Lambda-CDM theory - Woo or not?

[GeeMack]

Not necessarily, but the acceleration process would need to be nearly constant and nearly universal in scope. It would need to operate like the solar wind, but we wouldn't necessarily need to be in the center IMO.

So you say the acceleration process would need to be nearly constant and nearly universal in scope, and it would need to operate like the solar wind, which isn't nearly constant nor nearly universal in scope. Come on, Michael. You can't possibly be that stupid, can you? You're pulling our legs, right?

 

[edd]

It has to be nearly universal in scope... In fact it has to be so universal it needs to act on photons. What kind of EM field or mechanism based upon one does so without causing too much scattering?

 

[temporalillusion]

Not necessarily, but the acceleration process would need to be nearly constant and nearly universal in scope

Then it can't be a mass/EM attraction.

 

[Michael Mozina]

When spacetime stretches, it's literally the space itself that is expanding, not that matterwithin it.

That's one of those "claims" that fails to materialize in the lab. In the lab it takes "force' to generate acceleration of *OBJECTS*, and "space" never expands on it's own. The "space between objects" can increase since objects in motion will stay in motion, but in the lab, all "acceleration" requires force/curvature and it affects "objects", not "space.

The matter itself is being dragged along.

How would you go about demonstrating that in a lab? What kind of force/energy works on the 'space" between objects?

The fabric of "spacetime" can "expand" as the objects of mass that makeup spacetime expand and grow further apart over time. That's simply a function of objects in motion staying in motion. Acceleration however happens to "objects"., not "space".

 

[Tubbythin]

That's one of those "claims" that fails to materialize in the lab.

So what, the size of the lab is << size of universe.

In the lab it takes "force' to generate acceleration of *OBJECTS*, and and "space" never expands on it's own. The "space between objects" to increase since objects in motion will stay in motion, but in the lab, all "acceleration" requires force/curvature.

Pardon?

How would you go about demonstrating that in a lab? What kind of force/energy works on the 'space" between objects?

Why would we want do demonstrate it in a lab. We have a whole Universe out there to demonstrate general relativity.

The fabric of "spacetime" can "expand" as the objects of mass that makeup spacetime expand and grow further apart over time. That's simply a function of objects in motion staying in motion. Acceleration however happens to "objects"., not "space".

Pardon?

 

[GeeMack]

That's one of those "claims" that fails to materialize in the lab. In the lab it takes "force' to generate acceleration of *OBJECTS*, and "space" never expands on it's own. The "space between objects" can increase since objects in motion will stay in motion, but in the lab, all "acceleration" requires force/curvature and it affects "objects", not "space.

[...]

The fabric of "spacetime" can "expand" as the objects of mass that makeup spacetime expand and grow further apart over time. That's simply a function of objects in motion staying in motion. Acceleration however happens to "objects"., not "space".

The above gibberish is further support for my contention that Michael doesn't have the qualifications of an average English speaking ten year old to communicate sanely or intelligently on the subject of science.

 

[Mister Earl]

That's one of those "claims" that fails to materialize in the lab. In the lab it takes "force' to generate acceleration of *OBJECTS*, and "space" never expands on it's own. The "space between objects" can increase since objects in motion will stay in motion, but in the lab, all "acceleration" requires force/curvature and it affects "objects", not "space.

Sure it does. Space itself is stretched like taffy while flowing down into a black hole. That's why any light emitted by infalling matter can't pass through the event horizon; That's the boundary where space is flowing in quicker than the light can travel through it.

How would you go about demonstrating that in a lab? What kind of force/energy works on the 'space" between objects?

Gravity for one. It can bend or stretch the space between them. The sun already does this.

The fabric of "spacetime" can "expand" as the objects of mass that makeup spacetime expand and grow further apart over time. That's simply a function of objects in motion staying in motion. Acceleration however happens to "objects"., not "space".

I think that wouldn't explain our cosmological horizon, though. At (I think) 14.7B years out space is getting stretched away from us fast enough to where they recede from us at superluminal speeds, creating an effective "horizon". Anything that goes through that relative "horizon" to us is effectively lost forever. For all intents and purposes, it's out of the universe. If space were stretching subluminally and things were just accelerating, they wouldn't achieve superluminal speeds.

Again, I'm a layman, so I may or likely made errors in the above.

 

[Ziggurat]

Man the mental gymnastics are intense. You're claiming that the EM field produces negative pressure, and also claiming you can rule out the EM field because it does *NOT* produce negative pressure. Which is it?

No, Michael. Pay attention: the Casimir effect is a negative pressure which gets smaller when the separation distance is increased. On cosmological scales, it doesn't matter, not because it can't be negative, but because it's too bloody small.

