Is cherry picking evidence a hindrance to scientific progress?

[wolram]

According to this paper an amateur would never know.

http://arxiv.org/PS_cache/arxiv/pdf/0705/0705.2462v1.pdf

 

[gendou2]

This paper raises some interesting questions. It is healthy to take the time to question what we're taught. The overall tone of the paper is that of (in my opinion) very radical skepticism. This is less useful in science than a healthy skepticism.

Also, it seems like it was written by someone with a law degree, I noticed references to the legal system, which I found distasteful (like the beginning of page 6).

 

[wolram]

I have no idea if Richard Lieu has a law degree or not, he doe's seem to have been involved in writing papers on cosmology though.
As for radical skepticism i am not sure where the line is drawn with healthy skepticism,
may be it comes from frustration of not having a balanced overview of how cosmology progresses.

 

[George Jones]

I have no idea if Richard Lieu has a law degree or not, he doe's seem to have been involved in writing papers on cosmology though.

http://physics.uah.edu/FacultyPages/richardlieu.htm

As for radical skepticism i am not sure where the line is drawn with healthy skepticism,
may be it comes from frustration of not having a balanced overview of how cosmology progresses.

Lieu's opinions were the subject of thread

https://www.physicsforums.com/showthread.php?t=170753.

 

[gendou2]

I felt his skepticism was radical in section 3 on page 4, for example. The explanation for the CMB that it is left over from the origin of the universe is a wonderful discovery, which he paints as a naive conclusion through hypercritical questioning. I'm not saying this is a bad thing to do, but when I step back and look at the whole paper, I don't see where his frustration is coming from. Probably because I am a stupid amateur. Richard sure is bitter. :(

 

[russ_watters]

He's certainly calling the kettle black in a few places. For example, he decries the use of (in his opinion) unverified assumptions, yet suggests that the CMB could be caused by something going on in space that we don't know about.

Regarding the lack of spectral lines to measure redshift from - how is it reasonable to assume anything other than a black body spectrum, in the absence of them?

 

[mysearch]

While I am not qualified to comment on all the technical details, as Richard Lieu appears to be, I have mixed views about his article. Based on the following extracts, Lieu does not seem to consider cosmology a science in the same sense as physics or astronomy.

"Astronomy can never be a hard-core physics discipline, because the Universe offers no control experiment, i.e. with no independent checks it is bound to be highly ambiguous and degenerate.”

"Cosmologists should not pretend to be mainstream physicists, because there is only one irreproducible Universe and control experiments are impossible

“Thus I do not see the wisdom of funding agencies in planning such ambitious and expensive programs to perform dark energy research, to the detriment of other fields of astronomy, as though cosmology has now become a branch of physics, which it will never be.”

I would have thought cosmologists would have reacted strongly to such criticism and, if possible, taken apart Lieu’s arguments point by point. Does anybody know if this was done? For example, what does Lieu mean by hard-core physics discipline? As an outsider, it seems that much of modern theoretical physics is also based on mathematical assumptions, which lack the necessary empirical verification to be cited as proven fact at this time. However, such an example of “calling the kettle black” might not reflect well on either side of this scientific divide or attract research grants. Of course, any science predicated on a model where `normal` matter only constitutes 4% of the universe with the remaining 96% described in terms of 23% cold dark matter and 73% dark energy; which seems not to have been adequately explained by particle or quantum physics must expect its assumptions to be challenged as `unproven` in reference to Lieu’s comment about Scottish law.

While possibly a bit too tangential to this thread, William K. Clifford was a mathematician and philosopher, who wrote an essay entitled `The Ethics of Belief (1877)`, which draws the conclusion that “it is wrong always, everywhere, and for anyone, to believe anything on insufficient evidence” based on three lines of arguments:

o The Duty of Inquiry
o The Weight of Authority
o The Limits of Inference

Personally, in my limited reading, cosmology does try to generally adhere to the tenets of first two requirements, but may not always highlight when the third has been exceeded. In this respect, I think Lieu may have a point, but then again I have to accept that my opinion carries no weight of authority

 

[turbo]

Lieu is not the only professional in the field who feels that cosmology is not a science. Michael Disney (observational astronomer) made a very similar case a number of years ago, using many of the same arguments.

http://arxiv.org/abs/astro-ph/0009020

 

[wolram]

There are papers in the arxiv that (do Away) with dark energy and dark matter, so how do our theoris stand if 96% of the mass of the universe can be calculated away?

 

[turbo]

There are papers in the arxiv that (do Away) with dark energy and dark matter, so how do our theoris stand if 96% of the mass of the universe can be calculated away?

