Lambda-CDM theory - Woo or not?

[DeiRenDopa]

Since then it's been clearly established that you do, indeed, have "a very different view of what modern cosmology, as a science, is than almost everyone else who has posted to this thread"

I am an empiricist. I don't practice any branch of science in a "special" way. You're the one that wants to be give cosmology theories a free pass as it relates to empirical support of concept. I see no logical reason to do that.

Thanks again for taking the time to answer my questions, especially with the challenges of your family and work.

It's good to read these words, because there are few - if any - among the posters to this thread who would say otherwise about themselves ("I am an empiricist. I don't practice any branch of science in a "special" way.").

The confusion, to me at least, comes when I try to match what I understand by 'empirical' with your usage.

And it seems I am not alone ... ben m wrote this not long after you wrote the post I am quoting:

Inflation is a hypothesis. It's a good hypothesis in the opinion of most physicists, and a bad hypothesis in the opinion of a small number of people.

With inflation, we do exactly what we're supposed to do with hypotheses: make predictions and try to verify or falsify them using all available means. Your distinction between "controlled" and "uncontrolled" experiments is stupid and useless---you invented it yourself, and you redefine it on the fly such that "science you like" comes out on the good side and "science you don't like" comes out on the bad side.

There is no actual scientific-method objection to the fact that inflation is a hypothesis, nor to the observational model-testing apparatus that appears to confirm it. Nor would there be any objection to a non-inflation hypothesis which also passed such tests. (Not that you have suggested one.)

Great!

That's about as neat a summary of what an empiricist does (if said person is doing cosmology); namely, formulate hypotheses that are capable of being tested by observation or experiment.

The way you use the term 'empirical' seems to be quite special ... you demand that hypotheses are not only capable of being tested, but that actually be tested, and that the only valid tests are experiments. And so, in cosmology, where you recognise that you cannot perform experiments 'in the lab' on a blob of neutrons of mass ~10^30 kg, say, you demand that hypotheses be capable of being tested by observation and experiment.

(I'll get onto 'controlled experimentation' later)

I'm not alone in my skepticism of mainstream theory.

Indeed, that is most certainly true.

However, you are the only one expressing any such scepticism in this thread.

So the main thing that is still being discussed, in this thread, is how and why you, MM, regard modern cosmology (or at least LCDM models) as scientific woo.

It's "woo" because you can't 'predict' anything useful in a controlled experiment based on your belief in A) inflation, B)Dark energy C)Dark matter.

Help me out here, please.

Why "belief"?

The three things you list are not "beliefs", in the normal sense of the word, at least not how that word is customarily used in discussions of science.

What are they, then?

They are shorthands, for hypotheses, or (perhaps) something in models.

As such, they are no different than lots and lots of terms you find in modern astrophysics literature, for example 'cooling flow', 'wet merger', 'downsizing'.

There's something for me to celebrate in this part of your post, however: a criterion for how to determine if something is scientific woo, in the MM view of cosmology (namely, an inability to "'predict' anything useful in a controlled experiment based on" the concept/hypothesis in question)!

This is quite meaty, and I'd like to come back to it again later; in particular, I'd like to go into some detail on each of the three, in terms of this criterion.

Now there are many ways to go about answering that question (or set of questions); I've chosen a particular approach that involves first understanding the scope of what you regard as cosmology (and you've been most forthcoming on that topic, thanks), then determining what criteria you use to assess acceptability, within that scope.

This is one of those infamous red herrings. My personal beliefs are irrelevant. Can you empirically demonstrate inflation for us today? Yes or no? The answer is of course "no", and according to you folks, it can *never* be empirically demonstrated so it is a pure act of faith.

Why then should I believe in inflation? Lots of people come up with "woo" and proclaim it to be science. How is your inflation theory any more useful at predicting anything in a controlled experiment than say numerology or astrology?

We seem to have a break-down of communication ...

I don't know how you managed to derive something concerning "[m]y personal beliefs" from "understanding the scope of what you regard as cosmology [and] determining what criteria you use to assess acceptability, within that scope" - can you enlighten me please? Ditto re "pure act of faith".

I'm sorry to read that you think I'm "attacking" you; may I assure you that I'm not, and ask that you point me to the posts where you think I was (so I can modify my future posts so as to avoid giving you this perception)?

You have absolutely no particular reason to focus on any individual or any individual's personal beliefs.

