
Is the lopsided Universe telling us we need new theories - efficientarch
http://arstechnica.com/science/2014/03/is-the-universe-lopsided/
======
Steuard
This is a fascinating anomaly, and totally worth studying. But my perspective
as a physicist in a different but somewhat related field has always been to
tentatively assume it's just a statistical fluctuation.

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.

~~~
graycat
Okay, when I was in physics as a ugrad, it was a long time until the LHC! So,
my understanding of the now hot topics is from little more than just layman
reading!

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?

~~~
Steuard
The issue you're running into here is that you're focusing on the description
of this physics in terms of particles. That's usually a very convenient
perspective, but it tends to have issues when gravity/spacetime is doing weird
things (or even in an accelerated reference frame, which is sort of the same
thing).

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!]

~~~
graycat
Particle - field, okay. To me, a 'particle' is just a temporary entity that
happens when a field has an 'interaction' and decides to have its wave
function 'collapse' \-- then it has a new wave function.

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.

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gottebp
I ran across this before the Planck probe data had confirmed what WMAP had
found.

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](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.

~~~
dhimes
This is a really excellent link. Thank you.

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coldcode
Physics is a strange and wonderful science. The more we learn the more we
realize we don't understand. I've always believed that there are features of
the the structure of the universe(s) that we have no idea even exist yet. It's
like bringing Newton from the past, dropping him in an open field, and telling
him he is surrounded by wireless communications. He'd have no clue what that
meant. Likewise we are likely surrounded by things we don't have the
background yet to recognize.

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Myrth
It's unclear for me how observers can be sure that the differences they see
are actually originated far far away, and not result of local interference:
cloud or dark matter or whatever else. As far as I know, we have only 1 point
of perspective, our Earth. Of course I have no idea how exactly they observe
stuff, but that's the question I immediately have.

~~~
bladedtoys
Very roughly speaking there are at least three ways to measure distances.

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.

~~~
Steuard
But none of those techniques is applicable to variations in the CMB (the
subject of this article), which is a more or less uniform glow at constant
(and in some sense, maximal) redshift (and by definition, _behind_ the
"background" stars).

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).

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brlewis
[http://en.m.wikipedia.org/wiki/Betteridge's_law_of_headlines](http://en.m.wikipedia.org/wiki/Betteridge's_law_of_headlines)