The thing is, you're not even doing mental gymnastics here: you're just repeating the same lie about what we've said. No mental flexibility on your part at all.

You don't know how any form of acceleration works at cosmic scales.

Not so. General relativity gives pretty good answers to that question. If you want to claim general relativity is wrong, go ahead, but that's what your ideas require. And that position is... unsupported by any experiments on earth.

In fact you don't even know how solar wind works.

I know it's not being pulled outwards by a spherically symmetric charge distribution. Shell theorem, Michael. Once again, you refuse to learn even when knowledge is spoon-fed to you.

 

[tusenfem]

Birkeland believed that all suns were "cathodes in space". If that is true, they might have the effect of "pushing" each other apart, but the further apart they got, the weaker the acceleration would become.

As usual you are wrong again, when talking about Birkeland or plasmas or suns or whatevers. It was Sidney Chapman's (discarded) model that had only one charge coming from the Sun. In the case of Birkeland, the old Norse mentioned:

From a physical point of view it is most probable that solar rays are neither exclusively negative nor positive rays, but of both kinds“

Source: Kristian Birkeland, "Are the Solar Corpuscular Rays that penetrate the Earth's Atmosphere Negative or Positive Rays?" in Videnskapsselskapets Skrifter, I Mat -- Naturv. Klasse No.1, Christiania, 1916.

And as cathodes will only emit negative charges, either Birkeland was stupid, or Mozina is misinterpreting Christian.


Kewl, just gave a presentation today "Aurora and the Earth's Magnetotai: From Birkeland to THEMIS" at Graz in Space "summer university."

 

[Michael Mozina]

Sure it does. Space itself is stretched like taffy while flowing down into a black hole.

Actually GR describes events in "spacetime", not "space". "Space" is physically undefined in GR. It's the objects in spacetime that generate the effect you're describing. Note also that your taffy analogy is also another example of an "external" force that stretches the "atoms" apart as a result of that external force (your hands/black hole). In all such analogies (rope,taffy,ect), the force has an effect on the OBJECTS, not the space between them.

Gravity for one. It can bend or stretch the space between them. The sun already does this.

It bends the "spacetime" around the *OBJECT*, but all acceleration happens to "objects", not 'space". What force do you know that acts on "space" in the lab? Again, I"m not talking about spacetime or material objects, just "space" (whatever you mean by that).

I think that wouldn't explain our cosmological horizon, though. At (I think) 14.7B years out space is getting stretched away from us fast enough to where they recede from us at superluminal speeds, creating an effective "horizon". Anything that goes through that relative "horizon" to us is effectively lost forever. For all intents and purposes, it's out of the universe. If space were stretching subluminally and things were just accelerating, they wouldn't achieve superluminal speeds.

Well, it all depends. Is that observation an effect of superluminal speed, or just time dilation?

http://arxiv.org/abs/0911.3536

Again, I'm a layman, so I may or likely made errors in the above.

Don't sweat it. They are all "pros" and they make errors all the time, and of course I make a few as well.

 

[Mister Earl]

Actually GR describes events in "spacetime", not "space". "Space" is physically undefined in GR. It's the objects in spacetime that generate the effect you're describing. Note also that your taffy analogy is also another example of an "external" force that stretches the "atoms" apart as a result of that external force (your hands). In all such analogies (rope,taffy,ect), the force has an effect on the OBJECTS, not the space between them.

I blame my analogy. Ok, let's try it again. Long piece of taffy. You stick little pieces of gravel along the length of the taffy. Pull the taffy at both ends. The taffy is space/time stretching/expanding, and the stones move apart even though their velocity hasn't changed relative to the taffy they're stuck to.

It bends the "spacetime" around the *OBJECT*, but all acceleration happens to "objects", not 'space". What force do you know that acts on "space" in the lab? Again, I"m not talking about spacetime or material objects, just "space" (whatever you mean by that).

Then why are galaxies receding from us at faster rates without any other force accounting for the acceleration? Where is the energy coming from?

Well, it all depends. Is that observation an effect of superluminal speed, or just time dilation?

That's a question for the professionals here. I don't see why time wouldn't be affected as well, if spacetime itself is stretching.

Don't sweat it. They are all "pros" and they make errors all the time, and of course I make a few as well.

I'm a layman in science. I care nothing for being correct all the time. I wouldn't learn that way.

 

[edd]

Expanding space is sometimes discussed at perverse length as to how correct the analogy is. Perverse as people don't disagree what physical results GR gives whether you consider space expanding or not.
It's not so useful to think of space flowing into a black hole though, and the horizon you mention with regards to 'superluminal' expansion isn't at that point.