Huh?

An individual, most certainly; you are the only one, in this thread, trying to make a case that LCDM cosmology is scientific woo; indeed, you are the OP!

An individual's personal beliefs? Most certainly not ... as I noted (immediately above), we seem to have a disconnect ... you have read something into some of my words that were neither intended to be there, nor were there (as far as my words would normally be understood in discussions on topics like this, and in this particular section of the JREF Forum).

Can you empirically demonstrate inflation isn't a figment of your imagination, yes or no?

Most easily ... in an earlier post I referenced a recent paper on WMAP results, the abstract of which includes a reference to "inflation": "We constrain the physics of inflation via Gaussianity, adiabaticity, the power spectrum shape, gravitational waves, and spatial curvature."

So, clearly, and empirically, a demonstration that it isn't a figment of my imagination.

My opinions are irrelevant to this answer. If you asked me can I empirically demonstrate that gravity and EM fields exist in nature I would have no trouble demonstrating these things exist in nature in a controlled experiment, regardless of what opinions you might have on these subjects.

Ah, thank you again!

A light bulb just went off!!

OK, I will ask you: "Can you, MM, empirically demonstrate that gravity and EM fields exist in nature, in a controlled experiment, regardless of what opinions I, DRD, might have on these subjects?"

I assume that your answer will be a resounding "Yes, I can".

With that answer in hand, I will proceed to find out how.

EU theory is therefore a form of pure empirical physics, and its core tenets show up in real experiments.

You've used this term, "EU theory", several times before ...

... and I've asked you about it (but you've yet to answer).

In which paper(s) may one read definitive presentations of this?

And why "therefore"?

If you believe Lambda-CMD theory to be superior, how so?

Well, no, I can't ...

... for the simple reason that I do not know what "EU theory" is.

Perhaps, when I do know, I may be able to demonstrate the superiority of LCDM cosmological models, by applying the standard criteria used in modern cosmology (the science).

You can't demonstrate any of your "fudge factors" are real or exist in nature, so why should I go on and on about my own beliefs, when it's your beliefs that cannot be demonstrated?

I think we're getting away from science here, and into philosophy ...

DD's recent post is quite good in this regard; in any case, this post of mine is already too long.

The core tenets of EU/PC theory are easy to demonstrate.

I look forward to having you reference them, so I may go read them for myself.

Do they, perchance, have anything to do with "Plasma Cosmology"?

What's the problem with your theory and why should I give it a free pass as it relates to empirical support? Empirical support has nothing to do with the beliefs of Michael Mozina. It's not personal.

Indeed.

 

[Michael Mozina]

As you have been told over and over, yes.

Then do so. I can easily demonstrate EM fields exist in nature and they show up in controlled experiments. Show me physical empirical evidence that inflation exists outside of your head before you start pointing at the sky!

The theory can and does successfully predict the outcome of literally thousands of experiments every day.

Which might those be? Do you even understand the difference between actual "hard science" with real "hardware" and real control mechanisms, and "subjective interpretation"?

Every observation made by each of the tens of telescopes and other astro instruments around the globe and in orbit.

These are pure observations tell you *nothing* about the actual existence of magic elves, invisible unicorns or inflation faeries. If your inflation faeries don't do anything here on Earth, why do you figure they do something "out there somewhere"?

 

[Michael Mozina]

You skipped step 3 entirely!

3. Use of the hypothesis to predict the existence of other phenomena, or to predict quantitatively the results of new observations.

You didn't predict anything new! You used the observation of redshift, and observed background radiation to work out your math, and then you used the same observations to support your case! You could have done exactly the same thing with "magic invisible elf" math! In order for this theory to be useful you actually have to *predict* something *new* with your theory.

Let me give you an example of how this is supposed to work from EU/PC theory. Birkeland believed that the aurora were caused by electrical current. He worked out some math of course, but he didn't stop there. He built actual *experiments* with real "control mechanisms" and tested his ideas in a lab. During his "experiments" he ended up observing and writing about other phenomenon that were generated during his experiments and were likely to show up in space as a result of his theories. He wrote about and simulated solar wind from the sun. He wrote about and predicted coronal loops. He wrote about and predicted solar jets. He wrote about planetary rings. He realized that all of these things were likely to come into play in the solar system just as they came into play in the lab.

