# Is the clustering found in the universe a matter of perspective?

1. Aug 26, 2014

### socean

While reading about von Mises distributions I wondered if the distribution of clusters such as galaxies could be related to the way they are being "mapped".

Suppose we observing our universe from a particular perspective, perhaps described by something like a von Mises distribution, or other distribution model :

http://openi.nlm.nih.gov/detailedresult.php?img=2848649_1471-2105-11-126-3&req=4

Is there a theoretical distribution model to our universe? While the "shape" of pre-spacetime force/stuff is probably not a torus, its something, is it not? Is it possible to determine what it might be?

If we could change our distribution/perspective, everything would look entirely different would it not?

What might we learn if we used different distribution models for our cosmological data?

Would we still observe the same general laws of nature from the perspective of different distributions?

What might the stuff/force be that could have "shape"?

Last edited: Aug 26, 2014
2. Aug 26, 2014

### ohwilleke

So far, the universe appears to be topologically "flat", spherically symmetric, and mildly imhomogeneous with slight scale dependence. Clusters are evaluated in a four dimensional model based upon two spherically angular coordinates and red shift, in which the time/distance dimension is almost degenerate since the time span of astronomy is so short relative to the lifetime of the universe. So it is possible to compute clustering in a way that is not very dependent on the location of an observer simply by using tools such as 3D Euclidian distance.

A von Mises distribution is circular rather than spherical and the analog of a normal distribution which probably doesn't capture the observed distribution.

3. Aug 26, 2014

### phinds

The distribution of stuff in the observable universe is what it is. It wouldn't change positions just because it is being looked at from a different place (I'm omitting the time-lag of light for distance objects)

Likewise, the laws of nature don't change just because you change positions.

4. Sep 8, 2014

### ohwilleke

BTW, the observed "flat" topology of space-time comes from astronomy observations fitted to models of space-time. For example, the most precise measure of the flatness of the topology of space-time comes from the Planck satellite's cosmic background radiation measurements supplemented by other similar large section of the sky astronomy measurements of things like Baryon Acoustic Oscillations (basically a measure of ansitropy in visible matter).