 

[Michael Mozina]

No, Michael. Pay attention: the Casimir effect is a negative pressure which gets smaller when the separation distance is increased.

So you're saying that the EM field *CAN* generate "negative pressure"? It's just a "scaling" issue we're talking about?

On cosmological scales, it doesn't matter, not because it can't be negative, but because it's too bloody small.

So crank it up! The Casimir effect won't do it perhaps, but if you need to generate a larger EM field all you need is electricity, some charge and some external mass.

The thing is, you're not even doing mental gymnastics here: you're just repeating the same lie about what we've said. No mental flexibility on your part at all.

Oh baloney. You were claiming earlier that the EM field *COULD NOT* be "dark energy" because it couldn't generate negative pressure. Now you're telling me it *CAN* do exactly that, you simply have to scale it appropriately and modify it appropriately in terms how the EM field is created.

Not so. General relativity gives pretty good answers to that question. If you want to claim general relativity is wrong, go ahead, but that's what your ideas require. And that position is... unsupported by any experiments on earth.

Since GR is in no way dependent upon "dark energy", "inflation" or mythical forms of matter, your claim is moot. Since you can't accomplish your feat without your invisible friends being stuffed in there, your point is moot.

I know it's not being pulled outwards by a spherically symmetric charge distribution. Shell theorem, Michael. Once again, you refuse to learn even when knowledge is spoon-fed to you.

I guess you'll need to try a larger spoon? Care to elaborate? I'm not trying to use the Casimir effect to explain acceleration, I'm just using it as an example of an EM field generating an "acceleration".

 

[Michael Mozina]

I blame my analogy. Ok, let's try it again. Long piece of taffy. You stick little pieces of gravel along the length of the taffy. Pull the taffy at both ends. The taffy is space/time stretching/expanding, and the stones move apart even though their velocity hasn't changed relative to the taffy they're stuck to.

Actually I really *LIKE* (and actually agree with) your analogies just fine, but they don't work quite the way you imagine. You're always still "pulling" from the ends of the taffy, and the taffy is composed of physical objects/atoms (like a plasma). The atoms in your taffy are moving further apart. the gravel (heavier objects) don't 'stretch' as easily, but they "ride the atoms" in the taffy. IMO that is *EXACTLY* what's happening in space too. The plasma between the objects is being accelerated by an external force (like your fingers) and the space between the gravely objects expands accordingly.

Your analogies are all great, and all demonstrate what they describe alright, but the force is external and it works on the objects. The space between heavier objects changes over time as the space between the lighter objects (atoms in the taffy or plasma IMO) accelerate over time.

The only thing you have to change in your analogy to get to my perspective is change those pebbles of gravel to planets and suns and use plasma instead of taffy. In all other respects your position and mine are exactly alike, starting with that external force you apply with your hands.

 

[Mister Earl]

Actually I really *LIKE* (and actually agree with) your analogies just fine, but they don't work quite the way you imagine. You're always still "pulling" form the ends of the taffy, and the taffy is composed of physical objects (like a plasma).

I pull from the ends since there's no way of pulling on every bit of the taffy at once with only two hands. And the taffy isn't matter, it's the space the matter exists in.

The atoms in your taffy are moving further apart. the gravel (heavier objects) don't 'stretch' as easily, but they "ride the atoms" in the taffy. IMO that is *EXACTLY* what's happening in space too. The plasma between the objects is being accelerated by an external force (like your fingers) and the space between the gravely objects expands accordingly.

Wouldn't there be more of this plasma close to the sun where we are, than in intergalactic space? And if the rare amount of plasma out there is moving entire galactic clusters, why hasn't the Earth been burned to a crisp and fired out of orbit as ludicrous speeds?

Your analogies are all great, and all demonstrate what they describe alright, but the force is external and it works on the objects. The space between heavier objects changes over time as the space between the lighter objects (atoms in the taffy or plasma IMO) accelerate over time.

Why would expanding spacetime only affect some objects? A conveyor belt moves thin people at the same speed it does heavy people.

The only thing you have to change in your analogy to get to my perspective is change those pebbles of gravel to planets and suns and use plasma instead of taffy. In all other respects your position and mine are exactly alike, starting with that external force you apply with your hands.

I don't see how plasma could be moving galactic clusters while the Earth, which should be bathing in it, is left unscathed and still in orbit.

 

[Michael Mozina]

I pull from the ends since there's no way of pulling on every bit of the taffy at once with only two hands. And the taffy isn't matter, it's the space the matter exists in.

FYI, it's a little bit different in plasma. If you managed to create an external EM field, it could have an effect on all the charged particles at once.