There's the rub. If Dark Matter is to be eliminated, we would have to modify our theories regarding gravity. MOND seems to explain the flat rotation curves of spiral galaxies, even predicting the behavior of LSBs (low surface-brightness galaxies) about a decade before we got usable observations of them. The problem is that MOND is a special case that cannot be extended to gravitational anomalies on large scales, like the apparent excess in gravitational binding in clusters. This hints that a more general law is needed if DM is to be eliminated. Perhaps gravitational attraction is not the simple inverse square law of Newtonian gravity, nor Einstein's relativistic reformulation. Explaining the behaviors of galaxies and clusters of galaxies would then require not a constant "g" but a variable one - perhaps one that scales up or down with the matter density in each locale. This would be a radical move, indeed, and I don't see any real movement in that direction. Thanu Padmanabhan has modeled "empty" space as an elastic solid, much as Sakharov suggested in the '60's, and has suggested that gravity arises from matter's interaction with that space. Padmanabhan's formulation does not admit of vacuum polarization in the presence of matter, however, so it gets us no closer to a DM-free universe. Here is a link to his home-page with writings, etc. If you follow his citations, you'll find some interesting papers to keep you busy for a long time.

http://www.iucaa.ernet.in/~paddy/

 

[Chronos]

A simpler explanation is to include DM. Seeking alternatives is not a bad idea, but, comparing alternatives to DM should be part of the exercise. A better fit for alternative theories in specific observations is not a compelling result. DM is not disproven by any such observations to my knowledge. The alternatives thus far are much less convincing when examined with respect to all the observational evidence.

 

[mysearch]

Thanks for the reference to the Michael Disney paper. An interesting read. Again, would like to know whether any of the claims have been refuted in the 8 years since this paper was first published? However, I am not sure that the main thrust of either the Disney and Lieu papers is directly concerned with the specifics of any given model. IMO, Disney seems to be arguing that cosmology has oversold the validity of some of the science underpinning the current model, while Lieu seems to be suggesting that as a result of this oversell, research funding is now being misdirected. In this context, I found the Michael Disney paper more of a direct challenge to cosmology as a whole because it seem to question the very data on which any theoretical model is based and not just the one currently in vogue.

“Cosmology rests on a very small database: it suffers from many fundamental difficulties as a science, whilst observations of distant phenomena are difficult to make and harder to interpret.”

“Cosmology requires us to extrapolate what physics we know over huge ranges in space and time, where such extrapolations have rarely, if ever, worked in physics before.”

“Objects at cosmologically interesting distance are exceedingly faint, small and heavily affected by factors such as redshift-dimming and k-corrections, so it will obviously be very difficult, if not impossible, to extract clear information about geometry, or evolution, or astrophysics”

On a slightly philosophical note, I think Disney is right to highlight such issues, but also think that cosmology continues to serve an important need for many by questioning the nature of the universe from a scientific perspective. Again, IMO, science is entitled to speculate, but is not entitled to oversell a ‘cherry picked` model, when the limits of inference are known to have been exceeded; especially if the issues are not always readily understood by graduates of science, let alone the public at large.

 

[Nereid]

(bold added)

Thanks for the reference to the Michael Disney paper. An interesting read. Again, would like to know whether any of the claims have been refuted in the 8 years since this paper was first published?

What claims?

As in, a claim, made in the paper, which is sufficiently precise as to be capable of being "refuted" in principle?

If any reader is interested in compiling a list of such (potentially refutable) claims, I'd be interested in discussing the extent to which they may - or may not - have been refuted in the last ~decade.

[...] In this context, I found the Michael Disney paper more of a direct challenge to cosmology as a whole because it seem to question the very data on which any theoretical model is based and not just the one currently in vogue.

This might be a good place to start, looking for possibly refuted claims.

For example, SDSS hadn't started (in terms of producing results) when Disney wrote that paper; today it's original scope is long finished and 2+ extensions are close to the end.

On a slightly philosophical note, I think Disney is right to highlight such issues, but also think that cosmology continues to serve an important need for many by questioning the nature of the universe from a scientific perspective. Again, IMO, science is entitled to speculate, but is not entitled to oversell a ‘cherry picked` model, when the limits of inference are known to have been exceeded; especially if the issues are not always readily understood by graduates of science, let alone the public at large.

What such limits do you have in mind, mysearch?

 

[mysearch]

Hi Nereid,
I will try to respond to some of the issues you raised, more by way of clarification, as I am sure others are more qualified than myself to address specific issues, e.g. see Turbo-1 post #14. However, the general issue for many people reading these papers, as part of a learning process, is deciding between the claim and counter-claim. Therefore, I wanted to know whether an authoritative source had already effectively addressed any of the claims made in either paper.

If any reader is interested in compiling a list of such (potentially refutable) claims, I'd be interested in discussing the extent to which they may - or may not - have been refuted in the last ~decade.

I hope people will take up your offer. It would seem to be an excellent and educational undertaking for this forum.

For example, SDSS hadn't started (in terms of producing results) when Disney wrote that paper; today it's original scope is long finished and 2+ extensions are close to the end.

This is exactly the sort of detail I had in mind. Does this survey significantly undermine the central arguments of either paper? Again, post #14 seems to already be addressing this issue.

What such limits do you have in mind, mysearch?

In part, I was only making an indirect reference to my previous post (#7) about the principles of Clifford’s essay on the Ethics of Belief. Clifford defined the limits of inference as something, which goes beyond our direct experience and inferred from past experience but based primarily on the assumption, that what we do not know is like what we do know. In this respect, dark matter and dark energy not only go beyond our direct experience, but also appear to be nothing like what we currently know. Of course, this doesn’t make these ideas wrong, but might be an example where the limits of inference has been exceeded, at least, from the perspective of verifiable science. As I know you are more qualified to answer, maybe I could ask whether you think any aspect of the current model exceeds this limit in your view? (and where if appropriate)

 

[Nereid]

Hi Nereid,
I will try to respond to some of the issues you raised, more by way of clarification, as I am sure others are more qualified than myself to address specific issues, e.g. see Turbo-1 post #14. However, the general issue for many people reading these papers, as part of a learning process, is deciding between the claim and counter-claim. Therefore, I wanted to know whether an authoritative source had already effectively addressed any of the claims made in either paper.