These are actual "predictions" that were 'new' and not simply math formulas related to auroral events. Instead he predicted *new* observations, observations that would take 60 something years to finally demonstrate via satellite.

It's possible to 'predict' something new from an EM field "experiment" because EM fields actually show up in real experiments. Compare and contrast that now with inflation, which evidently doesn't exist anymore (assuming it ever did in the first place), so it's physically impossible to verify your claim that inflation did anything to anything else, ever. It's a pure act of faith and the only thing that supports it are the math formulas you created from your original observations, and you simply ignore the observations that don't jive with your postdictions. Never mind the "dark flows" and holes in the universe that you never correctly "predicted", somehow the universe is still homogeneously distributed anyway? Come on. The whole thing in one big circular feedback loop, held together by pure denial.

 

[DeiRenDopa]

http://arxiv.org/abs/0812.1970

Checkout this paper.

Let me be clear it is the fact that they cannot demonstrate that DE has any affect on anything that I criticize. I'm sure they can whip up what they call "evidence" from a "point at the sky with a math formula in hand" exercise, but I'd like to see a proof of concept first. In other words they can use EM fields to explain acceleration if they like because I can be sure EM fields exist in nature. In fact I have even seen a pretty good DE theory that does away with DE altogether in favor of EM fields, making Lambda-CMD theory a hybrid EU/+ magic inflation theory.

Um, ... er, ...

I think you may have misunderstood the paper somewhat, MM ...

... or perhaps "dark energy" (or both).

You see, one meaning of the term "dark energy" is as a shorthand, to capture the idea that there are a bunch of observations (millions, actually) that are consistent with a single parameter in CDM cosmological models and/or the Hubble relationship ... an empirical term, if you will.

Further, based on what you've written in this thread and others in this section of the JREF Forum, I'd be astonished if you could walk us all through this paper's "EM fields" section without making huge mistakes or getting angry about 'magnetic reconnection' (or both).

In any case, if "EU theory" is anything like what you defined plasma cosmology to be, in another thread, then it should be quite easy to show that what's in this paper and "EU theory" are fundamentally incompatible (or inconsistent, if you prefer). One more reason for me to look forward to your answers to my questions here:

First, I really, really would like you to clarify what the distinctions are between "EU theory", "EU/PC theory", and your version of Plasma Cosmology. As far as I can tell, reading your recent posts, you use them interchangeably (and so they are synonyms, at least as far as their relevance to cosmology is concerned), but I am far from sure of this conclusion.

 

[sol invictus]

dp

 

[Perpetual Student]

MM:
I have been an enthusiast of science all my (somewhat long) life. Having some mathematics background has provided me with some of the language of science so I have been able to muddle through scientific literature of many kinds over the years. I have never been happy with the seemingly mystical direction taken by modern cosmology, with a big bang, acceleration, DE, DM, etc. So, I continue to hope that more discoveries will make the universe more "intuitive."
However, after following this debate for quite a while now, here is my view of things.
First, astronomers notice an anomaly in distant type 1a supernovae observations. The data appear to indicate the expansion of the universe is accelerating. DE is hypothesized. Wow, that seems so weird!
Now that theory predicts other phenomena like a certain clustering of galaxies. That is observed. So, we have a theory that appears to have some merit but the evidence is still tenuous. In the future, more observations could lend more support or detract from the DE hypothesis. In my view, there is nothing conclusive here, but we have a working hypothesis.
If PC/EU theories had some promise as alternative explanations, they would have gained more traction by now within the physics/cosmology/astronomy community.
The point has been made quite well here that a lab demonstration of DE is no more feasible than a lab demonstration of space curvature. That means nothing in the context of astronomy, where lab demonstrations are not in the cards. Black holes, neutron stars, quasars, star and planetary formation, etc. can't be demonstrated in a lab either. But there are consistent theories and observations that give these objects and processes credibility. That's how science works. It's not all poking at stuff and measuring things in a lab. Certainly, astronomy and cosmology can't work that way.

 

[sol invictus]

T
Which might those be? Do you even understand the difference between actual "hard science" with real "hardware" and real control mechanisms, and "subjective interpretation"?

I do. Everyone else but you does too.

Astrophysical observations are not interpreted subjectively. They're interpreted using the known laws of physics, and in addition various possible competing theories - all of which are mathematical, not subjective. Theories that fit the evidence and correctly predict the results of additional observations are kept. Those that do not are discarded.

