The Hourglass Filler

How to Play

• Goal: Design an hourglass that takes exactly 60 seconds to empty
• Flip the hourglass to start the timer and sand flow
• Adjust neck width to control flow rate - narrower = slower but more jams
• Adjust neck length to affect jamming probability
• Shake to break jams when sand gets stuck (costs accuracy!)
• Click and drag in Widen/Narrow modes to sculpt the vessel shape
• Watch for arching - grains forming bridges that stop flow
• Smaller grains flow better but larger grains look more satisfying

Physics: Granular jamming occurs when particles form stable arches at constrictions. The critical arch width is approximately 4-5 grain diameters.