Technically, it's actually almost completely empty. Atoms are almost completely empty. Subatomic particles are made up of quarks. The way I see it, that glass is just make of energy that has assembled into infinitely small particles that group with others and form matter. IF that is true, that glass is completely empty. However, with what I stated before, it's ~99.999% empty

‎50% of "H2O" + 50% of air

Aw! That's hella gay! I've been saying that for years! Here's how I said it tho... "Some say the glass is half empty, some say the glass is half full... Well I say, it BOTH."

And 70% dark matter for those who watch space fan news!! =P