A glass that won't break: Oxide glasses are important for applications ranging from smartphone screens to window panes. One familiar feature of glass is that it fractures and shatters when rapidly deformed, limiting the number of potential uses. However, Frankberg et al. found that they could deform thin films of glassy alumina (Al ₂ O ₃ ) with high strain rates at room temperature (see the Perspective by Wondraczek). This surprising observation is supported by simulations of the material that show that dense and flawless glassy alumina samples can deform this way. The discovery provides important insight into designing new glasses that might be more fracture resistant. Science , this issue p. 864 ; see also p. 804