Part 3

Expressed in millions of leagues, this number is 170,392,000, and so, from the star on which I was, the Earth was distant 170 billions 392 thousand millions of leagues. The principle was thus established, and the problem was three parts solved. Now, here is the main point, to which I call your special attention, for you will find in it an explanation of the most marvellous realities. Light, you know, does not cross instantaneously from one place to another, but in successive waves. If you throw a stone into a pool of tranquil water, a series of undulations form around the point where the stone fell. In the same way, sound undulates in the air when passing from one point to another, and thus, also, light travels in space--it is transmitted in successive undulations. The light of a star takes a certain time to reach the Earth, and this time naturally depends on the distance which separates the star from the Earth.

[Sidenote: How the heavenly bodies are seen.]

Sound travels 340 metres in a second. A cannon shot is heard immediately by those who fire it, a second later by persons who are at a distance of 340 metres, in three seconds by those who are a kilometre off, twelve seconds after the shot at four kilometres. It takes two minutes to reach those who are ten times farther off, and those who live at a distance of a hundred kilometres hear this human thunder in five minutes. Light travels with much greater swiftness, but it is not transmitted instantaneously, as the ancients supposed. It travels at the rate of 300,000 kilometres per second, and if it could revolve, might encircle the Earth eight times in a second. Light occupies one second and a quarter to come from the Moon to the Earth, eight minutes and thirteen seconds to come from the Sun, forty-two minutes to come from Jupiter, two hours to come from Uranus, and four hours to come from Neptune. Therefore, we see the heavenly bodies not as they are at the moment we observe them, but as they were when the luminous ray which reaches us left them. If a volcano were to burst forth in eruption on one of the worlds I have named, we should not see the flames in the Moon till a second and a quarter had elapsed, if in Jupiter not till forty-two minutes, in Uranus two hours after, and we should not see it in Neptune till four hours after the eruption. The distances are incomparably more vast outside our planetary system, and the light is still longer in reaching us. Thus, a luminous ray coming from the star nearest to us, Alpha, in Centaurus, takes four years in coming. A ray from Sirius is nearly ten years in crossing the abyss which separates us from that sun. The star Capella, being the distance above mentioned from the Earth, it is easy to calculate, at the rate of 300,000 kilometres the second, what time is needed to cross this distance. The calculation amounts to seventy-one years, eight months, and twenty-four days. The luminous ray, therefore, which came from Capella to the Earth, traversed space without interruption seventy-one years, eight months, and twenty-four days before it was visible on the Earth. In like manner, the ray of light which leaves the Earth can only arrive at Capella in the same period of time.

[Sidenote: Time occupied in the transmission of light.]

QUÆRENS. If the luminous ray which comes from that star takes nearly seventy-two years to reach us, it follows that we see the star as it was nearly seventy-two years ago?

LUMEN. You are quite right, and this is the fact that I want you take note of specially.

[Sidenote: A belated courier.]

QUÆRENS. In other words, the ray of light is like a courier who brings despatches from a distant country, and having been nearly seventy-two years on the way, his news is of events that occurred at the time of his departure seventy-two years ago.

LUMEN. You have divined the mystery. Your illustration shows me that you have lifted the veil which shrouded it. In order to be still more exact, the light represents a courier who brings, not written news, but photographs, or, strictly speaking, _the real aspect_ of the country from whence he came. We see this living picture such as it appeared, in all its aspects, at the moment when the luminous rays shot forth from the distant orb. Nothing is more simple, nothing more indubitable. When we examine the surface of a star with a telescope we see, not the actual surface as it was at the time of our observation, but such as it was when the light was emitted from that surface.

QUÆRENS. This being so, if a star, the light of which takes ten years to reach us, were to be annihilated to-day, we should continue to see it for ten years, since its last ray would not reach us before ten years had elapsed.

[Sidenote: We see the past, not the present, aspect of the stars.]

