. Aspects of the origin of life. Life; Biochemistry; Biochemistry; Biogenesis. 86 S. L. MILLER that organic compounds might be synthesized by ultraviolet hght and by electric discharges in the proposed reducing atmosphere. Experimental support for these theories came from studies of the action of electric discharges on these gases [5-7]. The experimental results will be sum- marized, and some of their impUcations will be discussed. As a basis for discussion the following model of the primitive Earth is pro- posed. The atmosphere was reducing and the oceans covered an appreciable fraction of th
. Aspects of the origin of life. Life; Biochemistry; Biochemistry; Biogenesis. 86 S. L. MILLER that organic compounds might be synthesized by ultraviolet hght and by electric discharges in the proposed reducing atmosphere. Experimental support for these theories came from studies of the action of electric discharges on these gases [5-7]. The experimental results will be sum- marized, and some of their impUcations will be discussed. As a basis for discussion the following model of the primitive Earth is pro- posed. The atmosphere was reducing and the oceans covered an appreciable fraction of the surface of the Earth. The temperature is assumed to have been less than 100°. The sources of energy for the production of the initial organic compounds were ultraviolet Hght, electric discharge and high temperatures (under local conditions such as volcanoes). Although the level of radioactivity was higher than at present, the energy available was still quite small, and there is no evidence that the cosmic ray intensity was ever large enough to compare with the energy from the sun. The energy from ultraviolet hght would probably be greater than that from electric discharges. Because of the difficulties of working with ultraviolet hght in the region where the reduced gases would absorb (<2000 A), electric dis- charges were used in the first experiments. SPARK DISCHARGE —RUN i An approximation of the proposed model is shown in Fig. i. The apparatus is made of Pyrex with tungsten electrodes. The water in the small flask is boiled to promote circulation and to bring water to the region of the spark. The pro- ducts of the discharge are condensed and flow through the U-tube, which prevents circulation in the wrong direction. The non-volatile compounds accumulate in the small flask. The spark discharge is produced by a high fre- quency Tesla coil having a peak of 60,000 Fig. I. Spark-discharge apparatus. Please note that these images are extracted from scanned page imag
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