OK, let's start with turbo-1's list ...

As I read it - and I hope he will be quick to comment - nothing in his list is in either Lieu's or Disney's lists, or papers, except in the most tenuous, vague, and non-refutable form.

While I'm happy to do what I said in my previous post ("If any reader is interested in compiling a list of such (potentially refutable) claims [in Disney's paper], I'd be interested in discussing the extent to which they may - or may not - have been refuted in the last ~decade."), the last thing I wish to be involved with is an unfocussed, "let's throw in anything we can think of" discussion.

I hope people will take up your offer. It would seem to be an excellent and educational undertaking for this forum.

This is exactly the sort of detail I had in mind. Does this survey significantly undermine the central arguments of either paper? Again, post #14 seems to already be addressing this issue.

So let's start here, and restrict ourselves to just the Disney paper, shall we?

What are the specific, potentially refutable claims in Disney's paper?

With those in hand, we can then take a look at SDSS (and its extensions) and see whether it* addressed any of the Disney claims.

In particular, perhaps you - or turbo-1 - would like to map Disney's claims onto the four points in post#14?

In part, I was only making an indirect reference to my previous post (#7) about the principles of Clifford’s essay on the Ethics of Belief. Clifford defined the limits of inference as something, which goes beyond our direct experience and inferred from past experience but based primarily on the assumption, that what we do not know is like what we do know. In this respect, dark matter and dark energy not only go beyond our direct experience, but also appear to be nothing like what we currently know. Of course, this doesn’t make these ideas wrong, but might be an example where the limits of inference has been exceeded, at least, from the perspective of verifiable science. As I know you are more qualified to answer, maybe I could ask whether you think any aspect of the current model exceeds this limit in your view? (and where if appropriate)

I'll read your post again, and (if I can find it) Clifford's essay.

However, it seems this is going way, way beyond the limited scope of my post ... what's the point of getting knee-deep in this kind of thing if you cannot show that your primary source (Disney's paper) contains any potentially refutable claims (of relevance)?

* SDSS itself did not produce anything except a great deal of observational data; however, many people wrote papers based on that data, and many of those papers may have direct relevance to Disney's refutable claims (if there are any).

 

[mysearch]

Hi Nereid,

I believe there are a number different discussions going on here, which might be causing some confusion, at least, to me. So way of clarification:

o Wolram originally raised the Lieu paper in post #1. The essence of Lieu’s concerns, which might be refuted or challenged, seems to be summarised in Table-3 on page 9.

o I believe Lieu is a physicist, so all I wanted to know was whether the cosmology camp had responded to his apparent challenge. Hence my comments in post #7. By the way, the Clifford essay is not directly relevant to this discussion, it was written 130 years ago in the context of a secular debate. I only mentioned it, because some of the arguments regarding unsupported beliefs apply to science as well as theology, but should be treated as tangential to this thread.

o Turbo referenced the Disney article in #8, presumably as another professional source apparently questioning some aspects of modern cosmology.

o Again, in post #12, I was again asking whether cosmology had collectively responded to any of the issues in this article. Given your request for focus in post #19. I believe the main challenge to the science of cosmology lie in section 3, specifically bullets A-F on pages 3 & 4.

o I assume Turbo raised his comments concerning SDSS in response to your reference in post #13. This seems to be a separate debate that doesn’t appear to be directly linked to either of the Lieu or Disney papers, but presumably is being cited as another area for possible discussion. I have nothing to add to this discussion, but would be interested in learning more so will review the info via the revised link provided by Turbo, in post #17, simply to try and follow any subsequent discussion.

o Finally, I assume the quasar issue is a specific line item within the SDSS data. Therefore, again, it doesn’t seem directly related to the issues raised by either Lieu or Disney, although another possible issue for debate.​

While I realize that some of these issues may seem to be a sceptical challenge to modern cosmology, for many non-professional, but interested members of this forum it is very difficult to resolve the claim and counter-claim of this nature. Therefore, I hope that you can spare a little time to help people, like me, try to grasp all the issues being raised. Thanks

 

[turbo]

In the meantime, may I ask you to provide some specific details of how and where quasars* are covered in Disney's paper? in Lieu's?

* "modern cosmology's notion of the nature of quasars"

I posted the link to Disney's paper just to demonstrate that Lieu's arguments have been made before, in similar terms. I'm not going to bother trying to defend either of them, especially since they deal in generalities vs specifics.

I will add to Strauss' mysteries that the slope of quasar luminosity function at redshift ~3 and above seems to "take off" with no good theoretical reason given. Also, one has to look at the PS images he displays while giving his presentation to see additional theoretical problems including the shape and slope of the LF at the faint end:
"Fitting these data simultaneously is a challenge for modern models of quasar evolution."

 

[Nereid]

Hi Nereid,

I believe there are a number different discussions going on here, which might be causing some confusion, at least, to me. So way of clarification:

o Wolram originally raised the Lieu paper in post #1. The essence of Lieu’s concerns, which might be refuted or challenged, seems to be summarised in Table-3 on page 9.

o I believe Lieu is a physicist, so all I wanted to know was whether the cosmology camp had responded to his apparent challenge. Hence my comments in post #7. By the way, the Clifford essay is not directly relevant to this discussion, it was written 130 years ago in the context of a secular debate. I only mentioned it, because some of the arguments regarding unsupported beliefs apply to science as well as theology, but should be treated as tangential to this thread.

o Turbo referenced the Disney article in #8, presumably as another professional source apparently questioning some aspects of modern cosmology.

o Again, in post #12, I was again asking whether cosmology had collectively responded to any of the issues in this article. Given your request for focus in post #19. I believe the main challenge to the science of cosmology lie in section 3, specifically bullets A-F on pages 3 & 4.

o I assume Turbo raised his comments concerning SDSS in response to your reference in post #13. This seems to be a separate debate that doesn’t appear to be directly linked to either of the Lieu or Disney papers, but presumably is being cited as another area for possible discussion. I have nothing to add to this discussion, but would be interested in learning more so will review the info via the revised link provided by Turbo, in post #17, simply to try and follow any subsequent discussion.

o Finally, I assume the quasar issue is a specific line item within the SDSS data. Therefore, again, it doesn’t seem directly related to the issues raised by either Lieu or Disney, although another possible issue for debate.​

While I realize that some of these issues may seem to be a sceptical challenge to modern cosmology, for many non-professional, but interested members of this forum it is very difficult to resolve the claim and counter-claim of this nature. Therefore, I hope that you can spare a little time to help people, like me, try to grasp all the issues being raised. Thanks

As George Jones pointed out, in post#3 in this thread, there is already a thread on the Lieu paper, started ~18 months' ago (though wolfram seems to have not participated in it). That thread also contains some discussion of the points turbo-1 makes in his post (#14; turbo-1 did participate in that thread). Have you had a chance to read through it? It contains some quite good stuff, of direct pertinence to this thread; for example, how easy it is to fall into rabbit holes, get diverted from the original focus (look at how irrelevant inflation is to the specific concerns over LCDM cosmology, to take just one example). As I said earlier, I have no desire to engage in yet another rambling discussion, at least without first having established the scope in clear terms (and having participants agree to not go off-topic).

I suggest that if you'd like to discuss the points Lieu raises, specifically whether any 'counter-claims' have been made, you should do so by reviving that thread.

Again, in post #12, I was again asking whether cosmology had collectively responded to any of the issues in [Disney's] article. Given your request for focus in post #19. I believe the main challenge to the science of cosmology lie in section 3, specifically bullets A-F on pages 3 & 4. - mysearch

That's good enough for me; let's take a closer look at this, shall we?

Let's start by going through the 14 points; what do you think of them (in terms of their legitimacy re "difficulties for cosmology as a science")? Then we can look at bullets A-F next ...

 

[Nereid]

I posted the link to Disney's paper just to demonstrate that Lieu's arguments have been made before, in similar terms. I'm not going to bother trying to defend either of them, especially since they deal in generalities vs specifics.

[...]

"Disney's paper just to demonstrate that Lieu's arguments have been made before, in similar terms" - turbo-1

Well, as a matter of opinion, I think "Lieu's arguments" bear little resemblance to Disney's, either in terms of the specifics or the generalities ... except (possibly) in a way that's so vague and wishy-washy that clear discussion is all but impossible.

"I'm not going to bother trying to defend either of them" - turbo-1

OK, so why introduce the Disney paper then?

 

[turbo]

English is my first language and I think that the first sentence you quoted in you last post was sufficiently clear.

 

[Nereid]

English is my first language and I think that the first sentence you quoted in you last post was sufficiently clear.

So, IOW:

turbo-1: Disney's paper contains arguments that are similar to those in Lieu's paper.

Nereid: I disagree; there is little, if any, similarity in the arguments presented in the two papers.

I guess that ends the discussion on that point (at least by the two of us), right?

 

[turbo]

So, IOW:

turbo-1: Disney's paper contains arguments that are similar to those in Lieu's paper.

Nereid: I disagree; there is little, if any, similarity in the arguments presented in the two papers.

I guess that ends the discussion on that point (at least by the two of us), right?

Wonderful job of misdirection! You were the first to mention SDSS. In the spirit of the title of the thread, I pointed out several specific observations from SDSS that challenged modern cosmology, and have yet to be addressed, years down the road. As you know, I follow literature of quasars and AGNs fairly carefully, and many of Strauss' points came out in paper after paper over a number of years. His presentation at was a VERY handy condensation of the conclusions of those papers.

You seem not to want to discuss any of Strauss' observations but instead try to make me defend Disney's paper. My answer is that if you wish to selectively ignore the SDSS data that disagrees with concordance cosmology, the OP has his answer. Cherry-picking is alive and well. I will gladly discuss the SDSS data with you, as you well know. If you're up to it, fine.

 

[Nereid]

Wonderful job of misdirection! You were the first to mention SDSS. In the spirit of the title of the thread, I pointed out several specific observations from SDSS that challenged modern cosmology, and have yet to be addressed, years down the road. As you know, I follow literature of quasars and AGNs fairly carefully, and many of Strauss' points came out in paper after paper over a number of years. His presentation at was a VERY handy condensation of the conclusions of those papers.

