Lambda-CDM theory - Woo or not?

[Tubbythin]

I doubt it. No vacuum contains "negative pressure" or negative kinetic energy.

I can't recall one person on this forum has ever claimed a vacuum contains negative kinetic energy. I challenge you to find a single instance of this or to retract that statement.

Ya, and I've explained to you 50 times that a vacuum cannot and does not contain negative kinetic energy or negative pressure too, but you refuse to deal with that fact.

The negative pressure claim is not a fact. There is nothing to refute. You were wrong. Moreover you nicely illustrated that you don't even know what pressure is.

 

[Michael Mozina]

It's funny how you can see your side of this and not the other.

You happily linked to a paper about a plasma-redshift phenomenon that's unobservable in 20th-c Earth labs. You happily linked to a paper about f(R) gravity, a long-range modification of GR with no "cause" and with consequences observable in 20th-c Earth labs. Oh well.

(In other words, you don't actually have an "empirical physics" criterion, you just think it's a handy contrarian cudgel to swing at mainstream theories you dislike.)

Er, no. You missed the point entirely evidently. I don't particularly care for EITHER theory, nor am I emotionally attached to either theory. I'm just pointing out that even based on your own criteria for judging various theories, your theory isn't even unique in it's ability to offer solutions, and that one requires no 'dark evil sky energies' at all!

At the same time, in this world where 19th-century-classical-physicists like Birkeland discovered the only physics you claim to trust: when it comes time to actually figure out how cosmic baryons and photons behave---are there long range forces between stars? Do stars get caught up in a "plasma flow" in the galaxy? Do photons undergo a non-scattering redshift in diffuse plasmas? Does hot, current-carrying neon plasma get into a weird, cold, transparent state? Well, in those cases suddenly you ignore classical physics, or refuse to calculate it, or refuse to listen to calculations. Oh well.

On the contrary. I've listened to you. I've even agreed with some of your criticisms of early EU efforts to explain the same data. I PERSONALLY prefer a time dilation sort of explanation rather than "space expansion' sort of explanation, but that's just my preference.

(In other words, you don't actually have respect for empirical physics. You just have mainstream theories you dislike and will ignore any physics you need to in order to continue disliking them.)

No ben, you missed the point entirely. I was attracted to Birkeland's work because *IT WORKS IN THE LAB*. It's not just a pie in the sky theory about the sun and how it work, it's a WORKING DEMONSTRATION of key solar features, like solar wind acceleration of BOTH types of particles, "jets", loops, all the stuff he created in the lab that we now see in satellite imagery. My preference is for TESTED METHODS that WORK IN THE LAB. You folks are pretty much oblivious to what works or does not work in the lab. You could care less that you've never linked MR theory to neutron capture signatures or gamma rays. To you it's just "maths", not PHYSICS.

 

[Michael Mozina]

I can't recall one person on this forum has ever claimed a vacuum contains negative kinetic energy. I challenge you to find a single instance of this or to retract that statement.

This is why I say that you folks just "don't get it'. In order for you to even achieve a "ZERO" pressure from a vacuum, you would need to remove every form of kinetic energy from the chamber, including photons, neutrinos, etc. It's a physical impossibility of course, but that is what you would have to do to bring the "pressure' of a 'vacuum" to pure zero. The only way you could ever achieve 'negative pressure' from a "vacuum" is to get the vacuum to contain "negative kinetic energy" and that is a physical impossibility. You folks just "don't get it" even after all these discussions on kinetic energy and the fact that photons are the carrier particle of the EM field.

The negative pressure claim is not a fact. There is nothing to refute. You were wrong. Moreover you nicely illustrated that you don't even know what pressure is.

Guth's *ENTIRE* premise about expansion was based on his ASSUMPTION that the vacuum contained negative pressure. Baloney! You folks fall apart at the level of particle physics and kinetic energy. You just don't get it.

 

[Tubbythin]

Er, no. You missed the point entirely evidently. I don't particularly care for EITHER theory, nor am I emotionally attached to either theory. I'm just pointing out that even based on your own criteria for judging various theories, your theory isn't even unique in it's ability to offer solutions, and that one requires no 'dark evil sky energies' at all!

