one minute it 's all is truth beauty and is beauty truth , and does a falling tree in the forest make a sound if there 's no one there to hear it , and then just when you think they 're going to start dribbling one of 'em says , incidentally , putting a thirty-foot parabolic reflector on a high place to shoot the rays of the sun at an enemy 's ships would be a very interesting demonstration of optical principles , '' he added .