If you're talking about your average glass here on Earth, it's always full. Either it's 100% full of liquid, or 50% full of liquid and 50% full of air, or 0%

If you're talking about your average glass here on Earth, it's always full. Either it's 100% full of liquid, or 50% full of liquid and 50% full of air, or 0% full of liquid and 100% full of air. Any way you slice it, it's always full.