Lambda-CDM theory - Woo or not?

[Michael Mozina]

No, it doesn't! How many times do you need this explained to you?

You are *outrageous* in the statements you make. Let's see you jump off Earth, and accelerate away without *energy*.

Two objects will accelerate towards each other under the influence of gravity because their gravitational potential energy becomes more and more negative as they approach each other.

No. Two objects at some distance from each other have a positive *potential energy* that can be converted into *kinetic energy*. On the other hand, in my two bomb analogy, if there is *zero* distance between the two bombs, then there is no potential energy between them as a result of gravity. Distance can be equated with *potential energy*, but even without potential energy between them, there is potential energy inside each bomb that can be converted to kinetic energy again. Gravity won't cancel out the energy from the bombs. There is no point where a zero energy state exists in the bomb analogy. There is a constant *positive energy density* between them. Even space between the bombs as an experimental given only *adds* to the total energy of the system.

Acceleration requires a change in energy - it depends on the gradient of the potential.

The potential energy is positive in any distance between those two bombs. That positive potential energy will be converted to positive kinetic energy by the time they hit one another. Assuming the distance is small, it may not have much total effect. If the distance is great enough, perhaps it could liberate the energy inside each of the bombs! There is no "negative energy". There is *Potential energy* and *kinetic energy*, but gravity is not a "negative energy" that "cancels out" all the energy of the rest of the system.

You've ignored all the physical explanations given to you.

Your "explanations" were wrong. No "negative" energy is turned into kinetic energy. All we have is *potential energy* being turned into *kinetic energy* and that's it. You're so lost in your math that you can't see the forest for the trees!

You've ignored all the math we've shown you.

That is because you math is inapplicable to describing the *total system energy* and it is completely dependent upon an arbitrary frame of reference! You keep ignoring the key issue!

Just admit you were wrong and learn something.

I'll be happy to do that as soon as you demonstrate your claim. Show me how you achieve a "bang" from a "zero net energy" experiment. Show me how you achieve acceleration in "zero net energy" experiment.

I gave you one example of a *non accelerating* "bang", but even that requires *net positive energy*.

You folks are so fixated a mathematical equation that you forget to do your lab work to verify any of your claims. You will *not* achieve a "bang" from a "zero net energy" experiment in a lab.

 

[sol invictus]

I'll be happy to do that as soon as you demonstrate your claim.

So all those textbooks are wrong.... you'd better stop wasting your time on this forum, MM - you have a lot of letters to write to textbook publishers. Think of all those millions of kids being taught wrong physics!!

 

[Michael Mozina]

So all those textbooks are wrong....

Any that claim that there is "zero net energy" in the universe are most certainly wrong. Frankly I would assume that would only apply to *Lambda* oriented textbooks, and that was the whole point of my thread. Duh!

 

[sol invictus]

Any that claim that there is "zero net energy" in the universe are most certainly wrong. Frankly I would assume that would only apply to *Lambda* oriented textbooks, and that was the whole point of my thread. Duh!

Let's focus on the high school-level Newtonian dynamics you have so completely wrong, shall we? Care to comment on why all these references - which say gravitational potential energy is negative - are wrong?

30 seconds of googling results in this,, this, and this.

 

[Skwinty]

Positive Gravitational Energy.

Here's a paper titled "A Positive Gravitational Energy Test Application.
I have not read it yet, it's on my reading list, so I cannot comment.
Probably a wise decision.
Others may gain some insight however.


http://adsabs.harvard.edu/abs/1998ASPC..151..148N

 

[sol invictus]

Here's a paper titled "A Positive Gravitational Energy Test Application.
I have not read it yet, it's on my reading list, so I cannot comment.
Probably a wise decision.
Others may gain some insight however.

That paper is about a somewhat different different issue. As I've said repeatedly, one can define a non-zero energy in GR as minus the boundary terms for any region, and that reproduces +mc^2 for an isolated mass in an otherwise flat space. It's very much like defining the electric charge in a region as minus the "boundary charge" (the charge the boundary sphere has, given the total of all the electric flux lines that "end" on it).

