Dark Matter Blobs!

Reporting from the American Astronomical Society meeting in Seattle, Washington… In a brand spankin’ new press release from Hubble, we have the first-ever “3D map of the Universe’s Dark Matter scaffolding.”

First off, the result is quite kewl. We’re beginning to map the stuff that “outweighs” ordinary matter by a factor of six to one. Great work, COSMOS team!

The above image isn’t the primary image released, but it’s the one with which I find the greatest fault. By abstracting the blobs of dark matter without any reference to scale whatsoever, we’re left with no sense of how large the object is that we’re looking at. The primary image that accompanies the press release improves on the problem by labelling slices at 3.5, 5.0, and 6.5 billion years ago, but the size of the image on the plane of the sky is left undescribed—although the caption does clarify that “Each panel represents an area of sky nine times the angular diameter of the full Moon.”

Images such as the one above do a disservice to public understanding of astronomers’ work by abstracting the result completely from reality. The lack of scale I already complained about, but I have other issues as well“ The use of isosurfaces is non-intuitive for the vast number of people. The inclusion of half a box around the data provides a sense of dimension but could also confuse people. And a meaningless background haze does nothing in service of the rest of the image.

Great science, bad picture.