There's a word that for that procedure: "science".

These are pure observations tell you *nothing* about the actual existence of magic elves, invisible unicorns or inflation faeries. If your inflation faeries don't do anything here on Earth, why do you figure they do something "out there somewhere"?

Let's try an example. Suppose I had a new theory of gravity. It made some predictions that could be tested in labs on earth, but much of its scope could never be tested that way (the part concerning the motions of planet-sized bodies, for example). Now suppose this theory predicted precisely when the next eclipse would be - a feat that no other theory at the time could - and that prediction was born out to great accuracy.

Guess what? Everyone would regard that as powerful evidence that the theory was correct, even though there was no "control" on the experiment, and it could never be repeated (at least not until the next eclipse). And that's how Newton's law of gravity was accepted - of course that could not be tested in a lab, but what made it compelling is that it worked both for things that could be tested by lab experiments and for astronomical observations. And in fact even without the lab data, if it correctly predicted the motions of the planets, as observed with telescopes, it would still have succeeded as a theory (obviously).

General relativity, including inflation, is in much the same situation. Many aspects of it can be tested on earth, but obviously not those that relate to cosmology (how are you going to do a controlled experiment on the dynamics of galaxy clusters in a lab?). Because it's a tight and self-consistent mathematical theory, it makes a huge number of easily falsifiable predictions for the results of observations - and those predictions are born out every day, thousands of times. At any moment a set of observations could come along that falsify it, and if or when that happens, it will be abandoned and replaced by something that works. That hasn't happened yet.

Again, this is called "science".

 

[Michael Mozina]

Lambda-CMD theory and the Inflation Deity

Thanks again for taking the time to answer my questions, especially with the challenges of your family and work.

It's good to read these words, because there are few - if any - among the posters to this thread who would say otherwise about themselves ("I am an empiricist. I don't practice any branch of science in a "special" way.").

The confusion, to me at least, comes when I try to match what I understand by 'empirical' with your usage.

Humm. Really? Let's try another faith based analogy then. We'll call it:

"Lambda-CMD theory and the Inflation Deity"

What the mainstream has created is a dogmatic belief system that is not based on actual physics and experimentation, but upon “faith” in powers and forces that it can’t explain or demonstrate. The mainstream has created a “creation mythos”, a story about creation event that presumably occurred a long, long time ago. It has “mythological” elements as well, including density defying supernatural powers of inflation and dark energy. It goes something like this:

“In the beginning was the inflation deity. One day, (we’ll just call her) Nereid felt the need to be creative and the need to create other individuals, so the inflation deity selected a centralized mass/energy object and she breathed upon the empty space and “inflated” the object into the heavens and the earth. Looking out into the future with her superior understanding of physics, she looked upon her creation and she was well pleased. The inflation deity then rested.”

Like all deistic belief systems, I cannot rule out your inflation deity, but likewise I can’t demonstrate that a Deistic Nereid actually exists out there somewhere by looking upon the heavens either. The fact you added a bit of postdicted math formula to your creation story doesn’t make it any better. I can’t falsify anything! In the realm of “science”, it is up to the one making the claim to EMPIRICALLY demonstrate their claim. In this case, the mainstream claims that “inflation” exists or once existed in nature. Like a deistic belief system however, the inflation deity evidently doesn’t even bother to get involved in its creation anymore, so I can’t even physically hope to “test’ inflation. It has just fallen outside of the realm of empirical physics and it is now a religious dogma with nice math.

What the mainstream failed to do, and what they refuse to do, is actually demonstrate that inflation has any affect on nature before they started making up the inflation deity based on postdicted math formulas. When they find a problem based on actual observation, the formulas just gets stuffed with “dark energy” to fill in the gaps. They now go back to the same observations, and now attempt to use the inflation/dark energy formulas to demonstrate the existence of the inflation deity again, along with her newly discovered “dark energy” powers. You didn’t actually “predict” anything new, you simply created a circular feedback loop and a dogma that is based on pure observation and a series of falsified formulas and then new postdicted formulas.

