I have been using Stellarium to observe the position of my zenith at various times, I am now interested to know when my zenith is aligned with the universe axis implied by the CMBR data. Apparently this has one end near Sextans, Leo and Gemini and the other between Aguila and Equuleus. However I have also read that nearly everything we can see is within our galaxy so presumably will move relative to the "axis of evil"? Also, presumably the above positions of the ends of the axis place us on the axis as apposed to offset from it?

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    $\begingroup$ This sounds like an AstronomySE type question, imo. $\endgroup$
    – user108787
    Aug 16, 2016 at 15:17

1 Answer 1


The universe has no unique axis, it does not have anything to do with your or my zenith, and it has no axis of spatial symmetry. But there is a correct way to ask the question that you mean to ask, and to answer it. It's how we are moving with respect to the average expansion flow of the expansion of the universe. Not how we are located -- but how we move with respect to the universe average flow.

The universe is expanding in all directions at once. No symmetry axis. You can define a reference frame that moves along with the average flow of the expansion. It is called a commoving reference frame. It may have other names used casually, such as a 'cosmological frame'. In the commoving frame we would see the CMB as looking totally isotropic -- the same in every direction (on the average, with small fluctuations that are very important for understanding how matter in-homogeneities turned into galaxies and stars)

So what you really are asking is what is the earth's peculiar velocity with respect to that reference frame. It includes the velocity of the solar system with respect to the galaxy, the galaxy with respect to our local cluster, and finally the local cluster, all added vectorially. It is about 600 km/sec in the direction of the constellation Leo. That is 'your axis of evil'.

See http://ned.ipac.caltech.edu/level5/Sept02/Kinney/Kinney3.html


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