WORLDS AND METEORITES.
IT was a very old question, "Which came first, the egg or the hen P" and not a question which has as yet been answered. And, whatever astronomers and masters of spectre- actinic analysis may say as to the justice of Professor Norman Lockyer's scientific facts as detailed in the elaborate paper which
he read last week at the Royal Society, we can hardly think that, however complete may have been his success in proving that the origin of suns could be accounted for by the collisions of meteor's (supposing that meteors in sufficient numbers pre- ceded the suns), he was at all more successful in proving that, as- a matter of fact, meteors in countless numbers did precede the suns, and not the suns the meteors, than any of the sophists were in proving that the egg came before the hen. What the reasoning of the paper in question, if it be accepted by his scientific colleagues, appears to prove, is that " the existing dis- tinction between stars, comets, and nebulas, rests on no physical basis ;" and that it is possible to obtain many of the same spectra by subjeotiug meteoric stones to various degrees of heat in the laboratory, as are obtained from the nebulas, the comets, and the lessbrilliantly incandescent of the suns, while we fail to obtain the spectra of the more brilliantly incandescent suns, from Sirius upwards, only because we have no means of producing anything like the heat which is there at work. All this shows, no doubt, if it be verified by other scientific observers, that the variona astronomical, bodies in the universe are all of similar materials under very different conditions as to heat; and that, granted sufficient meteors and sufficient collisions for the raising of the temperature, suns might easily be conceived as the products of clashing showers of meteors. Still, that does not show that the meteors existed before the suns. Indeed, in his approximate calcu- lation of the numbers of meteoric showers, Mr. Lockyer assumes a space already sown thick with suns, whose attractions are, of course, the determining cause of the orbits of these meteoric showers as they are at present known. The calculations of Pro- fessor Schmidt, of Athens, and of Professor Newton, on which Mr. Lockyer bases his calculation, could not, of course, have been made without a complete solar system, in which the orbits of the meteoric showers are determined chiefly by the attraction of the sun; nor do we understand how observations which are so founded, could apply to a universe in which no sans existed. Hence, it seems to us that the ready-made suns are necessary in order to give Mr. Lockyer the basis for his estimate of the actual number of colliding showers of meteors ; and it is at least very doubtful if he could apply a theory which might explain the replenishment
and the variation of ready-made suns, to the first making of suns by unattached meteors with no fixed orbits at all. Granting Mr. Lockyer's demonstration that all the known astronomical bodies are originally ejusdem generic, and that their differences might arise from the degree of heat to which materials of the same kind are subjected under the heat produced by collisions between them when moving at an immense velocity, it seems not very easy to say whether the suns threw off the meteorites, which then cooled down, or whether the meteorites by crashing together produced the suns, or whether both processes have always gone on, the meteoric bodies sometimes producing the suns, and the suns sometimes throwing off meteorie bodies. Undoubtedly, Professor Norman Lockyer believes that both processes are now at work,
for the able writer who summarised his theory in yesterday week's Times, sums it up in these words :-
" We postulate only two known phenomena,—namely, the existence of meteorites in space, and the cumulative force of gravity. Starting from these we can explain in orderly sequence the origin of celestial species. Taking temperature as the criterion, we can arrange on the two arms of an ascending and descending curve the several orders of heavenly bodies. At the foot of the ascending curve come the individual meteorites, above them coma nebula, comets, and stars in successive stages of meteoritic condensation. The apex of the carve is occupied by stars of the Sirian group, in which the heat evolved by the condensation due to gravity has reached its maximum. The gradual process of cooling is represented on the descending arm by stare of the whir group and those of Claes III. b, and at last we again reach a temperature which, like that of the individual meteorites in space, is incapable of producing luminous phenomena. Is this the end ? We cannot say so, with any confidence. If collisions occur, as we know they do, and mast, between individual meteorites, we have no right to say that collisions cannot occur between the larger bodies- formed by the condensation of meteorites. ' New stare,' says Mr, Lookyer, ' whether