There are many other mathematical solutions to explain a redshifted universe. What’s wrong with this one for instance?

http://redshift.vif.com/JournalFiles/V14NO3PDF/V14N3EDW.pdf

 

[Michael Mozina]

MM:
I have been an enthusiast of science all my (somewhat long) life. Having some mathematics background has provided me with some of the language of science so I have been able to muddle through scientific literature of many kinds over the years. I have never been happy with the seemingly mystical direction taken by modern cosmology, with a big bang, acceleration, DE, DM, etc. So, I continue to hope that more discoveries will make the universe more "intuitive."
However, after following this debate for quite a while now, here is my view of things.
First, astronomers notice an anomaly in distant type 1a supernovae observations. The data appear to indicate the expansion of the universe is accelerating. DE is hypothesized. Wow, that seems so weird!
Now that theory predicts other phenomena like a certain clustering of galaxies. That is observed. So, we have a theory that appears to have some merit but the evidence is still tenuous. In the future, more observations could lend more support or detract from the DE hypothesis. In my view, there is nothing conclusive here, but we have a working hypothesis.

But it is only one of *many* competing ideas. For instance, there may be a quantum gravity theory that serves the same function. Now what?

http://redshift.vif.com/JournalFiles/V14NO3PDF/V14N3EDW.pdf

Which idea is "better", and why is it 'better'?

If PC/EU theories had some promise as alternative explanations, they would have gained more traction by now within the physics/cosmology/astronomy community.

I'll bet folk said that 20 years after Birkeland's death too about his ideas. I wasn't until the 70's that the mainstream reluctantly embraced even part of his ideas. At the rate they are going, it could take another 100 years for them to figure out solar wind, something Birkeland simulated and predicted over 100 years ago. They still haven't figured out that coronal loops are electrical discharges and Bruce and Alfven wrote all about it, not just Birkeland. I think if you study history a bit, you'll find that is a bit of a naive assumption.

The point has been made quite well here that a lab demonstration of DE is no more feasible than a lab demonstration of space curvature.

But gravity shows up in a lab, and EM fields seem to be able to replace DE, and then we just have the "inflation" problem again.

That means nothing in the context of astronomy, where lab demonstrations are not in the cards. Black holes, neutron stars, quasars, star and planetary formation, etc. can't be demonstrated in a lab either. But there are consistent theories and observations that give these objects and processes credibility. That's how science works. It's not all poking at stuff and measuring things in a lab. Certainly, astronomy and cosmology can't work that way.

I've got no problem with them "scaling" known and demonstrated forces of nature. I realize we can't physically duplicate a neutron star or a gravity well that is so large it creates an event horizon in a lab. I will therefore be happy to allow them to scale anything to size, as long as they can demonstrate it actually exists in nature. If they can't demonstrate that DE exists in nature, I have no use for DE. The same is true of inflation.

 

[Michael Mozina]

Exactly right.

I'll repeat it one more time - in GR the only way to avoid the conclusion that space is expanding (or contracting) is to add both a positive cosmological constant and positive spatial curvature (in exactly the right balance) - and even then the solution is unstable. Every other cosmological solution either expands or contracts.

So if you deny that space expands, you deny that GR is correct. But you told us you believe GR. Yet another contradiction.

There is no "contradiction". While GR may allow for just about anything given the right circumstances and *causes*, you have special problems with your theory that preclude you from just starting anywhere. You've chosen not to start with say a "multiverse" scenario, where anything might happen, but rather with a "centralized mass/energy object". You essentially started with "special relativity", where all the mass/energy has a common point of origin. How did all that mass energy get from something that was physically smaller than a breadbox, to a universe that is larger than 28 billion light years across in only 14 billion years? I want to hear you identify the "cause" of each and every part of your "expansion" mythos.

 

[Perpetual Student]

So, s. i., why is it that DE is thought to account for as much as 75% of the mass of the universe? That seems to be so out of proportion to the acceleration observed. Obviously, I'm missing something.

 

[Michael Mozina]

So, s. i., why is it that DE is thought to account for as much as 75% of the mass of the universe? That seems to be so out of proportion to the acceleration observed. Obviously, I'm missing something.

Probably the reason they need so much of the stuff is that they refuse to even consider the possibility it's an EM sort of expansion. Even in that scenario, you'll need a lot of carrier particles to do a huge mass transfer of energy. I really liked that quantum gravity paper by the way. I'm still digesting parts of it, and I'll probably have to read it through a few more times before I really grasp the implications well enough to say much, but I must say that it seems "better" at accounting for redshift than a Compton scattering approach. Of course you'd also have to give up your fixation on GR in favor of a quantum gravity theory, but hey, it seems almost inevitable from my point of view that a QM approach might be "better" at describing gravity than GR. I'm open to lots of possibilities, whereas the mainstream seems to be fixated on a single theory, a theory that is 96% mythology, and only 4% real physics.