In a closed universe (like an expanding closed cosmology) the boundary terms vanish (because there is no boundary) and therefore the total energy is always zero.

It's true that in asymptotically flat spaces, if the energy (defined using those boundary terms) can be negative, you have a problem. You'd have negative mass - repulsive gravity - and the theory would be unstable (and no - a cosmological constant is not an example of that). That's what that paper is about.

 

[Perpetual Student]

Any that claim that there is "zero net energy" in the universe are most certainly wrong. Frankly I would assume that would only apply to *Lambda* oriented textbooks, and that was the whole point of my thread. Duh!

I am curious about something. Established physics is based on a consensus of views of thousands of physicists throughout the world. These views have been painstakingly developed by brilliant people from Aristotle, Galileo, Newton, Plank, Einstein, etc. up to the present. These physicists are very smart people who have quite extensive training. Since you are challenging established physics, what exactly are your credentials? What is your training? I believe this is a fair question from a layman who is following this discussion.

 

[Skwinty]

It's true that in asymptotically flat spaces, if the energy (defined using those boundary terms) can be negative, you have a problem. You'd have negative mass - repulsive gravity - and the theory would be unstable (and no - a cosmological constant is not an example of that). That's what that paper is about.

Thanks, I will bear that in mind when I read the paper.

 

[Ziggurat]

Perpetual Student: it's possible he's had formal training, but just never understood it. Furthermore, given his penchant for blaming those with credentials for being part of a conspiracy, he's likely to see your challenge as confirmation of his unjustified victimhood.

Michael: I don't care about your credentials, but I do care that you are woefully ignorant, and you have yet to demonstrate the ability to do any math. If I have a force F(r)=1/r², what is the potential U(r)? Any first year physics student should be able to provide an answer. It's really a very simple calculation. Can you do it? I think you can't. I think your math skills and physics comprehension are so bad that you don't even know how one would go about answering that question. Can you prove me wrong?

 

[Michael Mozina]

Let's focus on the high school-level Newtonian dynamics you have so completely wrong, shall we? Care to comment on why all these references - which say gravitational potential energy is negative - are wrong?

It is entirely *reasonable* to treat gravity as a negative potential energy depending on the scenario in question and the mathematical model you're using. There's nothing wrong with seeing potential energy as being negative or positive for purposes of a mathematical formula. There is no problem with those textbooks because they are not claiming the net energy of the universe is *zero*!

The sign for potential energy is irrelevant for most mathematical purposes. We can launch spacecraft into orbit this way just fine. When we get to cosmology theories however, it has a distinct and direct impact on your personal belief about the universe having "zero net" energy. That is absolutely false. The potential energy can be seen as negative *or* positive depending on the frame of reference! Because the frame of reference is critical, you can't simply wave your hand, and ignore the physics!

In the two bomb analogy, any "distance" between the two objects will be converted into *positive* kinetic energy. If we set off the bombs, the energy release will be eternally traveling away from the blast and there is a constant net *positive* energy in the system.

How did you intend to get a "bang' in a lab from "zero net" energy? How did you intend to explain "acceleration" in a "zero net' energy environment?

 

[Michael Mozina]

I am curious about something. Established physics is based on a consensus of views of thousands of physicists throughout the world. These views have been painstakingly developed by brilliant people from Aristotle, Galileo, Newton, Plank, Einstein, etc. up to the present. These physicists are very smart people who have quite extensive training. Since you are challenging established physics, what exactly are your credentials? What is your training? I believe this is a fair question from a layman who is following this discussion.

No, wait minute. I'm not challenging any physics textbooks other than those that happen to claim we live in a "net zero" energy universe. That would likely only be found in a cosmology textbook. If you recall I agreed with you early on that we can set an *arbitrary* zero point and treat potential energy as negative for purposes of experimentation and such. There is nothing wrong with treating potential energy as negative, *unless* we're talking about the *total energy of everything*. Then we have some "physics" that must also be considered beyond a simple math formula related to launching spacecraft, or simple experiments. I'm not questioning "physics" as a whole, just their (Lambda proponents) understanding of "physics" as it relates to the net energy of the universe. This is a *very specific* issue, unrelated to 99.999999% of physics in general.

