]m^2[/math] as indicated by (2).
[math]F = G \ \dfrac{\dfrac{F^2}{a^2}}{r^2}[/math]
We simplify and cleared F.
[math]F = \dfrac{a^2 \ r^2}{G} \ \ \ \ \ \ \ \ \ (3)[/math]

Equation (3) reports that the force is directly proportional to the square of the distance. This is not what Newton's gravitational equation informs.

The gravitational equation and the second law, applied to the same system, result in something that we have not seen in school.

How should we understand equation (3)?

Let go slowly.

- A gyro don't exert opposition to parallel translation of it's axis. If you try change the direction of the axis, opposition appears.

- Think the following. With the large wheel in rest, the four little wheels are spinning. Later, with the small wheels spinning, the large wheel start rotation. This rotation causes parallel translation of the axis of the each little wheel. This kind of translation don't receive opposition from the little gyros. Then, except the mass, there isn't no influence of the little gyros on the rotation of the big wheel.

As I see the situation, the main question is the following. With the system like was described in the initial post of the thread, if we try to change the axis direction of the big wheel, what will happen? Will we find opposition or not?

2 hours ago, studiot said:

Feynman Demon = Son of Maxwell's Demon.

Combining an accurate observation with a sense of humor, you have achieved that I understand better and you have awakened a smile that makes me feel very good !!! Thanks.

On 22/10/2018 at 5:21 PM, Aphile said:

Why light speed?

You have asked a question that belongs to a set of three mutually related questions. Let's write the other two.

- Why the elementary charge?
- Why the elementary action? (That is, the Planck constant).

If you raise each question individually, there is no hope of response. If you investigate what the three questions imply together, there is hope.

I have not answered your question. Just now you know that you have raised one of the three fundamental questions in the context of physical constants. That is, in the context of the making of the universe. This is very commendable for a person unfamiliar with physics.

I confess that I am not familiar with the investigation of those three questions. That's why I can not specifically answer what you asked.

Less complications appear when you investigate the questions for the case of the vacuum. In electromagnetic terms, the speed of light in vacuum is expressed in the following way.

[math]C=\dfrac{1}{\sqrt{\mu_o \ \varepsilon_o}}[/math]

[math]\mu_o \ \rightarrow[/math] (magnetic) permeability of the vacuum

[math]\varepsilon_o \ \rightarrow[/math] (electric) permitivity of the vacuum

Permeability and permittivity are terms referring to the behavior of the vacuum with respect to the magnetic field and with respect to the electric field, respectively.

Speed C is not the only property related to that pair of terms. The propagation in the vacuum presents a characteristic impedance, expressed in the following way.

[math]Z_o = \sqrt{\dfrac{\mu_o}{\varepsilon_o}}[/math]

The impedance is measured in ohm.

Only the propagation in the vacuum presents impedance? No. Electric and elecrtronic circuits too. You know there are 4 ohm speakers, 8 ohm speakers, etc. You know that the microphone manufacturers specify the impedance, for example, less than 200 ohm. What is impedance? It is the relation between two magnitudes used frequently, the electric potential difference and the current.

In colloquial terms, we can say that the potential difference corresponds to the electrical amplitude. A singer connects the microphone to the amplifier. Suppose that the microphone input supports a maximum of 0.8 volt. If something is badly predisposed, it can happen that when the voice is emitted with a lot of energy the microphone generates more than 0.8 volt. The amplifier will trim the excess and the sound will lose quality. When an electric field is used to accelerate electrons, the energy that the electrons gain depends on the available   potential difference.

What is the current? 600 thousand trillion electrons constitute more electric charge than a trillion. Amount of charge and number of electrons are equivalent concepts. There are two signs of charge, so you can say the same for protons, positrons, muons and other types of particles that have electric charge. More particle, more charge. If there are electrons traveling and you have a method to measure how much charge crosses the reference plane at a given time, you can divide the charge by time and the quotient is the current.

As stated earlier, impedance is the relationship between potential difference and current. If you divide the first one by the second you calculate the impedance, in the case of a direct current. In that case the word changes, but the concept remains. In direct current it is said resistance and the value is expressed with real numbers. Alternating current varies as a function of time and, in this case, the use of complex numbers is frequent.

