The Age of the Stars

1888 Scientific American  
orbit shifts slowly frOID west to east, so as to describe an 1 1 thp. glaciers is so much the less in proportion as they entire circumference in twenty-one thousand years. In belong to a more recent epoch. . this interval the seasons undergo Illodifications that Upon the whole, the periodical return of great cu-H . invert the clilUate. When tbe perihelion passes to the I cUIupolar winters has for a starting poi�lt the cooling GENTLEMEN, it was the invention of the telescope winter sobtice, the
more » ... inter sobtice, the long axis then coinciding with the o . f the earth and . sun, and depends b es l des upon . the that gave the doctrine of evolution the basis illdispens solstitial line, the total duration of the spring and sllllultaneous actIOn of )1alf a doz . en agents, . W bICh, able to cause it to leave tbe earth and enter the solar summer of the boreal hemisphere exceeds that of the nearly all of them vanable, 1lI0dlfy each tJlue the s y stem . It was the use of telescopes that allowed autumn and winter by several days . The contrary 'oc-potency and extent of the glacial phenomen�. ?, he H erschel to apply it to the world of nebulre. It will now curs in tbe austral hemisphere, where the season� are t�lI'ee first, bO�'rowed from astronoll�y, are the m cl m abe spectrum analysis that will take charge of the stars. the opposite of our own. Autun . m and w . inter cOJ�lbmed tlO� of . the aXlS of the P?le�, th� dlsp l acer.n�nt of the In fact, the problem as to the stars is an extremely exceed the spring and S UUlmer JU duratlO n. Thls pro-I pel'lhehon, and the val'lat lOns m eccentnclty of the difficult one. The stars are simple' brilliant points. longation of the cold season in the antarctic regions terrestrial orbit. The �hree last, drawn fro ll� met e. or-The most powerful teles c opes show us still other stars which follows the variations in eccentricity of tbe ology, are the evaporatIOn of tbe seas, the o n entatlOn beyond . And even tbe more perfect the telescope .is, earth's orbit, and is now nearly eigbt days, connected of llIonntain chains with respect to humid winds, and the sm aller the I?oint must be. This point i8 sUlTounded with the circumstance that the sum of the hours of the altitude of peaks. with luminous r m gs and is often affected by phenomena the nights (tbat is to say, of the cooling) is much These prernises laid down, let us endeavor to deterof scintillation . greater than that of the bours of daily insol:;ttion, mi�e t�e geological epoch'at whi <: h the ' pa � ge o . f the The rings are due to the form of the luminous motion necessarily fa vors falls of snow and the formatIOn of penhehon to the summer solstICe co m clded wlth a itself, and scintillation is due to our atmosphere. In ice. cooling of the planet sufficientlYlllarked to bring upon all this there is nothing that regards the image itself An immense winding sheet of snow, capable at tbe the boreal hemisphere the first gr�at circumpo l� r win ' save to disfigu re it. The teleseClpe, therefore, is not an time of its maximum extension of reaching beyond the ter. It could not have been prevlOus to t he pliocene, instrument for such research. We must select another 40th parallel, covers the circulllpolar region . s of the be<;ause the rich fossil miocene � ora of Greenland an d method--tbat in which we separate the elementary rays soutb, whicb tbus become tbe seat of a glaClai cycle. Spltzberge� a!1d of ot)1er arctIC l ands <;l el � lOnstrates proceeding from the star studied. Instead of studying In measure as the perihelion, attendant upon the Uiat at thls tuue the Ice of the pol e s, If I t already the light from the stand point of the images that it may motion of the great axis (of which it occupies one of existed, bad Iittle thickness and area . After the defiglve us, we allalyze it, and the analvsb reveals to us the the extrelllities), approaches the vernal equinox, the nitive lifting of the principal chain of the Alps, Andes, chemical nature' of the body that sends thIOl light, and interval that exists between the cold and warm seasons, and Himalayas, that is to say, in the plioc E! ne period, even of those which, situated in the line of the rays, tending to disappear, the antarctic ice recedes t�)\vard I fa!:s of sno, � must have occ':lrred upon the sldes of the may modify them through absorption . the soutb pole, while that of the n()rth pole beg�ns to big-h sumllllts ; but the glaClers � hat resu � ted therefrom I need not, gentlemen, repeat the history of the dis make its way toward temperate latitudes . Fmally, were local and, so to speak, aCCIdental, hke those that covery and first applications of spectrum analysis, it when the perihelion reaches the sUlllmer solstice, wh!ch w. e obs �rve in our . day on t . he counterparts of th� C . orhas been so often done that it is unnecessary to dweil it does ten thousand five hund red years after startJllg dillera m eq uatorlal Amel'lca. I t � as at the begmnmg upon it. You still recall what a sensation was produced from the winter solstice. the climates are completely of tbe present era that the depress I On of the t e mpel · a · on the p u blic by the announcement that a chemical reversed. A great circumpolar winter prevails over ture was sufficiently pro . nounced upon the sur � ace . of analysis of the solar atmosphere had just been made, the boreal world while the austral regions see the the earth to allow tbe displacement of the penhehon and that the presence of most of our terrestr ial metals ancient ""Iaciers di'sappearing or receding. They will to bring about a glacial epoch in the north of Europe, had been detected in it. You know bow such analysis not resume their former extension until after a new of America and of Asia . I t was, in fact, at the lIloment so on extended to t.be stars and nebulre, and how science interval of ten thousand five hundred years, thus raising when the quaternary a g e wa s opening, t hat w as depo l'-was then capable, through testimony of sublime power, the periodical return of glacial action in each half of ited that formation characteristic of the glaciersth e of affil' l uing the material unity of the universe. The the globe to twenty-one thousand years. diluvium, so called because it was at first attributed to material unity of the universe-what a cOllquest for A third fact· or modi fies this action in each case, the deluge mentioned in Genesis. It is only in recent science! what :� veillifted befOl'e philosophers, savants now by increasing and now by decreasing its intensity. years that its true nature ha i! been recognized, and thinkers, and showing them a world open to their I speak of tbe variations that the eccentricity of the althougb Schimper, at tbe end of t!le last century, and labors and med i tations ! terrestrial orbit underg{)es under the disturbing influ-Charpentier, at the beginning of the present, an-�or our part, gentlemen, who are following the pro
doi:10.1038/scientificamerican02041888-10084bsupp fatcat:izbzu2m5obgn7mlqw6g34flxqy