Wouldn't there be more of this plasma close to the sun where we are, than in intergalactic space?

In terms of density per cubic kilometer, there is more plasma closer to the suns that further away. It's a distance issue. When you look at the distances between objects in space, the distances are vast. Over such distances, even a light plasma dispersed uniformly will contain more overall mass than the sun. In terms of density per cubic meter however, the atmosphere immediately near the sun is more dense than interstellar space.

And if the rare amount of plasma out there is moving entire galactic clusters, why hasn't the Earth been burned to a crisp and fired out of orbit as ludicrous speeds?

Instead it's been "heated just right". It's a "goldilocks" issue in the final analysis. The overall energy simply sustains the system, it doesn't "fry" it.

Why would expanding spacetime only affect some objects? A conveyor belt moves thin people at the same speed it does heavy people.

It has to affect all the objects or it wouldn't describe the events we observe. As far as we know *all* of spacetime is expanding, not just parts of it.

I don't see how plasma could be moving galactic clusters while the Earth, which should be bathing in it, is left unscathed and still in orbit.

The sun and earth "follow along" in the gravitational wake of the moving mass of the plasmas of interstellar and intergalactic space. The overall bulk of the mass of the universe is not found in the stars, but found in the mass between them. All you need to do is move the mass between them and the stars will follow along. It's easier to move the plasmas just as it is easier to "stretch" your taffy in your analogy. Your analogy actually rocks.

Out in intergalactic space, all you really have to "accelerate' are the charged particles and dusty plasmas. It's much easier to accelerate a single proton or charged helium ion with an Em field than it is to accelerate an entire planet. If you accelerate 10 times the mass of the stars in the form of protons and such, the stars will be attracted to the rest of the mass body. It's ultimately not any different than your analogies, and there's nothing wrong with your analogies, that's exactly how it works. It all starts with an external force.

 

[Mister Earl]

I don't see it working. Why should supermassive galaxy clusters be affected at all by vacuum-thin plasmas in interstellar space? The gravity between the clusters should utterly dominate any forces such meek materials could muster.

 

[Michael Mozina]

I don't see it working. Why should supermassive galaxy clusters be affected at all by vacuum-thin plasmas in interstellar space? The gravity between the clusters should utterly dominate any forces such meek materials could muster.

Keep in mind that the plasmas between the clusters also experiences acceleration, and again, there are vast distances between galaxies. It's still a distance issue.

 

[Ziggurat]

So you're saying that the EM field *CAN* generate "negative pressure"? It's just a "scaling" issue we're talking about?

By George, he might actually have it!

So crank it up! The Casimir effect won't do it perhaps, but if you need to generate a larger EM field all you need is electricity, some charge and some external mass.

I spoke too soon. What you're suggesting is no longer the Casimir effect. Once again, Michael: virtual photons don't behave the same way real photons behave. Real photons always produce positive pressure.

Oh baloney. You were claiming earlier that the EM field *COULD NOT* be "dark energy" because it couldn't generate negative pressure.

Nope. Sol said photons couldn't generate negative pressure. Everybody and their mother understood this to mean real photons, and real photons cannot produce negative pressures. But real photons don't cause the Casimir effect, so your imagined conflict doesn't exist.

you simply have to scale it appropriately and modify it appropriately in terms how the EM field is created.

Except that this is impossible to do that. If you try to crank up the field, well, it's no longer the vacuum field, which is what produces the Casimir effect.

I guess you'll need to try a larger spoon? Care to elaborate?

The observed acceleration is spherically symmetric. Therefore, the source driving it must be spherically symmetric as well. You posit that this source is external to the observable universe, meaning that it must form a shell around our observable universe. But for both electromagnetism and gravity, a spherically symmetric shell source has no effect inside the shell. Which means that if the observed acceleration is driven by something outside the observable universe, it's NOT acting through gravity or electromagnetism. So your alternative requires not only a source which we can't observe, but a force which is completely unknown.

What would you like to name your new force, Michael? And when can we expect to see it in a lab?

I'm not trying to use the Casimir effect to explain acceleration

I know that, Michael.

 

[Mister Earl]

I remember reading something once (and bear with my here, my memory can be horrible at times) about the theoretical model of the 11-dimensional universe. It stated something along the lines of "The reason gravity is so weak is because it's actually being generated from / bleeding into another dimension within the 4 that we can directly observe." Couldn't something like that account for dark energy as well? If gravity is the localized warping of spacetime due to mass, couldn't dark energy be kind of a polar opposite of gravity? Interacting with the universe non-locally (everywhere at once) and instead of contracting and bending space, it's speeding up and/or causing inflation? There's a neat symmetry to it, if you kind of squint at it and hop on one foot.