That, broadly stated, was the information which Helmholtz first conveyed to me in terms which I understood clearly; and for this service I have always been profoundly grateful to him. He showed me that the Faraday-Maxwell electromagnetic theory was incomparably simpler than I thought it to be, and also much more beautiful. I do not believe that in 1881 there was another physicist in continental Europe who could have given me that information, and perhaps not even in 1886, when I first read that wonderful address. My friend Niven in Cambridge, editor of the second edition of Maxwell’s great mathematical treatise, never volunteered to tell me how Maxwell answered the question: “What is Light?” Neither did Tyndall. I do not know whether Rayleigh or Stokes or anybody else in Cambridge when I was there could have done it as well as Helmholtz did. I shall describe later an historical event which indicates that they probably could not.
Toward the end of that semester I felt certain that I understood Helmholtz’s interpretation of Faraday, and of Maxwell’s answer to the question: “What is Light?” I then managed to have another discussion with Professor Koenig. He listened most attentively to my description of the Faraday-Maxwell electromagnetic theory as I had gathered it from Helmholtz; and it was, as far as I can recall it now, very similar to the description given above. This was my first lecture at the University of Berlin, delivered to a very intelligent audience of one person, dear little Doctor Koenig. It would have been a signal success if I had not closed it with a tactless remark, to the effect that Helmholtz, in his Faraday address, rejected every one of the four German electrical theories, and declared himself in favor of Faraday and Maxwell. Helmholtz intimated, and unfortunately I did not hesitate to say so to Doctor Koenig, that physicists of continental Europe had not accepted the English theory because it was above their heads. Finally I said that all this explained most satisfactorily why Kirchhoff paid so little attention to Faraday and Maxwell. Koenig looked at his watch, and, as if suddenly remembering an important engagement, he turned on his heels and left without his customary bow and greeting. His national pride was evidently wounded. I regretted it deeply. I did my best to make up with him and succeeded finally, by admitting unreservedly that, after all, the Faraday-Maxwell electromagnetic theory rested upon several bold assumptions which had not yet been verified by experiment. The German electrical theories also rested upon unverified assumptions, but I said nothing about that for fear of endangering the re-established entente cordiale between Doctor Koenig and myself.
Excellenz von Helmholtz had left Berlin for his summer vacation; among my German fellow students at the Physical Institute there was not much interest in Faraday and Maxwell. I do not know how difficult it is to conceal a deep secret, because I never had one to conceal; but I do know how hard it is to keep imprisoned in one’s heart the joy which one feels when the light of new knowledge rises above one’s mental horizon. I had planned to visit my mother during that summer; I had not seen her for nearly two years. Perhaps, I thought, I might find somebody in my native Banat to whom I could disclose the joy which I received from the revelation which came to me through Helmholtz. Kos, my teacher of fifteen years before in Panchevo, was no longer among the living; in fact, that school was no longer in existence, the Hungarian régime having replaced it by a Hungarian school. I would have liked nothing better than to tell him how Maxwell answered the question: “What is Light?”
In the beginning of August of that summer I was in Idvor again, carrying with me the two volumes of Helmholtz’s addresses. My mother received me with a heart which she described as overflowing with blessings which my visit and the visit of God’s grace upon Idvor was pouring into it. The golden harvest was all in, and it was the richest that Idvor had seen for many a year; the grapes in the old vineyards were beginning to ripen, and the peach-trees among the rows of vines in the vineyards were heavily loaded with the juicy fruit of ambrosial flavor; the melons in the endless melon patches looked big and flourishing, and suggested that at any moment they might burst with the fulness of their exuberant prosperity. The dark-green corn-fields seemed to groan under the heavy load of the young ears of corn, and the pasturelands alongside of the corn-fields were alive with flocks of sheep, carrying udders which reminded one of the abundance of milk, cream, and cheese such as Idvor had seldom seen. All these things my mother pointed out to me, and she assured me that by the grace of God she was enabled to be a bountiful hostess to me, because she had everything in great abundance which she knew I always liked. Melons, cooled at the bottom of a deep well; grapes and peaches picked before sunrise and covered up with vine-leaves to keep them cool and fresh; young corn picked late in the afternoon and roasted in the evening in front of a wood fire; cream from sheep’s milk supplied by the blessed sheep the day before. All these were sweet and delicious things; but have you ever tasted them when their sweetness is flavored by the love of an indulgent mother? If you have not, then you do not know what sweetness is. I warned my mother that her hospitality might transform me, as three years before, into a pampered pet who would be too slow to return to Berlin. Reminding me of the story which she had told me two years before, describing my climb up the steep and slippery roof of Bukovala’s mill in search of a star, she said: “You have done much climbing during the last two years, and I know that in your climbing you have found several real stars from heaven. One of them is now in Berlin and no sweets in Idvor will keep you away from it.” She guessed right, undoubtedly because she observed with what joy I kept up, during that vacation, my reading of Helmholtz’s addresses.
