The amazing supercomputer simulation in the video above takes you through 13 billion years of cosmic history, modeling the violent and dynamic processes that created the large-scale structure of our universe.
As you might imagine, recreating the entire universe in a computer is a bit of a challenge, mainly because of the huge range of scales that relevant processes happen at. Astronomers need to simulate a chunk of the universe that's about 330 million light-years across–large enough to contain all the important elements but not so large it crashes your supercomputer. But the movement of stars and gas (the smallest elements of cosmic structure) happens on scales generally around 3 light-years across, a difference of eight orders of magnitude. Getting all this detail is almost like creating a simulation of a person growing up that takes into account the action of every enzyme and DNA strand within their body.
To make things easier, most simulations have focused on dark matter and dark energy (which tend to operate on very large scales and make up 96 percent of the universe), mostly ignoring the contributions of ordinary matter. This produces a picture of the cosmic web, but is missing some important details.
Supercomputing power has increased enough for a team from MIT to create a simulation called Illustris that can handle all the elements in the 330 million light-year span, including things like stars, galaxies, and black holes. This new model traced the evolution of dark matter, dark energy, gas, and dust starting around 12 million years after the Big Bang. Results from this simulation were presented in an article in Nature on May 7.
In the earliest era of this cosmic model, dark matter dominates, becoming gravitationally attracted to itself and coalescing into enormous web-like structures, seen as blue streaks in the video above. Ordinary matter is attracted to spots with large concentrations of dark matter and clumps together into galaxies. Around 3 billion years after the Big Bang, relatively warm gas and dust can be seen throughout the simulation. Supermassive black holes form in the center of galaxies, spewing out massive bubbles of hot material and radiation as they consume matter. Giant stars also live and die in supernova explosions during this time, fusing hydrogen into helium and helium into heavier elements like carbon and oxygen. Around 8.5 billion years after the Big Bang, the simulation switches to show the distribution of these heavy elements (seen as pink and purple globs), important components in the formation of our planet and life on Earth.
"If this all sounds somewhat complicated, do not be fooled: It is extremely complicated," wrote cosmologist Michael Boylan-Kolchin, who was not involved in this new work, in an article accompanying the research in Nature.
Illustris needed to model the characteristics of many different elements including: the life and death of stars; the dynamics of gas and dust heating, expanding, and cooling; the creation of new elements through fusion; and the accretion of matter onto supermassive black holes. The details of almost all these processes are not known with high accuracy, making it remarkable that the simulation ended up with a model universe that looks an awful lot like our own.
