iPhone Duo Glass Is Weirder Than You Think

A brand-new folding iPhone cracked, its owner says, after fewer than twenty folds. In a lab, a robot once folded a folding screen half a million times. So what is going on with the glass? In theory, glass is stronger than steel. In practice, it breaks because of a scratch you can't see, a little water from the air, and maybe a single grain of sand. Here is why glass can fold at all, how a squeezed skin protects it, and what a fold really tests. As of late October, nobody has confirmed why the new iPhones crack, and Apple hasn't commented. Sources Griffith (1921). Philosophical Transactions of the Royal Society A. https://archive.org/details/philtrans... Ciccotti (2009). Journal of Physics D: Applied Physics. https://arxiv.org/abs/0901.2809 Tang et al. (2015). Journal of Non-Crystalline Solids. https://scholarsmine.mst.edu/matsci_e... Park et al. (2025). SID Symposium Digest of Technical Papers. https://sid.org/Portals/sid/Files/SID... Chamberlain et al. (2026). iFixit News. https://www.ifixit.com/News/119895/ip... #glass #iphoneduo #science 0:00 Fewer Than Twenty Folds 0:56 Glass That Bends 2:16 Stronger Than Steel 4:05 A Squeezed Skin 5:36 The Thief in the Air 6:34 Why a Few Folds Can Be Enough 9:30 The Glass in Your Pocket 10:16 The Glass You Hold A YJ Studio film.