Many a night during that summer I spent in my mother’s vineyard sleeping on sheepskins under the open sky and looking at the stars at which I looked fifteen years before, when I helped the herdsman to guard the village oxen during the starlit summer nights. I remembered the puzzles which I tried to solve at that time concerning the nature of sound and of light, succeeding in the case of sound and failing in the case of light. I rejoiced at the feeling that I had finally succeeded in finding from Faraday and Maxwell through Helmholtz that sound and light resembled each other, one being a vibration of matter, and the other a vibration of electricity. The fact that I did not know what electricity is did not disturb me, because I did not know what matter is. Nobody knows the exact nature of these even to-day, except, as Faraday suggested, that they are manifestations of force. David’s nineteenth Psalm, which I recited so often fifteen years before during my training in herdsmanship, conveyed a different meaning, and so did Lyermontoff’s line which says that “star speaketh to star.” They certainly spoke to me during those glorious August nights, when, covered with sheepskins, I lay in my mother’s vineyard and amid the deep silence of slumbering earth I listened to their heavenly tales. The more I listened the more I became reconciled to the idea that the language of the stars reaches me in the same way that human language does, when it speeds on over the telephone wire, conveyed by vibratory electric and magnetic forces; except that in the transmission of the telephonic message the vibratory forces glide along the conducting wire, whereas the stars pour out their waves of vibratory electromagnetic forces in ever-expanding spheres so that they may carry the heavenly message to every other star and to everything that lives, and to everything that has a being. I could not help telling my mother of my new knowledge which persuaded me that light is a vibration of electricity, very much like the vibration of the melodious string described in the Serbian figure of speech, familiar to her, which says:
My heart quivers like the melodious string under the guslar’s bow.
She always was the most attentive audience that I ever had, and the most responsive. Her wonderful memory, even at that time when she was seventy years of age, assigned to every essential event of her experience a suitable place, so that it became a vital chord in the symphony of her life. She never heard anything worth hearing without responding with one of these harmonious chords, and this was particularly true when I was speaking to her. On this particular occasion, referring to my new knowledge which I brought to Idvor from Berlin, she reminded me of my new knowledge about lightning which I had acquired from my teacher Kos, in Panchevo, some fifteen years before, and afterward tried to explain it to my father and his peasant friends, who accused me of heresy; and she recalled her defense of me. She suggested, jokingly, that if my father and his old friends had still been living they would perhaps accuse me again of heresy on account of some old legends which clashed with my new knowledge; and she assured me that she would defend me again. “God sends sunlight,” she said, “to melt the ice and snow of the early spring, and to resurrect from death everything that lay lifeless in the cold grave of the bosom of mother earth, chilled by the icy breath of winter. The same sunlight,” she continued, “awakens the fields, the meadows, and the pasturelands, and bids them raise the daily bread of man and beast; it also ripens the honey-hearted fruit in orchards and vineyards. If that is all done by the same heavenly force which hurls the lightning across the sombre summer clouds pregnant with showers, and also carries, as you say, the humble human voice over the wires between distant peoples, then I see in it a new proof of God’s infinite wisdom which uses one means only to do great things as well as small. Ko che ko Bog! Who can fathom the power of God!” I reminded her of her saying which she often addressed to me when I was a boy and which I quoted before, namely: “Knowledge is the golden ladder over which we climb to heaven,” and asked her whether she included in this the knowledge which I was describing to her.
“I include every knowledge,” she said, “which brings me nearer to God; and this new knowledge certainly does. Just think of it, my son: God has been sending his messages from star to star and, according to David, from the stars to man, ever since the creation of Adam, employing the very same method and means which man, imitating the divine method, is beginning to use when he employs electricity to carry his message to a distant friend. Your teachers who gave you that knowledge are as wise as the prophets and as holy as the holiest saints in heaven.”
When I told her of Faraday’s vision, that all things extend to and exist in every spot of the universe at the same time and that, therefore, all things are in perpetual contact with each other, every star feeling, so to speak, the heart-beat of every other star and of every living thing, even of the tiniest little worm in the earth, she answered: