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Were we really created from supernovas?

  1. Mar 30, 2014 #1
    Hello, I'm just doing some research on how life on Earth started (for my own reasons) and I seen that a theory was we came to be from the aftermath of supernovas.

    Is this the case? Has this been proved for sure?
  2. jcsd
  3. Mar 30, 2014 #2
    In the beginning the only matter was hydrogen. By fusion process in the star hydrogen forms to heavier element. Smaller stars stop forming element relative early. The last matter they build is lighter then iron. Then the gases expand and they then shrink to a dense dwarf. That's a well known fact and many smaller stars in different stages has been observed. I'm not sure if they get scattered and become part of other planets and stars.

    Big stars however eventually forms iron and after that nothing can keep the enormous mass in the same volume as before. That's because the fusion process after iron lose binding energy, so the energy to expand the mass get less and less but the mass and gravity is still the same. After forming iron they implode with an unbelievable pressure which actually can form these heavier elements. These leads soon to an supernova explosion. The matter from these definitely get scattered far away. Ending up in nebulous, stars and planets.

    If its proven? Yes big stars has been observed in many stages including supernovas. The light spectra from stars tells what elements they consist of as any spectra.
  4. Mar 30, 2014 #3


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    r-process nucleosynthesis in ejecta from neutron stars is an emerging candidate to explain heavy element production, e.g., http://arxiv.org/abs/1307.2939, The long-term evolution of neutron star merger remnants - I. The impact of r-process nucleosynthesis. The big bang produced only light elements, primarily hydrogen and helium with a sprinkling of elements through boron. Heavier elements are produced by stellar processes.
  5. Mar 30, 2014 #4


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    IMO that assertion needs justification.

    I don't have any problem with the experimental evidence that new stars consist mostly of hydrogen, and synthesize heavier elements through fusion.

    But given that most of the "known" universe appears to consist of dark matter and dark energy, neither of which are understood, it seems a bit presumptuous to assume that if our current models of the early universe predict that the all of the earliest matter was light elements, that prediction is beyond question.

    (But I'm no expert here - I haven't read much about cosmology since the books by George Gamow et al!)
  6. Mar 30, 2014 #5


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    Aleph, I don't think dark matter and dark energy are included in the term "matter". So while both dark matter and dark energy almost certainly existed, they aren't included in the discussion here because they aren't normal matter.
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