You seem not to want to discuss any of Strauss' observations but instead try to make me defend Disney's paper. My answer is that if you wish to selectively ignore the SDSS data that disagrees with concordance cosmology, the OP has his answer. Cherry-picking is alive and well. I will gladly discuss the SDSS data with you, as you well know. If you're up to it, fine.

Let's review how the bouncing ball got to this point, shall we?

= = = = = = = = =
turbo-1, post#8: "Lieu is not the only professional in the field who feels that cosmology is not a science. Michael Disney (observational astronomer) made a very similar case a number of years ago, using many of the same arguments."
= = = = = = = = =
Nereid, post#13 "[...] In this context, I found the Michael Disney paper more of a direct challenge to cosmology as a whole because it seem to question the very data on which any theoretical model is based and not just the one currently in vogue. - mysearch
This might be a good place to start, looking for possibly refuted claims.

For example, SDSS hadn't started (in terms of producing results) when Disney wrote that paper; today it's original scope is long finished and 2+ extensions are close to the end."
= = = = = = = = =
turbo-1, post#14: "SDSS is perhaps the most ambitious astronomical survey ever undertaken, and it has provided a wealth of new data. Unfortunately for cosmologists (or fortunately, if cosmologists are willing to re-group), some of the findings are quite inconsistent with their expectations." (it's a long post, but not a word about how SDSS is pertinent to the points made in Disney's paper (or Lieu's, for that matter).
= = = = = = = = =

... and the disconnect continues.

An excellent example of the kind of unfocussed discussion I mentioned earlier!

"You seem not to want to discuss any of Strauss' observations" - turbo-1

Would you please re-read my posts? I have not only asked you for your source (which you kindly provided, thank you again), not only listened to the presentation, and not only read all 100 of the supporting material's PPT slides, but asked you some specific questions about the points you made ... so that we will be on the same page in any discussion that may follow.

"but instead try to make me defend Disney's paper" - turbo-1

I'd love you to try to do that! However, my intentions are clearly stated in my posts ... I want to understand what you wrote (re the similarities between Lieu's and Disney's papers), and what connection - if any - there is between Disney's paper and the points you make about Strauss' presentation.

 

[Nereid]

[...]

For example, SDSS hadn't started (in terms of producing results) when Disney wrote that paper; today it's original scope is long finished and 2+ extensions are close to the end.

This is exactly the sort of detail I had in mind. Does this survey significantly undermine the central arguments of either paper? Again, post #14 seems to already be addressing this issue.

Not terribly relevant, but this is one 'i' I'd like to dot.

It would seem, from turbo-1's subsequent (to #14) posts, that "post #14" is not relevant to Disney's paper (or Lieu's), much less addresses the points in either, in any way.

What such limits do you have in mind, mysearch?

In part, I was only making an indirect reference to my previous post (#7) about the principles of Clifford’s essay on the Ethics of Belief. Clifford defined the limits of inference as something, which goes beyond our direct experience and inferred from past experience but based primarily on the assumption, that what we do not know is like what we do know. In this respect, dark matter and dark energy not only go beyond our direct experience, but also appear to be nothing like what we currently know. Of course, this doesn’t make these ideas wrong, but might be an example where the limits of inference has been exceeded, at least, from the perspective of verifiable science. As I know you are more qualified to answer, maybe I could ask whether you think any aspect of the current model exceeds this limit in your view? (and where if appropriate)

"Clifford defined the limits of inference as something, which goes beyond our direct experience and inferred from past experience but based primarily on the assumption, that what we do not know is like what we do know." - mysearch

Well, if that's the definition, it seems to me that almost all of modern science exceeds "https://www.physicsforums.com/showpost.php?p=2016182&postcount=7""!

But perhaps I've misunderstood this term (not as used by Clifford, who wrote long before the quantum revolution, but by you), so let me try to get a clearer picture ...

Which of the following do you think you have some familiarity with?

* http://en.wikipedia.org/wiki/Atmospheric_Cherenkov_telescope" ?

* work on the solar neutrino 'problem'?

* http://www.ligo.caltech.edu/" ?

* http://swift.gsfc.nasa.gov/docs/swift/swiftsc.html" ?

I ask because all of them - and a great many more examples - involve the production of 'data' or 'observations' which Clifford would surely have characterised as "go[ing] beyond our direct experience" and in which "the limits of inference has been exceeded" (of course, details matter, so that's my telegraphed conclusion, which gets well ahead of what you - or any other reader - may understand by each of the examples, re my intent).

Some of these are relevant to one of Lieu's points too, concerning controlled (laboratory) experiments.

 

[George Jones]

I've split off part of this thread into a new thread, Quasars and Cosmology. It's a bit of a hatchet job, but I've got to run to catch my bus. I might try make the split more smoothly, if possible, later.

 

[turbo]

Thanks, George.

 

[mysearch]

I have to say that I am saddened that this thread seems to have terminated in shouting in lots of bold type rather than continuing as a discussion and debate. However, before signing off, I wanted to respond to a few points.

As George Jones pointed out, in post#3 in this thread, there is already a thread on the Lieu paper, started ~18 months' ago

Thanks for the reminder. I usually follow George Jones pointers, but in this case I gave up too soon. There are 6 pages and 88 posts in this thread and I originally failed to find the appropriate references in the early posts. For those interested, the link is:
https://www.physicsforums.com/showthread.php?t=170753&page=6
Garth raises the issue of the Lieu paper in post #1 and also points to another thread, which may be useful to others, like me, who are trying to come up to speed with issues that others may have already discussed in the past, the resurrection of which may have caused some unintentional irritation. However, Wallace probably gives the most considered and helpful reply, I have seen to-date, see posts #3 & #6.

Well, if that's the definition, it seems to me that almost all of modern science exceeds "The Limits of Inference"!

It’s a definition, not necessarily the only definition. The only point that was really being made was that much of modern science, based on mathematics, is still speculative until some form of empirical verification can be provided. Therefore, as part of any learning process, rather than rote acceptance, I was interested in trying to understand the arguments for and against the Lieu and Disney papers, plus where such limits may have been exceeded. However, I think it may be more productive, if I spend my time reviewing the two earlier threads mentioned above, as suggested.

Some readers may also be interested in another paper, referenced by Garth in post #16, from which the following quote was taken:
https://www.physicsforums.com/showpost.php?p=1337905&postcount=16

‘We do not know anything - this is the first. Therefore, we should be very modest - this is the second. Not to claim that we do know when we do not- this is the third. That’s the kind of attitude I’d like to popularize. There is little hope for success.’ (Karl Popper)

 

[atyy]

"In an affort to address these questions, it should be noted that many other cosmological models can be constructed with a late time behavior similar enough to the standard model that it is difficult to exclude them with absolute certainty."
Computational Cosmology
Peter Anninos
http://relativity.livingreviews.org/Articles/lrr-2001-2/index.html

"So, even though we do not understand our universe, we have been quite successful in parametrising our ignorance in terms of well-chosen numbers."
Dark Energy and its Implications for Gravity
T. Padmanabhan
http://arxiv.org/abs/0807.2356

"Alternatives to CDM, a fundamental inflaton field and dark energy are all being
pursued actively."
Relativistic cosmology and large-scale structure
Christos G. Tsagas, Anthony Challinor, Roy Maartens
http://arxiv.org/abs/0705.4397

 

[wolram]

I guess the Lieu and Disney papers can only prove that there is a couple of disenchanted scientists out there, the thing i would like to ask is, is there any thing they say in these
papers that is untrue?

To my mind there is only one thing that can cripple modern cosmology, and that is the non detection of gravitational radiation.

Again to my mind, every thing else, dark matter, dark energy, fitting observations with theory will all ways be open to question.

I titled this thread (cherry picking evidence), can i ask, if there is a pro /anti LCDM debate,
is there any evidence the anti side could use?

 

[Nereid]

I guess the Lieu and Disney papers can only prove that there is a couple of disenchanted scientists out there, the thing i would like to ask is, is there any thing they say in these
papers that is untrue?

Some of the shortcomings of the Lieu paper are discussed in the other thread; let's continue the discussion there.

Regarding Disney's paper: mysearch kicked off with a good place to look (wrt anything that may be "untrue"), in https://www.physicsforums.com/showthread.php?p=2017281#post2017281":

"Let's start by going through the 14 points [in section 3]; what do you think of them (in terms of their legitimacy re "difficulties for cosmology as a science")?"

Why not contribute your own thoughts, wolfram?

To my mind there is only one thing that can cripple modern cosmology, and that is the non detection of gravitational radiation.

Again to my mind, every thing else, dark matter, dark energy, fitting observations with theory will all ways be open to question.

I titled this thread (cherry picking evidence), can i ask, if there is a pro /anti LCDM debate,
is there any evidence the anti side could use?

I'm not sure what "a pro /anti LCDM debate" is, and even if there is one, I wonder how it could be considered as science?

It may be an oversimplification to say that Disney thinks that (modern) cosmology cannot be science (or part of science, or ...), ever, even in principle, but I think he comes pretty close to saying that. In that respect, Disney is not so much "anti-LCDM" (whatever that means) as anti-cosmology*.

I myself think this is a fascinating question, and am quite interested to discuss it ... starting with the framework Disney provides in his paper. I think mysearch is also interested in this, but I wonder if anyone else who might be reading my post is also.

* for example (p8): "[...] the word ‘cosmologist’ should be expunged from the scientific dictionary and returned to the priesthood where it properly belongs"

 

[Nereid]

I have to say that I am saddened that this thread seems to have terminated in shouting in lots of bold type rather than continuing as a discussion and debate.

[...]

I have certainly used bold type a lot, and I am saddened that you, mysearch, have interpreted this as "shouting".

Over the years I have, in this forum and others, tried many orthographic devices to make clear what I write and distinguish it from what other's have written - colour, use of [ QUOTE ] tags, separators such as "= = = = = = =", font size and type, and so on.

Each method has its strengths and weaknesses, but the one that most closely meets my need (see below) is to take the core part of someone else's post, that I wish to comment on, and bold it. Why? Several reasons, including: colour (font size, font type) doesn't always get reproduced when text is copied, and quote tags are cumbersome when you need to do nesting (and they are also often lost when text is copied or posts quoted).

