How is molecular hydrogen detected?

twofish-quant

Maybe I don't care about convincing you. One thing about these sorts of conversations is that you often aren't trying to convince the person you are arguing with, but rather you are trying to convince a bystander.

It's constructive criticism. You certainly have the mathematical ability to do interesting things in physics, and personally, I think it's a shame that you are wasting it. I think that much of the problem is that you are "doing philosophy" rather "doing physics." Ultimately, what you seem to be looking for isn't there. If you keep asking for justifications, then at some point the response is "well that's just how the universe works."

A lot about doing physics is learning a *culture*. It's not my responsibility to convince you that you are wrong or right, and since you have no power over me, I really don't care that much if you are wrong or right. There's no requirement that you have to agree with the consensus (because the consensus is often wrong), but in order to have a reasonable discussion there *is* a requirement that you understand what the consensus is.

Ultimately, if you yourself care about learning the truth about the universe, then *you will have to convince yourself*. I can just point you in the right direction, but if that's not a road that you want to walk down, then there is nothing I can do. You can at this point argue that you find the evidence for deceleration to be unconvincing, but at this point you can't argue that no hasn't shown you the data, and there are enough references so that you can track down the rest of it if you are interested.

I do like it when people are interested in physics and cosmology, and I think that it's a real shame that you have spend so much effort on this particular issue with there are *thousands* of other problems that you could have spent your time and effort working on.

twofish-quant

Here's another way of thinking of it.....

I have point A. You can argue that all of the forces are balanced at point A, so it doesn't accelerate.

I have point B. You can argue that all of the forces are balanced at point B, so it doesn't accelerate.

AHA!!! You say, the universe must then be non-accelerating!!!!

But that doesn't work. If I start with point A as my origin, and then look at point B, I find that there is a force at point B pulling it toward point A. But wait, I just showed that the forces are balanced if I take point B as the origin? What gives?

The issue here is that the forces at point B when viewed from point A are *different* from the forces at point B when viewed from point B, because when you change coordinate systems then the forces change. But how can that be? Don't forces stay the same when you change between inertial coordinate systems?

Yes, but from point A's point of view, point B is not an inertial coordinate system, it's accelerating, and because it's accelerating, when you switch between point A and point B, the forces change. From point B's point of view, it's an inertial coordinate system, and A is accelerating. So when you switch between A and B, you have to change the forces to take into account the fact that the coordinate systems are non-inertial.

From A's point of view, there is a force on B pulling B toward A, and there is zero forces at A. Now when you switch to B's point of view, you are a non-inertial reference frame from A's point of view. To make it inertial, you have to subtract the forces that are acting on it. That causes the forces at B from B's point of view to go to zero, and then causes the A to go from zero force to the opposite of what was the force that A sees acting on B.

So if you take any point as the origin, you will see a force of zero for that point, but you will see non-zero forces for points other than the origin.

Now then you see how the universe works. We don't have any infinite clouds, but we have clouds that are "practically" infinite. You take something like the interstellar medium with a one light year cube, and then take a piece that is much, much smaller, and see how you calculate gravity.

twofish-quant

And if you do your bookkeeping right, you come up with the same answer. The important thing is to keep track of what reference frame you are in so that you can account for non-inertial effects correctly.

JDoolin

By the way, this is the sort of argument that I regard as "simple contradiction" and sometimes I might forget to respond to such a thing. What can I add when I make a statement "P," and then someone else argues "Not P?" My statement comes from reading Relativity, Gravitation, and World Structure. Your argument is just the negation of my statement.

Milne's model is fundamentally different from the Standard Model in the sense that whereas the standard model claims that the Big Bang was a whole lot of events shrunk down to a zero volume by a scale factor a(t)=0 at t=0. Milne's model is still a big bang, but a big bang of an entirely different character, where you simply have a single event at t=0.

I just wanted to clarify that, in case anyone was confused. There's no wiggle-room in Milne's model to say "No--it's not really a big bang, it's actually just space stretching." Milne's model is a literal "Big Bang" model.



