Lambda-CDM theory - Woo or not?

[INRM]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.