03 - The Paradox of Flow

In Episode 3 of Ways of Ice, we confront a central contradiction: how can ice be brittle as glass yet flow like honey? The episode explores the hidden mechanics of glacier movement, from basal sliding and regelation, to the historic 1840s rivalry between Louis Agassiz and James David Forbes over whether ice expands or flows. The physical paradox is ultimately solved in the 1950s by John Glen and John Nye. Through simple basement experiments, Glen discovered how ice deforms. This breakthrough established that a glacier's shape is entirely dictated by physics, providing the mathematical foundation for all modern climate and sea-level rise models.