One knew, of course, that it was not the red cape any more than it was the boots, the tights, the trunks, or the trademark "S" that gave Superman the ability to fly. That ability derived from the effects of the rays of our yellow sun on Superman's alien anatomy, which had evolved under the red sun of Krypton. And yet you had only to tie a towel around your shoulders to feel the strange vibratory pulse of flight stirring in the red sun of your heart.