What happens when you snip this glass #science #experiment

3-Second Blueprint (English)

1. Dripping molten glass into cold water freezes the outer skin first, and the shrinking core pulls that shell tightly inward.
2. Nearly 40 tons per square inch of surface compression clamps hammer cracks shut while locking the core under high tension.
3. Snipping the thin tail breaches the tensile core and propagates cracks at ~4,000 mph—the same physics behind tempered car glass.