High-speed atomic collisions create miniature 'event horizons' that govern how nuclei shatter.
March 31, 2026
Original Paper
Universal Geometric Scaling in Cosmic Ray Spallation: Evidence of a Dynamical Causal Horizon from AMS-02
arXiv · 2603.26824
The Takeaway
Using data from the International Space Station, researchers found that when cosmic rays smash into other atoms, they create a 'causal horizon'—a boundary similar to the edge of a black hole. This horizon generates a specific temperature that explains exactly how the atoms break apart, replacing complex nuclear math with a simple geometric effect.
From the abstract
The interpretation of high-precision cosmic ray spectra is fundamentally bottlenecked by uncertainties in fragmentation cross-sections. Traditional kinematic models, driven by phase-space expansions, typically predict complex, energy-dependent evolutions. However, AMS-02 measurements reveal that at high rigidities ($R > 30$~GV), secondary-to-secondary flux ratios (Li/B, Be/B, and Li/Be) strictly converge to energy-independent plateaus. To understand this anomaly, we explore a macroscopic geometr