Is the lopsided Universe telling us we need new theories
arstechnica.com
arstechnica.com
If you look at the graph at the bottom of the first page of this article, have a look at the error bars on those data points: every one of them is at least borderline consistent with the smooth theoretical curve. (Or, alternately, look at the light green region around the curve: that shows the unavoidable uncertainties that we expect based on our finite view of the universe. The points they're interested in almost all lie within that range.)
So yeah: it's a neat possibility, and it's great that people are looking into models to explain this (and to search for related predictions they can test). But it's not significant at a level that should get non-cosmologists tremendously excited at this point.
Or, as I can guess at Guth's inflation, there was a quark; space expanded explosively so that maybe any two 'sides' of the quark were pulled apart faster than the speed of light; so, the quark was split into two quarks, that is, some energy was converted into quark mass. But two quarks have an axis. Could that be the origin of the 'axis of evil'? Or, how the heck else to have Guth's inflation starting with the first split of something without having an axis, that is, in 3 space, a line for the axis and perpendicular to a plane? Or, from that first split that generated mass, how can we avoid an axis, sure, in some 'random' direction but, still, an axis?
What you really want to focus on is the question, "What are the (quantum) fields doing during inflation?" Those fields will typically be in a state with a whole lot of symmetry, and only small, random fluctuations away from that state will lead to perturbations in the CMB.
I might be able to frame this in the particle picture, too. The issue is that there wasn't just one quark! There's a whole intense thermal mass of quarks and other particles, and the energies are high enough (and times short enough) that more of them are being pulled from the vacuum and annihilating back into it all the time (this is largely a field-theory statement, I'm afraid). That mass of quarks is what's being pulled apart by inflation. So there's no single special original quark particle that triggers the whole thing. [Disclaimer: I'm not actually a cosmologist, so I welcome corrections on anything I've misstated there!]
I was trying to go back before there was a 'soup' of wave functions with lots of quarks or whatever the first 'particle' was. So, as I read Guth, there was a 'something', small enough to be essentially just a 'point', but with very high energy and energy density, and that density caused high space-time curvature, and the region with that high curvature expanded, explosively, on the way to something much flatter but much larger, in the first second so large as to be nearly as large as now and with density and curvature nearly as low as now. So, back to the 'beginning': There was just one particle/wave of very high energy in a very small region of very high curvature that got pulled by the expanding space-time and, presto, soon there was two particles or wave functions. That first separation is the one I am thinking about, and it had to have an axis.
And nearly all I have is just layman's descriptions of the curvature, wave functions, Guth's expansion, etc. so am typing stuff I really don't know about! In some of the math, my real field, I'm solid enough, but for the physics -- no.
There is a good write up on the alignment anomaly by theoretical cosmologist Dragan Huterer about it: http://www-personal.umich.edu/~huterer/PRESS/CMB_Huterer.pdf
Fascinating to see it still causing a ruckus all these years and a whole other probe later.
Furthermore, we're not measuring "things", we're measuring temperature. If a "thing" was blocking the CMB, it would do so by being a hotter thing. Thus, a "thing" can't create a cold spot just by obscuring the CMB... it can only create a hot spot, relative to the CMB.
Another place you can see this is in "dark matter" replacement theories. As unsatisfying as an invisible, undetectable particle is to answer the questions about the universe, it isn't enough to just explain one or two subquestions; you need to provide a better explanation of everything we see, including the places where it really, really looks like dark matter is the only feasible explanation (where galaxies collide and the visible matter appears to have gotten detacted from the dark matter halos, as seen by gravitational distortions, which is really hard to explain with any of the alternate theories).
It's "easy" to beat the consensus on one detail; it's proved pretty hard to beat the consensus across the board, even as the consensus is known by everybody to be unsatisfactory in some ways.
For "near by "objects on can use parallax: look at the object on a given date then again 6 months later and see how much it shifts against the back ground stars. Simply triangulate using the known distance from earth to sun as half the side of a triangle.
For "moderate" distances one can rely on certain variable stars that always have a known brightness. Then when you locate such a star, note how dim it is and calculate how far away it would have to be to have that brightness level.
For "far" distances one can measure the red shift. That is to say, on the large scale everything in the universe appears to be moving away from us. Further away object move faster than nearby objects. Thus if you can measure how fast something is receding from us you can tell how far it is. The technique for measuring speed like this is to measure the Doppler red shift.
I suppose that if this "axis of evil" were due to a pattern in nearby dust clouds we might be able to see some hints of paralax, but paralax would probably be difficult to measure for something as diffuse and broad as the pattern visible in this data.
It's my impression, for the record, that cosmologists are pretty confident that these variations aren't due to intervening dust. My sense is that the spectrum of the CMB in any given direction is very clearly a blackbody spectrum (the most precise blackbody spectrum in nature, in fact), so any absorption due to foreground matter should be pretty recognizable (and possibly even something they could correct for).