Lambda-CDM theory - Woo or not?

[Skwinty]

Thank's Sol,
Your comments have been most helpful.
Back to reading for me.
Perhaps I should enrol in math night classes to help me sort the wheat from the chaff.

 

[sol invictus]

I'm not avoiding anything, unlike you and sol and DRD and others that have never once touched my two bomb "bang" analogy. To his credit at least Derek took a shot (that's why I like him by the way). You folks are just plain cowards IMO.

You mean this?

Imagine a universe composed of only two hydrogen bombs, and we put them together side by side. Yes, we can play math games with gravity and rubber bands and show how potential energy can be view as "negative" and we can play with the potential energy and kinetic energy and see how it all balances out just fine on paper. You might then think the whole thing has a "zero energy state". This however does *not* take into account the energy contained in the mass itself which we can demonstrate by setting off both bombs and releasing some of that energy. The mass itself contains energy and it can be converted to energy. The "gravity" then of the mass is simply an indicator of how much energy is contained in the mass, but it does not offset that energy when we set off the bombs. Nothing is going to counteract that energy release and bring it all back together again.

I'm not sure what you want us to say about it.

The last sentence is very odd - why would anything need to "bring it all back together again"? The stuff about not taking into account the energy in the mass is total nonsense, obviously. We're talking about gravity - of course it takes into account the energy in mass; total energy (including that in mass) is what gravitates. As for setting off the bombs, it's irrelevant. No one is saying there isn't (positive) energy in mass, which for example can be converted to kinetic energy of bomb fragments.

It just illustrates that you haven't understood the basics of this discussion, and so it's kind of hard to respond to. It's a non-sequitor.

 

[sol invictus]

Thank's Sol,
Your comments have been most helpful.
Back to reading for me.
Perhaps I should enrol in math night classes to help me sort the wheat from the chaff.

It's very, very hard for a layperson to distinguish good cutting-edge science from crackpot or wrong stuff at the time it's produced. That's why there are so many stories in the media about revolutionary breakthroughs that you read about... and then never hear of again

If you don't have a few years to wait, about the only way to distinguish is to ask an expert. Or read papers/books by scientists with real accomplishments - Nobel winners, profs at the major universities, etc. Even then be cautious (Linus Pauling comes to mind).

Actually relative youth is also a good sign - sometimes good scientists turn crankier as they age and lose touch with the field more and more. But it's very rare to find a young crackpot with an academic position - the competition is too fierce.

 

[Michael Mozina]

You mean this?
I'm not sure what you want us to say about it.

I want you to notice that your math has limits when it comes to the energy contained inside matter. I want you to recognize that energy is neither created or destroyed. I want you to recognize that whatever *caused* the bang, it was due to "positive kinetic energy". That much would be a good start.

The last sentence is very odd - why would anything need to "bring it all back together again"?

It means that the energy will remain in motion eternally and kinetic energy will exist in a positive state eternally from that point forward in time, and there was *never* a net 'zero' energy state.

The stuff about not taking into account the energy in the mass is total nonsense, obviously.

No, it seems to be the point you missed entirely. Gravity is simply a "pointer to" what can only be called "stable kinetic energy". All you math seems to utterly ignore all the energy inside the matter that makes up the universe.

How do you folks even explain a two (unexploded) bomb "acceleration" in a net zero energy universe? There are two *giant* holes in your conceptual understanding of energy and the kinetic energy inside matter specifically.

Your statements are utterly and completely false. We live inside a 'positive energy density universe". That energy was neither created nor destroyed. These two "facts" preclude your "zero net" energy baloney from having any merit whatsoever.

 

[Ziggurat]

No, it seems to be the point you missed entirely. Gravity is simply a "pointer to" what can only be called "stable kinetic energy".

What the hell are you talking about? Kinetic energy means energy associated with motion. That's why it's called kinetic energy. Gravitational potential is based upon position, not motion. That's why everyone else except you doesn't call it kinetic energy: it isn't kinetic energy.

How do you folks even explain a two (unexploded) bomb "acceleration" in a net zero energy universe?

Easy: you can still convert energy from one form to another. Nuclear potential energy can decrease for a nuclear bomb, and when it does, it increases kinetic energy. Thing go boom. The total energy never even enters into the question, only the difference, but you can get positive differences when working with positive or negative numbers.

There are two *giant* holes in your conceptual understanding of energy and the kinetic energy inside matter specifically.

Said the man who can't distinguish between kinetic energy and potential energy.

Tell me: suppose I have a potential between two bodies of the form U(r)=1/r. What's the force F(r) between them? What about if I have a potential of the form U(r)=-1/r, what then is F(r)? Can you figure it out? The math is quite simple, and if you manage to do it correctly, you'll see that the sign has rather obvious physical consequences. But I don't think you can do even simple differentiation. Can you prove me wrong?

