Lambda-CDM theory - Woo or not?

Michael Mozina · Feb 11, 2009

After reading through the plasma cosmology thread today, I'm curious how mainstream Lambda theory would hold up to the same level of scrutiny? What exactly does Lambda-CDM theory "predict" without the use of unfalsifiable and unverifiable entities?

For instance, what empirical evidence supports the idea of inflation? No other known vector or scalar field found in nature will retain near constant density over several exponential increases in volume. The presumed homogeneous layout of matter used to be inflation's primary claim to fame, yet recent observations of "dark flows" would suggest that matter is not homogeneously distributed as "predicted" by inflation. What empirical evidence from controlled experiments demonstrates that inflation even exists in nature?

Dark energy? What is that? How do I get some? What controlled empirical test demonstrates it has any effect on nature?

What about all the so called "properties" of dark matter? How do we verify or falsify these ideas?

In what tangible and demonstrateable way is Lambda-CDM theory any "better" than any other cosmology theory?

Vorpal · Feb 11, 2009

ΛCDM is not really a theory. It doesn't explain the nature of Λ or CDM; it's just a model fitting observations. Its only explanatory components are those it adopts from cosmic inflation, which is, strictly speaking, a theory in its own right.

Michael Mozina said:
What exactly does Lambda-CDM theory "predict" without the use of unfalsifiable and unverifiable entities?

One can build a ΛCDM model out of several independent pieces of evidence; the 'prediction' would be that doing so out of some puts severe constraints on the remaining.

Michael Mozina said:
No other known vector or scalar field found in nature will retain near constant density over several exponential increases in volume.

That it's curious is something that could have been said of any phenomenon that was ever discovered, and that observations imply some effect that can be modeled as a Λ cannot be dismissed on some vaguely aesthetic grounds. But look on the bright side--it doesn't even break conservation of energy and fits snugly into the best theory of gravitation we have.

Michael Mozina said:
The presumed homogeneous layout of matter used to be inflation's primary claim to fame, yet recent observations of "dark flows" would suggest that matter is not homogeneously distributed as "predicted" by inflation.

How significant is the inhomogeneity?

Michael Mozina said:
Dark energy? What is that? How do I get some?

Sounds like good questions for a theory to try to answer. See the first part of this post.

Michael Mozina said:
What controlled empirical test demonstrates it has any effect on nature?

Besides the evidence used to build ΛCDM in the first place, a more recent piece is a study on galactic clusters. But I'm sure you can use google to find out what they're about; if you've a specific issue, just state the perceived problem clearly.

Michael Mozina said:
What about all the so called "properties" of dark matter? How do we verify or falsify these ideas?

We're slightly short on "properties", but we can check if it's there more easily. For example, one way see whether the amount of CDM forced by some types of data (say, supernovae and WMAP) matches the amounts by others (say, rotations curves of galaxies and a survey of the sky). Theoretically, one could also construct competitors and see if they can also explain the observations (e.g., MOND).

Michael Mozina said:
In what tangible and demonstrateable way is Lambda-CDM theory any "better" than any other cosmology theory?

It fits the data--and not just fits the data, but multiple independent types of data. It fits coherently into established physical theories. Perhaps there is much room for improvement, but those already seem very significant.

Reality Check · Feb 11, 2009

Michael Mozina said:
After reading through the plasma cosmology thread today, I'm curious how mainstream Lambda theory would hold up to the same level of scrutiny? What exactly does Lambda-CDM theory "predict" without the use of unfalsifiable and unverifiable entities?

For instance, what empirical evidence supports the idea of inflation? No other known vector or scalar field found in nature will retain near constant density over several exponential increases in volume. The presumed homogeneous layout of matter used to be inflation's primary claim to fame, yet recent observations of "dark flows" would suggest that matter is not homogeneously distributed as "predicted" by inflation. What empirical evidence from controlled experiments demonstrates that inflation even exists in nature?

Dark energy? What is that? How do I get some? What controlled empirical test demonstrates it has any effect on nature?

What about all the so called "properties" of dark matter? How do we verify or falsify these ideas?

In what tangible and demonstrateable way is Lambda-CDM theory any "better" than any other cosmology theory?

IMHO inflation is a bit theoretical - it is a pity that it explains so much!
I suggest you read about the observational status of inflation in WikiPedia.

Dark energy is the observation that the expansion of the universe is accelerating. We do not kow what the cause is (thus "dark") and the most probable cause is a from of energy - thus "dark energy".
"What controlled empirical test demonstrates it has any effect on nature?" = the above observation.
More evidence of dark energy is that the cosmic microwave background anisotropies indicate that the shape of the universe is close to flat. In order for this to happen, the density of matter in the universe has to be a certain value. Ordinary and dark matter accounts for only about 30% of the critical density.
Dark energy is what we call the other 70%.

The properties of dark matter are measured by observing its effects: Dark matter (and look at my signature).

The Lambda-CDM model is better than any other cosmological model because it matches many more observations than they do. As Wikipedia states: "It is the simplest known model that is in general agreement with observed phenomena".
N.B. there is no "Lambda-CDM theory" - you are thinking of the Big Bang theory.

sol invictus · Feb 11, 2009

Michael Mozina said:
After reading through the plasma cosmology thread today, I'm curious how mainstream Lambda theory would hold up to the same level of scrutiny? What exactly does Lambda-CDM theory "predict" without the use of unfalsifiable and unverifiable entities?

First, there is nothing in Lambda-CDM that is unfalsifiable or unverifiable.

Second, plasma cosmology (at least as presented in that thread) is simply wrong. It is ruled out by, for example, the existence of the sun.

I think the best way to think about scientific theories is as follows. You have some box of data you've collected. You want to find a theory that accounts for that data. All theories have some parameters which can be adjusted. So you adjust those parameters until the fit to the data is as good as possible - you can think of that as taking some data out of the box and using it to define the theory. Whatever data is left in the box is a "prediction" (note that the temporal order of when the data was collected versus when the theory was defined is totally irrelevant here - the theory is either right or wrong, and the detailed activities of scientists are obviously not relevant to nature).

For example, when Newton discovered his law of gravitation, he needed to fix maybe 6 or 7 parameters (initial positions and velocities) per orbiting body, plus the gravitational constant. Once he had done that accurately, he could predict eclipses, or when Jupiter would pass through some constellation, or whatever. More and more accurate data was collected, and it continued to be explained almost perfectly by his theory. His theory was extremely well supported - using maybe 50 numbers, he could predict (or "explain" if you prefer) tens of thousands more - all the future and past observations other than the ones used to fix those numbers. It was only when observation got very precise that a few problems emerged, which were solved by Einstein's GR.

Contrast that to the preceding theory of an earth-centered universe. The better the data got, the mode epicycles (parameters) had to be added. So nearly all the data in the box was needed to define the theory, leaving very little to test it with. That's the hallmark of a wrong theory.

By this standard Lambda-CDM is incredibly successful as a scientific theory. It predicts (at least some of) the results of every new observation we make. It contains maybe 30 parameters (of which perhaps 3 or 4 have to do with dark energy and dark matter), and yet it can account for and predict just about every cosmological observation ever made, of which there are probably millions. Yes, there are some problems, and often surprises - but they are all on the edge of statistical significance, so they do not constitute a serious challenge (the dark flows observation falls in that category), or they are simply aspects of the theory that had not been properly worked out or understood until data made it clear more work was needed.

Michael Mozina · Feb 11, 2009

Reality Check said:
IMHO inflation is a bit theoretical - it is a pity that it explains so much!

It's also a pity that you can't demonstrate it isn't a figment of your imagination. What empirical test demonstrates that inflation exists in nature? What other vector or scalar field known to exist in nature acts like inflation?

I suggest you read about the observational status of inflation[/URL] in WikiPedia.

Pointing at the sky and claiming "inflation did it" is not a controlled empirical test of concept. When did inflation cause anything to move in a controlled test? What other scalar field in nature retains near constant density over multiple exponential increases in volume?

Dark energy is the observation that the expansion of the universe is accelerating.

When was "dark energy" shown to ever cause anything to accelerate in a controlled empirical test here on Earth?

We do not kow what the cause is (thus "dark") and the most probable cause is a from of energy - thus "dark energy".

So it's not actually an "explanation", it's simply a fudge factor you can't actually justify or explain?

"What controlled empirical test demonstrates it has any effect on nature?" = the above observation.

What "observation"? An uncontrolled observation is not an "empirical test". When did inflation or DE ever do anything in a controlled test with real control mechanisms?

More evidence of dark energy is that the cosmic microwave background anisotropies indicate that the shape of the universe is close to flat. In order for this to happen, the density of matter in the universe has to be a certain value. Ordinary and dark matter accounts for only about 30% of the critical density.

What makes you think that "flatness" has anything to do with "Dark energy"? When did "dark energy" ever make anything "flat"?

Dark energy is what we call the other 70%.

To me that simply suggests that your theory is at least 70% fudge factor.

The properties of dark matter are measured by observing its effects:

Again, you are "assuming" that dark matter has some affect. To be honest I don't really have much trouble with MACHO forms of "dark matter", but those SUSY theories are quite a leap of faith.

The Lambda-CDM model[/URL] is better than any other cosmological model because it matches many more observations than they do.

It doesn't match anything without these persistent fudge factors. The only reason it "matches" anything is because it's stuffed with metaphysical entities that defy empirical testing and defy an actual "explanation".

There are plenty of other theories that "explain" these redshift observations. Go over to Arxiv and look up Ari Brynjolfsson. I'd post the links for you, but I need to have at least 15 posts to be able to post links.

sol invictus · Feb 11, 2009

Michael Mozina said:
It's also a pity that you can't demonstrate it isn't a figment of your imagination. What empirical test demonstrates that inflation exists in nature?

All of cosmology.

What other vector or scalar field known to exist in nature acts like inflation?

The Higgs bears many similarities.

Pointing at the sky and claiming "inflation did it" is not a controlled empirical test of concept. When did inflation cause anything to move in a controlled test?

When did Andromeda cause anything to move in a controlled test?

What other scalar field in nature retains near constant density over multiple exponential increases in volume?

Any scalar condensate does - that's simply a prediction of the model. It's not something you put in. For example, the Higgs condensate does the same.

So it's not actually an "explanation", it's simply a fudge factor you can't actually justify or explain?

Read my post above. You don't understand what scientific theories are.

What makes you think that "flatness" has anything to do with "Dark energy"? When did "dark energy" ever make anything "flat"?

That is part of the mathematics of the model, end of story.

To me that simply suggests that your theory is at least 70% fudge factor.

Complete and utter nonsense. Newton's theory for the orbits of planets doesn't work unless the sun exists and has the correct mass. So you might as well say Newton's theory is 100% fudge factor, since if you remove the sun it fails.

In the Lambda-CDM model we know exactly what dark energy is and quite accurately how much there is. Just like the mass of the sun, it's a parameter in a self-consistent model.

There are plenty of other theories that "explain" these redshift observations.

That's simply not correct. There are no alternatives that are anything close to consistent with data.

Michael Mozina · Feb 11, 2009

sol invictus said:
First, there is nothing in Lambda-CDM that is unfalsifiable or unverifiable.

How does one falsify or verify that inflation isn't a figment of Guth's imagination?

Second, plasma cosmology (at least as presented in that thread) is simply wrong. It is ruled out by, for example, the existence of the sun.

I'm not discussing PC/EU theory in this thread.

I think the best way to think about scientific theories is as follows. You have some box of data you've collected. You want to find a theory that accounts for that data. All theories have some parameters which can be adjusted.

Adjusting known parameters is one thing. Making up completely new forces of nature is quite another. Dark energy isn't a "parameter", it's a "fudge factor" of epic proportions. You're not even sure what it is!

For example, when Newton discovered his law of gravitation, he needed to fix maybe 6 or 7 parameters (initial positions and velocities) per orbiting body, plus the gravitational constant.

But we can empirically verify that gravity actually exists in nature and that it has an empirical affect on objects. How do I verify that inflation does anything to anything?

By this standard Lambda-CDM is incredibly successful as a scientific theory. It predicts (at least some of) the results of every new observation we make.

It didn't predict those "dark flows". In fact it hasn't actually "predicted" much of anything. Almost all of the variables are "postdicted" based on observation. Worse yet, these "postidictions" are based upon ideas and forces that are not even verifiable or falsifiable. How does one falsify inflation? What other known vector or scalar field in nature retains near constant density over multiple exponential increases in volume?

Michael Mozina · Feb 11, 2009

sol invictus said:
All of cosmology.

That isn't a "controlled test". That is an uncontrolled observation. I'm beginning to think that nobody in your industry actually understands what a "controlled experiment" actually is.

In the Lambda-CDM model we know exactly what dark energy is

Really? What is it? Where can I get some? Where does it come from?

and quite accurately how much there is.

How do you know how much is there if you can't tell me any of it's actually properties and show me a controlled test where X amount of "dark energy" move Y amount of matter a distance of Z?

That's simply not correct. There are no alternatives that are anything close to consistent with data.

Tell me then what exactly is wrong with his "interpretation" of redshift?

sol invictus · Feb 11, 2009

Michael Mozina said:
How does one falsify or verify that inflation isn't a figment of Guth's imagination?

There are many, many, many ways. If the CMB isn't a blackbody once foregrounds are subtracted. If there is a large tilt to the power spectrum of density perturbations. If the slices of spatial curvature and constant density differ by more than the size of perturbations. If the CMB has any of thousands of statistical features that are inconsistent with inflation. Etc. etc.

Adjusting known parameters is one thing. Making up completely new forces of nature is quite another. Dark energy isn't a "parameter", it's a "fudge factor" of epic proportions. You're not even sure what it is!

Nonsense. You don't know what you're talking about. The title of this thread tells you precisely what it is in the model you wanted to discuss.

But we can empirically verify that gravity actually exists in nature and that it has an empirical affect on objects. How do I verify that inflation does anything to anything?

Same way you do any other kind of experiment - gather data and compare it to theory.

It didn't predict those "dark flows".

They almost certainly don't exist. If they do, vanilla Lambda-CDM is wrong. That's a great example of how it's falsifiable, contrary to your assertions.

In fact it hasn't actually "predicted" much of anything.

Wildly wrong. It predicts the results of literally thousands of observations made every day.

Almost all of the variables are "postdicted" based on observation. Worse yet, these "postidictions" are based upon ideas and forces that are not even verifiable or falsifiable.

That's not even wrong - it just doesn't make sense. The model has some parameters. With some values for those parameters, the model is either consistent with data, or not. If you want to compare it to another model you can ask which requires fewer parameters, and which fits best when there's a discrepancy - but you're not even trying to do that.

drkitten · Feb 11, 2009

Michael Mozina said:
Adjusting known parameters is one thing. Making up completely new forces of nature is quite another.

That is, however, more or less exactly what Newton did.

The "force of nature" he made up is called "gravity."

And, yes, it seems obvious today, but it certainly wasn't then. Aristotle, for example, held that the same force that made rocks fall made steam clouds rise --- because rocks "belonged" down (as part of the element of Earth) while steam "belonged" up (as part of the element of Air). (That also explained why rocks sank in water; water "belonged" down, but not as far down, so it didn't fall as far.)

What held planets to their proper course in the heavens weren't "forces of nature" but large crystal spheres to which they were physically attached. God's own hot-glue, I suppose.

Newton got rid of that whole hot-glue stuff, but only by making up a completely new force of nature.

Michael Mozina · Feb 11, 2009

sol invictus said:
The Higgs bears many similarities.

What? It does not! No known vector or scalar field in nature retains a near constant density over multiple exponential increases in volume. You're just making stuff up as you go.

drkitten · Feb 11, 2009

Michael Mozina said:
That isn't a "controlled test". That is an uncontrolled observation.

Since when is an uncontrolled observation not an empirical test?

.... and then, after you answer that, you can explain how one performs a "controlled test" in cosmology. Where do you get your control universe?

Michael Mozina · Feb 11, 2009

drkitten said:
That is, however, more or less exactly what Newton did.

No he did not. He could empirically demonstrate that gravity was not a figment of his imagination. Compare and contrast that with Guth's inflation. Guth can't even show any example on Earth where inflation did anything to anything.

The "force of nature" he made up is called "gravity."

No. You can't "make up" an empirical and testable force of nature. I can easily show that gravity has an affect on objects in a controlled test. Show me how we "test" (complete with control mechanism) Guth's inflation theory? How can you demonstrate it actually exists in nature?

At no time has gravity been beyond our ability to empirically test. If I doubt the existence of gravity, I can jump up and see if I float off into space. I can easily demonstrate that I will fall back to Earth each and every time. Show me how inflation has any affect on my physical form.

Newton got rid of that whole hot-glue stuff, but only by making up a completely new force of nature.

You clearly are missing the point here. Gravity it "testable", right here on Earth, and it's not shy around a lab. I can empirically verify that it exists in nature. That has *never* been done with inflation. Guth simply "made it up" in his head. It can't be "tested" in a controlled test. I can't be shown to exist outside of human imagination. No other vector or scalar field in nature retains near constant density over multiple exponential increases in volume. It is literally a "supernatural" concept that came straight from the imagination of a single individual, specifically Guth.

Michael Mozina · Feb 11, 2009

drkitten said:
Since when is an uncontrolled observation not an empirical test?

Since the beginning of time. Pointing at an uncontrolled observation is not a "controlled test". It is simply an "observation". You do not seem to understand the difference between an empirical test of concept and an unsupported claim like "inflation did it".

.... and then, after you answer that, you can explain how one performs a "controlled test" in cosmology. Where do you get your control universe?

You don't and you don't have to. You simply have to demonstrate that inflation actually exists in nature before you start pointing at the sky and claiming inflation did it.

drkitten · Feb 11, 2009

Michael Mozina said:
Gravity it "testable", right here on Earth

Really?

All right, test it.

Show me that rocks fall because of a mysterious "force of nature" and not because they belong down.

I'd take your writings on twenty-first century physics a lot more seriously if you understood first-century physics.

Michael Mozina · Feb 11, 2009

sol invictus said:
They almost certainly don't exist. If they do, vanilla Lambda-CDM is wrong. That's a great example of how it's falsifiable, contrary to your assertions.

Gah! It is so aggravating to not be able to post links. Go to Google and type in "dark flows". They have been "observed" and yet inflation still has not been falsified. Those "holes" they found are another example of an observation that "should" falsify the idea, but again, it's just swept under the carpet. I can't wait till I hit 15 posts because so I can post a ton of links to these observations that defy the "predictions" of inflation.

Inflation hasn't even been "verified" to exist in nature in the first place!

Michael Mozina · Feb 11, 2009

drkitten said:
Really?

All right, test it.

Ok. I just picked up the pen off my desk, lifted it 5 inches and let go of it. Wanna guess what happened next? Show me how inflation can move that same pen.

Show me that rocks fall because of a mysterious "force of nature" and not because they belong down.

If it "belonged" where it happened to be located at the moment the pen would have stayed right where I left it. It didn't. It fell to the desk again. Why would it "belong" anywhere other than where it happens to be located?

I'd take your writings on twenty-first century physics a lot more seriously if you understood first-century physics.

I'd take inflation seriously too if you could demonstrate it has a physical affect on anything too. I can physically demonstrate that gravity has an effect on objects here on Earth and everywhere I might go to physically "test" the idea. Inflation is simply an imaginary idea that came from the imagination of one human being, specifically Alan Guth. Not once in the 25 years since he proposed the idea has anyone ever made a pen move due to "inflation". When then should I believe it has an effect on a whole physical universe?

drkitten · Feb 11, 2009

Michael Mozina said:
Ok. I just picked up the pen off my desk, lifted it 5 inches and let go of it. Wanna guess what happened next?

It went back to (closer to) where it belonged. (It actually "belongs" far lower than the desk, as proven by the fact that if you moved the desk, it would fall all the way to the floor.)

If it "belonged" where it happened to be located at the moment the pen would have stayed right where I left it.

No, because it "belonged" on the desk, as demonstrated that it went right back there as soon as you removed it from where it belonged?

Why would it "belong" anywhere other than where it happens to be located?

Why would it "belong" anywhere other than where it naturally goes unless you stop it?

And you still haven't shown that this "gravity" stuff exists or has any physical effect on anything.

Ziggurat · Feb 11, 2009

Michael Mozina said:
No he did not. He could empirically demonstrate that gravity was not a figment of his imagination.

And how did he empirically demonstrate that the same force which made apples fall also made the moon orbit the earth? He sure as hell didn't go out and measure the 1/r² nature of gravity - he made it up. Newton wasn't the first person to notice objects fell: he's the first person to propose a universal law of gravity.

Compare and contrast that with Guth's inflation. Guth can't even show any example on Earth where inflation did anything to anything.

Did Newton find an example on earth where the 1/r² dependence of the gravitational field did anything? Nope.

I can easily show that gravity has an affect on objects in a controlled test.

Well, actually, no, you probably can't. Empirical measurements of the 1/r² nature of gravity are beyond the capabilities of most individuals. They were beyond Newton's capabilities. So what did he do? He built a model, looked out into space, and tried to determine if his observations (and those of other astronomers) matched his model. Go figure: that's exactly what cosmologists are doing right now.

At no time has gravity been beyond our ability to empirically test.

Again, you are simply wrong. Newton had no controlled method of testing his 1/r² field theory.

If I doubt the existence of gravity, I can jump up and see if I float off into space.

Which will prove what, exactly? That gravity falls off as 1/r², like Newton proposed? No. All you will have shown is exactly what Galileo showed before Newton was even born: objects on earth fall. You will have demonstrated nothing about the universal nature of gravity, which is what Newton contributed.

billw · Feb 11, 2009

drkitten said:
.... and then, after you answer that, you can explain how one performs a "controlled test" in cosmology. Where do you get your control universe?

Edmund Scientific's:

http://scientificsonline.com/product.asp_Q_pn_E_3118100

It glows in the dark!

INRM · Feb 11, 2009

I read the wikipedia article about the Lambda CDM theory...

What I'm confused about is -- a universe without any spatial curvature -- how does that work with gravity present? I thought gravity had to do with a curvature in spacetime?

Also what does it mean if a universe has no topology?

INRM

Michael Mozina · Feb 11, 2009

drkitten said:
It went back to (closer to) where it belonged. (It actually "belongs" far lower than the desk, as proven by the fact that if you moved the desk, it would fall all the way to the floor.)

If it "belonged" where it was, it would not fall at all. Nothing "belongs" anywhere. Your notion of "belonging' is a human construct that has nothing to do with the pen's acceleration. Something "caused" the pen to fall.

No, because it "belonged" on the desk, as demonstrated that it went right back there as soon as you removed it from where it belonged?

If it move it away from the desk before I let it go, it doesn't fly back to the desk! It simply 'falls' and "accelerates". Why?

And you still haven't shown that this "gravity" stuff exists or has any physical effect on anything.

I can and have demonstrated that gravity has an accelerating affect on material objects. If it simply 'belonged' somewhere, it wouldn't matter where I moved the pen before I dropped it, it would return to where it "belonged". It doesn't. It simply falls.

Ziggurat · Feb 11, 2009

Michael Mozina said:
I can and have demonstrated that gravity has an accelerating affect on material objects.

Congratulations: you caught up to Galileo. You haven't done anything to prove Newton was right. It is not an encouraging sign that you don't even know the difference.

drkitten · Feb 11, 2009

Michael Mozina said:
If it "belonged" where it was, it would not fall at all.

But it didn't belong where it was. It belonged below where it was, which is why it fell.

Nothing "belongs" anywhere.

Assertion without proof.

Something "caused" the pen to fall.

Absolutely. It wasn't where it belonged, so it moved.

You still haven't demonstrated "gravity."

If it move it away from the desk before I let it go, it doesn't fly back to the desk!

Yes, we covered that. It actually "belongs" far below the desk, but the desk was preventing it from moving all the way to where it belongs. When you pick it up, you move it even farther from where it belongs; when you let it go, it moves as close as it can to where it belongs.

Why?

Because it's moving closer to where it belongs.

I can and have demonstrated that gravity has an accelerating affect on material objects.

Not yet.

If it simply 'belonged' somewhere, it wouldn't matter where I moved the pen before I dropped it, it would return to where it "belonged".

Not if it's physically prevented from moving there.

It doesn't. It simply falls.

Yes, if by "falls" you mean "moves in the direction that causes it to get closer to where it belongs."

But you still haven't shown me this whole "gravity" stuff.

Michael Mozina · Feb 11, 2009

Ziggurat said:
And how did he empirically demonstrate that the same force which made apples fall also made the moon orbit the earth?

Finally we seem to be getting somewhere. He didn't. He "assumed" that a "known force of nature" was "universal" in scope. The key here is that he demonstrated that gravity is real and has a real affect on real objects.

He sure as hell didn't go out and measure the 1/r² nature of gravity - he made it up. Newton wasn't the first person to notice objects fell: he's the first person to propose a universal law of gravity.

Actually he did in fact "measure" it based on controlled testing and repetition.

Did Newton find an example on earth where the 1/r² dependence of the gravitational field did anything? Nope.

Well, I "sort of" see where you're headed here as it relates to the 'math' side, but again, the existence of gravity is verifiable. Even if the math is not obvious, the force of gravity is obvious.

Well, actually, no, you probably can't. Empirical measurements of the 1/r² nature of gravity are beyond the capabilities of most individuals. They were beyond Newton's capabilities. So what did he do? He built a model, looked out into space, and tried to determine if his observations (and those of other astronomers) matched his model. Go figure: that's exactly what cosmologists are doing right now.

No. Newton could physically demonstrate that gravity has an effect on objects. He did indeed make up a mathematical model based on intuition and postdiction methods. On the other hand, the existence of gravity was never "unverifiable" at any stage of the process. Compare and contrast that with inflation that has zero affect on any material object on Earth.

Again, you are simply wrong. Newton had no controlled method of testing his 1/r² field theory.

You're ignoring the difference here between a "mathematical model" and a "force of nature". A force of nature can be "tested". I mathematical model is something that typically derives from such "tests". In Guth's case however he simply skipped the whole idea of showing that inflation was even real before stuffing it into a math formula.

I hear and agree with you about the mathematical modeling aspect, but the existence of gravity was never in doubt even if the math was "iffy" and somewhat speculative. Even aspects of that could be tested by using objects of different weights and comparing how they fell toward Earth. At no time did Guth demonstrate that inflation has any affect on anything. He simply stuffed it into a math formula and claimed "inflation did it".

drkitten · Feb 11, 2009

Ziggurat said:
Congratulations: you caught up to Galileo. You haven't done anything to prove Newton was right. It is not an encouraging sign that you don't even know the difference.

