![The "cosmic web", from a computer simulation. The colors represent the distribution of dark matter, which clumps into knots and filaments. In between are large cosmic voids, which contain very little matter of any kind. [Credit: Volker Springel and the Virgo Consortium, Max Planck Institute for Astrophysics]](https://sciencevspseudoscience.files.wordpress.com/2014/08/cosmic_web.png)
(Title shamelessly cribbed from Rose Eveleth.)
Perhaps more than any other artist, M.C. Escher used negative space explicitly as part of the artwork. The spaces between fantastic creatures become other fantastic creatures in complementary hues, the background of a weird impossible building becomes an incredible geometric landscape.
The Universe likewise has its negative spaces. While it is replete with galaxies and galaxy clusters, those are strung into long filaments and clumps, with huge voids in between. However, these are challenging simply to detect, much less characterize. How big are they? How many? And how empty are they, actually?
Two new studies show how to use cosmic voids as a powerful and complementary observational target to surveys of galaxies. In my recent article — which led off the August issue of Nautilus on “Nothingness” — I explained how empty space can be a way to explore dark energy and other cosmological phenomena.
If galaxies are cities, then the edges of a void are the suburbs, and the center is the deepest wilderness. But an atlas isn’t complete if it includes only cities and roads; it also needs the empty spaces in between. Scientists are increasingly entering the deep, dark wilderness of the void to complete their atlas, and in doing so are learning about other, greater dark presences in our universe. [read more….]
Galileo's Pendulum 