114 SESSION I. DISCUSSION 



mainly composed of hydrogen (according to Fesenkov the hydrogen departed into inter- 

 planetary space owing to thermal dissipation). 



As early as 195 1 wc proved in a strictly mathematical way that this was impossible [i]. 



Of course, at particular stages in the evolution of the atmosphere of the Earth, it may 

 have contained some, perhaps even a considerable amount of hydrogen, but the mass 

 of this hydrogen was always small compared with that of the Earth at any given time. 



The presence of ammonia and methane in the primaeval atmosphere of the Earth, 

 though only in small amounts (some mm at NTP) led to the atmosphere being impermeable 

 to ultraviolet rays of 2200 A. 



In considering the hypothesis that the primaeval organic compounds were synthesized 

 under the influence of the nearer ultraviolet part of the spectrum, we must make due 

 allowance for the absorption of ultraviolet rays by the various components of the atmos- 

 phere of that time. 



The agent which, together with V. I. Krasovskii, I suggested might have stimulated 

 the development of life, namely a liigh level of cosmic radiation during particular epochs 

 in the history of the Earth, has a definite advantage as against such mechanisms as ultra- 

 violet radiations from the sun or electrical discharges. 



Cosmic rays do not depend on the haphazard permeabihty of the atmosphere, they 

 act uninterruptedly and they penetrate water. The disturbances and changes brought 

 about in the structures of organic molecules by high-energy particles considerably surpass 

 the effects of ultraviolet photons with energies of some volts. 



We may note the possibiUties for asymmetric synthesis of organic compounds by the 

 action of cosmic rays while pointing out that a circularly polarized component in solar 

 radiation has not been discovered. 



Developments in physics and chemistry lead to the conclusion that there must certainly 

 have been epochs in the past when the intensity of cosmic rays was hundreds of times 

 greater than it is today. Advances in radiation biology show that this factor can hardly 

 have failed to produce an effect on organic substances. 



The object of this contribution is to direct the attention of specialized biochemists to 

 this important fact. 



REFERENCE 



I. I. S. Shklovskiï, Astron. Zh., 28, 234, 1951. 



H. A. Lyubimova (U.S.S.R.): 



(I want to make a few remarks about the original temperature conditions on the Earth.) 

 From the preceding papers it is clear that there are, at present, two different opinions as 

 to the original state of our planet. One postulates that the Earth w^as originally molten 

 (Fesenkov) while, according to the other, the Earth was relatively cold, or, more accurately, 

 its original temperature was not above that of its melting point (Urey, Slimidt). Both 

 hypotheses postulate the agglomeration of the planet from a dispersed medium. The 

 second opinion is increasingly supplanting the first. It must be emphasized that, from 

 the point of view of the question here being discussed, that of the origin of life on the 

 Earth, we should be mainly interested in the conditions prevailing on its surface. Such 

 being the case the following facts are of interest. 



The temperature of the surface of the Earth is now determined exclusively by the 

 activity of the Sun. Astronomical evidence about the evolution of the Earth shows that 

 the luminosity of the Sun has not greatly altered during the time life has existed on the 

 Earth and, thus, the action of the sun on the surface of the Eartli has been relatively 

 uniform. 



These facts, in themselves, suggest that the conditions on the surface of the Earth 

 which led up to the birth of hfc, existed for millions of years in the past. 



A knowledge of the temperature of the internal depths of the Earth makes it possible 

 to explain other factors without which the formation of life would have been impossible, 

 namely the oxygen-containing atmosphere and the origin of water, 



V. G. Fesenkov has formulated the requirements which must be met by a cosmogonie 



