Understanding through Discussion

QuickSearch

 Welcome! You are not logged in. [ Login ] EvC Forum active members: 65 (9073 total)
 85 online now: nwr, ringo, Tanypteryx, Theodoric (4 members, 81 visitors) Newest Member: MidwestPaul Post Volume: Total: 893,345 Year: 4,457/6,534 Month: 671/900 Week: 195/182 Day: 28/47 Hour: 0/0

 Announcements: Security Update Released

Author Topic:   Does the universe have total net energy of zero?
Member (Idle past 291 days)
Posts: 16112
Joined: 07-20-2006

 Message 181 of 404 (644758) 12-20-2011 1:38 PM Reply to: Message 165 by designtheorist12-19-2011 7:38 PM

Re: On the nature of negative gravitational energy – Part I
 How is energy extracted? What effect does the rope have when "tied" to an electrical generator?

You wrap it round the axle of the generator. The linear motion of the rope is converted into rotary motion of the axle is converted into electricity.

 Isn't there an energy output in "allowing" the mass to uniformly contract?

The force of gravity converts the potential energy of the parts of the shell into kinetic energy.

 This message is a reply to: Message 165 by designtheorist, posted 12-19-2011 7:38 PM designtheorist has taken no action

NoNukes
Inactive Member

 Message 182 of 404 (644767) 12-20-2011 2:24 PM Reply to: Message 159 by designtheorist12-19-2011 6:27 PM

Re: On the nature of negative gravitational energy – Part II
designtheorist writes:

 cavediver writes:No, it most certainly is not. Consider any of the vacuum solutions of General Relativity.

Now here you may be making a contribution. But perhaps not. Can you provide me with any link of explanation of this pithy statement?

As a starting point to appreciating cavediver's comment, let me suggest the wikipedia article on "Exact solutions in general relativity".

http://en.wikipedia.org/...t_solutions_in_general_relativity

The short answer is that the vacuum solutions are those solutions where the Tab tensor consists of all zeros. The solutions include gravitational fields despite the absence of matter and of energy other than that associated with the gravitational fields.

 This message is a reply to: Message 159 by designtheorist, posted 12-19-2011 6:27 PM designtheorist has taken no action

designtheorist
Member (Idle past 3073 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011

 Message 183 of 404 (644807) 12-20-2011 8:33 PM

How much energy is in empty space?
I still have not gotten my hands on the original paper published in 1962 or 1963 by Richard Feynman on zero net energy. Business has kept me away from the local university library (shorter hours during the Christmas vacation).

However, I did come across an interesting description/analysis/report of Feynman's calculations attributed to Arthur C Clarke. See http://www.checktheevidence.com/...rehouse%20of%20energy.htm

That some energy is stored is empty space is a reasonable, even inevitable, conclusion. But to say empty space has more energy than U-238... well, that seems a bit much to me.

If Feynman believed empty space stored that much energy, how could he hold to a net zero energy universe? Or, did Feynman later reject the idea of a zero energy universe?

 Replies to this message: Message 184 by hooah212002, posted 12-20-2011 9:20 PM designtheorist has replied Message 186 by Percy, posted 12-20-2011 9:36 PM designtheorist has taken no action

hooah212002
Member (Idle past 41 days)
Posts: 3193
Joined: 08-12-2009

 Message 184 of 404 (644812) 12-20-2011 9:20 PM Reply to: Message 183 by designtheorist12-20-2011 8:33 PM

Re: How much energy is in empty space?
 But to say empty space has more energy than U-238... well, that seems a bit much to me.

You know, this site does have code that allows you to work out proper math function if that is what is holding you back from showing your work. I mean, you've some nerve to call Feynman, Richard Fucking 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.

Put the FSM back in Chrifsmas

 This message is a reply to: Message 183 by designtheorist, posted 12-20-2011 8:33 PM designtheorist has replied

 Replies to this message: Message 185 by designtheorist, posted 12-20-2011 9:36 PM hooah212002 has replied Message 217 by designtheorist, posted 12-26-2011 7:22 PM hooah212002 has replied

designtheorist
Member (Idle past 3073 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011

 Message 185 of 404 (644813) 12-20-2011 9:36 PM Reply to: Message 184 by hooah21200212-20-2011 9:20 PM

Re: How much energy is in empty space?
I happen to be a big fan of Feynman, but that does not mean I think he is infallible. There is another possibility of course... that Clarke has misunderstood Feynman or that Cano has misunderstood Clarke.

I linked the website because I thought other inquiring minds here might be interested in it. If you are not interested, don't read it.

