The Earth in space: An essay on the origin of the Solar system

• Main Author: S. BURMAN
• Format: Article
• Language: English
• Published: Istituto Nazionale di Geofisica e Vulcanologia (INGV) 1964-06-01
• Series: Annals of Geophysics
• Online Access: http://www.annalsofgeophysics.eu/index.php/annals/article/view/5218

The origin of the sun and planets has been reviewed<br />from manifold considerations — nuclear, astrophysical, chemical and geophysical.<br />Basically, there are two schools of thought: monistic, which<br />postulates that the sun and the planets formed from some primordial system<br />of gases; and dualistic, which holds that the planets and meteorites had<br />genesis in the sun's collision wtili another star. The extreme improbability<br />of collision almost discards this hypothesis.<br />The present day accepted theories are, hence, the monistic ones, and<br />the one particularly favored is the Dust — cloud hypothesis — that the sun<br />condensed into a star due to the gravitational collapse of a massive interstellar<br />gas-cloud, and subsequently gave birth to planets as further evolution<br />of the cloud progressed. Studies of extinct radioactivities, within the<br />framework of the above hypothesis, give clue to the early history of the<br />solar system and in particular indicate that the time interval between the<br />start of condensation and the formation of the meteorite parent-bodies is<br />less six million years (Cameron). In this context the origin of stars from<br />" globules " or proto-stars has been briefly discussed.<br />A somewhat " exotic " theory of the formation of planets from the<br />sun which hinged on the concept of secular decrease of the ' constant ' of<br />gravitation with the age of the universe (Dirac's hypothesis) has been discussed.<br />The earth (with expansion of its volume) and other celestial<br />bodies might provide empirical confirmation of the concept of diminishing<br />gravitation — an important problem of general relativity. This new idea<br />of physics might revolutionise fundamental concepts in geology and geophysics.