Lambda-CDM theory - Woo or not?

[Tubbythin]

Any standard empirical, complete with "control mechanism" will do. The control mechanism can be extremely simple. In the case of neutrinos, they were able to turn on and off the "source" of neutrinos and make sure it had some affect on their experiments. I'm not particularly picky, as long as there is in fact a "control mechanism" involved in the "test".

Ok. So prove that the universe exists.

Put on your skeptic cap for a moment in put yourself in my shoes. You expect me to simply have "faith' in Guth's math formula *without* ever demonstrating it even works here on Earth.

Do you believe in galaxies? Have you made one on Earth?

I'm simply supposed to "accept on faith' that these formulas apply somewhere out in space but not here on Earth, and I'm supposed to accept on faith that inflation isn't a figment of his imagination based strictly on a unverifiable math formula. I'm also supposed to simply "accept on faith" that it has all the properties he assigned to it even though we now find "holes" and "dark flows' that are not predicted by these mathematical models. You don't find that somewhat "hard to swallow"?

No, "you" are expected to understand the theory and the evidence for it. Then "you" can find ways of testing the theory and trying to falsify it. Its pretty clear you haven't done the first part yet. (That's nothing to be ashamed or embarrassed about, I'll freely admit I only loosely understand a tiny little bit about inflation, and even then there's a decent chance I've got that completely wrong.)

 

[Michael Mozina]

And inflation is just gravity in the presence of a vacuum energy.

Please demonstrate this claim.

Ever hear of the Casimir effect?

How in the world is that related to inflation?

 

[Michael Mozina]

It does not.

In particular, it doesn't prove that some (unique) thing causes objects to accelerate, only that individual objects accelerate.

You'll have to define "unique" because gravity influences the movement of *all* material objects in exactly the same manner. That is not true of every force of nature. That make it unique.

It also doesn't prove that the same thing causes all objects to accelerate

If I doubt that idea, I can experiment with a lot of objects to demonstrate it does cause the *all* to fall.

-- that the acceleration of a falling pen is caused by the same thing that keeps the moon to its course in the heavens.

It would stand to reason that if gravity affects all things on Earth, it's likely to have some influence on other objects as well. It's not a huge leap of faith to assume the moon is also affected by gravity if everything you try is in fact influenced by gravity.

And most particularly, it doesn't prove that the force experienced by the moon is substantially less than the force that would be experienced by a moon-sized object sitting on the Earth.

Well, fortunately we can reach the moon if we have any doubts.

That says more about your competence as a mathematician and as an observer than it does about Guth, I'm afraid.

Baloney. I can't tell from a math formula alone if inflation exists in nature and has some influence on objects in nature. That requires empirical testing.

No, you can't. Newton's math says --- the stuff that makes it Newton's math as opposed to Galileo's -- that if you get far enough away from the Earth, you will experience less gravity. By definition, you cannot get far enough away from Earth to test this here on Earth.

But there can be no doubt that gravity exists. That's the point. Whether he could or could not demonstrate the validity of his math, his basic function of gravity was easy to demonstrate.

Cavemen knew that objects fall.

Cavemen could demonstrate it too. Guth can't demonstrate inflation has any influence on anything even with thousands of years of advanced technology.

 

[Michael Mozina]

Wrong. Something - most likely systematic error - has been observed.

That observation is in direct conflict with the theory of inflation too. Notice how you simply *assumed* it was some kind of error in the observation rather than an error in inflation? Why did you do that?

If or when the observations are solidly confirmed, vanilla inflation will be falsified (or at least it's very hard to see how to reconcile them).

If and when the observations are confirmed, a new brand of inflation will be invented to take the place of the old one. Who's kidding whom?

You've heard of it and yet you think it's been swept under the rug?

Ya because nobody is doing anything remotely related to "falsification" when it comes to inflation.

Don't be ridiculous - it was major news across the world. It's not being taken that seriously by the pros, because pros are very, very used to anomalies like that which come... and then go, because they aren't real.

Inflation isn't real either. It's a "concept" that the mainstream likes and refuses to falsify under *any* circumstance. Never mind the holes and flows in the theory, it must be correct anyway!

Extraordinary claims require extraordinary evidence, and the evidence so far is rather weak.

Inflation is an "extraordinary" claim. In fact it's a "supernatural" entity the defies all the known laws of nature. No other vector or scalar field is capable of inflation's density defying tricks. There is certainly no "extraordinary" support of the idea, in fact there is evidence the universe is not homogeneous at all and still inflation lives on. Go figure.

 

[Michael Mozina]

Einstein would be rather surprised to hear that, wouldn't he? Or haven't you heard of the general theory of relativity, in which there is no such thing as the force of gravity?

Hey, a real and legitimate complaint about my wording. Good for you.

 

[drkitten]

You'll have to define "unique" because gravity influences the movement of *all* material objects in exactly the same manner.

Prove it.

Prove that thing that causes an apple to fall is the same force that keeps the moon in its course, then.

If I doubt that idea, I can experiment with a lot of objects to demonstrate it does cause the *all* to fall.

Okay, do it, then. Start with the moon.

It would stand to reason that if gravity affects all things on Earth, it's likely to have some influence on other objects as well.

"It stands to reason"?

Since when were you accepting "it stands to reason"?

Sorry, that won't wash. I'm insisting -- this is YOUR standard, by the way -- on empirical proof in a controlled setting. If you can't drag the moon into your lab and build a control moon that's not subject to gravity, it doesn't count.

Because if you accept "it stands to reason," then Guth's math very definitely "stands to reason." In fact, it's a much better illustration of "reason," since it's quite rigorous, and backed up by lots and lots of observations.

It's not a huge leap of faith to assume the moon is also affected by gravity if everything you try is in fact influenced by gravity.

Huge? No. But I'm holding you to the same standard you're trying to hold Guth to. Demonstrate that the moon is subject to gravity with no leaps of faith whatsoever.

Well, fortunately we can reach the moon if we have any doubts.

Newton couldn't. Didn't stop him -- nor did it stop scientists from testing his theories, finding they agreed largely with observation, and accepting them.

Nor did it prevent later scientists from finding that Newton's theories didn't agree with later observations, and then rejecting Newton in favor of newer, more accurate theories.

.... and all that well before we could reach the moon.

I can't tell from a math formula alone if inflation exists in nature and has some influence on objects in nature.

I see. So, the reason that Guth is wrong is ... because you're a lousy mathematician?

What an interesting refutation.

 

[Michael Mozina]

Lambda-CDM is what we call a *model*. It's a complete hypothesis for how the Universe evolved from t=early (pre-inflation) to the present.

It's essentially a creation myth, not unlike any other creation mythos. It cannot be empirically supported anymore than any other creation story and is predicated upon the notion of superluminal expansion.

What do I mean by complete? I mean that the model tells you exactly what its guess is for the law of spacetime, and it tells you its guess for the list of gravitational source terms in the equation. THAT'S IT.

How is inflation in any way related to a gravity? It's stuffed into an equation related to gravity alright, but it was never shown to be related to gravity in any way. Its something I have to accept on "faith" alone.

Anyone can take this model and evolve it forward in time, make predictions. Other than those four components and standard GR, Lambda-CDM invokes no physics that isn't standard E&M/atomic/plasma/nuclear.

Um, I absolutely disagree. I know of no force called "inflation" that has any measurable affect on anything in any empirical test. It's not a force of "physics" in any physically tangible way. It's certainly not a part of "standard" GR as Einstein taught GR.

All scientists do is compare models to data. That's our job. Let's go ahead, shall we?

You seem to be missing a key issue here from my perspective. Your theory is based upon only 4% physics, and 96% metaphysics. No doubt it can manipulated into doing anything and everything if only 4% of your theory is based upon a "real" form of matter or energy. Let's try an analogy to see if I can make my point more clear.

Suppose I took Lambda-CDM theory and blatantly pilfered your math and simply changed some of the words. Suppose I take the three terms, inflation, dark energy and dark matter and I substitute them with "magic inflation", "magic energy" and "magic matter". How would your Lambda-CMD theory be in any way superior to my Lambda-Magic theory?

 

[Reality Check]

Suppose I took Lambda-CDM theory and blatantly pilfered your math and simply changed some of the words. Suppose I take the three terms, inflation, dark energy and dark matter and I substitute them with "magic inflation", "magic energy" and "magic matter". How would your Lambda-CMD theory be in any way superior to my Lambda-Magic theory?

You can change the words to "unicorn", "pixie" and "fairy" if you want. The words do not matter. The science and mathematics do matter. Changing the words does not change the model and its match to the measurements.

An example: I hereby rename gravity as "fairy dust" and "Newtons theory of gravity" becomes "Newton's theory of fairy dust". So what has changed? The theory still gives the same results.

 

[Reality Check]

You seem to be missing a key issue here from my perspective. Your theory is based upon only 4% physics, and 96% metaphysics. No doubt it can manipulated into doing anything and everything if only 4% of your theory is based upon a "real" form of matter or energy.

You seem to be missing a key issue here from the scientific perspective. Dark matter and dark energy as as real as "real" matter. We have observed dark matter and dark energy. We have observed "real" matter".

The only issue is that so far we have only observed dark matter and dark energy in the area of astronomy. It is likely that we will observe dark matter in the Solar System in the future. Given the weakness of dark energy it is unlikely that we will have a close by measurement of it.

 

[Ziggurat]

How is inflation in any way related to a gravity? It's stuffed into an equation related to gravity alright, but it was never shown to be related to gravity in any way.

How was the moon's orbit in any way related to falling apples? It's stuffed into an equation Newton pulled out of his rear end, but he never showed that it was related to falling apples in any way.

I know of no force called "inflation"

Of course you don't, because inflation isn't a force, it's a process. Orbits aren't a force either.

It's certainly not a part of "standard" GR as Einstein taught GR.

The field has advanced since Einstein. Especially in regards to observational data.

Suppose I took Lambda-CDM theory and blatantly pilfered your math and simply changed some of the words. Suppose I take the three terms, inflation, dark energy and dark matter and I substitute them with "magic inflation", "magic energy" and "magic matter". How would your Lambda-CMD theory be in any way superior to my Lambda-Magic theory?

It wouldn't be. But that doesn't mean what you seem to think it means: it means that if the math is good and it matches observations, the theory is good, and the labels you tack on are ultimately irrelevant.

 

[sol invictus]

That observation is in direct conflict with the theory of inflation too. Notice how you simply *assumed* it was some kind of error in the observation rather than an error in inflation? Why did you do that?

1) Because very similar claims have been made in the past, and were wrong.

2) Because that measurement is very, very hard.

3) Because even if the measurement itself is correct, it's extremely difficult to untangle correlations and do the statistics correctly.

4) Because inflation is very well-supported both theoretically and experimentally, and this goes against it.

5) Because in my informed opinion it is much more likely to be wrong than right.

6) Because all that said, I think it's very interesting and moderately exciting, precisely because if it is true, it means vanilla inflation is incorrect - and like everyone else interested in this stuff, something which proves an established theory is wrong or needs modification is very exciting.

If and when the observations are confirmed, a new brand of inflation will be invented to take the place of the old one. Who's kidding whom?

I don't understand. Of course if there's a version of the theory consistent with data, people will consider it. Why in the world wouldn't they?

Ya because nobody is doing anything remotely related to "falsification" when it comes to inflation.

Complete and utter nonsense. If anyone could falsify inflation, they'd become one of the most famous physicists in the world.

Inflation isn't real either. It's a "concept" that the mainstream likes and refuses to falsify under *any* circumstance. Never mind the holes and flows in the theory, it must be correct anyway!

You've demonstrated quite amply that you have very little knowledge of the topic, so why should anyone take your opinion seriously?

Inflation is an "extraordinary" claim. In fact it's a "supernatural" entity the defies all the known laws of nature.

Care to name even one?

No other vector or scalar field is capable of inflation's density defying tricks.

Now you're just repeating statements you know are false. There's a word for that.

Hey, a real and legitimate complaint about my wording. Good for you.

How are we to interpret that - that GR is merely semantically different from Newtonian gravity? Or that we should ignore the words you say?

 

[Perpetual Student]

His formula is
F=-GM₁M₂/r².

But on Earth in Newton's time it was impossible to compare this with, say,
F=-GM₁M₂/r
or

F=-GM₁M₂/r³.

I believe that the inverse square law [ 1/r² ] discovered by Newton was verifiable in his time by the orbits of the moon and planets. He explained the observation of Kepler that planets travel in orbital ellipses and Kepler's equal areas law. The hypothesis that gravity was universal and extended to falling objects on earth followed and was consistent with Galileo's observations. I have no ax to grind in this discussion; however I do believe any comparison of Guth's theory of inflation and Newton's universal law of gravitation is a stretch.

 

[Michael Mozina]

You seem to be missing a key issue here from the scientific perspective. Dark matter and dark energy as as real as "real" matter.

Well, in fairness, MACHO version of "dark matter" theory are in fact "real" in every conceivable way, even by my own standards.

We have observed dark matter and dark energy.

No. You have observed what you believe to be acceleration which you *interpret* to be related to "dark energy". You may also have observed "missing mass", but not "dark matter".

We have observed "real" matter".

Sure and and long as you stick to MACHO variations of DM theory I have no complaint.

The only issue is that so far we have only observed dark matter and dark energy in the area of astronomy.

Again, you didn't observe either of these things. Astronomers simply proposed these things as "gap fillers" in an otherwise failed theory of cosmology.

It is likely that we will observe dark matter in the Solar System in the future.

Why do you believe it to be "likely" that we will observe something in solar system in the future that we can't observe right now?

Given the weakness of dark energy it is unlikely that we will have a close by measurement of it.

FYI, there are "dark energy" theories out there that are directly related to, and attributed to EM Fields.

http://arxiv.org/abs/0812.1970

Even mainstream theory may *depend upon* EU Theory in the final analysis.

 

[Michael Mozina]

You can change the words to "unicorn", "pixie" and "fairy" if you want. The words do not matter. The science and mathematics do matter. Changing the words does not change the model and its match to the measurements.

So, in other words you can't *physically* differentiate between inflation and magic. As long as the math is good, the physics doesn't even matter, is that it?

An example: I hereby rename gravity as "fairy dust" and "Newtons theory of gravity" becomes "Newton's theory of fairy dust". So what has changed? The theory still gives the same results.

I'm afraid that the *physics* involved is also just as important as the *MATH*.

 

[Michael Mozina]

I have no ax to grind in this discussion; however I do believe any comparison of Guth's theory of inflation and Newton's universal law of gravitation is a stretch.

Thank you. At least someone around here is being reasonable.

 

[Michael Mozina]

How was the moon's orbit in any way related to falling apples?

Gee, I don't know, but if we throw the apple at a 45 degree angle, it doesn't fall directly back to earth, instead it sort of follows a curved arching pattern. If we pick it up and throw it harder, it goes further before it hits the earth. Do you figure Newton might have been smart enough to put two and two together?

It's stuffed into an equation Newton pulled out of his rear end, but he never showed that it was related to falling apples in any way.

No, his equations did not come from pure speculation, but from actual tests that worked on Earth and could also be applied to objects in space. Compare and contrast that with inflation which has never moved any apples on Earth.

Of course you don't, because inflation isn't a force, it's a process. Orbits aren't a force either.

Inflation is a "process" because you say so, or because you can demonstrate it? You do realize that folks are working on quantum gravity theories, right?

The field has advanced since Einstein. Especially in regards to observational data.

I'm not so sure. GR theory has been stuffed full of things that are in no way empirically verifiable or in any way related to gravity as far any any "test" is concerned. What's "evolved" is the use of metaphysical fudge factors, and the formulas themselves. Einstein rejected putting constants into GR, and I still think that was a wise choice, especially after observing the changes since Guth.