From my POV, one of the most important things in discussions like this is focus and clarity, and to achieve this I have found it critical to preserve the meanings contained in posts (or material referenced), as the basis from which discussion proceeds (or should proceed).

I hope this helps you understand what I have written better. If you have suggestions on how to achieve focus and clarity without giving the appearance of shouting, would you be kind enough to make them?

I'll comment on other points in your post (that I'm quoting) later.

 

[Nereid]

[...]

Thanks for the reminder. I usually follow George Jones pointers, but in this case I gave up too soon. There are 6 pages and 88 posts in this thread and I originally failed to find the appropriate references in the early posts. For those interested, the link is:
https://www.physicsforums.com/showthread.php?t=170753&page=6
Garth raises the issue of the Lieu paper in post #1 and also points to another thread, which may be useful to others, like me, who are trying to come up to speed with issues that others may have already discussed in the past, the resurrection of which may have caused some unintentional irritation. However, Wallace probably gives the most considered and helpful reply, I have seen to-date, see posts #3 & #6.

Well, if that's the definition, it seems to me that almost all of modern science exceeds "The Limits of Inference"!

It’s a definition, not necessarily the only definition. The only point that was really being made was that much of modern science, based on mathematics, is still speculative until some form of empirical verification can be provided. Therefore, as part of any learning process, rather than rote acceptance, I was interested in trying to understand the arguments for and against the Lieu and Disney papers, plus where such limits may have been exceeded.

It took me a while to grok that, but when I did, I suggested that there's a great deal more to the point than merely Lieu and Disney's papers!

And that's why I asked you about IACTs, the solar neutrino problem, etc: I feel that unless and until we have a good, mutual understanding of 'the limits of inference' in modern astrophysics (and, perhaps, modern physics in general), our discussion of what's in Lieu and Disney's papers would be vexing, if only because of the many times we will be 'talking past each other'.

Put this another way: both papers exist in a rich environment, full of concepts, theories, papers, people, egos, and more. Ergo, they can really only be understood if certain essentials about that environment are also understood ('limits of inference' is a good example).

However, I think it may be more productive, if I spend my time reviewing the two earlier threads mentioned above, as suggested.

Some readers may also be interested in another paper, referenced by Garth in post #16, from which the following quote was taken:
https://www.physicsforums.com/showpost.php?p=1337905&postcount=16

Ironic that it is Karl Popper you quote!

Let's see if others are interested in discussing this ...

 

[wolram]

Nereid.

I am pining my hopes on Advanced Ligo, if there is a null result i think we are in for a long wait for an explanation.

What other observations can be tested for in the (Laboratory)? Dark Matter, we can look for a WIMP, but if we do not find it, it is not very worrisome as DM can be some thing else, what is worrisome is how many guises can it be in, and is it science to say test from a to x
or run out of possibilities?

Particles? there is a wealth of them (axions) awaiting discovery.

Dark Energy, i do not have a clue about it's non existence or existence, or if it can ever be
more than a theory.

Obsevations, all i can say is i know of some of the difficulties, and it would not surprise me if
Z>7 or more distant galaxies are found.

 

[atyy]

To my mind there is only one thing that can cripple modern cosmology, and that is the non detection of gravitational radiation.

How about the Taylor and Hulse evidence for gravity waves? ie. a non-detection by LIGO etc wouldn't be reason to change GR, but rather an indication that gravity wave astronomy will have to wait 20-30 years, rather than just 10 years.

Again to my mind, every thing else, dark matter, dark energy, fitting observations with theory will all ways be open to question.

My sentiments too. I don't believe GR is the final theory (I don't believe in a final theory), but even sticking with GR, to establish LCDM beyond "parameterising our ignorance", we (ie. physicists, not me - I'm a biologist!) must rule out all other possible models that GR permits. This has not yet been done, at least in part because we can't observe all data needed to pin down a particular model (the observable part of the universe is getting bigger everyday), and also because we haven't enumerated all possible models that GR permits (eg. those not obeying the cosmological principle). Particulars apart, I think this attitude of skepticism is advocated in texts like Plebanski and Krasinski's and Schutz's.

 

[wolram]

How about the Taylor and Hulse evidence for gravity waves? ie. a non-detection by LIGO etc wouldn't be reason to change GR, but rather an indication that gravity wave astronomy will have to wait 20-30 years, rather than just 10 year

All the literature i have read predict advanced ligo will detect gravitiy waves, if it doe's not
i think there will be some head scratching, it seems there are many events per year that will be within the range of AL.

 

[wolram]

Scientists are so confident that ligo will detect gravity waves, and are all ready using non detection as a tool.

http://www.spaceref.com/news/viewpr.html?pid=24501

 

[atyy]

Scientists are so confident that ligo will detect gravity waves, and are all ready using non detection as a tool.

http://www.spaceref.com/news/viewpr.html?pid=24501

That's nice. Non-detection seems to me harder than detection - eg. did I just forget to turn the switch on? In this case, the non-detection seems consistent with known physics. How many or what sort of non-detections are needed to suggest new physics?

 

[Nereid]

Disney's 14 items (part I)

PARTICULAR DIFFICULTIES FOR COSMOLOGY AS A SCIENCE

4. Need to work with what we can currently detect. [But . . . ]
5. Local background very bright.
6. Distances very hard to determine (standard candles).
7. Observational Selection insidious.
8. Distant galaxies hard to measure and interpret unambiguously.
9. Luminosity Functions unreliable.

