The Right Coast

July 15, 2005
Big Bang go bang?
By Tom Smith

I know our readers want to keep up with developments in cosmology, so they need to know the Big Bang ain't what it used to be. Science is strange; it's all about what scientists are willing to say, and now some of them are willing to come out and say It never happened. This recent conference was important, apparently. Not exactly beach volleyball in Baja, judging by the photos.

Perhaps the most disturbing thing is that, uh, well, here . . .

The homogeneity and isotropy of the Universe – also
known as the Copernican principle – is a major postulate
of modern cosmology. Obviously this assumption
does not imply exact homogeneity and isotropy, but
merely that the observed cosmological inhomogeneities
are random fluctuations around a uniform background,
extracted from a homogeneous and isotropic statistical
ensemble. One may expect that the ever improving observations
of CMB fluctuations should lead to the greatest
vindication of this principle. Yet, there have been a
number of disturbing claims of evidence for a preferred
direction in the Universe [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
making use of the state of the art WMAP first year results
[11]. These claims have potentially very damaging
implications for the standard model of cosmology.
It has been suggested that a preferred direction in
CMB fluctuations may signal a non-trivial cosmic topology
(e.g. [1, 12, 13, 14]), a matter currently far from
settled. The preferred axis could also be the result of
anisotropic expansion, possibly due to strings, walls or
magnetic fields [15], or even the result of an intrinsically
inhomogeneous Universe [16]. Such claims remain controversial;
more mundanely the observed “axis of evil”
could be the result of galactic foreground contamination
or large scale unsubtracted systematics (see [17, 18, 19,
20] for past examples). A closer inspection of the emergence
of this preferred axis is at any rate imperative.

So the cute cocktail party phrase (the level at which I operate I'm afraid) to drop is "axis of evil" -- an apparent inhomogenity in universe stuff that should not be there, if the Big Bang theory is true. So if someone is acting all smart about the Big Bang, you ask, what about the axis of evil? (Personally, I still like the Big Bang, but tastes differ.) Maybe it's only that important satellite whose initials I can't remember [oh yeah, it's WMAP] is just screwing up, but some smart people don't think so. If the inhomogenity turns out to be the edges of a giant fishtank, or the inside of a giant shoe, it will put the whole ID debate in a new light . . .