 

[Ziggurat]

If you recall I agreed with you early on that we can set an *arbitrary* zero point and treat potential energy as negative for purposes of experimentation and such.

If the zero point for potential energy is arbitrary, then the zero point for total energy is likewise arbitrary.

There is nothing wrong with treating potential energy as negative, *unless* we're talking about the *total energy of everything*.

If it matters what the absolute value of total energy is, then it MUST matter what the absolute value of potential energy is. You CANNOT have one without the other. But you have conceeded it does not matter what the absolute value of potential energy is. You have contradicted yourself once again.

Then we have some "physics" that must also be considered beyond a simple math formula related to launching spacecraft, or simple experiments.

Physics which apparently cannot be formulated in any mathematical statement, and whose rules only you seem to be aware of.

I'm not questioning "physics" as a whole

Yes you are, your grasp of physics is just so bad you don't even realize it.

just their (Lambda proponents) understanding of "physics" as it relates to the net energy of the universe.

Except that (once again) this has nothing to do with inflation or Lambda theory.

 

[Perpetual Student]

No, wait minute. I'm not challenging any physics textbooks other than those that happen to claim we live in a "net zero" energy universe. That would likely only be found in a cosmology textbook. If you recall I agreed with you early on that we can set an *arbitrary* zero point and treat potential energy as negative for purposes of experimentation and such. There is nothing wrong with treating potential energy as negative, *unless* we're talking about the *total energy of everything*. Then we have some "physics" that must also be considered beyond a simple math formula related to launching spacecraft, or simple experiments. I'm not questioning "physics" as a whole, just their (Lambda proponents) understanding of "physics" as it relates to the net energy of the universe. This is a *very specific* issue, unrelated to 99.999999% of physics in general.

Yes, you have challenged basic physics. Here is one example: After reviewing some sources, it appears universally held that gravity is treated as negative energy, which you have strenuously challenged.

 

[Perpetual Student]

MM:
So, what are your credentials in this debate? As a layman trying to follow all this, it's a fair question.

 

[DSo]

MM is using his two bomb analogy as the reason for believing that the total energy density of the universe must be positive.

Is it a fair question to ask how at time zero, there were two bombs and only two bombs in the universe? Bombs are highly ordered states of matter, pieces of precision engineering. The universe we live in does not remotely resemble this situation.

Just a layman here, but I have a nagging suspicion that arguments from the perspective of thermodynamics means that this analogy is not appropriate for a discussion about the total energy density of the universe we live in.

Like I said, I’m just a curious layman following this thread so, ahem, bombs away ….

 

[Michael Mozina]

MM:
So, what are your credentials in this debate? As a layman trying to follow all this, it's a fair question.

Exactly what type of "credentials" do I need to see a physical empirical idea demonstrated in real life in an empirical experimental setting?

I think it's rather ironic and rather revealing that the word you chose: "layman" originally had a religious overtone. The idea is that one needed to be a "cleric" to understand the "faith' properly. The irony here is that this whole Lambda-inflation-free-lunch belief system is also based on "leaps of faith", several of them in fact. The reason my "credentials" seem to be required now is due to the fact that none of these claims can be empirically demonstrated, and therefore the conversation turns to me instead of the claims within the theory.

Inflation? Evidently no one can or ever will demonstrate it. It will forever be an act of "pure faith".

Dark Energy? Nobody knows what it is, but they absolutely postively *certain* that is has no net energy and yet it somehow accelerates a whole universe. Neat stuff! Where do I get some? Oh ya, nobody knows.....

Expansion of space? It never happens here on Earth, only in their "religion".

Zero net energy in the universe? Well, only if you *ignore* all the energy contained in mass, light, etc and pay no attention whatsoever to kinetic energy or the sunshine on your face.

