Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 61 (9042 total)
100 online now:
AZPaul3, kjsimons, nwr (3 members, 97 visitors)
Newest Member: maria
Post Volume: Total: 886,022 Year: 3,668/14,102 Month: 288/321 Week: 104/44 Day: 20/26 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Does the universe have total net energy of zero?
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 136 of 404 (644397)
12-17-2011 2:15 PM
Reply to: Message 120 by cavediver
12-13-2011 2:53 AM


Re: Hamiltonian definition of energy always equals net zero
What an interesting post!

So you wrote "General Relativity is almost the statement that the gravitational energy is always equivalent to the mass-energy."

From your statement I'm supposed to understand that in the hamiltonian definition of energy that net zero energy is a given or law but under other definitions of energy it is not? Don't you think you could have been a tad more clear? The phrase "almost the statement" was completely obscure. You did not talk about any of the other definitions of energy in which the universe does not net out at zero.

I really think you could contribute to this discussion if you wanted to but you seem to reluctant to write clearly or in a manner that cannot be misunderstood. Try bringing your A-game.


This message is a reply to:
 Message 120 by cavediver, posted 12-13-2011 2:53 AM cavediver has not yet responded

Replies to this message:
 Message 138 by NoNukes, posted 12-17-2011 2:19 PM designtheorist has not yet responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 137 of 404 (644398)
12-17-2011 2:18 PM


On the nature of negative gravitational energy – Part I
Gravitational field energy has been described as always negative. Several different analogies or illustrations have been put forward to explain gravitational energy is negative. I would like to examine these more closely. And if you have other explanations, I would like to read and think about them.

One explanation is that gravitation is negative because positive energy is required to remove an orbiting body (like the moon) from its orbit. Let’s try taking the opposite example and see if it works. Anti-gravity due to dark energy is accelerating the expansion of the universe. Galaxies are moving away from each other more quickly all the time. In order to slow or stop this acceleration, one would have to apply positive energy in the opposite direction. Does that mean anti-gravity is negative energy? Can both gravity and anti-gravity both be negative? It seems we can dispense with this approach as a good illustration.

Others say gravitational energy is negative energy because it is always attractive. Let’s examine that claim more closely. It is said there are four major forces in the universe (or possibly five if you count dark energy as an antigravity force).
-gravity
-electromagnetism
-weak force
-strong force

Electromagnetism and the weak force were joined into the electroweak force so we can consider that as one. Electroweak is definitely both attractive and repulsive depending upon the charge.

The strong force is always attractive to a distance of about 1 femtometer. At greater distances, it has no power at all. No one every claims the strong force is negative energy, do they? Again, it seems we can dispense with this illustration as well because it is not consistent.

I once read the best popular explanation or description of negative gravitational energy is in Alan Guth’s book “The Inflationary Universe.” In Appendix A on page 289, Guth begins by writing “Since the negative energy of a gravitational field is crucial to the notion of a zero-energy universe, it is a subject worth examining carefully. In this appendix I will explain how the properties of gravity can be used to show that the energy of a gravitational field is unambiguously negative.”

Dr. Guth begins with some descriptions of how gravity works on a hollowed out sphere. (Think of a tennis ball without the fuzzy outer covering.) While this is an interesting thought experiment once engaged by Isaac Newton, it is not very practical since we don’t experience many hollowed out planets.

On pages 292 and 293, Dr. Guth gets to the heart of his explanation with Fig A2. He describes Figure A2:

Thought experiment to understand the energy of gravity. Part (a) shows a hollow spherical shell of mass, and the gravitational field lines that it produces. There is a force on each piece of the shell, pulling inward. Part (b) shows how energy can be extracted as the shell is allowed to uniformly contract. Each piece of the shell is tied by a rope to an electrical generator, producing power as the piece is “lowered” toward its final position. Part (c) shows the final configuration, which includes a gravitational field in the shaded region where no field existed before. Thus, the creation of the gravitational field is associated with the release of energy.

Part (a) is a three-dimensional sphere, represented in Figure A2 as a large circle. The gravitational field lines pointing at the circle end at the point of the circle. They do not proceed to the center of the hollow sphere.

Part (b) is a somewhat smaller circle (intermediate-sized) circle. Outside of the circle are figures representing ropes and generators. This is the stage at which energy is extracted.

Part (c) shows a smaller circle. The ropes and generators are gone. The original larger circle is represented by a dotted line. The area between the smaller circle and the dotted circle is shaded. The gravitational lines now extend past the dotted circle and stop at the smaller circle.