It wouldn't be. But that doesn't mean what you seem to think it means: it means that if the math is good and it matches observations, the theory is good, and the labels you tack on are ultimately irrelevant.

The physics is not irrelevant. If you can't physically distinguish between magic and inflation, there's a serious problem with your physics.

 

[Michael Mozina]

1) Because very similar claims have been made in the past, and were wrong.

Such as?

2) Because that measurement is very, very hard.

And? How do you know it's wrong just because it's "hard"?

3) Because even if the measurement itself is correct, it's extremely difficult to untangle correlations and do the statistics correctly.

And of course the "correct" method would necessarily be in alignment with inflation theory, is that it?

4) Because inflation is very well-supported both theoretically and experimentally, and this goes against it.

Inflation has *ZERO* (NO, NONE, NADA) experimental (with real control mechanisms) support! That is pure baloney! It's purely "theoretical" in nature and completely shy around a real lab.

5) Because in my informed opinion it is much more likely to be wrong than right.

In other words your biases told you so.

6) Because all that said, I think it's very interesting and moderately exciting, precisely because if it is true, it means vanilla inflation is incorrect

Does that mean you want to create a more exotic version if the current one is falsified even by your own standards?

- and like everyone else interested in this stuff, something which proves an established theory is wrong or needs modification is very exciting.

Except you are already convinced that it's not wrong to begin with?

I don't understand. Of course if there's a version of the theory consistent with data, people will consider it. Why in the world wouldn't they?

People like what they know and what they are used to and they tend to resist change.

Complete and utter nonsense. If anyone could falsify inflation, they'd become one of the most famous physicists in the world.

You can't falsify something that was never verified to exist in nature in the first place! Inflation's only claim to fame is the presumed homogeneous nature of the universe and even that is in hot dispute at the moment.

You've demonstrated quite amply that you have very little knowledge of the topic, so why should anyone take your opinion seriously?

I know plenty about this topic, including the fact you can't support your beliefs via empirical testing. Why should I take inflation seriously if you can't physically demonstrate that it's not a figment of your imagination?

Care to name even one?

Sure. No known vector or scalar field will retain near constant density throughout several exponential increases in volume. Only inflation does that supernatural trick.

Now you're just repeating statements you know are false. There's a word for that.

There is nothing false about my statement. Name one other known vector or scalar field known in nature that works like inflation and retains constant density, even with it's volume increases exponentially? There a word for that too - SUPERNATURAL!

How are we to interpret that - that GR is merely semantically different from Newtonian gravity? Or that we should ignore the words you say?

Talk about false dichotomies. You should interpret my statement to mean that I agree that my use of terms was "sloppy" in that one instance.

 

[Perpetual Student]

Thank you. At least someone around here is being reasonable.

Nevertheless, until there's a better model than cosmological inflation, it still is (and has been for some time now) the best model that fits the data. So what's the beef?

 

[Michael Mozina]

Nevertheless, until there's a better model than cosmological inflation, it still is (and has been for some time now) the best model that fits the data. So what's the beef?

The "beef" is that you can't demonstrate it exists in nature before you started trying to stuff it into a math formula and pointing to the sky and claiming "inflation did it". That's the beef.

Whereas "gravity" can be shown to influence objects here on Earth, as far as I can tell inflation is purely a mental creation of Alan Guth, and that is all it will ever be.

 

[Perpetual Student]

The "beef" is that you can't demonstrate it exists in nature before you started trying to stuff it into a math formula and pointing to the sky and claiming "inflation did it". That's the beef.

Whereas "gravity" can be shown to influence objects here on Earth, as far as I can tell inflation is purely a mental creation of Alan Guth, and that is all it will ever be.

As previously mentioned, I agree that a comparison with gravity is not reasonable; consequently, in my view, inflation does not have the same kind of standing as gravity. I agree that inflation does appear to have a lot of "ad hoc" aspects, but, as I said, it's the best model we currently have.