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The dp/dt formulation does not change the argument, by the way. The point is you are dealing not just one force, but a sum of forces.
[tex]\sum \vec F = \frac{d\vec{p}}{dt}[/tex]
And if the sum of those forces is zero, there is no acceleration, and there is also not a change in momentum.

I have not intended to ignore any of your arguments, except for those which are "simple contradiction" or "strawmen." If you have arguments of some other variety that you feel I have ignored, please repeat them.

JDoolin

I think I begin to understand something of where this is going. I appreciate your further explanation.

The essential difference then, between Milne's Model and the Standard Model is whether two observers will disagree on simultaneity of distant objects(in Milne's Model), or whether two observers will disagree on the forces on distant objects(in the Standard Model.)

Thank you for giving further explanation here.

I still think that ignoring the relativity of simultaneity is a flaw, but I also realize now that I was misunderstanding Einstein's argument.

He was literally saying that the force on a distant particle is an observer dependent quantity, while time is an observer independent quantity. That seems amazing to me, and I will have to think about it further.

Wouldn't that mean, observationally, that all objects in the universe should be accelerating toward us?

Chronos

I agree with TQ, JDoolin, your arguments appear philosophical and you seem to refrain from mathematically sound assertions. I would like to see the math.

twofish-quant

That's not true. Standard Model (version 2012) says absolutely nothing about what happens at t=0 a(t)=0. Standard model (version 2012) breaks once you exit the inflationary era.

Maybe Standard Model (version 2020) will have something to say about this.

If the "big bang" was of an entirely different character, then you have a problem because we have lots of good observations of the big bang. Once you have the scale factor a(t), you can calculate nuclear reaction rates, and once you do that, you get helium and deuterium abundances.

There *is* a paper which a I cited, in which people have claimed that you can get correct abundances in a Milne-Dirac universe, but that involves 1) assuming that the universe consists of 50% anti-matter and 2) assuming that anti-matter is repulsive. The other thing is that they end up calculating supernova velocities which are now known to be wrong.

Right, the dp/dt argument was wrong, but the reference frame argument still stands.

If the sum of the forces is zero, you still get acceleration if you measuring the sum with respect to a non-interial reference frame. Once you pick a point to be your frame reference, then all other points become non-intertial, and if the sum of the forces is zero in those reference frames, you still have acceleration.

This happens a lot with gravity. If I'm in an elevator in free fall, I measure zero force. Even though all the forces are zero in my local reference frame, I'm still acclerating because those forces are defined in a non-interial reference frame. Once you've chosen one point in the universe, then all of the other points are non-interial therefore the fact that you get zero net force in those other frames is irrelevant.

The trouble is that I have no idea what you think is a simple contradiction or strawman unless you tell me.

Ultimately, the only argument is "we look at the universe and it doesn't work that way".

If you take the cosmological calculation, it is equally valid in large gas clouds of indefinite size and uniform density. If Milne was right and there is no net internal gravitational force in a large cloud of uniform density, then gas clouds wouldn't collapse to form stars, but they do.

Bobbywhy

Without putting total trust in the validity of Wikipedia, here are two excerpts from the Wiki page on the “Milne Model”:

“Incompatibility with observation
Even though the Milne model as a special case of a Friedmann-Robertson-Walker universe is a solution to General relativity, the assumption of zero energy content limits its use as a realistic description of the universe. Besides lacking the capability of describing matter Milne's universe is also incompatible with certain cosmological observations. In particular it makes no prediction of the cosmic microwave background radiation nor the abundance of light elements which are hallmark pieces of evidence that cosmologists agree support Big Bang cosmology over alternatives.

At the time Milne proposed his model, observations of the universe did not appear to be in a homogeneous form. This, to Milne, was a deficiency inherent in the competing cosmological models which relied on the cosmological principle that demanded a homogeneous universe. “This conventional homogeneity is only definite when the motion of the particles is first prescribed.” With present observations of the homogeneity of the universe on the largest scales seen in the cosmic microwave background and in the so-called "End of Greatness", questions about the homogeneity of the universe have been settled in the minds of most observational cosmologists.”

http://en.wikipedia.org/wiki/Milne_model

twofish-quant

First of all, let's not talk about the standard model since that's a moving target. What goes for the standard model will change over time. If it turns out that there is some massive observational flaw in the supernova data and the deceleration parameter is zero, then Milne's model will be Standard Model - version 2020.