According to Dr. Guth, energy is extracted and the gravitational field is enlarged and together this proves gravitational field energy is negative. Really, Dr. Guth? According to this thinking, the smallest particle would have the largest gravitational field.

Perhaps I am missing the point, but let’s examine this. It appears that energy is extracted from the hollow shell of mass by reducing the size of the mass. If one reduces the mass, then the strength of the gravitational field is reduced. The fact the region of the field is increased is meaningless.

None of these illustrations or descriptions of gravity show persuasively that gravitational energy is negative. But even if they did, all the illustrations are dealing with local effects. Everyone agrees that the local effects of gravity are about one-billionth of the positive energy of the local mass.

If the universe-wide effects of gravitational energy are so strongly negative, where are the illustrations and descriptions of that negative energy?


Replies to this message:
 Message 157 by cavediver, posted 12-19-2011 6:18 PM designtheorist has responded
 Message 176 by kbertsche, posted 12-20-2011 11:58 AM designtheorist has not yet responded

  
NoNukes
Inactive Member


Message 138 of 404 (644399)
12-17-2011 2:19 PM
Reply to: Message 136 by designtheorist
12-17-2011 2:15 PM


Re: Hamiltonian definition of energy always equals net zero
really think you could contribute to this discussion if you wanted to but you seem to reluctant to write clearly or in a manner that cannot be misunderstood. Try bringing your A-game.

I should point out that many of the people here understand what cavediver is saying from the concise words he did post.

I'll read whatever rebuttals you provide to my last posts. You are welcome to have the last word.


This message is a reply to:
 Message 136 by designtheorist, posted 12-17-2011 2:15 PM designtheorist has not yet responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 139 of 404 (644400)
12-17-2011 2:21 PM


On the nature of negative gravitational energy – Part II
Can gravitation ever equal the rest energy of mass of the universe?

Let’s say, for the sake of argument, that the gravitational field is negative. We know the local effects of gravity are quite small. Gravity is the weakest of the four forces, but it does act over large distances. Some people claim that on a cosmic scale, the negative energy of gravity is equal to the positive energy of the universe. Let’s examine that more closely.

Gravitation is a secondary form of energy. That is, its existence is dependent on the existence of matter. The reflection in the mirror is real, but the reflection only exists because there is an object to reflect. The reflection is real but it has a secondary existence. A shadow is real, but it only exists because there is a light source and an object blocking the light. While the analogy to gravity may not be perfect, it is obvious. Without mass or energy, there is no gravity. How then can gravity have the same amount of energy as mass? Can gravity release thermal energy in the same way a star can? Can gravity display kinetic energy the way galaxies and planets can? Can gravity create anti-gravity?

How can the existence of a secondary object be as real or as powerful as the primary object? People take it that we live in a zero net energy universe. Why? Is that a tenet of their faith? Where is the evidence?

When we look at the evidence for the power of gravity, it is easiest to look at the local level. At the local level, gravity is one-billionth the power of the rest energy of mass as normal densities such as planets and luminescent stars. Gravity can be greater within the event horizon of the black hole, but there are not enough black holes to come close to equalizing the positive energy of the universe.

Another of my major interests when starting this thread was on the possible existence of negative energy in other forms. Based on the reading I’ve done so far, extremely small amounts of negative energy can exist at the quantum level for very short periods of time, but nothing close to equaling the positive energy of the universe. Quantum negative energy is negligible.

“Fortunately (or not, depending on your point of view), although quantum theory allows the existence of negative energy, it also appears to place strong restrictions - known as quantum inequalities - on its magnitude and duration. These inequalities were first suggested by Ford in 1978.”
http://www.bibliotecapleyades.net/...ergy/negativeenergy.htm


Replies to this message:
 Message 155 by cavediver, posted 12-19-2011 6:04 PM designtheorist has responded

  
NoNukes
Inactive Member


Message 140 of 404 (644401)
12-17-2011 2:28 PM
Reply to: Message 132 by designtheorist
12-17-2011 1:31 PM


Re: A Simple Thought Experiment
I don't know if he is right. He clearly identifies this position as outside the establishment. Sometimes it is good to look outside the establishment way of thinking on things.

If you don't even believe this stuff, why should I? Do you seriously believe that this quote demonstrates a controversy.


This message is a reply to:
 Message 132 by designtheorist, posted 12-17-2011 1:31 PM designtheorist has responded

Replies to this message:
 Message 141 by designtheorist, posted 12-17-2011 3:59 PM NoNukes has responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 141 of 404 (644402)
12-17-2011 3:59 PM
Reply to: Message 140 by NoNukes
12-17-2011 2:28 PM


Re: A Simple Thought Experiment
How are you defining controversy? Is it controversial if an informed person holds a contrary opinion? I think that is a reasonable definition in the circumstances. I thought it was intriguing that he came to the view that light did not warp space when discussing the same topic that brought me to the issue - dark energy.

I think it is clear that GR has not come to terms with dark energy. The theory needs to be modified. Is the modification Gower is proposing the right one? I don't honestly know but I do think it is worth considering.

For me, it is important to consider the facts, the quality of the evidence and the conclusions drawn from the evidence. I am unwilling to simply believe in GR theory when so much new evidence is calling it into question. Are you still a firm believer in GR as received from the establishment on high?


This message is a reply to:
 Message 140 by NoNukes, posted 12-17-2011 2:28 PM NoNukes has responded

Replies to this message:
 Message 180 by NoNukes, posted 12-20-2011 12:45 PM designtheorist has responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 142 of 404 (644403)
12-17-2011 4:23 PM


Is net zero energy universe "not even wrong?"
The key to science, as Richard Feynmann used to say, is comparing theory to observation/experiment. "If (the theory) disagrees with experiment, it's wrong."

https://www.youtube.com/watch?v=S3Rvy-ft1bI

Physicist Wolfgang Pauli used to describe certain ideas as "not even wrong," meaning they were incomplete and not falsifiable. It appears now that the concept of net zero energy is built in to certain definitions of energy within the theory of general relativity. If you use hamiltonian definition energy, then the math will always come out to zero. This is absolutely fine... unless you care about science. Science has to compare the theory to observation.

If a new discovery is found and it does not change the theory, that tells you something is wrong. Feynmann was the first to theorize about a net zero universe back in 1962/63 - before we knew about the accelerating universe or even the CMB radiation. Perhaps the theory was viable at that point (I don't think so) but how can the theory still be viable after the discovery of the anti-gravity force of dark energy and the accelerating universe?

In 2009, Berman wrote a paper on the zero energy universe using the same pseudotensor method used before the discovery of dark energy and the accelerating universe. Is this science?

If the theory is not falsifiable, it is not science. If you cannot compare the theory to observation, it is not science. If new discoveries (like dark energy!) do not cause a complete rethinking of the issue, it is not science!

I'm going to try to get my hands on a copy of Lawrence Krauss's book "A Universe from Nothing." If he discusses dark energy, I will be surprised.

Update: It seems the book will not be available until next month.

Edited by designtheorist, : No reason given.

Edited by designtheorist, : No reason given.

Edited by designtheorist, : I changed the order of the two main points to clarify the issue.


Replies to this message:
 Message 143 by Dr Adequate, posted 12-19-2011 9:47 AM designtheorist has responded
 Message 148 by Modulous, posted 12-19-2011 12:27 PM designtheorist has responded

  
Dr Adequate
Member
Posts: 16112
Joined: 07-20-2006


Message 143 of 404 (644579)
12-19-2011 9:47 AM
Reply to: Message 142 by designtheorist
12-17-2011 4:23 PM


Re: Is net zero energy universe "not even wrong?"
So if something is inevitable according to the laws of physics, we can just ignore it?

This message is a reply to:
 Message 142 by designtheorist, posted 12-17-2011 4:23 PM designtheorist has responded

Replies to this message:
 Message 144 by designtheorist, posted 12-19-2011 10:12 AM Dr Adequate has responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 144 of 404 (644580)
12-19-2011 10:12 AM
Reply to: Message 143 by Dr Adequate
12-19-2011 9:47 AM


Re: Is net zero energy universe "not even wrong?"
So if something is inevitable according to the laws of physics, we can just ignore it?

I don't understand your question. What kinds of inevitable things are being ignored?


This message is a reply to:
 Message 143 by Dr Adequate, posted 12-19-2011 9:47 AM Dr Adequate has responded

Replies to this message:
 Message 145 by Dr Adequate, posted 12-19-2011 10:18 AM designtheorist has responded

  
Dr Adequate
Member
Posts: 16112
Joined: 07-20-2006


Message 145 of 404 (644583)
12-19-2011 10:18 AM
Reply to: Message 144 by designtheorist
12-19-2011 10:12 AM


Re: Is net zero energy universe "not even wrong?"
I don't understand your question. What kinds of inevitable things are being ignored?