10. Geometry, astrophysics and evolution often entangled.

3. Need to extrapolate physics over huge distances.
12. Human time-frame so short compared to cosmic.

2. Universe opaque for 56/60 decades since Planck era.
11. Physics of early Universe unknown (and unknowable?)

1. Only one Universe.

14. The singularity.
13. Origin of inertia.

I've re-ordered them somewhat.

In this post I'll comment on them from the POV of whether cosmology is unusual in having difficulties like these.

The first six are easy ... I think it would be quite difficult to find a branch of modern science that doesn't have something like these to contend with. Not the specific ones of course, though much of astrophysics has these specifics, but things like these are found in every branch of science that studies the real world, from linguistics to economics to ecology to climate science to geology to ...

The next (10.) is a transition item, it has characteristics of the first six and the next two.

These two (3. and 12.) are common to all 'deep time' sciences, such as geology and paleontology, with a key part of physics supplying the equivalence of 'huge distances' and 'deep time'.

The next two (2. and 11.) are just plain weird, when taken in conjunction with each other (and 3.). For example, 2 is only a 'difficulty' if you accept that 3 and 11 are not! Be that as it may, almost by definition, only two other branches of science share this difficulty - particle physics and astrophysics (again, equating time with distance in the usual way).

The penultimate one (1.) is, of course, a common difficulty for many branches of science, if you take "Universe" to mean "one and only one of". For example, the world economy, the English language, the psychology of Homo sapiens (the species), the Cambrian, ...

And the last two, well, I pass. I have no idea what Disney means by these, as 'particular difficulties'. Do you, dear reader?

Summary: except for the last two (maybe), it would seem that cosmology-as-a-science is not particularly unusual in the sense of having to address rather knotty 'particular difficulties'.

 

[wolram]

Number 6 on your list, standard candles.

I really do not know if any thing other than parallax measure is reliable, we have parallax measure for a small part of our galaxy.
I guess one can all ways argue that some thing effects light travel, but i know very little on the subject.

 

[turbo]

And the last two, well, I pass. I have no idea what Disney means by these, as 'particular difficulties'. Do you, dear reader?

The origin of inertia is a huge problem that has not been addressed by GR. Einstein felt that it arose from matter's interaction with the local "ether" in which it embedded, as well as gravitational effects. He rejected "spooky action at a distance" in his Leiden address in 1920, and expressed that more forcefully in his 1924 essay "On the Ether". Inertia was one of Fenman's favorite unexplained things, as well.

 

[Nereid]

The origin of inertia is a huge problem that has not been addressed by GR. Einstein felt that it arose from matter's interaction with the local "ether" in which it embedded, as well as gravitational effects. He rejected "spooky action at a distance" in his Leiden address in 1920, and expressed that more forcefully in his 1924 essay "On the Ether". Inertia was one of Fenman's favorite unexplained things, as well.

OK, thanks.

Accepting this, for now, at face value, why does it make for a "PARTICULAR DIFFICULT[Y] FOR COSMOLOGY AS A SCIENCE"?

I mean, none of the weird stuff to do with quantum mechanics is on his list (to take just one example), despite it surely being just as huge a problem/an unexplained thing ...

 

[Nereid]

Number 6 on your list, standard candles.

I really do not know if any thing other than parallax measure is reliable, we have parallax measure for a small part of our galaxy.
I guess one can all ways argue that some thing effects light travel, but i know very little on the subject.

Quite.

But what's that got to do with being a "PARTICULAR DIFFICULT[Y] FOR COSMOLOGY AS A SCIENCE"?

Sure, it's a difficulty, and it affects cosmology (and most of astrophysics, and no doubt other sciences too), but these sorts of difficulties are not unusual in many (most?) sciences ...

 

[wolram]

Quite.

But what's that got to do with being a "PARTICULAR DIFFICULT[Y] FOR COSMOLOGY AS A SCIENCE"?

Sure, it's a difficulty, and it affects cosmology (and most of astrophysics, and no doubt other sciences too), but these sorts of difficulties are not unusual in many (most?) sciences ...

I really do not know Nereid, When is science without a non elastic measuring stick useful?
Parallax is non elastic if there is a standard metric that every one agrees on, what can we deduce beyond that?
Edit for clarity ,with an elastic ruler.

 

[mysearch]

The intention is not to stoke up a debate that appears to have run its course, but I happened to come across 2 quotes, when reading about an entirely different topic, which I felt might be worth adding as a footnote to this thread.

The idea is to try and give all the information to help others to judge the value of your contribution; not just the information that leads to judgement in one particular direction or another. Richard Feynman

In this spirit of full disclosure, maybe you might like to look at a few basic questions in the following thread: https://www.physicsforums.com/showthread.php?t=282764

Concepts that have proven useful in ordering things can easily attain an authority over us such that we forget their worldly origin and take them as immutably truths. They are then rubber-stamped as a "sine-qua-non of thinking" and an "a priori given". Such errors often make the road of scientific progress impassable for a long time. Albert Einstein

As such, questioning accepted wisdom should not always be seen as sceptical, especially within any declared learning process.