ORIGIN OF EARTH 13I 



development of matter ^\ hen a new and more effective form 

 of motion makes its appearance. 



Theory of the origin of the Earth. 



Unfortunately, we have, as yet, no single comprehensive 

 theory as to the way in which the Earth was formed. How- 

 ever, all the astronomical, geological, physical and chemical 

 facts bearing on the problem which we can assemble and 

 all the generalisations w^hich have been made by contempor- 

 ary cosmogonists of different outlooks conspire to convince 

 us that large amounts of the simplest organic compounds 

 must have arisen abiogenically on the Earth at the time of 

 its formation and during the first period of its existence, 

 and that these compounds arose by purely chemical, abio- 

 genic means long before life made its appearance. 



As early as the end of the eighteenth century W. Herschel"^ 

 put forward an ingenious idea, which later received the 

 wholehearted support of Laplace,^"® namely that the stars 

 and constellations are not something unchanging but that 

 they arose at various times (and are still arising) and that 

 they undergo processes of gradual development, the various 

 stages of which can be observed in the sky. 



This idea has been thoroughly substantiated by a number 

 of astronomical facts which have since been established, in 

 particular by investigation by V. Ambartsumyan"^ of stellar 

 associations. These associations seem to be unstable because 

 the attractive forces between the stars of which they are com- 

 posed are weaker than those of the galaxy as a whole (espec- 

 ially the more central parts of it). The stars comprising 

 these associations are therefore flying apart and, according 

 to Ambartsumyan's calculations, the associations cannot re- 

 main in being for long, at most for some tens of millions of 

 years. Judging from what we can now^ observe of them, 

 these associations and the stars of which they are composed 

 have arisen recently. Thus, the process of the formation of 

 stars is still taking place now. Alongside of this there 

 occurred, and still occurs, the formation of planetary systems 

 analogous to our o^vn solar system. The findings of recent 

 years and, above all, the studies of E. Holmberg"' indicate 

 that systems of this kind are widely distributed in the uni- 