Apparently, the laws of physics (as known to us) make it inevitable that the net energy of the universe should be zero. And it seems that the very inevitability of the conclusion is your pretext for discounting it.


This message is a reply to:
 Message 144 by designtheorist, posted 12-19-2011 10:12 AM designtheorist has responded

Replies to this message:
 Message 146 by designtheorist, posted 12-19-2011 12:15 PM Dr Adequate has responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 146 of 404 (644595)
12-19-2011 12:15 PM
Reply to: Message 145 by Dr Adequate
12-19-2011 10:18 AM


Re: Is net zero energy universe "not even wrong?"
Apparently, the laws of physics (as known to us) make it inevitable that the net energy of the universe should be zero. And it seems that the very inevitability of the conclusion is your pretext for discounting it.

You seem to be displaying significant faith in the magic of science. I am going to explain some elementary aspects of the standards of science. Please forgive me if you know all of this. You probably do, but I think it is best to cover the ground anyway.

Just because someone has a PhD or wears a white coat does not mean he is right or even that what he is doing is science. Science is about open inquiry. If a scientist claims they have achieved a particular result in a published and peer-reviewed paper, the conclusion is not automatically added to our body of knowledge until the result has been replicated. If another person says "I don't believe you. Show me your data, methods and code," then the standards of science require the data, methods and code be shared so the experiment can be replicated. All the best peer-reviewed journals have policies on these matters. In fact, in the modern world, scientific data is supposed to be archived so anyone can analyze it. It is one of the basic tenets of science that scientists are supposed to be skeptical.

See http://en.wikipedia.org/wiki/Data_sharing
http://en.wikipedia.org/wiki/Scientific_data_archiving

The claim the net energy of the universe should always be zero is a theory. It is not a law. Only under certain definition of energy (hamiltonian) does the net energy level come out to zero every time. This definition was developed prior to the discovery of dark energy. So how valid is that definition of energy now?

Any theory needs to be confirmed by experiment or observation in some way. Joseph Silk (and others) have claimed the theory of zero net energy has been confirmed by observation. Silk actually claimed "measurement." I can find no evidence this is true. No one on this forum has put forward any papers which have attempted to estimate the actual positive and negative energy of the universe.

When the theory was first put forward by Feynmann in 1962/63, it is possible he attempted some estimation of positive and negative energy. I have not yet been able to find that article. But if the theory was somewhat viable in the early 1960s, the discovery of the antigravity of dark energy and the resulting accelerating universe seem to make the theory completely untenable today.

The problem seems to be that no one has thought through the issue of the accelerating universe and how it affects the theory of zero net energy.

In order for the theory of zero net energy to command any form of respect, it would need to show some confirmation by observation. And after the confirming observations were published, it would have to be replicated by others.


This message is a reply to:
 Message 145 by Dr Adequate, posted 12-19-2011 10:18 AM Dr Adequate has responded

Replies to this message:
 Message 147 by Dr Adequate, posted 12-19-2011 12:22 PM designtheorist has responded

  
Dr Adequate
Member
Posts: 16112
Joined: 07-20-2006


Message 147 of 404 (644597)
12-19-2011 12:22 PM
Reply to: Message 146 by designtheorist
12-19-2011 12:15 PM


Re: Is net zero energy universe "not even wrong?"
You seem to be displaying significant faith in the magic of science. I am going to explain some elementary aspects of the standards of science. Please forgive me if you know all of this. You probably do, but I think it is best to cover the ground anyway.

Just because someone has a PhD or wears a white coat does not mean he is right or even that what he is doing is science. Science is about open inquiry. If a scientist claims they have achieved a particular result in a published and peer-reviewed paper, the conclusion is not automatically added to our body of knowledge until the result has been replicated. If another person says "I don't believe you. Show me your data, methods and code," then the standards of science require the data, methods and code be shared so the experiment can be replicated. All the best peer-reviewed journals have policies on these matters. In fact, in the modern world, scientific data is supposed to be archived so anyone can analyze it. It is one of the basic tenets of science that scientists are supposed to be skeptical.

See http://en.wikipedia.org/wiki/Data_sharing
http://en.wikipedia.org/wiki/Scientific_data_archiving

The claim the net energy of the universe should always be zero is a theory. It is not a law. Only under certain definition of energy (hamiltonian) does the net energy level come out to zero every time. This definition was developed prior to the discovery of dark energy. So how valid is that definition of energy now?

