THE GIANT TELESCOPE

Lake Wakatip Mail, Issue 3828, 8 January 1929, Page 7

THE GIANT TELESCOPE

» | CALIFORNIA'S HEW SCHEME I WONDERS OF STELLAR PHOTOGRAPHY j I j I';, i ’ 111 j ■ il M. Ti i'.i'.S.. j m tin,' () IjjjCJ r\ - or. j 1 1 ha-. 1,1 , u 1- nil 1 y : i; •.! i • > • < i= l ■' i l5';J t 1 | i j, | ja ) |; i vi‘ b"eii ) I To v ii i -si lor coil - , i a Uliii all;! inaiiii, nance of a 10l '• ..< ( ,pe wiHi a n-llector of dßlm i;i dotI 1 , n_. ( . w i’:i|(hli- llil' W I!! i i I H| ilia 1:; r ■; I ■ I : yxi-.i 11 ;' I'cth.-clnr. which i: i hat ii[ i lie j,i Mia j>i.ijt-• t wil hj some ; mldclim • :s. ! i! V.M.. kii-'v. n l‘i a.-tronoim-r. lint i he I rail- I nir! imi of a large I ;■!' tope, oven , !ai "■ a' -i* Uliii in diameter. 1 1 ■ 1 !■.‘•an l under lla 1 most earelul consideration j Ini- -niiiie years; indeed. '-pecd'a a linn I ana estimates on this scab 1 appeared in A ii-ru i I in I lie ‘ Public;-!. ions ol l In- A-l ronomical Soeiels ol (lie Tacihe, with tin.- cun I'm I on I stulvni'-nl ilia t- such a telescope could bo biiill and used ii only iho money could bo provided. Rut iiiai: uionoy ran into millions of pounds, and no peixoii or body oi persons • seemed ready to iace so large an expenditure. Recently it was whEpeied, almost witTi awe.' that ilie proposal might no! > remain entirely vicionary. 'Hie man; j who has more than om;o made possible a '.peat .scientific advance, Hcorge El- • fry Hale, though his health had given j 1 nay under iho strain oi Ids demoted '■ work lor science, has fortunately so far I , recovered as to “ take hold ; an *' Ob- i , sarvaiory Council ” has been const 1-j . tilled under bis chairmanship, and ; ; Uiongli tin* proposed diameter ol_ the- ’ mirror has been reduced from dOOin I <> J 1 •iDUin, for reasons easily understood. i j there is now every prospect that within j , leu years this giant will come into be-1 ing and open our eyes to now wonders. I j LOUD POSSE'S TELESCOPE. | >. What advance in particular do we v expect to make? Judging from the 1 case of its predecessor, the JOUin, its 1 most, striking usefulness may turn out j a l,u be in some direction at present tin- - ( foreseen or barely loreseen. Rut it, will > 1 almost certainly extend the achieve-1 ments of the iuiJiu, one of which has ' been sensational enough to deserve spe- ; 1 rial mention; indeed, it is largely the;* 5 prospect of bettering this particular ; <’ achievement that has crystallised a vis- j’ ion of the future into a definite and , ' practical scheme ol tiio present. Lot us cast our memories back nearly i 1 a century to IS-10, when Lord i,fosse ‘ co m pie let! his great 6tt re Hector-, which , 1 excited the wonder ol the world. |)e; s Quineey wrote an essay about it, which 1 is still so much alive that a passage r from it was set for translation into k Laiiu prose as one oi this year's prize 1 compositions at Oxford (vol. 111. in iflack’s edition, pp. .1.(59-17(5). Tim im-! :l portanco of the results expected may i ' be gauged from these lew sentences of; i Do ( v )uiucey : ‘ !- " i ask peremptorily, docs it stand’ ( with good sense, is it reasonable, that v earth is waning, science drooping, man looking downward, precisely in that 1 epoch when, first of all, man’s eye is I arming itself tor looking eifeetively into, t the mighty depths of space? A new. era for the human intellect upon a path that lies amongst its most aspir- I ing is promised, is inaugurated, by! Lord Russo's almost awful telescope.” ST A ItS AND NERULTE. Sue!i expectations, high as they were, ; were not altogether disappointed. Lord itusse secured an advance in two direr - ! lions; lie could see lainter stars, and he saw them more clearly defined, a Hence some of the nebula 1 which a smaller telescopes had seen as coiilmu- 1 ous hazy masses, presumably of gas, 1 i were with the new weapon “resolved ’' i into myriads of Liny faint stars. Two s inferences naturally presented them- r selves: (lie first, that the jiebuho which r tins great telescope failed so to resolve r might be resolved into stars ii an even v bigger telescope could be made; ami, jj secondly, tliat, all the nebula: were cun- v seijiienl !y distant comnmnii ics of stars —bow distant it was scarcely possible even to guess, and (piite impossible to i measure. At that lium astronomers g could only measure the distance oi one s or two stars comparatively close to u the light from which could reach us in ( a few years. 1 j In subseij non I; years three iniporlanl (■ events uimlilied the situation thus skcteiied. Firstly, in 1591 the spectrascope showed that some ot the iielmkc, at any rale, were masses of luminous j gas, nut eollectiojis ol stars. Secondly, although no telescope larger than Lord 1 fosse's was built until well on into the present century, photography (about . I.ssu) provided an alternative to in- _ creasing the size of telescopes in Hie ' prolongation oi exposure. Expose a 1 plate in a telescope for a few minutes 1 and images will be obtained oi the '' lairiiy bright stars; ex pose for an hujrr , and the lainter stars appear in addi- 1 ' lion; expose it for a Jiundrcd hours 1 and slars much lainter still will bv v photographed, it might seem that the \ .shortness of a night would prevent such i lung exposures, but with proper care ! t it is tonnd possible to close up the | telescope as daylight approaches, and L to resume the exposure on the next ‘ line night, (.'uiinilativo exposures have | , been, eivmi in ibis way lor more i.han ; v Rill hundred hours, and it might seem ! j that by mere patience and industry; , the possessor of a moderate telescope j could secure the advantages of a larger ■ one, by reaching lainter and fainterj to an almost imlefniito extent. Ho can certainly secure, some ol these j advantages, but not all, ax will appear I in a moment. j Lit; I IT A MILLION YEARS o.\ jj 1 j 1 is \\ A i j j Tiie ihird (went which Ims coiuplotoly i I alien d (lie silnaiion is that within I-be j j last decade a inclin'd of measuring the I distances of the stars and ol the nebu- | i;e which contain stars, even whoa limy | 4 art; almost incredibly remote, lias been! \ discovered. Among the millions ol , star, which .shine steadily there are , .some hundreds, called Cepheids, which , \ a ry tlieir liglit in a peculiar way. ( some of them in a few hours, others in ( a lew days; and the gist o' the dis- ; covery is that those which lake longest ( to 'vary are I he brightesl. Ry merely watching such a star so as to note 1 how soon tlie changes repeal we can j tell how bright it really is, however j faint it may -seem to us owing to its j .. rea I distance. .And, in hud , hy corn- , paring wiiat. seems with what, really is j we can infer ihal distance. ! !uts has j an immense slaai iorward been talveiv J ■ in | Im exploration oi flic universe. Dr rtvibblo irairmd llm great lOOin

j L| io many Ii ny stars sliown jia Ii a doxci | infi-rivil, and by comoari.-on with ila-i j ■ ei'iiung bright ne—a s i lie dr-tanee ol Hi | 11 ■ 1 1 iii;I was iiiiiml io b” a million ligii / yeaiw. All the hail-dozen gttve cm J .--i- ain;• ■i i that the hj tit w!■■: •! of I lie kind. Smaller and laiuier iia bull'.. 1 y.ei-e -imuariv pie' t ( >gr, i p !u. d Why v. as Hi) ; ? \Vii., cmihl not ill man - are !o be noted. •/ r a pi in tv •i> I: • • ex pus are ; we ntu-t lake anaj'-'me beeanse the horses are changing ta-o position: rapidly. ’1 he lar.-> are .-hang ii: ; g mil. tlmir positions, hut liteii I:ri l ' lit 11 *..s .a, and by long (exposures wa should lose jits I whal wo watit lo_ itiM i 1 eiice ibe project which had beer under sernam, but not very liopeinl. (omaueralrm ini sumo years has now taken definite shape. THE LLviiTS OF THE IgA i \ tdiSE? {>r Hubble's succosscs, and even more perhaj.is the check which put an end to them, have given a. new impulse to the project. There i-,, further, a feature of Hie situation wiiicii can only be bandied somewhat delicately !e-t too great an itni>n'«io.n may nuidveiTeitlly be made if the (listanees already gauged could be extended as Hie substitution of a yui.iin telescope for a luUui might extend litem they would a]>pro<teli, not perhaps Einstein’s suggested limn to space, but at any rate a respectable fraction oi ii. Einstein’;-, work bad; him to think that, space is nut indefinitely extended like a Hat plane, but limited like the surface of a spftero wliicli returns into itself, ami that just as there is a radius for this surface in two dimensions so there is a radius for space in three, for which he has assessed a value. If we could measure distances comparable with tins value we might learn something, even if at present we scarcely know what. We may be tempted to sneer at such strange ideas; many people sneered at Einstein's predictions that rays of light could be bent by gravity, until tiro eclipses of J. 919 and 1992 proved that lie was triumphantly right. in any ease il is clear that a larger telescope can make an advance which cannot lie made in any other way, and it is delightful to find that the decision to make one (even though produce has restricted the size to 2UUiu rather than .‘SUU) has been taken and tlie money actually provided, it is delightful to lind that Dr Halo is again able to take the lead in the enterprise, and especially is it delightful to us in England to sec prominent among the names of those whose help has been gratefully acknowledged that of Sir (’’harles Parsons son ol the Lord Rosso who made the great lift telescope eighty years ago—all the more because he has himself come nobly to the aid ol the RiilHh optical industry iu the great (.roubles; wliicli befell it alter the war.