seen in connection with nebula, or not, are produced by the clash of meteor swarms.' Thus we know that individual meteorites collide, and that meteor swarms also clash with one another. May it not be that suns and stars themselves are also liable to collisions P In that case the curve above described would be Mooed by the junction of the descending with the ascending arm, the cycle of the universe would be complete, and we might say of the Cosmos, as the geologist Hutton said of the earth, that it exhibited no traces of a beginning and no evidence of an end. This, however, is pure speculation. It is the transcendental extension of the hypothesis to a region wholly outside the range of observation and experience. ' In recorded time,' says Mr. Lockyer, 'there has been no such thing as a " world on fire," or the collision of masses of matter as large as the earth, to say nothing of masses of matter as large as the sun; but
the known distribution of meteorites, throughout apace indicates that such collisions may form an integral part of the economy of Nature.' "
But Mr. Lockyer's theory, if it is really intended to account for the origin of all suns, must assume billions upon billions of meteorites in the place of every sun, and these, originally at least, moving about wildly, not in orbits, but in straight lines continually subjected to small deflections, and with all sorts of different velocities, till a few great masses had been accumulated to determine the orbits of the rest. Is that in any sense a simplifi- cation of the problem of the origin of worlds P Is it not rather assigning a more complex cause than the effect itself ? But what we chiefly want to draw attention to is this,—that if Mr. Lockyer is right as to the identity in kind of all the original substances of the different celestial bodies, there is nothing in the fact that he is able to obtain from meteoric stones in the laboratory, the same spectra which are obtained from nebulas, comets, and the cooler suns, to make it more likely that the suns come of colliding meteorites, than that meteorites come of cooling suns and fragments of suns. Indeed, the writer who explains Mr. Lockyer's theory, and who maintains that the latter process does take place, even suggests that these cooled-down suns and fragments of suns may come into collision again, and so get heated up to their former tran- scendental beat. Surely this does not answer the question, "Which came first the sun or the meteoric stone P" any more than the old Greek sophists were able to answer the question, " Which came first, the egg• or the hen ?" When we are told that organic matter must necessarily have appeared in the uni- verse later than inorganic matter, we know what is meant,— namely, that inorganic matter can subsist without organic matter, but that organic matter cannot subsist without inorganic matter. But nothing of the kind is maintained by Mr. Lockyer as to meteorites and suns ; indeed, if we understand his theory aright, he holds that either suns may come out of the collisions of meteorites, or meteorites out of the break-up of suns.
What seems certain is that the force of gravity, and innumer- able forces of projection of all magnitudes, affect the various particles of matter in the universe ; further, that this matter is composed of an infinite number of highly " manufactured articles," as the chemical atoms have been termed, and that these highly manufactured articles go through a most won- derful course of further manufacture before they carry matter up to the most elementary stage of any kind of life ; moreover, that all theses marvellous processes appear to extend over all space within reach of our observation, and to suggest at least, in the most forcible manner, unity of origin. If that be so, whether the minister embodiments of all these forces precede in point of time the more gigantic embodiments of them, or succeed them, or are co-ordinate with them, seems to us a matter of no very great interest, whichever way it be determined, if it ever can be determined. But surely it can hardly be decided for us in which order the story ought to be told, only by proving to us that, under certain circumstances, you can produce the star spectra by subjecting meteoric stones to a given amount of heat. So, too, you can produce steam by boiling water ; but then, you can also produce water by condensing steam. Both processes are always taking place, and we cannot know whether the water existed before the steam, or steam before the water, or whether bothwere always in existence. What had to beehown, if all suns were to be proved aggregations of meteorites, is that meteorites without suns to organise their orbits once existed in multitudes sufficient to produce innumerable collisions, and so build themselves up into suns; and that this is much more likely than that already existing suns could have thrown off the crowds of meteorites of which astronomers have evidence.