Any theory needs to be confirmed by experiment or observation in some way. Joseph Silk (and others) have claimed the theory of zero net energy has been confirmed by observation. Silk actually claimed "measurement." I can find no evidence this is true. No one on this forum has put forward any papers which have attempted to estimate the actual positive and negative energy of the universe.

When the theory was first put forward by Feynmann in 1962/63, it is possible he attempted some estimation of positive and negative energy. I have not yet been able to find that article. But if the theory was somewhat viable in the early 1960s, the discovery of the antigravity of dark energy and the resulting accelerating universe seem to make the theory completely untenable today.

The problem seems to be that no one has thought through the issue of the accelerating universe and how it affects the theory of zero net energy.

In order for the theory of zero net energy to command any form of respect, it would need to show some confirmation by observation. And after the confirming observations were published, it would have to be replicated by others.

When you wish to say something remotely relevant to the point I was discussing, please let me know.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 146 by designtheorist, posted 12-19-2011 12:15 PM designtheorist has responded

Replies to this message:
 Message 149 by designtheorist, posted 12-19-2011 12:59 PM Dr Adequate has responded

  
Modulous
Member (Idle past 1042 days)
Posts: 7789
From: Manchester, UK
Joined: 05-01-2005


Message 148 of 404 (644598)
12-19-2011 12:27 PM
Reply to: Message 142 by designtheorist
12-17-2011 4:23 PM


Re: Is net zero energy universe "not even wrong?"
Perhaps the theory was viable at that point (I don't think so) but how can the theory still be viable after the discovery of the anti-gravity force of dark energy and the accelerating universe?

Because dark energy has negative energy associated with it because as far as I know it has an associated mass that 'creates' a gravitational field. The zero energy postulate suggests that the negative energy as the result of the gravitational field cancels out the positive energy content of the stuff in question.

Is your problem with this that you do not think that dark energy has an associated mass? Do you have any sources which indicate that dark energy is massless?

The fact that dark energy has negative pressure which acts against gravity is irrelevant.


This message is a reply to:
 Message 142 by designtheorist, posted 12-17-2011 4:23 PM designtheorist has responded

Replies to this message:
 Message 150 by designtheorist, posted 12-19-2011 1:20 PM Modulous has responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 149 of 404 (644604)
12-19-2011 12:59 PM
Reply to: Message 147 by Dr Adequate
12-19-2011 12:22 PM


Re: Is net zero energy universe "not even wrong?"
When you wish to say something remotely relevant to the point I was discussing, please let me know.

Everything I wrote was relevant. You used the word "inevitable" when talking about an unconfirmed theory which only applies under certain definitions of energy and was first theorized prior to the discovery of dark energy.


This message is a reply to:
 Message 147 by Dr Adequate, posted 12-19-2011 12:22 PM Dr Adequate has responded

Replies to this message:
 Message 151 by Dr Adequate, posted 12-19-2011 1:22 PM designtheorist has not yet responded

  
designtheorist
Member (Idle past 2771 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 150 of 404 (644607)
12-19-2011 1:20 PM
Reply to: Message 148 by Modulous
12-19-2011 12:27 PM


Re: Is net zero energy universe "not even wrong?"
Because dark energy has negative energy associated with it because as far as I know it has an associated mass that 'creates' a gravitational field. The zero energy postulate suggests that the negative energy as the result of the gravitational field cancels out the positive energy content of the stuff in question.

We really don't know a lot about dark energy except that it has an antigravitational effect. Is it your view dark energy can be converted into dark matter in the same way ordinary energy can be converted into ordinary matter? This would be unusual because dark matter has normal gravity and dark energy is antgravitational.

Is your problem with this that you do not think that dark energy has an associated mass? Do you have any sources which indicate that dark energy is massless?

We don't know much about dark energy except it is antigravitational. I do not have a view regarding dark energy and an associated mass. It would be interesting area of inquiry. It would seem that if dark energy can be converted into mass, it would probably be converted into a mass with antigravitational effects.

The fact that dark energy has negative pressure which acts against gravity is irrelevant.

No. This is the point. Gravity is not the all-powerful cosmic force we once thought. On a cosmic scale, anti-gravity is more powerful than gravity. That is why we can see the expansion of the universe is accelerating.


This message is a reply to:
 Message 148 by Modulous, posted 12-19-2011 12:27 PM Modulous has responded

Replies to this message:
 Message 152 by Modulous, posted 12-19-2011 1:40 PM designtheorist has responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2021