How does olive oil prevent noodles from sticking?

[iScience]

my dad adds olive oil when boiling water for pasta, he says it's so that the noodles don't stick, but doesn't all the oil remain on the top? so even if some of the olive oil were to rub on the noodles while pouring the noodles in, wouldn't it just float to the top again? so how does olive oil prevent the noodles from sticking?

 

[Borek]

Physics behind is quite involved, start here: http://en.wikipedia.org/wiki/Wetting

Note that wetting doesn't refer to interactions between just water and solid, but any liquid (be it oil) and any solid (be it noodle).