 

[sol invictus]

I want you to notice that your math has limits when it comes to the energy contained inside matter.

Completely wrong - as I told you. Not only is that energy included, it could be the entire source of the gravitational field

I want you to recognize that energy is neither created or destroyed.

That's true, and I've said so repeatedly.

I want you to recognize that whatever *caused* the bang, it was due to "positive kinetic energy". That much would be a good start.

Nonsense.

It means that the energy will remain in motion eternally and kinetic energy will exist in a positive state eternally from that point forward in time, and there was *never* a net 'zero' energy state.

It means that if you ignore the gravitational contribution, yes.

No, it seems to be the point you missed entirely. Gravity is simply a "pointer to" what can only be called "stable kinetic energy".

Gibberish.

How do you folks even explain a two (unexploded) bomb "acceleration" in a net zero energy universe?

No idea what you're trying to ask. If you mean, how can a state with zero total energy explode - read the last 50 posts. The total energy is completely irrelevant (except in GR).

There are two *giant* holes in your conceptual understanding of energy and the kinetic energy inside matter specifically.

No, you just have no clue what these terms even mean.

 

[Dancing David]

Well, since I can't observe inside the event horizon, I don't know what the energy arrangement might look like inside that event horizon. It could be a flowing mass of Higgs particles for all I know. It could be that some "structure" is able to resist compression. I don't really know. I just have a hard time believing that there isn't a *physical* process involved that has a larger than zero diameter.

The Plank length is greater than zero.

 

[Dancing David]

Sure, but this isn't one of them.



The term "neutral" is a bit vague. Even a net "neutral" (in terms of math) universe would not accelerate.

I don't know.

How many things that cannot be demonstrated must I have faith in to believe in your theory?

A) inflation
B) net zero energy
C) expanding space
D) dark energy
E) non baryonic "dark matter"

Are there anymore skeletons in that closed that I should know about?

yes, i am a witch and a nihilist.

I'm not avoiding anything, unlike you and sol and DRD and others that have never once touched my two bomb "bang" analogy. To his credit at least Derek took a shot (that's why I like him by the way). You folks are just plain cowards IMO. When you can't handle something you turn your back and start running while hurling personal insults as you go. Step up to the plate and address my point now. We can begin with a *positive energy* scenario and create a *bang* from preexisting energy. It's easy to envision and it's easy to even demonstrate in a lab.

You are still avoiding what i said, until we can look past the universe it will be hard to answer.

Please now tell me how I might create a "bang" out of "zero net energy"? I don't suppose you can do that in lab?

I don't suppose you have a clue.

The bang is what Hoyle called it, and it stuck. I suppose he should explain it to you.

I have stated that it is what it is, a theory that explain what happened since ~10^-36, I would say that we have seen what appears to be the result of an expansion since that time, but as to a 'bang', more speculation and semantics, no way to currently look at the universe when it is before that point.

Could be positive, could be neutral, could be Burrito and Coyote.

So really, you can make a Universe in the lab?

Please do tell.

Please by all means start up with the name calling, it just makes you look silly.

 

[temporalillusion]

It demonstrates there is *energy* is this physical universe.

No one has said there isn't energy in the universe, no wonder you get frustrated, arguing with points no one is making.

What's mind boggling is you missing the point willfully or otherwise.

You didn't respond do my rewording of your argument, you just carried on as if I'd said nothing.

You said "Stand in the sunshine. Did gravity take away the heat from the sun from you?".

So in your mind, what you think people are saying here is that because gravity is negative energy, it should take away the heat of the sun somehow.

So in your mind negative energy from gravity will somehow take heat away from the sun. Which means in your mind, positive energy from gravity will ADD heat to the sun.

And that's nonsense, which is why I said your statement doesn't make any sense.

 

[Tim Thompson]

Singularity

I think the resistance to the idea is notion of *infinite* density at a *point*. I don't have a problem with the idea of a massive object with an event horizon, but I have to admit to being skeptical about the notion of infinite density.

The notion of infinite density at a point comes from "popular" level expositions and is certainly not a proper interpretation of general relativity, so you have little to fear there. There is a big difference between ...

(A) The limit of 1/x as x approaches zero is infinity

and

(B) The value of 1/0 is infinity

The former is correct, the latter is not. The singularity is one of those 1/0 places, and that quantity is not infinity, it is undefined, which means that general relativity has nothing at all to say about what happens at that point. That's why I have said before that general relativity fails at the singularity. A quantum theory of gravity, or a quantized version of general relativity, is needed to get rid of the singularity and determine what really happens at the singular point.

 

[Skwinty]

A quantum theory of gravity, or a quantized version of general relativity, is needed to get rid of the singularity and determine what really happens at the singular point.

Is Quantum Theory of Gravity considered to be a field theory. Wiki gives that impression, but lacks citations.

Also, as I asked before, please comment on what can be asserted about the actual density/volume of blackholes and what Baryshev asserts about "Natural limits of contraction" vis a vis his math.

In my laymans understanding, they both seem to say the same thing.

Thanks

 

[Reality Check]

Is Quantum Theory of Gravity considered to be a field theory. Wiki gives that impression, but lacks citations.

Also, as I asked before, please comment on what can be asserted about the actual density/volume of blackholes and what Baryshev asserts about "Natural limits of contraction" vis a vis his math.

In my laymans understanding, they both seem to say the same thing.

Thanks

I think that I can answer this: They are not the same thing.
Baryshev asserts that black holes do not exist and so they have no "actual density/volume". He does state a maximum radius for any massive body so you can work out the density for yourself.
His math is correct - but his theory is not really stated (see sol invictus's previous posting).

GR asserts and observations confirm that black holes exist. The actual density/volume of the mass in a black hole is classically infinite, i.e. a singularity. There is no known force that can prevent the singularity from forming but scientists suspect that there may be new physics at the Planck length. This might prevent an actual singularity from forming but just makes the density enormous, e.g. Sag A* would be 4.3 million solar masses in a volume of radius 1.6 × 10^-33 centimeters.

 

[Skwinty]

His math is correct - but his theory is not really stated (see sol invictus's previous posting).

Yes, I did read Sol's post. On re-reading the paper, the abstract starts with "A retrospective analysis of the field theory of gravitation, describing the gravitational field in the same way as other fields of matter in the flat space-time is done". So, is this really a "Baryshev theory" and should he have included the math for the entire theory?

GR asserts and observations confirm that black holes exist. The actual density/volume of the mass in a black hole is classically infinite, i.e. a singularity. ......, e.g. Sag A* would be 4.3 million solar masses in a volume of radius 1.6 × 10^-33 centimeters.

Tim Thompson said this in a previous post
"The singularity is one of those 1/0 places, and that quantity is not infinity, it is undefined, which means that general relativity has nothing at all to say about what happens at that point. That's why I have said before that general relativity fails at the singularity. A quantum theory of gravity, or a quantized version of general relativity, is needed to get rid of the singularity and determine what really happens at the singular point. "

Now, I dont dispute the existence of black holes, but the notion of infinite density in essentially zero volume is a deal breaker.

Now, in the quantum theory of gravity, the carrier is the hypothetical graviton. How does this not fall into a field theory of gravitation, given that quantum field theory describes all known physical interactions.

Thanks for your input, perhaps you can clarify my aging thought processes.

ETA> I also interpret the fact that the field theory of gravity specifically omits blackholes to get rid of the infinities and complex math.
Just a thought, I can't say for sure.

 

[sol invictus]

Yes, I did read Sol's post. On re-reading the paper, the abstract starts with "A retrospective analysis of the field theory of gravitation, describing the gravitational field in the same way as other fields of matter in the flat space-time is done". So, is this really a "Baryshev theory" and should he have included the math for the entire theory?

Yes, as far as I can tell. But I didn't have time to read the whole thing carefully - maybe it's in there somewhere.

Now, I dont dispute the existence of black holes, but the notion of infinite density in essentially zero volume is a deal breaker.

To amplify Tim's point, GR breaks down at the singularity. And in truth it breaks down before you get there, because everything we know about the world tells us there are corrections to GR that become much more important than GR itself when the density is very high. So really we can only trust GR down to some short distance from the would-be singularity, and not beyond. It's a lot like the big bang that way.

Now, in the quantum theory of gravity, the carrier is the hypothetical graviton. How does this not fall into a field theory of gravitation, given that quantum field theory describes all known physical interactions.

"How can A not be B given that A is B?"

QFT does not describe all known physical interactions - it does not describe gravity.

As I said, many, many attempts have been made to find a QFT for GR, and all have failed. That doesn't prove it's impossible, I suppose. But the evidence is pretty strong - and then there is string theory, which is not a field theory in any remotely conventional sense, but is a theory of quantized GR.

 

[Michael Mozina]

The Plank length is greater than zero.

True. I guess I'm just not convinced I can even be sure it's a "plank length" in size rather than say a large condensate of excited Higgs. I don't really know what might be inside the event horizon.

 

[Skwinty]

not[/I] describe all known physical interactions - it does not describe gravity..

Thanks Sol, I should have said that QFT is a theoretical background for describing physical interactions (not all). Gravity should be described with the other interactions and perhaps that is the objective of such a theory.

 

[Michael Mozina]

I don't know.

