Simulacrum

Computer simulations, or models, have been developed to decode many complex phenomena, from ocean currents to structural loads to weather forecasting to filling a mold with hot nylon.

 

Complex interactions can be very time-consuming because of the sheer magnitude of calculations involved. What a given particle affects every other particle, and there are trillions of particles, the calculations involved are astronomical in number.

 

And when the subject is astronomical, they become truly crushing.

 

All previous attempts at modeling the formation of spiral galaxies has been hampered by the sheer number of calculations required, and the high degree of accuracy required form each calculation.

 

"Until now, numerous lower-resolution computer simulations had failed to generate a spiral galaxy similar to our own—slight bulge in the middle with a large, well-formed disk surrounding it—instead creating one with an impossibly large bulge-to-disk ratio. Turns out that this was caused because the low resolution of the models averaged gas densities over too large an area which resulted in low-density stars."

 

But now NASA has run a simulation on their Pleiades supercomputer with sufficient resolution to produce the familiar spiral galaxy that we all know and love. And live in. Scientists can use this model to study how galaxies form in real life, and now they have a much clearer picture of how this happens. In fact, this simulation confirms the current theory of galactic formation called the Cold Dark Matter theory:

 

"The Cold Dark Matter theory posits that right after the Big Bang, gravitational forces influenced the minute variations in density of dark matter, slowly clumping them together into large and larger forms. These clumps eventually became gravity wells that, in turn, pulled together the remaining visible matter into the galaxies we see around us."