Skip to main content

Problems Related to Interplanetary Matter (1961) / Chapter Skim
Currently Skimming:

THE ORIGIN OF THE SOLAR SYSTEM
Pages 1-6

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 1...
... As soon as one is willing to accept less powerful neutron sources, a variety of possibilities suggest themselves, so that it becomes difficult to be sure which stellar sources have been mainly responsible for the synthesis of the heavy elements. We start with neutron capture on a slow time scale, in which heavy elements are slowly built up in a capture chain starting with the abundant elements of the iron peak.
Read the entire page →
From page 2...
... It therefore becomes of interest to estimate the time required for the distribution of fresh radioactivity to the interstellar medium, for the formation of the star cluster of which the Sun was a member, for the contraction of the Sun, and for the formation and cooling of the planets (or at least of the meteorite parent bodies)
Read the entire page →
From page 3...
... According to this criterion, twice the thermal energy of the gas cloud plus the potential energy of gravitation must be less than zero. Therefore, for a uniform spherical gas cloud, contraction can take place only for temperatures below .,2/3 1/3 T - n 30 which means that T must be less than about 7o K if the cloud has a typical mass M of about 1000 solar masses and a density n of about 10 particles per cm3.
Read the entire page →
From page 4...
... Further contraction is luminosity controlled, with density in the protosun becoming a smooth function of the radius and with a substantial central condensation taking place. At this point also the requirement of the conservation of angular momentum will make the protosun gravitationally unstable at the equator, so that further contraction must be accompanied by mass loss.
Read the entire page →
From page 5...
... following the dynamical collapse when an outer solar convection zone can build an external dipole field which can interact with the nebula to brake the Sun's rotation. At each stage an intense acceleration of charged particles may take place, thus producing extensive nuclear spallation throughout the nebula (support for this view is found in the lithium-rich spectrum of T Tauri type protostars -- Herbig 1956)
Read the entire page →
From page 6...
... Cameron: In my model all the time scales for formation of the meteorite parent bodies are the same; the subsequent history may be different. Anders: Some calculations by Goles and Fish reveal that the cooling times for melted asteroids containing the complement of K " which would have been present 4.
Read the entire page →

Key Terms

  • free fall
  • time scale
  • heavy elements
  • fast time
  • meteorite parent

  • parent bodies
  • fall time
  • slow time
  • gas cloud
  • fall collapse

  • magnetic field
  • neutron capture
  • cooling times
  • star formation
  • instability criterion

  • decay time
  • similar time
  • produce heavy
  • effective free
  • heavy element

  • strong magnetic
  • principal cooling
  • internal magnetic
  • relatively slow
  • thermal pressures

  • slow process
  • thermal disruption
  • slow expansion
  • thermal histories
  • molecule cooling


    • This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
    More information on Chapter Skim is available.