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

 Replies to this message: Message 191 by hooah212002, posted 12-20-2011 11:51 PM designtheorist has taken no action

Percy
Member
Posts: 20770
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.1

 Message 186 of 404 (644814) 12-20-2011 9:36 PM Reply to: Message 183 by designtheorist12-20-2011 8:33 PM

Re: How much energy is in empty space?
I think Hooah is referring to the latex dBCode. For example, this:

$\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

Will produce this:

--Percy

 This message is a reply to: Message 183 by designtheorist, posted 12-20-2011 8:33 PM designtheorist has taken no action

designtheorist
Member (Idle past 3073 days)
Posts: 390
From: Irvine, CA, United States
Joined: 09-15-2011

 Message 187 of 404 (644815) 12-20-2011 9:40 PM

Some interesting papers on dark energy
I am not claiming to have digested these papers yet, but I thought others here might be interested in how they might inform our discussion.

http://arxiv.org/pdf/astro-ph/0207347

http://arxiv.org/pdf/hep-th/0603057

http://arxiv.org/PS_cache/astro-ph/pdf/0406/0406504v2.pdf

The first two papers are highly cited and provide some interesting background to the topic. The third is not highly cited; it simply proposes research but is interesting in its own way.

designtheorist
Member (Idle past 3073 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 NoNukes12-20-2011 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

NoNukes
Inactive Member

 Message 189 of 404 (644817) 12-20-2011 10:30 PM Reply to: Message 188 by designtheorist12-20-2011 10:00 PM

Re: A Simple Thought Experiment
 The simplest explanation for dark energy is the energy associated with the vacuum; it is mathematically equivalent 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.

What relevance do you think the comment has?

As I see it, the sentence simply suggests that one possible model for dark energy isn't working out to well. How is it helpful to reaching your conclusion regarding the net energy of the universe?

Edited by NoNukes, : No reason given.

 This message is a reply to: Message 188 by designtheorist, posted 12-20-2011 10:00 PM designtheorist has replied

 Replies to this message: Message 190 by designtheorist, posted 12-20-2011 11:50 PM NoNukes has replied

designtheorist
Member (Idle past 3073 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 NoNukes12-20-2011 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

 Replies to this message: Message 192 by NoNukes, posted 12-21-2011 12:10 AM designtheorist has taken no action Message 193 by Dr Adequate, posted 12-21-2011 3:53 AM designtheorist has taken no action

hooah212002
Member (Idle past 41 days)
Posts: 3193
Joined: 08-12-2009

 (1)
 Message 191 of 404 (644820) 12-20-2011 11:51 PM Reply to: Message 185 by designtheorist12-20-2011 9:36 PM

Re: How much energy is in empty space?
 If you are not interested, don't read it.

Since you seem to not have understood what I thought to be a fairly simplistic accusation, I'll put it in even simpler terms (I hope): you are attempting to re-write portions of physics and are disagreeing with some of the best and brightest physicists of our time and of time past. You are simply quoting bits and pieces and saying "I don't agree with this" or "this doesn't seem to be correct" and all the while you have yet to actually show your work. The models of cosmology you are dismissing have the maths to back them up and it would seem to me, a layperson to the extreme, that it would be wise of you to do the same in your attempted refutation. Now, don't take this as a hand wave away, because you very well could be on to something, but when proven members such as cavediver, son goku and NoNukes who have already shown their work, disagree with you, I am inclined to err on the side of caution and trust their judgment.

It's a simple request: show your work. This does not mean link to some papers and say that you "haven't had time to digest them", but use the code this site has and show your actual work. Unless, of course, my initial preconceived notion of your being just an IDer trying to bastardize science to garner proof for a designer is true and you've no intent on actually doing the science. I'll give you the benefit of the doubt for now, though.

Edited by hooah212002, : No reason given.

Put the FSM back in Chrifsmas

 This message is a reply to: Message 185 by designtheorist, posted 12-20-2011 9:36 PM designtheorist has taken no action

NoNukes
Inactive Member

 Message 192 of 404 (644822) 12-21-2011 12:10 AM Reply to: Message 190 by designtheorist12-20-2011 11:50 PM

Re: A Simple Thought Experiment
 designtheorist writes: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?

I think you are wrong about some things. But I think the cause of your peeving is not finding the support for your ideas that you expect to find.

For one thing, simply adding a cosmological constant doesn't have to lead to a static universe solution. The equations have many solutions. You are thinking of Einstein's Field Equations as though they were simple algebra rather than a set of inter-related differential equations. Some of the papers do talk about that a bit, but it might be helpful to at least look at Wikipedia before you wade into papers full of math that you aren't likely to be able to follow. I cannot follow all that much of the math.

We don't know all that much about dark matter. That much is true, but it is the attempt to model it as vacuum energy that has resulted in those discouraging calculations. The failure does not mean that gravitational theory is wrong.

