What did the early universe look like?
Advances in computing could help astronomers turn back the cosmic clock. Earlier this year, Japanese astronomers used ATERUI II, a supercomputer that specializes in astronomy simulations, to reconstruct what the universe may have looked like as early as the Big Bang.
ATERUI II is helping the researchers investigate cosmic inflation—the theory that the early universe expanded exponentially from one moment to the next. Astronomers agree that this expansion would have left extreme variations in the density of matter that would have affected both the distribution of galaxies and the way they developed.
By comparing 4,000 simulations of the early universe—all with different density fluctuations—against the real thing, scientists could rewind time and ask why some places in the universe are rife with cosmic activity while others are barren.
Masato Shirasaki, an assistant professor at the National Astronomical Observatory of Japan, says that question would be almost impossible to answer without these simulations. The project requires a huge amount of data storage (about 10 terabytes, equivalent to 22,000 episodes of Game of Thrones).
Shirasaki’s team developed a model of how the universe is thought to have evolved and applied it to each of the simulations to see which result may be closest to how it looks today. This method made it easier to explore the physics of cosmic inflation.
In the next few years, Shirasaki’s methods could help shorten the observation time needed for future efforts like SPHEREx, a two-year mission slated for 2024 involving a spacecraft that will orbit Earth and gaze at nearly 300 million galaxies across the sky. With these leaps in computing, our understanding of the universe is expanding, bit by bit.