Cat Curling

No cats were curled during the making of this video…

7 Responses to “Cat Curling”

  1. Peter, an OT question/comment. Would be very interested in your opinions on what could be the explanation of Fig 1 of http://arxiv.org/abs/1401.1146
    Surely this is beyond anything predicted by CDM (or its variants).
    Thanks
    shantanu

  2. yes, apologies for that. but just curious about what you think about this paper/plot (as I haven’t seen a discussion of this intriguing paper on any blog/forum)
    Hence thought if asking about it in some post.

    • Interesting is that, while the paper is not a review, the reference list makes up half of the page count (11 of 22)! One certainly can’t claim that the authors have ignored previous work in the field. 🙂

      As to figure 1, as the authors note, this discusses something long known to proponents of MOND. Also, as the authors point out, whatever one thinks of MOND, the observational facts pointed out by MOND proponents are a) beyond dispute and b) don’t have an obvious explanation in non-MOND physics. I suggest reading up on the MOND literature where you will find copious further references. There is a lot to learn, even if one does not believe in MOND.

      Why hasn’t the paper been discussed on any blog or forum? Dozens of papers appear every day, most are published in refereed journals. Thus, all are presumably worth discussing. If all were discussed, few would have time to read new papers, much less write them. As a result, usually only really important papers are discussed. While this might also be a really important paper, it might be difficult to discuss constructively. My impression is that the MOND people (and, by extension, non-MOND people concerned with the same phenomenology) usually have both a broad and a deep understanding of many areas of both astronomy and astrophysics. This is necessary because of the problems they face, but even most professional astrophysicists don’t have such broad knowledge.

      • Philip, I am aware of this constancy of acceleration in variety of systems in MOND literature (see eg fig. 4 of 0806.2585) However these authors don’t work on MOND and have done more precise measurements.

        Anyhow from talking to people who work on Lambda CDM or its variants) they are not aware of this constancy of acceleration (either before or after the Loeb/Walker paper) and hence wanted to draw attention about this to see if people at least have speculations on what could be going on.

      • Right; the pointer to MOND was because such literature has good references to observations.

        With regard to lambda, it shouldn’t play any role at the scale of galaxies or even clusters, so “lambda CDM” is really irrelevant here. What is relevant, of course, are structure formation, galaxy formation and evolution etc which will depend on the nature of the CDM.

        Maybe the paper will alert a larger portion of the community to this interesting observational fact. 🙂

  3. Philip,
    by lambda-cdm I meant people who believe in dark matter and always assume NFW profiles.
    anyhow most of them are unaware of these observational regularities. In fact 2 years ago, I heard a standard talk on particle dark matter by Rocky Kolb and I asked him about Tully -Fisher relation and he was dismissive of it (even though it is an established observational fact since 70s
    his reply was “fishy tully relation” 🙂

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