Take a look at the summary in section 5.4 of the paper. I believe that gives the authors' assessment of the state of things known and unknown.

Edited by NoNukes, : No reason given.

 This message is a reply to: Message 190 by designtheorist, posted 12-20-2011 11:50 PM designtheorist has taken no action

Member (Idle past 291 days)
Posts: 16112
Joined: 07-20-2006

 (1)
 Message 193 of 404 (644832) 12-21-2011 3:53 AM Reply to: Message 190 by designtheorist12-20-2011 11:50 PM

Re: A Simple Thought Experiment
 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.

* sighs *

The cosmological constant has different effects depending on its value.

Einstein chose the value (c/√4πGρ)2 (where c is the speed of light, G is Newton's constant, and ρ is the energy density of the universe). This results in a static universe (although, as was later shown, an unstable one).

If you choose a different value for the cosmological constant you get a different universe with different properties.

The cosmological constant is not defined by what Einstein wanted it to do, but by the role it plays in the equations of GR.

 When you add these facts up, it seems ridiculous to me that people are still claiming we have a net zero energy universe.

Well that was a complete non sequitur, wasn't it? Your inability to understand the cosmological constant doesn't even relate to the energy of the universe.

 This message is a reply to: Message 190 by designtheorist, posted 12-20-2011 11:50 PM designtheorist has taken no action

 Replies to this message: Message 194 by cavediver, posted 12-21-2011 4:23 AM Dr Adequate has taken no action

cavediver
Member (Idle past 2883 days)
Posts: 4129
From: UK
Joined: 06-16-2005

 (1)
 Message 194 of 404 (644839) 12-21-2011 4:23 AM Reply to: Message 193 by Dr Adequate12-21-2011 3:53 AM

Re: A Simple Thought Experiment
 designtheorist writes: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.

 Dr Adequate writes:* sighs *The cosmological constant has different effects depending on its value......The cosmological constant is not defined by what Einstein wanted it to do, but by the role it plays in the equations of GR.

Thank you. The "peeves" comment had completely drained any enthusiasm whatsoever to continue replying to this nonsense. I'm glad that someone still has the stomach for it.

Edited by cavediver, : No reason given.

 This message is a reply to: Message 193 by Dr Adequate, posted 12-21-2011 3:53 AM Dr Adequate has taken no action

vimesey
Member
Posts: 1309
From: Birmingham, England
Joined: 09-21-2011
Member Rating: 2.6

 (12)
 Message 195 of 404 (644871) 12-21-2011 10:50 AM

Parable
One day, a man pushed his car into a mechanic's workshop, and told the mechanic that he couldn't get the car to start.

The man was intelligent and well educated, and knew that cars worked using an internal combustion engine, to ignite a mixture of petrol and air, driving pistons in the engine to turn an axle and then the wheels of the car.

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.

The man was worried about this, because although he had heard about a carburetor, he didn't fully understand what it did - and he had certainly never heard of a throttle valve. He was suspicious that the mechanic was trying to rip him off, because as far as he was concerned, the internal combustion engine simply mixed fuel and air, ignited them, drove pistons and turned an axle and wheels, and this didn't sound complicated. Certainly his understanding did not include carburetors and throttle valves.

The mechanic explained that he had been trained very well in the rather more complex intracacies of how an internal combustion engine worked, and had many years' experience in how they functioned and how they could be fixed.

But the man was an intelligent man, and told the mechanic that his explanation was wrong and that it must be the case that something was preventing the fuel and air mixing, igniting, driving the pistons and turning the axle and wheels.

The mechanic patiently explained that yes, this was the case, due to the cracked throttle valve in the carburetor, but because the man did not know what a throttle valve was (and had only an outline of an idea of what a carburetor was), he continued to believe that the mechanic was trying to rip him off, and insisted that the mechanic was wrong and that it must be the case that something was preventing the fuel and air mixing, igniting, driving the pistons and turning the axle and wheels.

This discussion continued for many fruitless hours, until eventually the mechanic gave up, and the man left the mechanic's workshop, satisfied that he had avoided being ripped off.

And the moral of this story ? The mechanic (and the rest of his intelligent customers, who knew very little of carburetors and throttle valves, but who trusted the mechanic that he did) drove away that evening and went to many interesting and entertaining places. The man and his car, though, remained stuck in the workshop, feeling happy that they hadn't been ripped off, but going nowhere.

 Replies to this message: Message 196 by Aware Wolf, posted 12-21-2011 2:36 PM vimesey has taken no action Message 197 by Larni, posted 12-21-2011 4:32 PM vimesey has taken no action Message 208 by designtheorist, posted 12-24-2011 7:58 AM vimesey has taken no action

 Date format: mm-dd-yyyy Timezone: ET (US)