What purpose do giraffe antennas serve?

There seems to be some disagreement about the purpose of these peculiar-looking stalks. The horns contain a lot of veins, leading some scientists to speculate that they may serve as cooling towers for the animal, a place where the body can release heat. Another theory suggests that the horns may be the vestiges of antlers, left over from the giraffe's ancestors. And the African Wildlife Foundation states authoritatively that the horns protect the giraffe's head from blows.