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Cherry picking evidence?

  1. Dec 28, 2008 #1

    wolram

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  3. Dec 28, 2008 #2
    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).
     
  4. Dec 28, 2008 #3

    wolram

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    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.
     
  5. Dec 28, 2008 #4

    George Jones

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  6. Dec 28, 2008 #5
    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. :(
     
  7. Dec 28, 2008 #6

    russ_watters

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    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?
     
  8. Dec 29, 2008 #7

    mysearch

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    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.
    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:smile:
     
    Last edited: Dec 29, 2008
  9. Dec 29, 2008 #8

    turbo

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    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
     
  10. Dec 29, 2008 #9

    wolram

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    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?
     
  11. Dec 29, 2008 #10

    turbo

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    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/
     
  12. Dec 29, 2008 #11

    Chronos

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    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.
     
  13. Dec 30, 2008 #12

    mysearch

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    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.
    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.
     
    Last edited: Dec 30, 2008
  14. Dec 30, 2008 #13

    Nereid

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    (bold added)
    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.
    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.
    What such limits do you have in mind, mysearch?
     
  15. Dec 30, 2008 #14

    mysearch

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    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.
    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.
    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)
     
    Last edited: Dec 30, 2008
  16. Dec 30, 2008 #15

    Nereid

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    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.
    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?
    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).
     
  17. Dec 30, 2008 #16

    mysearch

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    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 realise 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
     
  18. Dec 30, 2008 #17

    turbo

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    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."
     
  19. Dec 30, 2008 #18

    Nereid

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    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 ...
     
    Last edited: Dec 30, 2008
  20. Dec 30, 2008 #19

    Nereid

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    "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?
     
  21. Dec 30, 2008 #20

    turbo

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