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Author Topic:   Does the universe have total net energy of zero?
designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 188 of 404 (644816)
12-20-2011 10:00 PM
Reply to: Message 180 by NoNukes
12-20-2011 12:45 PM


Re: A Simple Thought Experiment
This article discusses the possibility GR may need to be modified or replaced since the discovery of dark energy.
http://arxiv.org/pdf/0803.0982
I particularly like this comment from the paper:
The simplest explanation for dark energy is the energy associated with the vacuum; it is mathematically equiv- alent to a cosmological constant. However, all attempts to compute the vacuum energy density from the zero-point energies of all quantum fields yield a result that is many orders of magnitude too large or infinite.

This message is a reply to:
 Message 180 by NoNukes, posted 12-20-2011 12:45 PM NoNukes has replied

Replies to this message:
 Message 189 by NoNukes, posted 12-20-2011 10:30 PM designtheorist has replied

  
designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 190 of 404 (644819)
12-20-2011 11:50 PM
Reply to: Message 189 by NoNukes
12-20-2011 10:30 PM


Re: A Simple Thought Experiment
I haven't read the whole article yet. I only read the abstract and skimmed through some of the Open Issues and Challenges.
For one thing, it peeves me to see dark energy referred to as the Cosmological Constant. In Einstein's mind the lambda was all about maintaining a static state universe. Dark energy does not do that. Second, it appears "all attempts" to compute it have failed spectacularly. This tells me we do not know enough about the nature of dark energy. Do you think I'm wrong on that point?
Also from the abstract
Cosmic acceleration could arise from the repulsive gravity of dark energy — for example, the quantum energy of the vacuum — or it may signal that General Relativity breaks down on cosmological scales and must be replaced.
This tells me, contrary to your earlier claims, the failure to compute dark energy properly is calling GR into question.
When you add these facts up, it seems ridiculous to me that people are still claiming we have a net zero energy universe.

This message is a reply to:
 Message 189 by NoNukes, posted 12-20-2011 10:30 PM NoNukes has replied

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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 208 of 404 (645196)
12-24-2011 7:58 AM
Reply to: Message 195 by vimesey
12-21-2011 10:50 AM


Not a Bad Parable - I Fixed It
One day a man pushed his car into a repair shop because it would not start. He watched the mechanic at work on his car, interested to see him dismantling pieces of it and examining them in some detail.
After a time, the mechanic came to the man and said that he was afraid that the throttle valve in the carburetor had cracked, and that he would need to order some new parts to fix his car.
Knowing his rights under the law, the man asked if to see the broken parts. The following conversation ensued:
"May I see the carburetor's broken throttle valve?"
"Why would you want to see that? You won't know what your looking at."
"I will if you explain it to me."
"You still won't understand it. I'm a trained mechanic. Trust me."
"I know my rights under California law. I wish to see the parts."
"Other people don't ask to see the parts."
"I'm not other people. Please show me where it is broken."
"I can't."
"You are right that you can't. My car doesn't have a carburetor. It has fuel injection."
"If you knew that, why did you ask to see the parts?"
"I wanted to know how far you would take this farce and if you were dishonest enough to show me a carburetor off another car. Now put the car back in the condition it was in when I brought it or I will sue."
As the car was being put back together, the man did some research and found a reputable repair shop down the street. He pushed his car there and asked them to take a look. Within a few short minutes, the mechanic found the problem. The coil wire had become detached. He pressed the coil wire back in place and the man drove down the street with a smile on his face.
P.S. I left off the bit about the dishonest mechanic being surrounded by dark energy. It seemed a bit over the top.

