The Universe Is Not Expanding Uniformly

Well; this is “interesting”…

“A few weeks ago, researchers announced the discovery of a ‘dark flow’ of invisible matter tugging at distant galaxy clusters at the edge of the universe. Now comes more evidence of unseen and unknown forces in the cosmos, but this time its closer to home. A group of researchers have discovered that our particular part of the Universe — out to a distance of 400 million light years — is not expanding uniformly in all directions as expected. To be exact, the expansion is faster in one half of the sky than in the other. ‘It’s as if, in addition to the expansion, our ‘neighbourhood’ in the Universe has an extra kick in a certain direction,’ says Mike Hudson from the University of Waterloo in Ontario, Canada. ‘We expected the expansion to become more uniform on increasingly larger scales, but that’s not what we found.’ If confirmed, their findings will result in a new understanding of the origin of structure in the universe and possible revisions to the standard cosmological model.”

Read the full article here.

One of the basic principles in Cosmology is that there is no preferred direction, or in other words, at cosmological scales the Universe looks the same (in terms of gross observations) in every direction when viewed from every point in the sky.

This would seem to call that into question.

I suppose you could argue that we need to increase the size of what we’ve thought of as the cosmological length scale; perhaps the inflationary Universe’s much larger size than what we can actually see if now necessary.

Or it could be that the cosmological principle of homogeneity is broken. Which would be really interesting…

(All of course assuming this is verified.)

Author: Nicholas Knisely

Episcopal bishop, dad, astronomer, erstwhile dancer...