In a vacuum, obviously, there is no material thing that is responsible for the characteristic impedance of propagation. This means that the impedance is a property of the electromagnetic field. Why does the impedance appear in material devices? Because there are electromagnetic fields in the internal structure of matter. In each small region of the interior of matter there are electromagnetic fields. The impedance of an amplifier, a microphone, etc. , depends ultimately on the resultant of those constitutive fields.

Why have I devoted attention to the concept of impedance, when the initial question of the thread is related to the speed of light? Because that set of three intimately related questions, mentioned previously, has the following property.

[math]2 \ \alpha \ \dfrac{h}{e^2} = \sqrt{\dfrac{\mu_0}{\varepsilon_o}}[/math]
[math]\alpha \ \rightarrow[/math] fine structure constant
[math]h \ \rightarrow[/math] Planck constant
[math]e \ \rightarrow[/math] electron's charge

The fine structure constant is a dimensionless term. That is, it does not have units. It is purely numerical.

Each dimensional term, which have units, is established by definition. Definitions are not properties of nature. They are conventional statements, that is, statements voluntarily established by scientists. The virtue of a good scientist is to propose, as far as possible, definitions consistent with what is observed in nature. That does not diminish the conventional character of the definitions.

A dimensionless term is independent of definitions. Where does it come from then? After squeezing the brain, the conclusion is that it truly corresponds to a condition proper to nature. That means that other physicists could use very different definitions of these that we use and, sooner or later, the fine structure constant would be found in the physics they have made. The same dimensionless constant that we find in our physics.

You have put, at the beginning of the thread, a question belonging to a set of three mutually related questions. That set is equivalent to a single fundamental question. Is the next.

A dimensionless term, without units, that is without references to measurable magnitudes, should be calculable in a purely theoretical way, without the need for experimental data. How could someone do that? The person should analyze a phenomenon whose mathematical approach leads to the need to prove a theorem. That is, the need for a purely theoretical development, which does not need to use experimental data. By constructing rectangle triangles and measuring their sides, you can make data tables and come to suspect that the square of the hypotenuse is equal to the sum of the squares of the sides. But it is possible to demonstrate that by developing a theorem, in a purely theoretical way, without the need to measure triangles in practice. Thus the Pythagorean theorem has been proved. To answer the three questions mentioned previously, we need the value of the fine structure constant to be determined by a theorem.

Is that task possible? I bet my life yes.

Which theory allows to prove this theorem? I bet my life that classical electrodynamics allows to do that. (Surely many weapons are pointing towards my body to kill me, haha).

If one assumes that classical electrodynamics allows doing that, a question immediately arises. Why the proof is not in the textbooks, if since the publication made by Maxwell until now more than 150 years have passed? I bet my life that the fault lies with the corporations, that they have maintained tense situations, fierce competitions and wars all over the world, all that time. And they still continue to disturb all human activities and dedications, including the activities and dedications of scientists.

I have asked this to a luthier. He said that the unbreakable case would be better if it had a little flexibility. And he said that if I'm thinking of throwing the bundle from the terrace, it would be better an internal padding that does not copy the shape of the guitar and that was parallelepiped, so that the ends of the guitar in length and width support tangentially on the padded.

Now an aggregate of mine. The weight of the case is not interesting, because the acceleration in free fall is independent of the mass.

Uniting everything is the following. If everything is identical except the weight of the case, no guitar is less likely to be damaged. Regarding the padding, in case of not meeting the tangentiality suggested by the luthier, it would be better loosed, because the effect is a little closer to what the tangential support would do.

45 minutes ago, swansont said:

The question was which aether? The one proposed hundreds of years ago and eliminated in 1905 (the luminiferous aether), or subsequent introductions? They aren't the same.

Some writings of recent times allow us to suppose that some scientists think, more or less, something similar to the following. The vacuum of the QED is a hive of activity, regardless of whether we adjective as real or virtual to each component of that activity. And a lot of that activity is spontaneous, that is, it does not need a causative agent. And because it does not need that, it's incessant, it operates all the time without interruption. Then, as a net result of all that activity, all portions of the vacuum house a content. And in all the portions the content has the same characteristics. This activity that fills the void is very similar to the presence of a physical medium. That idea decisively implies a density (of mass) greater than zero in all points of space, which according to E = mC2 implies an energy density greater than zero. In the case of the quantum hotbed, is there a single possibility for energy density or are there several?