 

[DeiRenDopa]

[...]


Not necessarily.
http://arxiv.org/abs/astro-ph/0602500
Ari attributes this to the same basic mechanisms that are involved in redshifting photons. You'd have read the whole paper (it's one of his shorter ones actually) to appreciate his position but:



Those are pretty much his views in a nutshell.



It may in fact be at "equilibrium" as far as relative movement is concerned. In theory you'd expect the energy sources of stars to run out over time, so I can see the wisdom of assuming we live in a finite and less than eternal universe. Picking an "age" of the universe however seems, well, pretty arbitrary.

Um ...

Michael, several folk have pointed out that the ideas presented in the series of Ari Brynjolfsson papers are fatally flawed.

Further, if indeed the following is so, then why are you still promoting this material?

I am an empiricist. I don't practice any branch of science in a "special" way.

After all, the AB ideas fail any empiricist's central criterion: testable hypotheses developed from them are inconsistent with observations.

Further squared, you have not been able to provide any material which claims to show that this 'plasma redshift' has been confirmed in real experiments with proper controls (which seems to be the core criterion, in your version of empiricism); has the situation changed in the last few days?

Further cubed, these ideas seem to meet the MM criterion for being scientific woo:

It's "woo" because you can't 'predict' anything useful in a controlled experiment based on your belief in [plasma redshift]

And finally (further to the fourth), I provided you a list of tests that I thought the AB ideas failed, based on your agreeing to try to explain them ... and you have not yet responded (perhaps you've been too busy?).

 

[Ziggurat]

How did all that mass energy get from something that was physically smaller than a breadbox, to a universe that is larger than 28 billion light years across in only 14 billion years?

Space itself expands. That's what GR says: that doesn't involve anything moving faster than light, because that is a local speed limit on matter moving through space, not a limit on how space itself behaves. If you cannot accept this notion, then you are objecting to general relativity. You are free to do so, but you are not free to keep claiming that you believe in general relativity while denying a result that comes straight from it. Again: this is all without inflation, dark energy, or dark matter: just vanilla general relativity with only ordinary mass and electromagnetic energy. Your objection about the size being too large for its estimated age is meaningless: general relativity allows for infinitely large universes of finite age. If you do not believe this to be possible, then your objection is to general relativity itself. It is clear from your refusal to acknowledge this that you simply do not understand general relativity. That is excusable: it's a tough subject, and very non-intuitive. But your repeated posturing on the subject while being thusly ignorant will earn you no friends here.

 

[Michael Mozina]

Um ...

Michael, several folk have pointed out that the ideas presented in the series of Ari Brynjolfsson papers are fatally flawed.

Er, you've also been shown where inflation theory is fatally flawed too. Did you "give it up" over the course of a week?

I at least provided you another paper on a quantum gravity theory to consider. Did you look at that one yet?

Further, if indeed the following is so, then why are you still promoting this material?

Well, for one thing, I haven't really had time to go through what you perceive to be "flaws" in his work yet, so I'm not convinced it has any fatal flaws as you call them. I'm sure it has "problems", but then so does your redshift inflation deity. I'm open to a lot of possibilities as it relates to *interpreting* redshift.

Further squared, you have not been able to provide any material which claims to show that this 'plasma redshift' has been confirmed in real experiments with proper controls (which seems to be the core criterion, in your version of empiricism); has the situation changed in the last few days?

Not at all, but if *anything goes*, I can consider a whole range of other options, including Ari's work, that paper by Mathew Edwards, and anything else that seems reasonable and has some hope of being tested in a physical manner. I can never hope to test your inflation deity, because evidently it's dead, or disinterested in it's creation.

And finally (further to the fourth), I provided you a list of tests that I thought the AB ideas failed, based on your agreeing to try to explain them ... and you have not yet responded (perhaps you've been too busy?).

