In another installment of “winding down science at the NCSA” (a series that I wish wasn’t happening), this month sees a report on a huge computational simulation on the formation of black holes [2].
This is a particularly apt “last paper” for the National Center for Supercomputing Applications (NCSA), because the center was founded by astronomers who wanted to enable large scale computational cosmology. Indeed, one of the coauthors of the new paper is Mike Norman, who was one of the first users of “the cray” when NCSA opened, and probably used as much compute time over the decades as any single user. So it is very appropriate for him to be involved in this “final” effort.
The new study also shows that, if NCSA accomplished nothing else, it has contributed to major advances in the computational modelling of black holes!
The study itself is pretty far beyond my own understanding of the early universe and galaxy formation. But I do understand the significance of the 72 terabyte dataset, results of large scale multiphysics simulations.
The project used these earlier computations to identify “areas of interest” (two 40 megaparsec cubes), which they simulated at even finer detail. These new simulations yielded interesting new understandings of conditions in the early universe, and how block holes could have formed at that time, which is the subject of the paper.
This paper also represents the transition to the next systems. The original 72TB dataset was computed on Blue Waters at Illinois a few years ago. The new computations used the newer and continuing “Stampeded2” in Texas.
I’ll note that the science team is located in a number of institutions, and ran the simulations remotely over high speed internet connections. This methodology has always been the case, these computational astronomers are nomads, always hunting cycles where ever they can be found. (Mamas, don’t let your babies grow up to be computational astrophysicists.)
On a historical note, it is no coincidence that supercomputing centers like NCSA and today’s descendants have always been leaders in high speed networking. There’s only a handful of high end computers, and the users are all over the world. So we had to invent network technology, just to do the job. And out of that, came a minor side-project: the world wide web.
You’re welcome.
- NCSA, Black hole research featuring simulations from the Blue Waters supercomputer published in Nature, in NCSA News. 2019. http://www.ncsa.illinois.edu/news/story/black_hole_research_featuring_simulations_from_the_blue_waters_supercompute
- John H. Wise, John A. Regan, Brian W. O’Shea, Michael L. Norman, Turlough P. Downes, and Hao Xu, Formation of massive black holes in rapidly growing pre-galactic gas clouds. Nature, 2019/01/23 2019. https://doi.org/10.1038/s41586-019-0873-4
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