How a single star can reshape an entire galaxy
Phys.org • • science
Key Points:
- New research from Leiden University reveals that variations in galaxy simulations, even from identical starting conditions, reflect the inherent chaotic nature of galaxies rather than flaws in modeling.
- By running hundreds of Milky Way-like galaxy simulations with minute initial differences, researchers observed that small changes can lead to significant structural variations, exemplifying a cosmic butterfly effect.
- The study clarifies conflicting past results by showing that the degree of gravitational "softening" in simulations affects how chaos manifests, with less softening revealing more realistic chaotic behavior.
- Key galaxy features, such as the central bar, consistently form across simulations, but finer details like spiral arm structure become unpredictable after about a million years, highlighting the Milky Way's intrinsic unpredictability over short timescales.
- Despite this chaos, galaxies retain recognizable spiral forms, resolving the paradox of galaxies behaving both smoothly and chaotically, and offering a framework to improve the reliability of future galaxy models.