Description

This is a visualization of the distribution of galaxies out to a distance of about a 700 million light years or about 5% of the distance to the edge of the visible universe. This simulation depicts some of the largest scale structures in the entire universe.

Purpose

Until the early 1980s, astronomers and cosmologists assumed that the very large scale distribution of matter in the universe was relatively uniform. This assumption came about largely because of the big bang theory that tells us that the universes expanded from a tiny point some 15 billion years ago. Margaret Geller, an astronomy professor at Harvard university, has the idea to actually map the galaxies and take a look at what their distribution actually looks like (shocking!) What she found was that they were not distributed uniformly at all but that there are unimagineably huge clumps and voids. This simulation shows the distribution in 3 dimensions. You can see a number of features that are not visible in 2 dimensions. For example:

• The Great Wall is not really much of a wall:
  The largest known structure is called the "Great Wall". It is the swath of galaxies visible across the top of the circle when you start the simulation. In 3 dimensions, however, you can see that the "wall" is not really much of a wall at all. It only really looks like a wall from one particular angle.
  
  
• The "Great Wall" and the "Pieces Perseus Supercluster" may be linked
  Another thing that you can see in 3 dimensions is that two of the largest structures in the visible universe may actually be linked. The Pieces Perseus supercluster is the cluster of galaxies visible to the lower right when you start the simulation. In 3 dimensions, you can see that the gap between the Great Wall and this cluster runs right through the plane of the Milky Way. This means that the gap in galaxies may actually be due to galaxies being hidden by the dust in our own galaxy and that in reality, these two features may be linked!

Features

• User configurable isosurface boundaries
  To make the clumps of galaxies more visible, we draw isosurfaces around them. The threshold value for the isosurfaces can be changed by the user in order to more clearly see the distribution of galaxies.