The Big Bang - Woo or not?

Zeuzzz

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In the beginning there was nothing, which exploded. - Terry Pratchett.

So. Woo or not?

MODERN COSMOLOGY: SCIENCE OR FOLK TALE?

Abstract:

In a survey for non-astrophysicists we compare the number of independent measurements which support Big Bang Cosmology, with the number of auxiliary hypotheses such as Dark Matter, Dark Energy and Inflation, and their associated free parameters, needed to shore it up. We find such parameters still outnumber the relevant observations, with no real sign of an improving trend over time. Precision, which is improving, doesn’t necessarily guarantee the soundness of the interpretation. Noncosmologists are thus entitled to be sceptical of such a weakly supported superstructure, which is currently composed of 5 separate theories piled on top of one another.


This thread should be about all the points raised in the above quoted article on the Big Bang and modern cosmology. If you cant be bothered to read it and contemplate what is being said, then please don’t post anything. It makes some very pertinent points.
 
Concluding paragraph (and yes I read it all):

So non-cosmologists are entitled to remain sceptical of the so called Precision version of Big Bang Cosmology even though it fits much of the data rather well, and some aspects of it, such as Expansion, are far more robust than others. Given the number of its free parameters [seventeen], so it ought. It may be healthier, as well as more exciting, to admit that we are surrounded by great mysteries which will provide challenges for generations to come. More fundamentally, as Daniel Boorstin the historian of science remarked: " The great obstacle to discovering the shape of the Earth, the continents and the oceans was not ignorance but the illusion of knowledge. Imagination drew in bold strokes, instantly serving hopes and fears, while knowledge advanced by slow increments and contradictory witnesses. " (19). If we are not appropriately sceptical about? Cosmology today then the current myth, if myth it is, could likewise hold up progress across all of extragalactic research for generations to come.

So I guess the answer is, "No it's not Woo".
 


Well, it certainly makes sense to keep track of the number of free parameters in a theory. If you can find another theory which fits the data as well and has fewer free parameters, it's superior and you've made progress.

However, the counting he does in Table 1 is complete nonsense. It's just totally wrong. He seems to be pretending that each of the experimentally determined values he lists in column four are single measurements. But that is absurd - each of those values is determined from thousands, millions, even billions of measurements. One only needs a tiny subset of those to determine the relevant parameters; all the millions of measurements that remain are checks of the theory!

Think of it like this: you have some set of data which you keep in a box. You have a theory that seeks to explain that data. All theories contain some parameters, so you have to pull out some data from the box and use it to fix those parameters. Once the parameters have been fixed your theory is unique and makes predictions for everything remaining in the box. If it agrees well you're happy, at least until you find a theory which does as well with fewer parameters. Ideally, you only need one single data point to fix a parameter! In practice it's better to use an average over many measurements to reduce the effects of errors and other uncertainties, but even then you're only using 1 number (it's just that it's an average). All the remaining numbers are checks on the goodness of the fit of your theory to reality.

In this case, how much data do we need to fix those cosmological parameters? Let's pick 1: H_0, the Hubble constant. We can determine H_0 in many, many ways, and that's the point. We pick one way - for example, we measure the average redshift-distance relation for some set of standard candles - and then we make sure our answer is consistent with all the other ways we could measure it. And even within the set of standard candles (say, type 1A supernovae) we make sure that they are all in agreement to within some reasonable errors (from peculiar velocities, measurement error, etc.). So in the end we used 1 number to fix H_0, and then we predicted (or postdicted) literally millions of data. Counting all that data as 1 measurement is just totally wrong.

By the way, there are mathematical formulae, which are occasionally used in hypothesis testing and theory comparison, which formalize what I said above. If this guy were serious he would have used one to do this analysis, rather than this ridiculous "significance". But the answer would have been overwhelmingly against his (plainly) forgone conclusion, so I assume that's why he didn't.
 
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Terry Pratchett said:
An alternative, favored by those of a religious persuasion was that A'Tuin was crawling from the Birth place to the Time of Mating, as were all the stars in the sky which were, obviously, also carried by giant turtles. When they arrived they would briefly and passionately mate, for the first and only time, and from that firey union new turtles would be born to carry a new pattern of worlds. This was known as the Big Bang hypothesis.
Woo.
 
A theory that changes and grows as new evidence is sought out:

Not woo.
 
Originally posted by Terry Pratchett:
An alternative, favored by those of a religious persuasion was that A'Tuin was crawling from the Birth place to the Time of Mating, as were all the stars in the sky which were, obviously, also carried by giant turtles. When they arrived they would briefly and passionately mate, for the first and only time, and from that firey union new turtles would be born to carry a new pattern of worlds. This was known as the Big Bang hypothesis.

Woo.

How dare you.

:D
 
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Mike Disney is always worth reading, and this document doesn't disappoint.

One way to look at this is as a contribution to HPS (History and Philosophy of Science), a semi-quantitative method for addressing the demarcation problem: define a method for determining FPs, draw a timeline, populate a table, turn the handle and you have a crude measure of how close to non-science a theory is ... done implicitly, using an example (modern cosmology).

If so, then we can test the method, by applying it some other part of science, evolution say, or the Standard Model in particle physics.

I haven't tried myself - maybe some rainy afternoon I will - but I suspect almost nothing in modern science would have a "Significance", today, significantly smaller than when the new idea (theory) was first introduced.

If so, then all this 'Disney method' tells us is that for every question a new theory answers, more questions present themselves ...

Needless to say, and true to form, this Disney material contains a number of errors, ranging from omission (e.g. his history of DM is, um, skewed let us say) to commission (e.g. H0), several of which may be severe enough to knock big holes in his conclusion even if his method were sound.

