The Universe Is Awesome

As a cosmologist I get to learn some pretty amazing things about the universe, and that's part of the reason I love what I do. To share these facts with others, and to remind myself, I've enlisted the artistic talents of my sister to create images that go along with snippets of awesome. Enjoy!

Void Universe

Posted on February 17, 2013

While waiting for my sister to once again find the time to create artful interpretations of awesome facts about the universe, I inadvertently made art at work!

Most of the universe is void, containing not much matter and very few galaxies.

This is a thin slice through a simulation that calculates the evolution of dark matter particles under gravity as the universe expands. The big, colorful points are void particles, with different colors representing different voids; these are plotted over little black points of wall, filament, and halo particles that represent the collapsed structures in the universe. The voids, instead of collapsing to form stuff (i.e. galaxies form in the dark matter halos), are regions of space that matter flows away from because they are less dense than their surroundings.

It turns out that voids occupy most of the volume of the universe, perhaps around 90%, while only containing perhaps 30% of the mass. These numbers depend on the physics of structure formation, including whether Einstein's general relativity theory is correct on large scales. But they also depend on how you define a void and so could change depending on whom you ask on what day of the week. Researchers in my field are slowly converging on the best ways of defining voids in both simulations of dark matter and observations of galaxies.

Cosmic Noise

Posted on November 1, 2012

The popcorn noise on old TVs is caused by leftover radiation from when the Universe was very young, emitted only a few hundred thousand years after the Big Bang.

This one might take a bit of explaining, but for that I will simply direct you to NASA's excellent "Universe 101" site, set up for the WMAP satellite that precisely measured the cosmic background radiation. In the image above, the TV noise is represented by actual data from WMAP.

More Stars than Sand

Posted on October 2, 2012

There are more stars in the observable Universe than there are grains of sand on all the beaches on Earth.

This is because the universe is SO AMAZINGLY HUGE! Perhaps even infinitely so!