beauty is in the eye of the beholder, may be it also means that without an observer, beauty cease to exist. Beauty is only beauty when someone is looking at it.
But I honestly think that beauty is not only physical, but also psychological, for it happened that because of some people's actions, although they were considered beautiful, I started to find them ugly, in the true sens of the word, as if I was looking beyond the envelop and seeing the actual content within. Just an opinion thought :) cheers