LUMEN. It is precisely so. In short, the rays of light that proceed from the stars do not reach us instantaneously, but occupy a certain time in crossing the distance which separates us from them, and show us those stars not as they are now, but such as they were at the moment in which those rays set out to transmit the aspect of the stars to us. Thus we behold a wondrous _transformation of the past into the present_. In the star we observe we see the past, which has already disappeared, while to the observer it is the present, the actual. Strictly speaking, the past of the star is positively the present of the observer. As the aspect of the worlds change from year to year, almost from day to day, one can imagine these aspects emerging into space and advancing into the infinite, and thus revealing their phases in the sight of far-distant spectators. Each aspect or appearance is followed by another, and so on in endless sequence. Thus a series of undulations bears from afar the past history of the worlds which the observer sees in its various phases as they successively reach him. The events which we see in the stars at present are already past, and that which is actually happening there we cannot as yet see. Realise to yourself, my friend, this presentation of an actual fact, for it is of importance to you to comprehend the precession of the waves of light and to understand the essential nature of this undoubted truth. The appearance of things, borne to us by light, shows us those things not as they are at present, but as they were in that period of the past which preceded the interval of time needed for the light to traverse the distance which separates us from those events.

We do not see any of the stars such as they are, but such as they were when the luminous rays that reach us left them.

[Sidenote: The planet Earth as seen from afar.]

_It is not the actual condition of the heavens that is visible, but their past history._ Moreover, there are distant stars which have been extinct for ten thousand years, but which we can see still, because the rays of light from them had set out before they were extinguished. Some of the double stars, the nature and movements of which we seek with care and toil, ceased to exist long before astronomers began to make observations. If the visible heavens were to be annihilated to-day we should still see stars to-morrow, even next year, and for a hundred years, a thousand years, and even for fifty and a hundred thousand years, or more, with the exception only of the nearest stars, which would disappear successively as the time needed for their luminous rays to reach us expired. Alpha of Centaur would go out first, in four years, Sirius in ten years, and so on.

Now, my friend, you can easily apply a scientific theory in explanation of these strange facts of which I was witness. If from the Earth one sees the star Capella, not as it is at the moment of observation, but as it was seventy-two years before, in the same way from Capella one would see the Earth as it was seventy-two years earlier, for light takes the same time to traverse the distance either way.

QUÆRENS. Master, I have followed your explanation attentively. But, I ask you, does the Earth shine like a star? Surely she is not luminous?

[Sidenote: The other planets seen from afar.]

LUMEN. She reflects in space the light of the Sun; the greater the distance the more our planet resembles a star. All the light that radiates from the Sun on its surface is condensed into a disc that becomes smaller and smaller. Seen from the Moon our Earth appears fourteen times more luminous than the full Moon, because she is fourteen times larger than the Moon. Seen from the planet Venus the Earth appears as bright as Jupiter appears to us. From the planet Mars the Earth is the morning and the evening star, presenting phases like those of Venus to us. Thus, although our Earth is not luminous herself, she shines afar like the Moon and the planets, by the light that she receives from the Sun, and reflects into space.

Now the events taking place on Neptune, if seen from the Earth, would have a delay of four hours; in like manner the view of life on the Earth could only reach Neptune in the same time; nearly seventy-two years, therefore, separate Capella and the Earth.

QUÆRENS. Although these views are new and strange to me, I now understand perfectly how, since the light was nearly seventy-two years in traversing the abyss which separates the Earth from Capella, you beheld not the Earth as it was in October 1864, the date of your death, but as it appeared in January 1793. And I comprehend quite as clearly that what you saw was neither a phenomenon of memory, nor a supernatural experience, but an actual, positive, and incontestable fact, and that in very truth what had long passed away on the Earth was only then present to an observer at that distance. But permit me to ask you an incidental question. In coming from the Earth to Capella did you cross that distance even more quickly than light?

[Sidenote: Thought swifter than light.]

LUMEN. Have I not already anticipated your question in telling you that I crossed this distance with the swiftness of thought. On the very day of my death I found myself on this star, which I had admired and loved so much all my life on the terrestrial globe.

QUÆRENS. Ah, Master, although everything is thus explained, your vision is not the less wonderful. Truly it is an astonishing phenomenon that of seeing thus at once the _past in the present_ in this extraordinary manner. Not less marvellous is the thought of seeing the stars, not such as they are when one makes the observation, nor as they have been simultaneously, but as they have been at different epochs according to their distances, and the time that the light of each has taken in coming to the Earth!

