Has science changed that vision of the early childhood days? What does that light convey to my mind to-day? The answer to this question was born during my lifetime, and the gradual unfolding of its profound meaning gave me the sweetest thrills of my life. Faraday and Maxwell told me that light is a manifestation of the activity of electrical force. The discovery of the Roentgen rays and of radioactivity taught me that the primordial sources of electrical force are the positive and the negative electrons, the electrons and the protons, the building stones of matter, and that light is radiation, that is, propagation into space of the electrical energy from the atomic structures in which the electrons with their motions determine the character of the structure and its energy content. Then came Thomson, the same Thomson who scared me away from Cambridge, because I thought that he was too young to be my teacher of physics, and he suggested that the electrons possess an inertial mass on account of the electrical energy which is stored up in them. This suggestion led to the generalization that all electrical energy has mass possessing not only inertia but also gravitational action. Who does not know to-day of this generalization, and who has not heard of Einstein and of his verified prophecy that a beam of light will be deflected by gravitational force? A beam of light represents electrical energy and electrical energy is gravitationally active just like any other mass considered by Newton. A star radiating light radiates electrical energy, and, therefore, it throws out to us a part of its own mass. When this radiation reaches us we can say, therefore, without indulging in figures of speech that the star is visiting us. I am not indulging in a flowery figure of speech when I call solar radiation the balmy breath of the heavenly bridegroom, the glorious sun.