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To: Robert A. Cook, PE

When the sun reaches it's asymptotic giant branch star phase, it will certainly create carbon, but in general you're correct. Through most of its lifetime the sun can't generate anything close to a heavy nuclei.

However, I think you're on to something. At some point in the universe's development it became too big to scatter heavy nuclei everywhere we see them now. I think your approach could be used to set limits on when the heavy nuclei must have been created and what kind of stars must have created them.

The approach I was trying to suggest was to look at the stars in the early universe to determine how many heavy nuclei they could've created. Current ideas suggest that early stars were enormous. They should have been able to get close to producing heavy nuclei before going nova and scattering heavy nuclei all over the neighbor hood.

You're much better suited to make the calculations than I am since you've had some experience calculating cross-sections for fusion reactions.

Using this approach it might be possible to set limits on the size of the stars in the early universe, possibly to determine which came first, galaxies or central galactic black holes, maybe even set limits on the size of galactic black holes, and to set limits on the time when heavy nuclei would have had to be generated to create the distribution we see now.


66 posted on 02/16/2007 8:36:25 AM PST by <1/1,000,000th%
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To: <1/1,000,000th%; Physicist
The penalty, of course, to assuming super-heavy stars very early in the universe is that you generate black holes (after the supernova) that tend to recapture the ejected material.

Alternate: If the superstar dust cloud mass is enough to form a black hole, and the dust cloud collapse time is as short as indicated above (< 3/4 million years) then what would prevent the black hole from forming before or during stellar evolution: at a period when all of its material would go down the hole and none be available for ejection?

We still would assume that the time, heat and pressure to go from first fusion (H + H and H - D, etc) to second generation fusion ... up to the final layer is not enough to overcome the black hole limits of gravity and distance.
67 posted on 02/16/2007 8:44:59 AM PST by Robert A Cook PE (I can only donate monthly, but Hillary's ABBCNNBCBS continue to lie every day!)
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