He hasn't even caught up to Galileo; he's still losing to Aristotle. He's yet to show me that it's not as simple as "things made of the element of the Earth belong in the sphere of Earth, which is below the sphere of Water, which is below the sphere of Air, which is below the Sphere of Fire."

drkitten · Feb 11, 2009

Michael Mozina said:
Finally we seem to be getting somewhere. He didn't. He "assumed" that a "known force of nature" was "universal" in scope. The key here is that he demonstrated that gravity is real and has a real affect on real objects.

He demonstrated?

Riiiiiiiight. Because, of course, before Newton no one knew that objects fell.

Actually he did in fact "measure" it based on controlled testing and repetition.

No, that was Galileo who did that. Leaning Tower of Pisa and all that?

So what was Newton's actual contribution?

Michael Mozina · Feb 11, 2009

Ziggurat said:
Congratulations: you caught up to Galileo. You haven't done anything to prove Newton was right. It is not an encouraging sign that you don't even know the difference.

The only difference here is the mathematical aspects of the parts that Newton added. The existence of gravity is easily demonstrateable. What I find discouraging is the fact you refuse to acknowledge the difference between a force of nature that *can* be demonstrated and verified and a concept that is purely imaginary and has no empirical support. Guth's inflation can't be "verified" or "tested" here on Earth. It can't be shown to have any affect whatsoever on any material object. It is simply an "imaginary" idea with a nifty math formula.

Tubbythin · Feb 11, 2009

Michael Mozina said:
At no time has gravity been beyond our ability to empirically test.

So I suppose the ancient Egyptians could have tested for frame dragging?

Michael Mozina · Feb 11, 2009

drkitten said:
He demonstrated?

Riiiiiiiight. Because, of course, before Newton no one knew that objects fell.

No, that was Galileo who did that. Leaning Tower of Pisa and all that?

So what was Newton's actual contribution?

His actual contribution was a mathematical model. No one doubted that gravity existed and no one could deny it either. Guth can't get inflation to do anything to anything here on Earth. He simply "made it up" and stuffed it into a math formula. Unlike gravity, you can't emprically demonstrate that inflation actually exists in nature.

Tubbythin · Feb 11, 2009

Michael Mozina said:
The only difference here is the mathematical aspects of the parts that Newton added. The existence of gravity is easily demonstrateable. What I find discouraging is the fact you refuse to acknowledge the difference between a force of nature that *can* be demonstrated and verified and a concept that is purely imaginary and has no empirical support. Guth's inflation can't be "verified" or "tested" here on Earth. It can't be shown to have any affect whatsoever on any material object. It is simply an "imaginary" idea with a nifty math formula.

I suppose you don't believe in stars either, since you can't make them here on Earth either.

Michael Mozina · Feb 11, 2009

Tubbythin said:
I suppose you don't believe in stars either, since you can't make them here on Earth either.

Actually Birkeland's model was "emprical" in nature and it wasn't shy around a lab. He was able to "simulate" solar wind acceleration, coronal loops, jets, etc.

Ziggurat · Feb 11, 2009

Michael Mozina said:
The only difference here is the mathematical aspects of the parts that Newton added.

But that is everything. Without it, you don't have a theory of universal gravity, you have a theory of things on earth falling. The moon sure as hell doesn't fall to the earth like an apple does, so how do you know gravity has anything to do with the orbit of the moon? You need a theory. Newton pulled his out of his head. He did not measure the 1/r² nature of gravity. And yet, he was able to gain confidence that his theory was correct. How could he do that? You can't brush that under the rug as if that's some trivial sideshow: that was the heart of the theory.

The existence of gravity is easily demonstrateable.

Which is why it happened before Newton.

What I find discouraging is the fact you refuse to acknowledge the difference between a force of nature that *can* be demonstrated and verified and a concept that is purely imaginary and has no empirical support.

Oh, but it does have empirical support. Exactly the same sort of empirical support that Newton had for his 1/r² theory: astronomical observations.

Guth's inflation can't be "verified" or "tested" here on Earth. It can't be shown to have any affect whatsoever on any material object. It is simply an "imaginary" idea with a nifty math formula.

At the time, Newton's 1/r² theory couldn't be shown to have any effect whatsoever either. It too was just a "nifty math formula". Did people believe his theory because he was such an authority figure? Did he have confidence in the theory himself just because of his own ego? No. Can you tell me why his theory became accepted without direct experimental measurements of the 1/r² dependence?

Tubbythin · Feb 11, 2009

Michael Mozina said:
Actually Birkeland's model was "emprical" in nature and it wasn't shy around a lab. He was able to "simulate" solar wind acceleration, coronal loops, jets, etc.

And the neutrinos? And the emission spectrum? Etc...

Michael Mozina · Feb 11, 2009

Ziggurat said:
But that is everything.

No, it's not. There is a *physically demonstratable* aspect you keep ignoring.

Without it, you don't have a theory of universal gravity, you have a theory of things on earth falling. The moon sure as hell doesn't fall to the earth like an apple does, so how do you know gravity has anything to do with the orbit of the moon? You need a theory. Newton pulled his out of his head. He did not measure the 1/r² nature of gravity. And yet, he was able to gain confidence that his theory was correct. How could he do that? You can't brush that under the rug as if that's some trivial sideshow: that was the heart of the theory.

He could do this by "testing" his theory and by varying the conditions. He could select different objects to drop. He could vary the height of the drop. He could drop things simultaneously and watch what happened and compare his results to his mathematical model. At no time was his idea "unverifiable."

Oh, but it does have empirical support. Exactly the same sort of empirical support that Newton had for his 1/r² theory: astronomical observations.

No. Gravity works *right here on Earth". It's not shy around labs on Earth. It can be tested here on Earth. Show me one empirical demonstration of inflation here on Earth. They are not even in the same league. You keep ignoring the physical aspect of gravity and the fact we can physically test it here on Earth. We can't do that with inflation. Inflation doesn't exist and it has no known or verified affect on objects.

At the time, Newton's 1/r² theory couldn't be shown to have any effect whatsoever either.

False. The objects were *always* affected by gravity and math formulas could be compared to the physical drops he performed.

It too was just a "nifty math formula".

But it was a math formula that could be "tested" here on Earth.

Did people believe his theory because he was such an authority figure?

No, they believed him because he could show that gravity affected objects on Earth.

Guth can't do that with inflation. It's just a made up concept and a math formula that has no practical or useful application on Earth.

Michael Mozina · Feb 11, 2009

Tubbythin said:
And the neutrinos? And the emission spectrum? Etc...

I hate to break it to you, but fusion is demonstrateable here on Earth. I don't have to go anywhere to show that it's a viable energy source. Likewise I can demonstrate that fission and fusion processes are capable of releasing neutrinos here on Earth, and I can measure the influence of neutrinos on ordinary empirical experiments right here on Earth. You're only digging a deeper hole for yourself. Guth never demonstrated that inflation did anything to anything here on Earth. He simply "created" a math formula, pointed at the sky and claimed "inflation did it". There is a big difference between something that can be demonstrated here on Earth and something that cannot be demonstrated at all.

Gate2501 · Feb 11, 2009

Michael Mozina said:
Guth can't do that with inflation. It's just a made up concept and a math formula that has no practical or useful application on Earth.

How about all the light/radiation that reaches earth from space, proving that inflation exists?

What do you want? A mini-universe in a lab on earth that you can poke and prod?

It seems like your qualifications for "proving" these matters, would cause an environment where the pursuit of any cosmological knowledge is pointless. Is that what you want?

Michael Mozina · Feb 11, 2009

Falsification of Inflation:

http://www.space.com/scienceastronomy/080923-dark-flows.html
http://www.livescience.com/space/scienceastronomy/070823_huge_hole.html

Ooops. The layout of matter is *not* homogeneous as "predicted" by "inflation". Now what?

Tubbythin · Feb 11, 2009

Michael Mozina said:
He could do this by "testing" his theory and by varying the conditions. He could select different objects to drop.

But they all fall with the same acceleration.

He could vary the height of the drop.

You think he had equipment sensitive enough to measure the variation of g on Earth with height?

No. Gravity works *right here on Earth". It's not shy around labs on Earth. It can be tested here on Earth. Show me one empirical demonstration of inflation here on Earth.

Show me an empirical demonstration of a galaxy here on Earth. No? Then Galaxies can't exist by your logic either.

But it was a math formula that could be "tested" here on Earth.

So how did he measure 1/r² nature on Earth?

Tubbythin · Feb 11, 2009

Michael Mozina said:
I hate to break it to you, but fusion is demonstrateable here on Earth. I don't have to go anywhere to show that it's a viable energy source. Likewise I can demonstrate that fission and fusion processes are capable of releasing neutrinos here on Earth, and I can measure the influence of neutrinos on ordinary empirical experiments right here on Earth. You're only digging a deeper hole for yourself. Guth never demonstrated that inflation did anything to anything here on Earth. He simply "created" a math formula, pointed at the sky and claimed "inflation did it". There is a big difference between something that can be demonstrated here on Earth and something that cannot be demonstrated at all.

You missed the point entirely. By your logic, if you cannot make it on Earth it is just maths. Since you can't make a complete star on Earth, stars don't exist. This is your ridiculous logic thats digging a hole for you.

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