This message is a reply to:
 Message 195 by vimesey, posted 12-21-2011 10:50 AM vimesey has not replied

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 Message 211 by Percy, posted 12-24-2011 9:15 AM designtheorist has replied

  
designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 213 of 404 (645357)
12-26-2011 4:01 PM
Reply to: Message 211 by Percy
12-24-2011 9:15 AM


Re: Not a Bad Parable - I Fixed It
Vimesey's parable is about how preconceptions can get in the way of understanding, causing feelings of distrust and making communication difficult. Seems to describe this thread pretty well.
I see Vimesey's parable as illustrating the importance of believing those in authority and positions of power. This is the antithesis of the scientific method. Science does not proceed on faith. It proceeds on evidence. The man in Vimesey's parable never asked for evidence. He simply had faith the mechanic was dishonest. The fact so many commenters here liked the parable is bad for science. It shows that people don't understand the importance of asking for evidence. I have already linked to Wikipedia articles on data sharing and data archiving.
Your parable is about why you shouldn't trust anyone who refuses to show you evidence. Is anyone in this thread refusing to show you evidence?
My parable is about the importance of asking for evidence, especially when you have reason to doubt. You ask if anyone is refusing to show me evidence. They have not refused, but neither have they shown me evidence. The only evidence put forward relates to pseudotensors and we have already discussed why this is not acceptable. It is possible the claim of zero total net energy can be disproven if the evidence ever comes out. Without evidence, I cannot disprove it. All I can do, and what I have done, is show why I think it is unlikely to be true. I am looking forward to reading the book by Krauss to see if he presents evidence or just assumes it.
A more accurate parable might be if the mechanic eventually threw his hands up in frustration and walked away because the customer kept insisting on referring to the engine as energy.
Your point is unclear to me. I certainly agree that it is important that terms are defined and agreed upon. Am I missing an important point here?

This message is a reply to:
 Message 211 by Percy, posted 12-24-2011 9:15 AM Percy has replied

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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 217 of 404 (645386)
12-26-2011 7:22 PM
Reply to: Message 184 by hooah212002
12-20-2011 9:20 PM


Re: How much energy is in empty space?
I mean, you've some nerve to call Feynman, Richard (expletive deleted) Feynman!, into question without so much as linking to some math proof that you've worked out elsewhere, let alone showing us directly. You've spent this whole thread calling numerous great minds into question and you've not even written up 2+2.
Calling into question those who have gone before is, at least in part, what science does. The fact you have the faith to accept the claim (third or fourth hand) that the energy of empty space is infinite or greater than the energy of U-238 of the same volume is... well... you have more faith than a scientist should ever have.
I have just found a web page by John Baez which discusses this issue in some detail. The answer Baez puts forward and I find convincing is that the energy density of the vacuum is very close to zero - approximately 7 10-27 kilograms per cubic meter or positive energy density of about 6 10-10 joules per cubic meter.
Perhaps more importantly from an educational point of view is Baez explains how the different answers were arrived at. Baez writes "The moral is: for a question like this, you need to know not just the answer but also the assumptions and reasoning that went into the answer. Otherwise you can't make sense of why different people give different answers." See http://math.ucr.edu/home/baez/vacuum.html
I agree with Baez completely. I would add that observations, such as those done by WMAP and cited by Baez, trump any theory which may disagree with observation. Feynman's agreement on this point is on the record.
How does the energy density of the vacuum affect calculations of the net energy of the universe? Energy density of the vacuum refers to dark energy. While the density of dark energy is quite low measured by cubic meter, WMAP considers it to be about 74% of the energy of the universe. Consider also that gravitational field energy becomes stronger when matter is dense (like black holes) and is quite small otherwise. It would appear the negative gravitational field energy would be quite small, much smaller than the positive energy of the universe.
Regarding actual calculations, we will have to wait until we see some from those claiming the net energy is zero.