[Sidenote: Light.]

LUMEN. I venture to say that the natural astonishment that you feel in contemplating this truth is only the prelude to the things which I have now to unfold to you. Undoubtedly, it appears at first sight very extraordinary, that by removing to a distance in space, one can become a witness of long past events, and remount as it were the stream of time. But this is not more strange than what I have yet to communicate to you, and which will appear to you still more imaginary if you can listen a little longer to the narrative of that day which followed my death.

QUÆRENS. Go on, I beg of you, I am eager to hear you.

III

[Sidenote: Lumen sees his own life on Earth.]

LUMEN. On turning away from the sanguinary scenes of the Place de la Révolution, my eyes were attracted towards a habitation of somewhat an antique style, situated in front of Notre Dame, and occupying the place of the present square in front of the cathedral. I saw a group of five persons before the entrance of the cathedral, who were reclining on wooden benches in the sunshine, with their heads uncovered. When they rose and crossed the square, I perceived that one was my father, younger than I could remember him, another my mother, still younger, and a third a cousin of mine who died the same year as my father, now nearly forty years ago. I found it difficult at first to recognise these persons, for instead of facing them, I saw them only from on high above their heads. I was not a little surprised at this unlooked-for meeting, but then I remembered that I had heard that my parents lived in the Place Notre Dame before my birth. I cannot tell you how profoundly I was affected by this sight; my perception seemed to fail me, and a cloud appeared to obscure Paris from my view. I felt as though I had been carried off by a whirlwind; for, as you are aware, I had lost all sense of time. When I began again to see objects distinctly, I noticed a troop of children running across the Place de Panthéon. They looked like school children coming out of class; for they had their portfolios and books in their hands, and were apparently going to their homes, gambolling and gesticulating. Two of them attracted me especially, for I saw they were quarrelling and just preparing to fight, and another little fellow was advancing to separate them when he received a blow on the shoulder and was thrown down. In an instant a woman ran to help him; this was my own mother. Words fail me to tell my amazement when I perceived that the child to whose rescue my mother came was _my own self_. Never in my seventy-two years of earthly life, with all the unlooked-for changes and strange events with which it was crowded, never in all its surprises and chances have I felt such emotion as this sight caused me; I was completely overcome when in this child I recognised--_myself!_

QUÆRENS. You saw yourself?

LUMEN. Yes, myself, with the blond curls of six years of age, with my little collar embroidered by my mother's hands, my little blouse of light blue colour, and the cuffs always rumpled. There I was, the very same as you have seen in the half-effaced miniature that stood on my mantelpiece. My mother came over to me, and sharply reproving the other boys, took me up in her arms, and then led me by the hand into the house, which was close to the Rue d'Ulm. There I saw that, after passing through the house, we reappeared in the garden in the midst of a numerous company.

QUÆRENS. Master, pardon me a criticism. I confess to you that it appears to me impossible that you could see yourself; you could not be two persons; and since you were seventy-two years old, your infancy was passed, and had totally disappeared. You could not see a thing that no longer existed. I cannot comprehend how when an old man you could see yourself as an infant.

LUMEN. Why cannot you admit this point on the same grounds as the preceding ones?

QUÆRENS. Because you cannot see yourself double, an infant and an old man, at the same time.

[Sidenote: A logical inference.]

LUMEN. Look at the matter more closely, my friend. You admit the general fact, but you do not sufficiently observe, that this last

## particular is logically inferred from that fact. You admit that the

view I had of the Earth was seventy-two years in coming to me, do you not? that events reached me only at that interval of time after they had taken place? in short, that I saw the world as it was at that epoch? You admit, likewise, that as I saw the streets of that time I saw also the children running in those streets? You admit all this?

QUÆRENS. Yes, decidedly.

LUMEN. Well, then, since I saw this troop of children, and myself amongst them, why do you say I could not see myself as well as the others?

QUÆRENS. But you were no longer there amongst them!

LUMEN. Again, I repeat, this whole troop of children has ceased to exist. But I saw them such as they were at the moment the ray of light left the Earth, which only reached me at the present time. And as I could distinguish the fifteen to eighteen children in the group, there was no reason why I should disappear from amongst them because I myself was the distant spectator. Since any other observer could see me in company with my comrades, why should I form an exception? I saw them all, and I saw myself amongst them.

QUÆRENS. I had not fully taken in the idea. It is evident, in short, that seeing a troop of children, of whom you were one, you could not fail to see yourself as well as you saw the others.

[Sidenote: Lumen sees himself a child.]

LUMEN. Now you can understand into what a state of surprise I was thrown. This child was really myself, flesh and bones, as the vulgar expression has it--myself, at the age of six years. I saw myself as well as the company in the garden who were playing with me saw me. It was no mirage, no vision, no spectre, no reminiscence, no image; it was reality, positively myself, my thought and my body. I was there before my eyes. If my other senses had the perfection of my sight, it seemed as though I should have been able to touch and hear myself. I jumped about the garden and ran round the pond, which had a balustrade around it. Some time after my grandfather took me on his knees and made me read in a big book. It is not possible for me to describe my astonishment. I must leave you to imagine what it was to me, and to realise the fact, now that you understand upon what it was based. Suffice it to say, that I had never received such a surprise in my life. One reflection especially puzzled me. I said to myself, this child is really me, he is alive, he will grow up, and he ought to live sixty-six years longer. It is undoubtedly myself. And on the other hand, here I am, having lived seventy-two years of the terrestrial life. I who now think and see these things, I am still myself, and this child is me also. _Am I then two beings_, one there below, on the Earth, and the other here in space--two complete persons and yet quite distinct? An observer, placed where I am, could see this child in the garden, as I see him, and at the same time see me here. I must be two--it is incontestable. My soul is in this child; it is no less here. It is the same soul, my own soul. How can it animate two beings? What a strange reality! For I cannot say that I delude myself, or that what I see is an optical illusion, for both according to nature, and by the laws of science, I see at once a child and an old man--the one there beyond, the other here where I am, the former joyous and free-hearted, the other pensive and agitated.

QUÆRENS. In truth it is strange!

[Sidenote: Lumen sees himself a young man.]

[Sidenote: Lumen witnesses the events of the Hundred Days.]

LUMEN. Yes, but no less true. You may search through all creation and not find such a paradox. Well, to proceed with my history, I saw myself grow up in this vast city of Paris, I saw myself enter college in 1804, and perform my first military exercises when the First Consul was crowned Emperor. One day as I passed by the Carrousel I got a glimpse of the domineering and thoughtful face of Napoleon. I could not remember having seen him in my life, and it was interesting to see him thus pass across my field of view. In 1810 I saw myself promoted to the Polytechnic School, and there I was talking of the course of studies with François Arago, the best of comrades. He already belonged to the institute, and had replaced Monge at the school, because the Emperor had complained of the Jesuitism of Binet. I saw myself, in like manner, all through the brilliant years of my youth, full of projects of travels for scientific exploration, in company with Arago and Humboldt, travels which only the latter decided to undertake. Later on I saw myself during the Hundred Days, crossing quickly the little wood of the old Luxembourg, and then the Rue de l'Est and the avenue of the garden of the Rue St. Jaques, and hastening to meet my beloved under the lilac-trees. Sweet meetings all to ourselves, the confidences of our hearts, the silences of our souls, the transports of our evening conversations, were all presented to my astonished sight, no longer veiled by distance, but actually before my eyes. I was present again at the combat with the Allies on the Hill of Montmartre, and saw their descent into the capital, and the fall of the statue in the Place Vendôme, when it was drawn through the streets with cries of joy. I saw the camp of the English and the Prussians in the Champs-Élysées, the destruction of the Louvre, the journey to Ghent, the entrance of Louis XVIII.

[Sidenote: Napoleon at St. Helena.]

The flag of the island of Elba floated before my eyes, and later on I sought out the far Atlantic isle where the eagle, with his wings broken, was chained. The rotation of the Earth soon brought before my eyes the Emperor in St. Helena sadly musing at the foot of a sycamore-tree.

[Sidenote: Historical events appear in succession.]