Yes, I've been busy and it's been a busy week. I have three threads going on here alone, and several other discussions at other boards as well. You've yet to meaningfully respond to any of my key objections to your theory. Instead you have fixated on trivia associated with my personal beliefs. Empirical science is not dependent upon the beliefs of an individual. It can be demonstrated in a physical way. Only faith requires the participation of the individual.

 

[sol invictus]

There is no "contradiction".

There is a complete contradiction, one which is obvious to everyone but you. You say the expansion of space is nonsense etc. etc., and at the same time that GR is empirically verified. But the expansion of space is an absolutely central part of GR.

While GR may allow for just about anything given the right circumstances and *causes*, you have special problems with your theory that preclude you from just starting anywhere. You've chosen not to start with say a "multiverse" scenario, where anything might happen, but rather with a "centralized mass/energy object".

No, this is completely wrong. I didn't "start" with anything. I can take the universe as it is today, in the region we can see - nothing more, nothing less - and use that as an initial condition to run time either forward or backward, according to the equations of GR. That analysis leads immediately to expanding (to the future) space. There is no assumption and no ambiguity.

How did all that mass energy get from something that was physically smaller than a breadbox, to a universe that is larger than 28 billion light years across in only 14 billion years? I want to hear you identify the "cause" of each and every part of your "expansion" mythos.

I already answered this question, and you ignored the response.

So, s. i., why is it that DE is thought to account for as much as 75% of the mass of the universe? That seems to be so out of proportion to the acceleration observed. Obviously, I'm missing something.

It's in proportion. Think of it like this - you shoot two equal projectiles out in opposite directions in empty space and observe their trajectory. The force of gravitational attraction of one on the other is proportional to its mass, and as long as they are slowing down (i.e. accelerating towards each other) at the right rate, you know that's the only force acting. But instead, you observe that the projectiles have started to accelerate away from each other. That means there is another force acting on them which is larger than the force of attraction. Since the force of attraction on one was proportional to the mass of the other projectile, if this new force is coming from gravity, its source must be a mass that's larger (but not much larger, since the acceleration isn't very big). I've ignored the 1/distance square here, but since both dark energy and the mass in the universe are more or less equally spread around that actually doesn't affect this.

See the point? If there was zero acceleration, it would mean the average density of dark energy was about the same as matter. Since the acceleration is positive, it means it's greater than matter.

 

[DeiRenDopa]

MM:
I have been an enthusiast of science all my (somewhat long) life. Having some mathematics background has provided me with some of the language of science so I have been able to muddle through scientific literature of many kinds over the years. I have never been happy with the seemingly mystical direction taken by modern cosmology, with a big bang, acceleration, DE, DM, etc. So, I continue to hope that more discoveries will make the universe more "intuitive."
However, after following this debate for quite a while now, here is my view of things.
First, astronomers notice an anomaly in distant type 1a supernovae observations. The data appear to indicate the expansion of the universe is accelerating. DE is hypothesized. Wow, that seems so weird!
Now that theory predicts other phenomena like a certain clustering of galaxies. That is observed. So, we have a theory that appears to have some merit but the evidence is still tenuous. In the future, more observations could lend more support or detract from the DE hypothesis. In my view, there is nothing conclusive here, but we have a working hypothesis.

But it is only one of *many* competing ideas. For instance, there may be a quantum gravity theory that serves the same function. Now what?

Indeed, there may be.

When such an idea is proposed, and it passes the usual (empirical) tests (as well as the ones about internal consistency, of course), then we will all be in a position to answer this question (and many others). Until that day ...

http://redshift.vif.com/JournalFiles/V14NO3PDF/V14N3EDW.pdf

Which idea is "better", and why is it 'better'?

I'm not sure which idea you are referring to, but Mathew Edwards' one, per that link, fails many tests (e.g. it is clearly inconsistent with QED, the most precisely tested part of physics today - check out his 'virtual photons', for example).

I must say I'm somewhat surprised you'd even suggest this one, MM; after all, it certainly fails whatever the "controlled experiment" test is that you have been insisting on.

If PC/EU theories had some promise as alternative explanations, they would have gained more traction by now within the physics/cosmology/astronomy community.

I'll bet folk said that 20 years after Birkeland's death too about his ideas. I wasn't until the 70's that the mainstream reluctantly embraced even part of his ideas. At the rate they are going, it could take another 100 years for them to figure out solar wind, something Birkeland simulated and predicted over 100 years ago. They still haven't figured out that coronal loops are electrical discharges and Bruce and Alfven wrote all about it, not just Birkeland. I think if you study history a bit, you'll find that is a bit of a naive assumption.