Just one serious, methodological, error (for now): independent corroboration of an FP is irrelevant in this method ... IF CBR (Penzias and Wilson) THEN eta (photon to baryon ratio), well and good; however eta may then be tested by other means, quite independent of WMAPs, BOOMERANGs, etc. And such tests have been done, and eta independently constrained, which surely should be somehow acknowledged? An FP independently corroborated should count more than one with just one leg to stand on, shouldn't it? In the 'Disney method' it doesn't, and can't.
 
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The article has some really bad points:
The Lambda-CDM model has exactly 6 parameters not "18 free parameters (only 17 independent)". There are another 5 parameters derived from the 6 basic parameters.


BBC is not a single theory but 5 separate theories constructed on top of one another. The ground floor is a theory, historically but not fundamentally grounded in General Relativity, to explain the redshifts – this is Expansion, which happily also accounts for the Cosmic Background Radiation. The second floor is Inflation – needed to solve the horizon and ‘flatness’ problems of the Big Bang. The third floor is the Dark Matter hypothesis required to explain the existence of contemporary visible structures, such as galaxies and clusters, which otherwise would never condense within the expanding fireball. The fourth floor is some kind of description for the ‘seeds’ from which such structure is to grow. And the fifth and topmost floor is the mysterious Dark Energy idea needed to allow for the recent acceleration of the Expansion, apparently detected in supernova observations.
BBC is actually 4 theories - a computer simulation of the ΛCDM model in 2005 shows the large-scale struture of the universe emerging without any fifth theory. I would also reorder his floors:
  1. Expansion supported by redshift and CMB.
    There is other evidence ruling out a infinite, static and eternal universe (the Lyman-alpha forest) and there is always Olbers paradox to resolve.
  2. Dark Matter which is needed to support several observations and has actually been directly observed.
  3. Dark Energy actually detected in supernova observations. It is also needed to account for the fact that the CMB shows that the universe is very close to flat.
  4. Inflation is more theoretical but explains a lot.
The author does not know that "Dark Matter" and "Dark Energy" are not "deliberately inscrutable" names. They are placeholders for whatever is causing the effects that we have observed.

He dismisses the 2001 papers by Allan Sandage and Lori M. Lubin about the Tolman surface brightness test with "Contemporary cosmologists mutter about “Evolution”".
 
Not.

The important point to note is that merely being wrong does not make something woo. Whether the big bang actually happened or not, theories about it are scientific, evidence based theories that are falsifiable and subject to change based on new evidence. The question of whether theories about the big bang are correct and what evidence supports them is an interesting one, but to try to dismiss them as woo is just plain stupid.
 
For now it is the best we got. It seems to be fitting observational evidence. It (so far) does not seem to have thrown up any insumountable problems

Mind you, there might be some kid in junior school who is discovering maths - and already plotting the new mathematical model of the universe
 
Considering that the OP could not defend any of the theories they present from a wet paper bag...


There was not 'nothing' prior th the "Big Band Event", there was the Hall, we can not see the Hall because all we can do is Listen to the Music. We can surmise the Players from the Music They Play. We can't tell what the Hall looks like or even if there is a Score or a Conductor.

Um Zeuzzz, any good hypothesis to explain the red shift phenomena?
 
Not woo.

And I agree with sol invictus; parameter counting as a measure of a model's applicability incredibly naive.

Disney's 'toy model' suggests that you can get the BBC model to fit anything at all just by tweaking its free parameters. This is very far from being true; it is powerfully constrained by its structure and interlocking theories - general relativity, quantum mechanics and the standard model - all of which have to work consistently with one another to produce the cosmology we observe. This is why you can't just take any model with lots of free parameters, as cranks are wont to do, and perform a parametric fit to observations.

And frankly, Disney exhibits a bias that just gets up my nose. To quote: "Just because professionals cling to such a flimsy theory, there being no other within their current grasp, need not discourage the rest of us from being a good deal more detached." What, is he saying that _because_ professional cosmologists are, um, professional, that they are necessarily _less_ able to recognize problems with the standard models? And that _not_ being a professional is an advantage in the pursuit of the grand cosmological Truth?

I call ******** on Disney; if anyone's selling folk-tales, it's him.
 
In the beginning there was nothing, which exploded. - Terry Pratchett.

I'm just going to comment on this. The Terry Pratchett quote is not an accurate description of the Big Bang. I imagine he did not intend it to be one.
 
As usual, there's a big difference between what cosmologists actually do, and what crackpots crow about the "flaws" in.

Disney's paper suggests that Big Bang cosmology is the result of fitting 17 free parameters to 13 data points. If this is what we had done, our results would indeed be nonsense and/or fraudulent; there's no way to honestly report results or error bars from an underconstrained fit.

Fortunately, real precision cosmology is very highly overconstrained. WMAP's classic paper http://arxiv.org/abs/astro-ph/0302209: they extract a handful of cosmological parameters from fits with more than 1400 independent data points. The result passes any relevant statistical test (they report Chi-squared).

Disney's mistake appears to be that he takes, e.g., "the cosmic microwave background" to be a single data point. It isn't. It's a spectrum, with a very particular shape including dozens of peaks and valleys; every wiggle in this shape helps to probe a different cosmological parameter.
 
In the beginning there was nothing, which exploded. - Terry Pratchett.

As opposed to "In the beginning, erm, well there wasn't a beginning. And yet we're still here and we haven't run out of hydrogen. And the sky isn't bright at night because erm mumble mumble. And the Hubble relationship, well that's just one of those things. And plasma makes the world go round. Well the galaxy actually."
 
Notice how those who label real scientific theories "woo" are almost always peddling real woo themselves?
 

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