Dark Matter? I hear the non baryonic variety is quite tasty in the springtime. Supposedly the universe has many times more of this stuff than the dirt in my backyard, but the whole lot of astronomers on the planet can't produce a single gram of the stuff in a real "experiment".

Now of course I would obviously understand this 'faith' so much better if I'd only taken more Calculus courses in college. FYI I did take several of them by the way but my real love was software. Alas I will forever be a "layman" as well, forever unable to "see the light" only because I "lack faith" in metaphysical mumbo jumbo wrapped up in endless math.

I think the only way I'll overcome this view and turn the attention where it belongs is to take apart Guth's original inflation paper and point out his errors. I've got programming to finish up tonight and at work tomorrow, but when I get time, I'll start with Guth's monopole killing inflation mythology paper and point out the errors.

Note that I offered you a legitimate physical way to explain an expanding physical universe based on "positive energy density" from start to finish, where potential energy is simply turned into kinetic energy. Do you really think that any of these guys/gals will demonstrate an expanding matter scenario from a "vacuum" here on Earth? Honestly? They can't even make a single atom go "poof" in a vacuum today. What makes you think they'll get a whole universe to go "poof" out of a vacuum, ever? Guth does not understand the nature of a vacuum or the kinetic energy inside of a "non-vacuum". That's where all this trouble began.

I think the only way I will overcome this view as a "layman" is to simply take apart Guth's original paper, idea by idea and show how it falls apart in terms of kinetic energy and conservation laws of energy. Stay tuned.

 

[Michael Mozina]

MM is using his two bomb analogy as the reason for believing that the total energy density of the universe must be positive.

Actually I just demonstrated that an expanding material universe *can be* created from a positive energy scenario. Let's see the "net zero" folks do that now with "zero net energy".

Is it a fair question to ask how at time zero, there were two bombs and only two bombs in the universe? Bombs are highly ordered states of matter, pieces of precision engineering. The universe we live in does not remotely resemble this situation.

It wouldn't resemble a highly ordered state after the explosion however.

Just a layman here, but I have a nagging suspicion that arguments from the perspective of thermodynamics means that this analogy is not appropriate for a discussion about the total energy density of the universe we live in.

Hmm. The universe we live in is full of moving particles of kinetic energy. My analogy ends up with an "expansion" of material objects. Granted they would be small objects, but it would result in expansion of objects of matter. I'd like to see that done now from "net zero' energy.

 

[Michael Mozina]

Yes, you have challenged basic physics. Here is one example: After reviewing some sources, it appears universally held that gravity is treated as negative energy, which you have strenuously challenged.

I didn't challenge the idea you could *treat* gravity that way, but consider something for a moment. Gravity is simply a *curvature*, not a "force" in GR, so how can it be a "negative energy"? It clearly does take energy to launch a rocket into space, but the whole thing is a "net positive" release of "net energy", and that potential energy of the rocket in orbit is simply turned back into ordinary kinetic energy. If our universe was a clumped together bit of mass, you might be able to claim it has a "zero net" energy. Since it's expanding *and accelerating*, that isn't possible.

 

[Ziggurat]

Gravity is simply a *curvature*, not a "force" in GR, so how can it be a "negative energy"?

Changes in curvature produce work. Therefore, there is potential energy associated with that curvature. Since you get positive work when curvature increases, curvature must carry negative potential energy, because more curvature is a lower potential energy state. Just as it does in standard treatments of Newtonian mechanics, gravity carries negative potential energy. I note that you still haven't calculated those potentials I challenged you to. Seems like I was right: you can't do any math.

It clearly does take energy to launch a rocket into space

-5 + 3 = -2. Wow: who'da thought I could add a positive number to a negative number and still get a negative number. Clearly, I must have made a math error somewhere.

 

[tusenfem]

Expansion of space? It never happens here on Earth, only in their "religion".

Wow, and even Alfvén states that the universe is expanding in his book "Worlds and Antiworlds". Are you saying that Alfvén made a mistake?!?!?!