You know, a funny thing happened in the last 100 years ... or rather, several funny things ...

Those parts of Birkeland's work that withstood the tests of hundreds of empiricists who came after him were modified, adopted, and became part of mainstream space science, geophysics, etc.

Those parts which failed such tests have been dropped (e.g. his ideas on planetary rings*.

And yes, sometimes it does take several decades for an idea to be tested sufficiently well that it can be accepted, modified, or left to gather dust (e.g. neutrinos, and the 'solar neutrino problem'); other times acceptance comes very quickly indeed (e.g. "dark energy", the empirical shorthand; two independent teams found the same signal in high-z SNe Ias, more or less at the same time).

But I'm still trying to understand what you mean by "PC/EU theories" (PS was merely quoting you), or "EU theory", or "EU/PC theory", or ...

The point has been made quite well here that a lab demonstration of DE is no more feasible than a lab demonstration of space curvature.

But gravity shows up in a lab, and EM fields seem to be able to replace DE, and then we just have the "inflation" problem again.

It's certainly a nice idea, but, as I said in a post that has only now gone up, I think you've misunderstood "dark energy", that paper, or both.

That means nothing in the context of astronomy, where lab demonstrations are not in the cards. Black holes, neutron stars, quasars, star and planetary formation, etc. can't be demonstrated in a lab either. But there are consistent theories and observations that give these objects and processes credibility. That's how science works. It's not all poking at stuff and measuring things in a lab. Certainly, astronomy and cosmology can't work that way.

I've got no problem with them "scaling" known and demonstrated forces of nature. I realize we can't physically duplicate a neutron star or a gravity well that is so large it creates an event horizon in a lab. I will therefore be happy to allow them to scale anything to size, as long as they can demonstrate it actually exists in nature. If they can't demonstrate that DE exists in nature, I have no use for DE. The same is true of inflation.

You said something like this earlier, and I asked for some clarification on it.

Would you mind responding to that post of mine please?

* yes, I went and looked them up; and frankly I'm surprised you thought to include them in your earlier post.

 

[DeiRenDopa]

[...]

Yes, I've been busy and it's been a busy week. I have three threads going on here alone, and several other discussions at other boards as well.

[...]

Best I let you get on with it then.

I'll check in here, every so often, to see how this thread and the one on PC being woo are coming along ...

 

[Michael Mozina]

There is a complete contradiction, one which is obvious to everyone but you. You say the expansion of space is nonsense etc. etc., and at the same time that GR is empirically verified.

Do you have comprehension problem or just a weird desire to twist my words? I said *gravity* shows up in empirical experiments and I therefore don't care which math formulas you use to describe it, be it Newton's equations, Einstein's Equations, or some QM theory on gravity. I can tell that gravity exists in nature. That's what I said.

But the expansion of space is an absolutely central part of GR.

It's a central part of what you call GR, but you never actually "explained" how GR applies since you have a "special" relativity scenario in play just prior to your "bang".

No, this is completely wrong. I didn't "start" with anything. I can take the universe as it is today, in the region we can see - nothing more, nothing less - and use that as an initial condition to run time either forward or backward, according to the equations of GR.

Even then it doesn't necessarily lead us to a "singularity". What's wrong with Alfven's "bang" theory then?

That analysis leads immediately to expanding (to the future) space. There is no assumption and no ambiguity.

Bull. A) You *assume* redshift is related to expansion. B) you make up equations based on assumption A).

I already answered this question, and you ignored the response.

Where? Did you list any 'causes' for any of this expansion?

See the point? If there was zero acceleration, it would mean the average density of dark energy was about the same as matter. Since the acceleration is positive, it means it's greater than matter.

Gah. If there was zero acceleration and some signs of deceleration your inflation theory would have been accurate. Since it shows signs of acceleration, instead of seeing that as a falsification of your original theory, you simply stuffed your theory with more 'gap filler' and called it "dark energy". Give me a break.

 

[Ziggurat]

It's a central part of what you call GR

It's also a central part to what Einstein called GR. Hell, it's in basically every GR textbook out there, including the ones written before dark matter, dark energy, and inflation were even thought of. You are the only one who thinks expansion of space itself isn't an intrinsic part of GR.