
New discovery shatters previous beliefs about Earth’s origin - upen
http://sciencebulletin.org/archives/5252.html
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helthanatos
>How the Earth was formed and what type of planetary materials were part of
that formation are issues that have puzzled generations of scientists. Is this
saying anything about the big bang theory or just earth's early composition?

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wbhart
I don't think it says anything about the Big Bang. The earth is supposed to
have formed from the remnants of supernovae, not elements produced by the
initial nucleosynthesis of the Big Bang. Indeed, most of the elements earth is
made from are believed to have come from the insides of stars, not from the
Big Bang.

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contravariant
In fact the Big Bang didn't even create any elements, it was way to violent
for that.

Only after things had cooled did the first atoms form, which I believe was
almost exclusively hydrogen.

Fusion inside stars and supernova did the rest.

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M_Grey
Lots and lots of Helium too, and (it's believed) Lithium as well. That's it
though, everything else is stardust or the interaction of stardust with cosmic
rays and the like.

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contravariant
Ah according to Wikipedia it's believed to be around 25% helium-4, that's more
than I thought it was. The rest is almost entirely hydrogen though.

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M_Grey
It's amazing when you consider the abundance of heavier elements in our
universe today, that virtually all of it was created in stars, isn't it?!

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AstralStorm
There is no abundance. You simply happen to be living in a planet, by
definition made out of heavier atoms.

Even active stars are mostly hydrogen.

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M_Grey
Considering that "in the beginning" was mostly hydrogen and helium, I'd say
that the present state of affairs is an "abundance". Granted, nothing is in
abundance other than spacetime though if you want to be picky about it
through.

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M_Grey
So... what does this imply for the formation of the planets in our solar
system?

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AstralStorm
They have not appeared around the same time in some sort of a massive
breakdown of a large amount of matter and none is a direct extrasolar capture,
but they did catch substantial extrasolar matter.