I don't know how you intend to explain acceleration with zero net energy. Even in an arbitrary zero setting exercise, acceleration requires energy.

yes, i am a witch and a nihilist.

You're funny. At least I know you have some redeeming qualities.

You are still avoiding what i said, until we can look past the universe it will be hard to answer.

That's why I'm not really into the "prophetic" method of cosmology. We can however demonstrate a "bang' today with a *positive energy density* from start to finish.

Could be positive, could be neutral, could be Burrito and Coyote.

The term "neutral" doesn't mean anything. There is a positive amount of available energy in the universe today. I have no evidence that there has ever been a time when that was not true.

So really, you can make a Universe in the lab?

I can simulate a "bang" in lab using "positive" energy. How would you simulate a "bang" with "zero net" or "neutral" energy? How would you explain acceleration on top of that 'Bang" using zero net energy? Even the "bang" part is going to be impossible to simulate with 'zero net' energy, let alone the acceleration component. Even in you mathematical examples, it takes energy to separate two objects and make them accelerate.

 

[sol invictus]

I don't know how you intend to explain acceleration with zero net energy. Even in an arbitrary zero setting exercise, acceleration requires energy.

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

Acceleration requires a change in energy - it depends on the gradient of the potential. In Newtonian dynamics it makes no difference whatsoever what the value of the total energy is - in fact that number is completely meaningless and unmeasurable.

This is literally high school physics - it's in every high school physics textbook.

You've ignored all the physical explanations given to you. You've ignored all the math we've shown you. You've failed utterly to answer any of the questions we've asked you that clarify your confusion. You've ignored all the references and links you've been given that show gravitational potential energy is negative. What's wrong with you? Just admit you were wrong and learn something.

 

[Michael Mozina]

No one has said there isn't energy in the universe, no wonder you get frustrated, arguing with points no one is making.

Well, you're making an argument that is equally false. There is no "net zero" involved in a "positive energy density universe". Whereas a simple "bang" is easy enough to simulate using positive net energy, how did you folks intend to simulate a zero net energy "bang" exactly? How did you intend to explain an *acceleration* component with zero net energy?

You didn't respond do my rewording of your argument, you just carried on as if I'd said nothing.

You said "Stand in the sunshine. Did gravity take away the heat from the sun from you?".

So in your mind, what you think people are saying here is that because gravity is negative energy, it should take away the heat of the sun somehow.

What does "gravity is negative energy" mean to you? In my two bomb analogy, yes, gravity would tend to make them attractive to one another, but in no way does it indicated the entire energy state of the whole thing is "net zero". Where and how did you cancel out the energy from the sun?

So in your mind negative energy from gravity will somehow take heat away from the sun. Which means in your mind, positive energy from gravity will ADD heat to the sun.

And that's nonsense, which is why I said your statement doesn't make any sense.

Your statement that gravity is "negative energy" is what makes no sense. Yes, you can use a minus sign in a gravity oriented equation, but in no way does that make gravity a form of 'negative energy'. Even the distance between two objects would not make the energy state more "negative". Suppose I put space between the two bombs as a "given condition"? All that would do is add *potential energy* to the system as a function of their gravitational attraction to one another. It would in no way lessen the amount of total energy. In fact mere distance would result in *more total energy* in the system. Gravity is not "negative energy". It could be seen as a form of "potential energy". It all depends on your frame of reference.

 

[Dancing David]

I don't know how you intend to explain acceleration with zero net energy. Even in an arbitrary zero setting exercise, acceleration requires energy.



You're funny. At least I know you have some redeeming qualities.



That's why I'm not really into the "prophetic" method of cosmology. We can however demonstrate a "bang' today with a *positive energy density* from start to finish.

Sure but what has that got to do with starting a universe.?

There are somethings where our current models break down.

The 'Big Bang' is a label applied by Hoyle in derision and it has stuck.

For many reasons it could have a better name, but that is the one that stuck.

The label 'the expanding space time universe' just does not stick.

So how are you modeling the expanding space time with an explosion?

The term "neutral" doesn't mean anything. There is a positive amount of available energy in the universe today. I have no evidence that there has ever been a time when that was not true.

Sure, but there is something different about gravity. And really, you can show that the universe is positive with energy. Okay.

I can simulate a "bang" in lab using "positive" energy. How would you simulate a "bang" with "zero net" or "neutral" energy? How would you explain acceleration on top of that 'Bang" using zero net energy? Even the "bang" part is going to be impossible to simulate with 'zero net' energy, let alone the acceleration component. Even in you mathematical examples, it takes energy to separate two objects and make them accelerate.

Again, I think that a 'bang' is a label that does not explain much, catchy though it may be.

It sure looks as though space time is expanding.

Maybe is , maybe isn't.