The Snowball on Steroids: Why Entrainment is the Deadliest Word in Himalayan Hazards: Think a mountain slide stays the same size as it falls? Think again. Banta uses a sticky dough ball analogy and forensic data from the 2021 Chamoli and 2017 Swiss Bondo catastrophes to expose the terrifying science of entrainment—the process where a falling rock-ice mass scours riverbeds and swallows boulders, multiplying its volume five-fold into an unstoppable fluid battering ram.