Video Credit: Illustris Collaboration, NASA, PRACE, XSEDE, MIT, Harvard CfA; Music: The Poisoned Princess (Media Right Productions)
How did we get here? Click play, sit back, and watch. A new computer simulation of the evolution of the universe — the largest and most sophisticated yet produced — provides new insight into how galaxies formed and new perspectives into humanity’s place in the universe. The Illustris project — the largest of its type yet — exhausted 20 million CPU hours following 12 billion resolution elements spanning a cube 35 million light years on a side as it evolved over 13 billion years. The simulation is the first to track matter into the formation of a wide variety of galaxy types. As the virtual universe evolves, some of the matter expanding with the universesoon gravitationally condenses to form filaments, galaxies, and clusters of galaxies. The above video takes the perspective of a virtual camera circling part of this changing universe, first showing the evolution of dark matter, then hydrogen gas coded by temperature (0:45), then heavy elements such as helium and carbon (1:30), and then back to dark matter (2:07). On the lower left the time since the Big Bang is listed, while on the lower right the type of matter being shown is listed. Explosions (0:50) depict galaxy-center supermassive black holes expelling bubbles of hot gas. Interesting discrepancies between Illustris and the real universe do exist and are being studied, including why the simulation produces an overabundance of old stars.
Illustration Credit: Zosia Rostomian (LBNL), SDSS-III, BOSS
Explanation: How large do things appear when far away? When peering across the universe, the answer can actually tell us about its average gravitational history and hence its composition. Toward this goal, the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey-III (SDSS-III) has measured slight recurring density enhancements in galaxy densities up to six billion light years away (redshift 0.7), when the universe was about half its current age. These density ripples are known as baryon acoustic oscillations (BAOs) and are expected to emerge from the early universe at a known size scale. BOSS’s measurements of this size scale indicate a strong universe component of dark energy, and so bolsters previous indications of this unusual composition. Pictured above is an artist’s illustration depicting exaggerated BAOs in the distant universe.
Flash Animation Credit & Copyright: Cary & Michael Huang
What does the universe look like on small scales? On large scales? Humanity is discovering that the universe is a very different place on every proportion that has been explored. For example, so far as we know, every tiny proton is exactly the same, but every huge galaxy is different. On more familiar scales, a small glass table top to a human is a vast plane of strange smoothness to a dust mite – possibly speckled with cell boulders. Not all scale lengths are well explored – what happens to the smallest mist droplets you sneeze, for example, is a topic of active research – and possibly useful to know to help stop the spread of disease. Theabove interactive flash animation, a modern version of the classic video Powers of Ten, is a new window to many of the known scales of our universe. By moving the scroll bar across the bottom, you can explore a diversity of sizes, while clicking on different items will bring up descriptive information.