Second, I'm explicitly not using the standard model of cosmology (2012), but something that is "close enough" that we can argue meaningfully about it. I'm using a Newtonian model of cosmology which is the zeroth order approximation. The Newtonian model includes assumptions that are *known* to be wrong (i.e. the speed of light is infinite) and results in conclusions that are also *known* to be wrong (i.e. Newtonian models don't take into account geometric curvature).

The reason I'm arguing based on a Newtonian cosmology is that neither you or I know general relativity well enough to have a reasonable discussion based on Friedmann-Walker models. The differences between Newtonian cosmology and FLRW are well known enough so that we can argue in a Newtonian world, and then figure out the implications once we add in GR.

The good thing about Newtonian models is that people have a good intuition about Newtonian. If you are in a falling elevator, the forces that you measure *will* be different than for a stationary observer. The other thing about thinking in Newtonian terms is that it's not out of the question that I can think of some experiment that you can perform in your living room that shows that a different gravity model (i.e. Milne) is wrong.

Do this in an elevator or a subway car. If you are in a subway car that suddenly stops, it should become obvious that forces are an observer dependent quantity.

Note that we are in a Newtonian model where we are *assuming* that time is observer dependent. If you go into GR, you don't use forces at all. If you use the concept of "force" and then you add in special relativity, then you get a total mess.

Yes. Gravity does that.

You throw a ball in the air, and it accelerates toward the ground. If you throw it hard enough then it may not ever hit the ground, but there is still acceleration toward the ground. An apple drops from a tree, it goes to the ground.

Now we know this to be wrong. Things are accelerating *away* from us. You toss a ball in the air, it speeds *away* from you. This is weird. Shocking even. But that's what we see.

twofish-quant

This isn't strictly true. I had a link to a paper that claimed that you can get CMB and light elements in a Milne-Dirac universe. You can search for it on the Los Alamos preprint server. The trouble is that in order to get those numbers you have to assume that the universe is 50% anti-matter and that anti-matter repels each other.

This is one of those papers that is totally nutty until something happens. If people do AEGIS and it turns out that anti-matter gravity is repulsive then someone is got a free trip to Sweden.

One thing about productive physicists is that every productive physicist I know of has at least one nutty idea. I know of a Nobel Prize winner that was convinced that black holes didn't exist, to the point that no one dared mention those words in front of him. However, he was productive because he had lots of ideas, so instead of spending 100% of his time disproving black holes, he spent 1-5% of his time on this, and then 30% of his time on stuff that got him the Nobel Prize.

There's a famous astrophysicist who was President of the AAS who has some truly crazy ideas about astrophysical jets (he doesn't think they exist). The thing is that he is nice about it. He isn't going to talk about astrophysical jets unless you ask him to talk about astrophysical jets, and if you ask him to talk about them, he'll calmly tell you a theory which everyone else thinks is truly wacko. But he spends most of his time on star formation.

It's the ability not to be totally consumed by one idea that distinguishes Roger Penrose from Halton Arp. Penrose has some truly nutty ideas. It's that he has enough pokers in the fire, that *something* is going to hit paydirt.

One problem with the original poster is that he is mining for gold in California. There was once a lot of gold in California, but people came in and took it all, so there's not much left. We are talking about arguments from the 1930's, and anything that was "paydirt" in 1930 has been mined out. Now if you want to mine the Amazon rain forest or the moon for gold, that's different.

Chronos

We can agree the current model has warts. That does not mean it is wrong, merely incomplete. We can improve on a model that is incomplete, we cannot improve on a model that is wrong.

JDoolin

Maybe I am refraining a little bit, because I still remain concerned that anything I say might be construed as "original research." Besides which, for all I know, I may well not even be competent to make "sound" assertions.

