Are There Cosmic Microwave Anomalies?


The WMAP team has just released a new set of papers based upon seven years of data from their experiment. For a summary of how this new data has sharpened some of their previous results, see the Cosmological Interpretation paper. They have also gone over claims by many groups to have found deviations from the standard cosmological model in their earlier data sets (for example claims to have found “the unmistakable imprint of another universe” which “points to string theory being on the right track.”) In a paper entitled Are There Cosmic Microwave Background Anomalies, the WMAP team reports:

In most cases we find that claimed anomalies depend on posterior selection of some aspect or subset of the data… We examine several potential or previously claimed anomalies in the sky maps and power spectra, including cold spots, low quadrupole power, quadropole-octupole alignment, hemispherical or dipole power asymmetry, and quadrupole power asymmetry. We conclude that there is no compelling evidence for deviations from the LCDM model

They give a humorous example of the problem that plagues typical claims to have found such anomalies, showing that the CMB sky map clearly contains the initials of Stephen Hawking, “aligned neatly along a line of fixed Galactic latitude.”

Update: For the WMAP team’s summary of its new results for the public, see here.

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13 Responses to Are There Cosmic Microwave Anomalies?

  1. Bee says:

    Coincidentally, I used the SH in the CMB example in my recent post Is physics cognitively biased?.

  2. Robert says:

    The only question I have is why the aliens don’t know that Steven’s initials are SWH, at least according to his email address.

  3. Christine says:

    A simple search in the arxiv with “cmb” and “anomalies” gives 110 hits. Several have been published in peer-review journals.

    I have read none of these, thanks to my skeptic-meter, which is becoming exponentially more severe with time, or specially when other people’s skeptic-meter goes down in the opposite direction.

  4. Low Math, Meekly Interacting says:

    However, there have been no sightings of the Virgin Mary in the CMB (yet), which is somewhat encouraging.

  5. neo says:

    No virgin mary, but an axis of evil (the devil?) has been sighted.

  6. Nige Cook says:

    “… clearly contains the initials of Steven Hawking …”

    Typo: it’s spelt “Stephen”:

    You escaped 5 points on item 8 of the index of Prof. Baez, since he only credits you if you misspell Hawking’s surname, see: which gives

  7. Peter Woit says:

    OK, typo fixed. I tend to get this wrong because my brother spells it the other way…

  8. Luca Signorelli says:

    While I’ve always suspected most of the claimed anomalies weret at best wishful thinking, I can’t help being disappointed – the “void” looked really as some interesting mystery to study…

  9. Jeff McGowan says:

    OK, question from a mathematician. I was looking at the WMP results page that Peter links to, and found it quite interesting. I’m confused however by the neutrino result, they say the WMP data give you 4.34 \pm .87 species of neutrino, and the standard model gives you 3.04, so it seems to me the WMP data is indicating there is a problem with the standard model, no?

  10. Peter Woit says:


    Not really. See
    for an explanation of the signficance of an experimental result being 1.5 standard deviations away from the expected value.

  11. Jeff McGowan says:


    Thanks, I was assuming the \pm was more like 3 standard deviations, silly me 🙂


  12. steve newman says:

    what do you make of this article which appeared a week ago?

    has this been,/ will it be/, responded to by anyone??

    it seems like a serious questioning of whole map, and therefore
    of all the conclusions drawn from the map.


    “A remarkable inconsistency between the calibrated differential time-ordered data (TOD) of the Wilkinson Microwave Anisotropy Probe (WMAP) mission, which is the input for map-making, and the cosmic microwave background (CMB) temperature maps published by the WMAP team is revealed, indicating that there must exist a serious problem in the map making routine of the WMAP team. This inconsistency is easy to be confirmed without the use of WMAP map-making software. In view of the importance of this issue for cosmology study, the authors invite readers to check it by themselves.”
    [762] arXiv:1001.4643
    Title: Inconsistency between WMAP data and released map
    Authors: Hao Liu, Ti-Pei Li,
    1Key Lab. of Particle Astrophys., Inst. of High Energy Phys., Chinese Academy of Sciences, Beijing
    2Department of Physics & Center for Astrophysics, Tsinghua University, Beijing, China
    3Department of Engineering Physics & Center for Astrophysics, Tsinghua University, Beijing, China

  13. John Baez says:

    I’ll make an exception and give Peter 5 crackpot points anyway. He can afford them.

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