October. 1913. 



KNOWLEDGE. 



371 



antecedent to a further outburst. Here again the 

 behaviour of variable stars is an indication ; although 

 some of these stars are remarkably regular in their 

 changes, others are not, and generally the fainter the 

 minimum the more rapid and brighter the following 

 maximum. 



In building up the above hypothesis the follow- 

 ing facts of observation have been borne in mind : — 



1. The mutation of heavy elements, such as 



uranium (atomic weight 238-5) into 

 helium (atomic weight 4) with an enormous 

 liberation of energy spread over thousands 

 of millions of years. 



2. The changing of stars into nebulae of which 



some four or five cases are known, whereas 

 the reverse process is unknown. 



3. Gaseous stars (spectra showing helium and 



hydrogen, with or without bright lines) are 

 very light, their density not exceeding one- 

 ninth that of the Sun, whilst their gravitative 

 power seems to be " nil." Thus the brilliant 

 close pair a Crucis shows no orbital motion, 

 whilst the essentially wider solar-type star 

 a Centauri is a rapid binary pair. (N.B. 

 — -Wider is used in a mathematical sense 

 and includes the effect of surface luminosity ; 

 so far as distance alone goes, a Centauri 

 is not so wide as a Crucis.) 



4. Nebulous matter is found near most stars of 



the gaseous types — thus the nebulous regions 

 of Orion are in the midst of helium-type 

 stars ; nebulous matter is unknown near 

 solar-type stars. 



As, under the explosion hypothesis, the Sun is 

 liquid it cannot maintain its temperature by con- 

 traction, because liquids are virtually incompressible, 

 hence Helmholz's theory of the maintenance of solar 

 heat is not applicable. It is further improbable that 

 gaseous or stellar-type masses always contract as 

 they radiate heat ; on the contrary, Kelvin's investi- 

 gations indicate very strongly that such masses of 

 gas may expand. The argument that spiral nebulae 

 are systems in formation, overlooks the palpable fact 

 that these objects are exceedingly faint. Long 

 exposure photographs give very misleading pictures 

 of spiral nebulae. In nearly every case the total 

 brightness is less than any one of its neighbouring 

 small stars. It would be of the same order of 

 reasoning to assert that islands are formed out of 

 wisps of cirrus cloud. 



The commonly received view that gaseous stars 

 are hotter than liquid or sun-type stars has perhaps 

 been engendered by the classification really based 

 on the nebular hypothesis, viz., that white stars are 

 the hottest and that sun-type stars already show 

 signs of cooling, but Huggins clearly shows that 

 solar-type stars are the hotter — thus in his " Atlas 

 of Spectra," 1899, page 85, he says: — 



" In strong contrast with this falling off in Vega 

 at about X 3,700 the continuous spectrum of the 

 solar stars, Procyon and notably Capella — that is to 



say, the narrow bright intervals between the 

 numerous strong dark lines, ... is obviously 

 far more intense." And it may fairly be asked, if 

 the gaseous or stellar type of star is the hotter, why 

 it should not show metallic lines in its spectrum. 

 The answer, under the new hypothesis, is that such 

 stars no longer contain substances of high atomic 

 weight, as these substances have disintegrated into 

 the simpler gaseous elements. 



One cannot imagine the process, in a universe 

 tending to uniformity and to a maximum of entropy, 

 by which a simple gas, such as nebulium is, can be 

 transformed into complex atoms containing enormous 

 stores of energy. The reverse process seems to be a 

 more fitting one ; it starts with heterogeneity and 

 finishes with homogeneity. In short, Laplace's 

 nebular hypothesis as a representation of nature is 

 quite untenable, as it is contrary to observation and 

 to known chemical and thermodynamical laws ; in 

 spite of this, literally volumes of mathematical 

 deductions (but not by its author) have been drawn 

 from it. 



I have added a list of references to various 

 modern authorities whose views have influenced 

 my own ; some numerical results have been quoted. 



References. 



Barnard. — "The Temporary Stars. On the present 



appearance of some of these bodies." Astro- 



nomische Nachrichten No. 4655, 1913, May 



20th. 



Nova Cygni, 1876 : Its appearance is distinctly 



hazy. 



Nova Aurigae, 1891 : Its image is ill-defined. 

 Nova Sagittarii, 1898 : It is always hazy and 

 ill-defined. 



Nova Lacertae, 1910 : It presented the appearance 

 of a very small nebula, less than 2-in. in diameter, of 

 a bluish-white colour. 



Chamberlin, Moulton and others. "Contributions 

 to Cosmogony and the Fundamental Problems of 

 Geodesy." " The Tidal and Other Problems," 

 1909. 



This is a remarkable work, which is published 

 under cost price by the Carnegie Institution of 

 Washington, but it is so poorly advertised that its 

 circulation is far below its real merits. For this 

 reason, I venture to quote some of the conclusions 

 reached in it. 



Chamberlin: — "The application of the most 

 radical and the most rigorous method of estimating 

 the f rictional value of the present water-tides . . . 

 seems to show that they have only a negligible 

 influence on the Earth's rotation . . . The tides 

 of the lithosphere are chiefly elastic strains, and have 

 little retardative value . . . The accelerative 

 forces seem to be also negligible . . . There 

 has been no such change in the rate of the Earth's 

 rotation ... as to require to be seriously 

 considered in the study of the Earth's deformations." 

 (Page 59). J j xa 



Chamberlin writes (page 23) : — " There can be no 