I don't have the time or energy to type up a lot of LaTeX, and I am not sure you'll be happy with the level of math content here, but I want to summarize my point-of-view, and maybe if you can just see the things I'm seeing, it would help to communicate.

http://www.spoonfedrelativity.com/mi...fication-1.swf
http://www.spoonfedrelativity.com/mi...fication-2.swf
http://www.spoonfedrelativity.com/mi...fication-3.swf
http://www.spoonfedrelativity.com/mi...fication-4.swf
http://www.spoonfedrelativity.com/mi...fication-5.swf

You see, there is nothing here about "the data" at all. I have no data. I haven't seen the data. My only argument is a philosophical one: I don't think it is right to throw away Lorentz Transformations. I think that special care should be made to try to figure out possible structure of the universe based on the POSSIBILITY that Milne was right. I'm not saying certainty. I'm saying POSSIBILITY.

JDoolin

I would like to see that paper, because that sounds like someone taking the Milne model seriously. It also sounds not at all nutty to me. Okay, maybe a little nutty. Speculative, but definitely in the realm of possibilities. Considering we've surely never had any anti-matter in large enough quantities, and around long enough to get a measure of it's gravitational field, have we?

Bobbywhy

I followed Halton Arp for years, thinking intrinsic redshift was a characteristic of quasars and that quasars were "connected" to low-redshift galaxies. I even wanted to believe the Tifft quantizatiion of redshifts. After many years of trying I gave up and got on with my learning process. My lesson learned: do not let wishful thinking and emotion control my science.

Oh Jonathan Doolin, I watched and listened carefully to -1, -3, -4, and -5 above. -2, as you say, is not functional right now. Too bad, though, as the first time through those four I was confused. So, I watched and listened to all four a second time. Now I am a trained listener and a professional public speaker (Toastmasters International=28 years) but, unfortunately, I never could figure out what message you were trying to communicate in each of those four modules. Perhaps your written script could be revised to be more coherent and to clearly address the point you want to make. The point is I couldn't find the point. Do the titles "spoonfedrelativity" intimate that even babies should understand your explanations?

Since you seem to have some great passion for Milne's Cosmology, could you simply write up a clear, professional paper with all your work and ideas, and then send it to some publisher that would then submit your work to peer review. Would that not either prove or disprove your approach?

Cheers, Bobbywhy

JDoolin

Thank you. Yes the original intent of the SpoonfedRelativity site was to communicate Special Relativity and eventually General Relativity in the clearest way possible. That was before I realized that Special Relativity and cosmological General Relativity were in direct conflict, and the FLRW metric assumes as one of its premise that the Lorentz Transformation equations are invalid at large distances.

Since then the website has become a big confusing question mark. It doesn't Spoonfeed anyone anything; instead it is a list of all of the arguments that have been accumulated over the years. At this point, it represents a personal cache of memories of what I was trying to do during Christmas Break or summer breaks a year, or two years or three,or many years ago,

However, I am finding that the Jing videos and the stylus tool might be a much better tool to use to keep track of what I am doing, figure out how to MAKE my point, and eventually come up with a better explanation.

JDoolin

The video-2 is functioning just fine. There are several animations in it. Mathematica was not functioning so I couldn't show you the program behind it. I suppose I could attach the .nb (Mathematica notebook) file if you'd like. Say the word, and I will try to locate it. (Though not today, I am totally out of time for this project today!)

twofish-quant

Yes. This is something that people are aware of, and I remember my cosmology professor mentioning it in an early lecture. It's not an assumption so much as a consequence. Once you start with the premise that the universe is isotropic and homogenous, then at large distances things are going to be flying away from each other at > c, and Lorenz transformation will break down.

Essentially, if you try to do cosmology using special relativity, you end up getting a big inconsistent mess. So you either do things with Newtonian gravitation or else you do it with full general relativity.

The reason that Einstein is considered a genius, is that once you figure out that the speed of light is finite, it's not easy to come up with a theory of gravity that's consistent. The "obvious" ways of adding relativity to gravity don't work.

There are people that believe that if Einstein hadn't come up with the key ideas, that we'd still be struggling trying to figure out how to make gravity work with relativity.