That doesn't mean that the glass is half full/empty. Haven't you heard of http://en.wikipedia.org/wiki/Capillary_action? It may sound like a cheap metal band, but it's actually serious bzns.
Not only that, but we haven't been given the shape of the glass. If it's not an ideal cylinder we're going to need a mathematical expression of the shape as well as the chemical make-up of the liquid and the atmosphere, atmospheric pressure, and the temperature of the environment.
Okay, okay, it's half-full of vodka and half-full of...oh, blast, what passes for humor with the young people these days...farts? Is "farts" funny...or no...? :unsure: