Times and Seasons of Other Worlds.

Te Aroha News, Volume VII, Issue 453, 12 March 1890, Page 4

Times and Seasons of Other Worlds.

By Sir Robert S. Ball, F.R.S., Astronomer Royal for Ireland. [all eights reserved.] it is particularly interesting to compare the circumstances attending our residence on this earth with the corresponding conditions that would be found if we could change our abode from this globe to another planet. I propose in the present paper to discuss a few of the points which.arise when we consider such questions. In.the first place we must remember that our bodies have been specially organised and adapted bo suit our surroundings on bids particular world. I do not think it is at all probable that a man could exist even for five minutes on any other planet or any other body in the universe. We know that even within the limits of our own earth, each one of us has to be provided with a constitution appropriate for a particular climate. An esquimaux is suitably placed in the Arctic regions, a negro on the equator, and were they to change places it is hard to say whether the heat would nob have killed the Esquimaux even before the cold killed the negro, but such an attempt at acclimatisation would be easy when compared with that which would be required before an inhabitant adapted to one globe could accommodate himself to a residence on another. Indeed, there seem to be insuperable difficulties iu supposing that there can be any residence for man or for any beings nearly resembling man elsewhere than on his own earth.

Let us specially review a few of the other globes, beginning with the sun. I think we need nob givo many reasons to show that a man could not live there long. Every boy knows how a burning glass can kindle a piece of paper by concentrating the sun’s rays. Some great burning glasses have. been constructed with which iron, steel, and even flints have been actually melted by the sun’s heat, lb can be proved that the sun himself must be hotter than any temperature that can be produced in the focus of the most powerful burning glass. We certainly cannot conceive any organised beings which would find a congenial residence in a temperature vastly hotter than that of the most powerful furnace that has ever been known. Assuredly there can be no life on the sun. The next celestial world to the sun in importance is, of course, the moon. Could! we find here an eligible abode for mankind ? The moon would, no doubt, provide the necessary alternation from day to . night, but the.day on the moon would last for a fortnight, and then there would he black night fer another fortnight. During the long day the moon would 1.0 terribly scorched, a circumstance which would bo hardly compensated for by the fact than even if we survived the scorching we should certainly be frozen to death during the ensuing night. Bub there would be other insuperable difficulties attending an attempt to make an abode on the moon. The absence of water is one of them, while a still more immediate trouble would arise from the deficiency, if not total absence, of air suited for respiration. Indeed, it is almost impossible for us to conceive what an airless world would be like. Fishes out of water would be nob more uncomfortable than we should find ourselves. Bub suppose that we managed to bring a supply of oxygen that might enable us to avoid suffocation by theuseof artificial respiration, we should still find the moon a very strange world. We could hear nothing, for sound oxists not except in air. We could strike no match or light no fire. We could feel no wind and see no clouds. There would be also an embarrassment of a different kind which I do nob see any way of obviating. Suppose that we were actually on the moon, and that ive had in some way obtained the necessary provision both of air and of water, and had begun to walk about, we should experience sensations of a novel description. The extraordinary lightness of everything would be specially noticeable. Take a lump of iron which weighs 61bs on the earth, you would find on the moon that it seemed to weigh only as much as one pound would do on the earth. Everybody knows that it requires considerable exertion to lift a 561 b weight here, bub on the moon it would hardly require as much effortas you ordinarily have to put forth to lift lOlbs. Indeed, the weight of every object on the moon would be reduced to the sixth part of that which the same object has on the earth. No doubt in some ways this might prove a convenience to the moon dwellers. Their bodies would partake of the general buoyancy ; walking and running would be amazingly facilitated, and the same effort that would enable you to jump over an obstacle three feet high here would carry you with ease over a wall 18 feet high on the moon. A good cricketer can throw a ball about a hundred yards here. If he made the same exertion on the moon he could throw the ball over a third of a mile. The diminished gravitation would prove of service iu athletic performances on the moon. Not only would a bicycle be driven along with unparalleled ease and rapidity if the lunar roads were smooth, but even the disagreeable process of taking a header over tho handles would lose its terrors, for the lunar bicyclisi would almost fall as gently as if he were lying down on a bed of down. It may, hovvever, be questioned whether our bodies would be adapted for a life under such conditions. It seems almost certain that as the muscular system of the human body has been arranged to work with the particular gravitation that is found on this earth, it would be impossible for it to suit a gravitation which had only a sixth of the intensity for which the muscles were intended. On these grounds we conclude that neither the times nor the seasons, neither the gravitation nor the other distinctive features of the moon, would permit it being an endurable abode for life of the types we are acquainted with. Let us now consider some of the more distant worlds and examine their claims to be regarded as possible homes for beings in any degree resembling ourselves. There are many of these worlds with regard to which we may at once decide in the negative. Could we, for instance, live on a planet like Neptune ? It lies 30 times as far from the sun as we do. The share of the light and heat from the sun which a Neptunian inhabitant would receive, could only be the nine-hundredth part of that which is dispersed to every dweller on this earth. This fact alone would seem to show an insuperable obstacle to the existence of any life on Neptune resembling those types of life with which we are familiar. The orbit of Neptune is also so vast that tho planet requires a period of 165 years in order to complete a single revolution. The changes of the Nepturian seasons, if indeed, Neptune can be said to have any seasons at all, must therefore be extremely protracted. A man who was born at midwinter in Neptune would have reached extreme old age if he survived until the next ensuing midsummer. I cannot discuss the times and seasons of all the celestial bodies, so I liav9 taken a few typical instances. Neptune was suitable, as being the most remote planet. Now let us speak of Jupiter, tho greatest planet. The day and night on Jupiter are

both extremely short, for together they do not quite amount to ten hours. Jupiter’s year, however, is almost twelve of our years. Although a man on Jupiter would only receive one-fcwenty-fifth part of the heat of the sun that he would do on the earth, yet it does not seem likely that there would be reason to apprehend that Jupiter would bo uninhabitable from cold. Quite tho contrary is the case. Indeed, it seems nob unlikely that the excessive heat of Jupiter would be found intolerable by beings with nerves like ours. This heat has, however, nob come from the sun ; it is the internal heat of the planet itself, which has nob yet sufficiently cooled down from that original fiery state, in which every body of our system seems to have had its origin. Jupiter certainly has an atmosphere, but we do not know from what gases that atmosphere may be constituted. It might consist of materials noxious, if not actually poisonous ; and in any case it is extremely unlikely that it should contain both the ingredients and the proportions suited for our respiration. But there are independent grounds for knowing that Jupiter must be an impossible home for beings constituted as we are. On the moon every object would be deprived of five-sixths of its weight, because the moon is a comparatively small globe. Were we, however, to be transferred to Jupiter, the weight of every object would receive an extraordinary augmentation. Our muscles would be found utterly inadequate to their work. Walking, or even standing, would involve the most fearful exertion, while rising from bed in the morning would be a difficult, indeed, probably an impossible process. I see no likelihood that Jupiter can at present be the home of any life whatever, certainly not of any living things constituted as we are.

We may dismiss from our present consideration such bodies as the comets, though times and seasons they have with a vengeance. A comet moves during the greater part of its course through the depths of space at illimitable distances from the sun. Out there, the comet traverses regions where the cold would be absolutely incompatible with life of any type conceivable by us. Then for a brief period, to be measured in months, weeks, days, or even hours, the comet is wheeling around the sun, where it is often exposed to a frightful temperature suflicient to fuse and even to vapourise bars of wrought iron, A comet, indeed, is not a likely abode for life, though I ought to mention that comet 3 often contain the element carbon. This is a very singular fact when it is remembered that carbon is one of the substances essentially associated with life in the forms in which we know it.

There is, however, one body in our system whose times and whose seasons accord so closely with our own that it is impossible not to believe that life of some kind may there be found. The length of the day and night together on Mars is 24 hours 37 minutes ; that is practically only about baif-an-hour greater than the corresponding period for our own globe. The year of Mars is, no doubt, longer than ours, being about a year and eleven months. The size of Mars'is less than the size of our earth, and, therefore, the gravitation on Mars is nob so great as we have here. Ido not mean bo say that it is the least likely that any man, woman, or child transplanted from this earth to Mars could live and thrive there. The temperature might be endurable, and water appears to be not wanting, but I do not think we have any reason toexpeebthafc the atmosphere would suit human beings either in quantity or quality. Still, the conditions on Mars are so nearly parallel to those we have that it seems reasonable to think that the ruddy planet is a suitable home for some types of life. Of the other planets, such as \ enus, we know too little to say anything with regard to their times and seasons, while about the countless worlds which depend upon those other suns, the stars, we must be content not to know anything whatever. The End.