This message is a reply to:
 Message 184 by hooah212002, posted 12-20-2011 9:20 PM hooah212002 has replied

Replies to this message:
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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 218 of 404 (645390)
12-26-2011 7:34 PM
Reply to: Message 216 by Percy
12-26-2011 5:00 PM


Re: Not a Bad Parable - I Fixed It
It isn't that they haven't shown you any evidence but that your preconceptions have made you already decide which evidence is acceptable.
Perhaps you missed the reasons the pseudotensor argument was rejected. The pseudotensors are not based on observational cosmology. Observation always trumps theory. Many people reject pseudotensors saying they do not apply to general relativity. Since the pseudotensor approach gets the same result both before and after the discovery the universe is accelerating, it is not an approach that inspires confidence. Every good scientist wants observation when it is possible. Thanks to WMAP, our observational ability has greatly improved. But I have not been able to find any calculations of net energy based on the new observations yet. One may be available but it has not been put forward here. I am still looking.
It's ironic that you're complaining about a focus on authority at the expense of evidence since that is your own modus operandi.
That seems an odd comment since I am the one asking for evidence. The final outcome does not really matter to me. I believe all truth is one. If net energy is zero, it does not disprove the existence of God. The chance net energy is zero seems impossibly low. Extraordinary claims such as that one demand extraordinary evidence, which at this point is lacking.

This message is a reply to:
 Message 216 by Percy, posted 12-26-2011 5:00 PM Percy has replied

Replies to this message:
 Message 222 by Percy, posted 12-27-2011 6:25 AM designtheorist has replied
 Message 225 by NoNukes, posted 12-27-2011 11:36 AM designtheorist has replied

  
designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 221 of 404 (645427)
12-26-2011 10:38 PM


Calculating negative equivalent mass for gravitational fields
Earlier we saw Hawking had described the ratio of rest energy of earth's particles to be one billion times greater than earth's negative gravitational field energy. As Hawking explained, the gravitational field energy is becomes much stronger when the particles are denser.
I just found an interesting website on this point. The author writes:
To get some idea about the amount of equivalent mass associated with the negative energy in the gravitational fields, it may be instructive to calculate the ratios of negative gravitational mass to ordinary mass for known objects.
See UltraDNS Client Redirection Service
Bradford presents a table of information of mostly known objects. Near the bottom, he includes 'Entire Universe.' He calcs the entire universe mass as 2 X 10^50 kg. He calcs the negative mass ratio of the gravitational field as -9 X 10^-4. To put this in standard notation, the mass of the universe is 20,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 kgs and the negative mass ratio is -0.0009.
There are a couple of caveats that go along with this calculation. Bradford admits he may be low on the gravitational equivalent because "the formula provides the minimum amount of negative equivalent mass. The maximum value, however, is not easy to determine because one would need to know the mass density profile of the object with radius."
A second caveat is that Bradford does not discuss dark energy. One has a right to wonder about the age and provenance of these numbers.
For a thread that is low on actual numbers, I thought it worthwhile to present it here.

  
designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 223 of 404 (645476)
12-27-2011 10:03 AM
Reply to: Message 222 by Percy
12-27-2011 6:25 AM


Re: Not a Bad Parable - I Fixed It
A better example was when you rejected Feynman because he isn't infallible, and I didn't see any evidence presented.
The Feynman discussion had to do with Cano's description of Clarke's analysis of Feynman's work. I did not present any evidence because none seemed necessary to me as the result was patently absurd. I did not know where the error occurred - with Feynman, Clarke or Cano - but it obviously was incorrect.
If you still think that result is plausible, please see the web page from Baez above. He explains how the different answers are arrived at, including the answer that empty space has infinity rest energy. It is clear that renormalization is necessary to get rid of the infinity but renormalization is not exactly satisfactory.
My guess is that either Clarke or Cano picked up Feynman's calculations prior to the renormalization, a step Feynman certainly knew was necessary.
BTW, in case it is not obvious, if empty space had infinity rest energy per cubic meter, there is no way the gravitational field energy could offset it so that the result could be net zero energy universe. But I am not about to declare victory on the basis of an obvious absurdity.
Edited by designtheorist, : No reason given.

This message is a reply to:
 Message 222 by Percy, posted 12-27-2011 6:25 AM Percy has replied

Replies to this message:
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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 226 of 404 (645491)
12-27-2011 11:56 AM
Reply to: Message 225 by NoNukes
12-27-2011 11:36 AM


Re: Not a Bad Parable - I Fixed It
That's fine, but you haven't reported any observations that the net energy is not "about" zero. What you are either ignoring or failing to understand is that net energy being "about" zero is not incompatible with an expanding universe.
Did you happen to read the web page by John Baez I linked above? According to the calculations he presents, the ratio of negative energy to positive energy is off by more than three decimal places. That is not close. I don't know if these calcs were done before or after the discovery of dark energy, so the difference could be even greater.
Edited by designtheorist, : Typo!

This message is a reply to:
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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 228 of 404 (645504)
12-27-2011 12:55 PM
Reply to: Message 224 by cavediver
12-27-2011 11:00 AM


Re: Not a Bad Parable - I Fixed It
You are talking pure gibberish again. Renormalisation (a process typically used in quantum field theory) has nothing to do with the calculations that Feynman was performing (purely classical, i.e. non-quantum).
The Baez page made it clear the only way to get to infinity (or to the enormous but finite result) was through quantum field theory. I'm not sure why you are claiming Feynman was not working in quantum theory.
Regarding pseudotensors being valid objects or not, perhaps I should have said "some people" instead of many people. Wikipedia says:
Some people object to this derivation on the grounds that pseudotensors are inappropriate objects in general relativity, but the conservation law only requires the use of the 4-divergence of a pseudotensor which is, in this case, a tensor (which also vanishes).
See Stress—energy—momentum pseudotensor - Wikipedia

This message is a reply to:
 Message 224 by cavediver, posted 12-27-2011 11:00 AM cavediver has replied

Replies to this message:
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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 230 of 404 (645507)
12-27-2011 1:06 PM
Reply to: Message 227 by cavediver
12-27-2011 12:22 PM


Re: Not a Bad Parable - I Fixed It
1) That wasn't John's site, it was Bradford's.
My mistake. It was Bradford, not Baez.
2) Bradford's mass of Universe figure is way out. Once corrected, you will see he will get equivalent negative mass ~ positive mass, as already shown by Feynman, Modulus, and just about everyone else.
I have not been able to locate the 1962/63 Feynman paper yet (too old to be available online and the university libraries are closed between terms) so I don't know if his calculation was based on observation or pseudotensors. The Berman paper offered by Modulus was based on pseudotensors. Evidence for the position is completely lacking. What I find tedious are your unsupported assertions.

This message is a reply to:
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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 231 of 404 (645509)
12-27-2011 1:16 PM
Reply to: Message 229 by NoNukes
12-27-2011 12:55 PM


Re: Not a Bad Parable - I Fixed It
Even if empty space has a large finite energy, you still have to deal with whether that energy would generate a gravitational field and a corresponding negative energy.
Gravitational field energy cannot be strong in empty space since it is overpowered by the pressure of dark energy.
Regarding my comment about Feynman and renormalization, you write:
That's complete nonsense. It simply isn't the kind of thing someone who understood renormalization would ever say.
Why would you say such a thing? Isn't it possible someone could present results prior to renormalization? I bet I can find modern papers, within the last decade, that do it. I don't know much about the history of renormalization. Was it commonly done in the 1960s? I imagine it was. I simply cannot imagine that Feynman would consider energy density of a cubic meter of empty space to be infinity as even possibly physical. I can imagine Feynman writing up a paper saying "This is my result. I have not figured out how to do the renormalization yet." I don't understand what you are trying to say.
Edited by designtheorist, : Typo!
Edited by designtheorist, : No reason given.

