Unlike many materials, glass is amorphous, meaning it has no crystal structure. Due to the amorphous nature, glass has no slip planes, which allow other materials like metal to deform. This means that when a force, especially a concentrated force, like a sledgehammer strike, is applied to the glass, it will fracture. As a brittle material, any cracks that start will easily propagate and spread throughout, causing the glass to shatter. Let’s try it out.