Once again you choose to use a ridiculous phrase rather than make a scientific argument. I can't believe you actually think it helps you make a point. It makes you look like a fool who is incapable of making a scientific argument and must resort to childish insults. Pathetic.

 

[Tubbythin]

This is why I say that you folks just "don't get it'. In order for you to even achieve a "ZERO" pressure from a vacuum, you would need to remove every form of kinetic energy from the chamber, including photons, neutrinos, etc.

No you don't. You need a negative pressure that has a larger magnitude than any positive pressures.

It's a physical impossibility of course, but that is what you would have to do to bring the "pressure' of a 'vacuum" to pure zero.

Nope. Wrong.

The only way you could ever achieve 'negative pressure' from a "vacuum" is to get the vacuum to contain "negative kinetic energy" and that is a physical impossibility.

No you don't. What you actually need is for the derivative of energy with respect to volume to be positive. Nothing to do with negative kinetic whatsoever.

You folks just "don't get it" even after all these discussions on kinetic energy and the fact that photons are the carrier particle of the EM field.

Nope. You don't get it. If -dE/dV is negative then pressure is negative.

Guth's *ENTIRE* premise about expansion was based on his ASSUMPTION that the vacuum contained negative pressure. Baloney! You folks fall apart at the level of particle physics and kinetic energy. You just don't get it.

Nope. You can repeat it as many times as you like. Pressure still = -dE/dV Michael. You can moan about particle physics and kinetic energy all you want. It doesn't change the fact that pressure is defined as -dE/dV not in terms of particles or kinetic energy.

 

[DeiRenDopa]

FYI ben,

I used the contact page of Ari's website today to send him a link to your original complaint (post), and a nice message that was intended to solicit his feedback about your criticism.

http://www.internationalskeptics.com/forums/showpost.php?p=7393481&postcount=4593

Does that post sufficiently explain your criticism or is the something else I should add?

Let's see now ...

No word from MM on this, so:
a) MM did not, in fact, send an email
b) MM sent an email, but Ari did not reply
c) Ari replied, but MM has been too busy with his O (50) 'repeat' of a handful of his fave bits of nonsense/illogic/Mozphysics*
d) Ari replied, but MM canna make head nor tail of the reply (i.e. it contains math(s), not just ordinary words)
e) Ari replied, but MM realized, upon understanding the gist of the reply, that ben m was correct (and MM woz rong)
f) ...

* O is shorthand for of the order of n; repeat as in 'wash, lather, rinse, repeat'

 

[ben m]

On the topic of pressure, Michael is still stuck in a vague mental picture of particles "dark" particles bouncing around the vacuum and "pushing" on things, and this pushing represents a pressure, which is of course positive. Dark energy's "pressure" has nothing to do with anything pushing on stars and galaxies; it only has to do with fact that spacetime responds to energy densities, and if there were a fluid with negative pressure it would have to have an energy density, and spacetime's response to that energy would have the same sign as its response to dark energy.

Remember, Michael, that these terms were all coined by working GR experts. They were coined by people for whom the substitution "p = -dE/dV" is so obvious as to not need explaining. The terminology was not coined to be transparent to random plasma-cosmology aficionados. Too bad this has hung you up for so long.

 

[Michael Mozina]

Let's see now ...

No word from MM on this, so:
a) MM did not, in fact, send an email
b) MM sent an email, but Ari did not reply

b) would in fact be the correct answer. Why don't you folks try contacting yourself this time with a more detailed explanation of your criticism and see what happens? I'm actually quite curious to hear his answer.

 

[Michael Mozina]

Once again you choose to use a ridiculous phrase rather than make a scientific argument. I can't believe you actually think it helps you make a point. It makes you look like a fool who is incapable of making a scientific argument and must resort to childish insults. Pathetic.

Fine. That's probably a valid criticism actually. Care to address the point this time without the term "evil' in there? Why choose one solution over another?

 

[Michael Mozina]

No you don't. You need a negative pressure that has a larger magnitude than any positive pressures.

You aren't going to get that from a "vacuum". You tried to get that from a SECOND PLATE in the Casimir experiments you cited to support your nonsense.

No you don't. What you actually need is for the derivative of energy with respect to volume to be positive. Nothing to do with negative kinetic whatsoever.

You folks REALLY don't grasp the nature of a vacuum, mostly because you don't seem to know much at all about subatomic physics. It's like suddenly the whole universe becomes "math only" from your perspective and you ignore the mass speed limit implications related to the particle kinetic energy contained in the vacuum. You folks REALLY don't get it.

*IF* (and only if) you had ANOTHER OBJECT or more stuff to work with OTHER THAN your 'vacuum', your argument might have merit. In other words if you used charge attraction, or external gravity to another object to PULL from the outside, your theory might have merit. You're trying to get a VACUUM to PULL on your mass blob thingy, but a vacuum is PHYSICALLY incapable of doing that!

Nope. You don't get it. If -dE/dV is negative then pressure is negative.

You can't get a -dE/dV out of a "vacuum" without changing the volume of the vacuum.

 

[ben m]

your theory isn't even unique in it's ability to offer solutions, and that one requires no 'dark evil sky energies' at all!

Agreed. So what's all the baloney about scientists "ignoring" alternatives, or dark energy being "unfalsifiable", and all this?

They're all hypotheses. Dark energy and the CC are formally indistinguishable. Quintessence is close but may be resolved separately soon. f(R) gravity is an ugly fit, but it probably can fit. These are still-valid hypotheses. We don't know which one is true, or if a yet-unthought-of hypothesis is better than any of them. We're working on that.

The giant void is, IIRC, now ruled out. This is a recently-valid hypothesis.

Grey dust is ruled out. "plasma redshift" is ruled out. Halton Arp's weirdness, whatever it was, is ruled out. Alfven-Klein is ruled out. Every "plasma cosmology" hypothesis I've ever seen has been ruled out. In other words, every attempt to explain the data using "laboratory physics" (baryons, plasmas, tired light) has produced nonsense.

The Universe is doing what it is observed to be doing; however it's doing it, it's not doing it using ordinary baryonic physics. Get used to it.

 

[Michael Mozina]

On the topic of pressure, Michael is still stuck in a vague mental picture of particles "dark" particles bouncing around the vacuum and "pushing" on things, and this pushing represents a pressure, which is of course positive.

Ding, ding, ding.

Dark energy's "pressure" has nothing to do with anything pushing on stars and galaxies; it only has to do with fact that spacetime responds to energy densities, and if there were a fluid with negative pressure it would have to have an energy density, and spacetime's response to that energy would have the same sign as its response to dark energy.

If you think you can explain that process with MHD theory in place of that constant, be my guest. Just don't tell me "magnetic reconnection did it". I'd buy the "expanding fluid dynamic" idea a whole lot faster than "expanding magical vacuum".

Remember, Michael, that these terms were all coined by working GR experts. They were coined by people for whom the substitution "p = -dE/dV" is so obvious as to not need explaining. The terminology was not coined to be transparent to random plasma-cosmology aficionados. Too bad this has hung you up for so long.

Too bad you can't demonstrate that "negative pressure from a vacuum" claim in the lab. But oh ya, you can't even tell me where "dark energy" comes from, let alone how to "control" it, so what else should I expect, right?

 

[Tubbythin]

You aren't going to get that from a "vacuum".

Why not?

You tried to get that from a SECOND PLATE in the Casimir experiments you cited to support your nonsense.

Huh? Which plate is the first and which is the second?

You folks REALLY don't grasp the nature of a vacuum, mostly because you don't seem to know much at all about subatomic physics.

Ok. Since your an expert why don't you give us the lowdown?

It's like suddenly the whole universe becomes "math only" from your perspective and you ignore the mass speed limit implications related to the particle kinetic energy contained in the vacuum. You folks REALLY don't get it.

What mass speed limit implications? What particle kinetic energy contained in the vacuum. How would you relate this to the definition of pressure P=-dE/dV?

*IF* (and only if) you had ANOTHER OBJECT or more stuff to work with OTHER THAN your 'vacuum', your argument might have merit. In other words if you used charge attraction, or external gravity to another object to PULL from the outside, your theory might have merit. You're trying to get a VACUUM to PULL on your mass blob thingy, but a vacuum is PHYSICALLY incapable of doing that!

No I'm not. I'm suggesting that for a vacuum dE/dV is positive.

You can't get a -dE/dV out of a "vacuum" without changing the volume of the vacuum.

And what happens if you increase the size of the vacuum?

 

[ben m]

Too bad you can't demonstrate that "negative pressure from a vacuum" claim in the lab. But oh ya, you can't even tell me where "dark energy" comes from, let alone how to "control" it, so what else should I expect, right?

Does anyone claim, erroneously, to "know" where dark energy comes from?

No. They hypothesize. I know you have trouble with this word. It's tiresome.

 

[Tubbythin]

Too bad you can't demonstrate that "negative pressure from a vacuum" claim in the lab.

Erm. Casimir effect anyone?

 

[Michael Mozina]

Why not?

Because it is physically incapable of holding a -E!

Huh? Which plate is the first and which is the second?

It doesn't matter with is 1 and which is 2. You only have *1* mass blob thingy object in a vacuum to work with, not two.

Ok. Since your an expert why don't you give us the lowdown?

I've done that already a bunch of times. How did you intend to hold negative kinetic energy (-E) in the vacuum? What would you even add or subtract from a "perfect" vacuum to hold 'negative pressure/kinetic energy'?

What mass speed limit implications? What particle kinetic energy contained in the vacuum. How would you relate this to the definition of pressure P=-dE/dV?

I relate to it having a constant positive amount of kinetic energy. How do you relate to it with billion upon billions of neutrinos flowing through it?

No I'm not. I'm suggesting that for a vacuum dE/dV is positive.

If your claims worked, you should be able to create a vacuum that holds negative pressure. You've only shown me TWO PLATE experiments where the EM field is clearly "attracting" the two plates. Guth's mythical vacuum contains no second plates. It has NO THING (not a single thing) to work with other than positive kinetic energy that will constantly push INTO, not pull away from his mass blob thingy.

And what happens if you increase the size of the vacuum?

You'll need to add solid pistons and chambers to the outside of our universe. Are you prepared to do that?

 

[Michael Mozina]

Erm. Casimir effect anyone?

Er let's see you do it without a second plate anyone? Guth didn't have a second plate to work with, and the vacuum pressure never goes below zero in a Casimir experiment.

 

[DSo]

Erm. Casimir effect anyone?

Darn it! I awoke from my coma in 2010. Or is it 2009?

Stupid Neutrinos messing with the space-time continuum!

 

[Michael Mozina]

Darn it! I awoke from my coma in 2010. Or is it 2009?

Stupid Neutrinos messing with the space-time continuum!

FYI, believe it or not, I have very little problem with the notion of neutrinos traveling faster than photons. However, after reading Tim's last post on that thread, I'm skeptical that will turn out to hold up over time.

 

[Reality Check]

Er let's see you do it without a second plate anyone? Guth didn't have a second plate to work with, and the vacuum pressure never goes below zero in a Casimir experiment.

Er let's see you display your ignorance once again.
The Casimir effect is an example of negative pressure. Negative pressure occurs in other ways, e.g. a non-zero cosmological constant in GR (look - no metal plates !)

There is no 'vacuum pressure' in a Casimir experiment except that trivial fact that they are done in a vacuum chamber so that the gas pressure can be reduced. No one with any brains expects the gas pressure to go below zero.
What is actually measured in Casimir experiments is an negative net pressure, i.e. the repulsive forces exerted by any remaining gas molecules are much smaller than the attractive forces exerted by the vacuum fluctuations.
P.S. You probably remain ignorant of the fact that attractive forces by definition means a negative pressure.