This message is a reply to:
 Message 229 by NoNukes, posted 12-27-2011 12:55 PM NoNukes has replied

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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 239 of 404 (645524)
12-27-2011 4:07 PM
Reply to: Message 232 by cavediver
12-27-2011 1:22 PM


Re: Not a Bad Parable - I Fixed It
What the hell are you gibbering about now? Feynman worked on many things in his life. At the moment, we are talking about a classical back-of the-envelope calculation he performed that has nothing to do with quantum theory.
I see where you are confused. Feynman's name has come up on this thread in respect to two separate calculations. One is the net zero energy calculation. The other has to do with the energy density of empty space. According to Cano, Clarke wrote about Feynman's calculation saying the energy density of one cubic meter of empty space was infinity. I'm saying that is clearly an unphysical result and Cano and Clarke must be talking about Feynman's calculation prior to renormalization. It is an open question in my mind whether renormalization was a common practice in Feynman's time, but I think it is clear Feynman would recognize the result as unphysical.
So who are these "some people"? I note that no reference is given so you simply have a single unattributed comment from Wikipedia, which goes on in the same sentence to point out why these "some people" are wrong!! And from this, you (DT) have the gall to state (that you (DT) have rejected the pseudotensor argument).
I quoted Joseph Silk in Message 11 saying:
On large enough scales, once one counts all the black holes, stars, and empty space, the overall energy of the universe is close to zero (as measured).
I have clearly stated that I am more interested in observational cosmology because observation trumps theory. I am not expert in GR but the pseudotensor argument would be more persuasive to me if it was not controversial or was clearly confirmed by observation. Observational evidence for net zero energy, on this thread at least, is clearly lacking. The only observational calculations presented so far show the ratio of positive to negative is not 1 but is off by three decimal places.
Regarding the rejection of the pseudotensor argument, I was referring to myself. I make no claims about others either accepting or rejecting the argument.

This message is a reply to:
 Message 232 by cavediver, posted 12-27-2011 1:22 PM cavediver has replied

Replies to this message:
 Message 241 by cavediver, posted 12-27-2011 4:21 PM designtheorist has replied

  
designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 240 of 404 (645525)
12-27-2011 4:15 PM
Reply to: Message 235 by NoNukes
12-27-2011 1:41 PM


Re: Discussing physics, not parables...
And again, dark energy overcomes gravitational energy only on super cosmic distances. For example, neither dark energy nor vacuum energy prevents the Milky Way galaxy from being drawn into a collision with the Andromeda galaxy by gravity.
On local levels, gravitational energy is almost trivial compared to rest energy of matter. According to cavediver, it is only on cosmic scales that gravitational energy can scale up to offset the positive energy of matter. I'm saying that is nonsense since dark energy overcomes gravitational energy on cosmic scales.
Why don't you give us something other than handwaving and assertions.
I was able to find Bradford's table, but not much else. I'm clearly asking for observational evidence to support the position of net energy of zero. I have not found any and no one here has provided any. Until I have the evidence in hand, how can I find where the mistake was made?
I think it is time to put this thread on hiatus. We are approaching the 300 comment mark which will trigger the summation and Krauss's book is not even out yet. I would like to save some comments for discussing his evidence if he presents any.

This message is a reply to:
 Message 235 by NoNukes, posted 12-27-2011 1:41 PM NoNukes has replied

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designtheorist
Member (Idle past 3833 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011


Message 243 of 404 (645550)
12-27-2011 9:27 PM
Reply to: Message 242 by NoNukes
12-27-2011 4:45 PM


Re: Discussing physics, not parables...
My position is that you haven't presented any evidence that the net energy is not "about" zero, where "about" means close enough to allow a quantum fluctuations origin.
The only evidence based on observation I have found so far was the Bradford table I linked above. When the ratio is off by more than three decimal places, you cannot say the net is "about" zero.
No observational evidence has been put forward by the net zero side.

This message is a reply to:
 Message 242 by NoNukes, posted 12-27-2011 4:45 PM NoNukes has replied

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