[meteorite-list] Mammoth Stew, shooing nuisances away from the fire

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Fri, 21 Dec 2007 18:13:59 -0600
Message-ID: <01d901c8442f$8d6e58f0$b64fe146_at_ATARIENGINE>

Hi, All,

    ...he says, trying to divert the topic back to The Topic,
yes, there are discontinuities in the carbon isotope balance
that are associated with impact phenomena, but it's a very
compolicated (and confused) picture that is not yet sorted
out.

    Carbon 14, which is the marker used in dating because
of its short (<6000 year) half-life, is produced by energetic
neutrons. But in defense of the humble neutron, you have
to pound a piece of matter awfully hard to kick a bunch of
neutrons loose; they stick to the job. No thumping a planet
with a 10-mile rock is going to do it, not a puny little whack
like that. No, you got to hit'em harder.

    You can generate neutrons by smacking "stuff" with x-rays,
gamma rays, high-rolling electrons, and yes, other neutrons.
Different elements respond more or less generously in the
number and kind of neutrons they cough up. (Some uranium
isotopes are easy, like that girl down the periodic table there..)

    But there is a correlation between impacts and the C14
record. Why? How is Carbon 14 produced? The principal
means is by energetic neutrons striking Nitrogen 14 and
muscling a proton out of the nucleus and taking its place,
thus becoming a Carbon 14 atom. The neutron in this
scenario is played by Al Pacino as Michael...

    The energetic neutrons come from cosmic rays. The
twiggy part is how wide we open the door to cosmic rays.
The term "cosmic" ray is a mixed bag; some are cosmic
(galactic) in origin, but the term is also used for SEP's
(solar energetic particles) and anomalous radiation from
the distant heliopause. Read all about it:
http://en.wikipedia.org/wiki/Cosmic_ray

    Solar activity affects the Earth's magnetic shielding and
that affects the degree that cosmic rays can only penetrate
the atmosphere, so the rate of neutrons penetrating down
deep into the atmosphere is controlled by the solar winds
control of the magnetosphere's control of cosmic rays.

    Whew!

    By the time the neutrons get deep into the atmosphere,
they've slowed down and are not making C14 anymore.
No, instead they're regulating the rate of cloud production,
which is the chief mechanism for the regulation of the Earth's
temperature, so basically Global Warming is controlled
by Extragalactic Black Holes and other sources of energetic
particles countless millions of light years away.

    Carbon 14 is also produced when the Local Monkeys
set off nuclear toys in the atmosphere, whose resulting showers
of neutrons increased very measurably the amount of C14
in the atmosphere. Bad habit.

    Living things are picky eaters. They do not like carbon
atoms in all the different flavors they come in and spit them
out -- Pwah! -- and eat only C12. Burning fossil fuels which
used to be living things produces C02 that is C(12)02, thus
diminishing the ratio of C14 in the atmosphere.

    So, the excursions in the Carbon 14 levels that have been
associated with impacts PROBABLY comes from disruptions
in the Earth's upper and outer atmosphere and its magnetic
field which allow a greater flux of cosmic rays to penetrate.

    The Earth's magnetosphere varies constantly, is dependent
on the strength of the Earth's magnetic field, which is currently
declining and occasionally goes away altogether, for reasons
we know Jack Nothing about.

    Secondarily, the amount of C14 in cosmic debris, meteoritic
dust, interplanetary dust, cometary dust, supernova dust is
much higher than the terrestrial levels of C14, so increases in
the amount of any one of these things that fall into the atmosphere
would also have an affect on terrestrial C14 levels. The bigger
the infall, of course, the bigger the affect.

    Any sudden increase in radiation from beyond the Earth
(a Type II supernova 200 light years away or closer) would
be very noticeable in the record even though we might not be
able to identify it as such. The passage through the solar
system of an interstellar cloud of debris from such an event
would be even more noticeable and even harder to identify.

    As far as identifying C14 increases with impacts, claims
have been made about Tunguska, which made a tiny C14
spike, but:
http://www.jamesoberg.com/ufo/tungus.html
    "...carbon-14 expert and Nobel laureate Willard Libby
reported on results of measurements of tree rings in Arizona.
There was a small rise in the carbon-14 level following 1908,
to be sure, but it was matched by other erratic ups and
downs over the years and could have been a random jump.
Libby calculated the force of the blast at Tunguska and
the radiation that would have been released had the blast
involved thermonuclear reactions. He concluded that the
low levels of carbon-14 he found, even if completely
attributable to the blast, could still only count for no
more than fifteen percent of the whole force of the
detonation. Other carbon-14 tests in Norway, meanwhile,
showed absolutely no rise at all following 1908, so these
tree-ring experiments are strong evidence that the Tunguska
Event did not involve significant nuclear reactions, if any."

    Of direct product of neutrons by an impact... if it occurs,
the amount is small. In theory, even lightning can produce a
tiny amount of C14 (high energy electrons knock a neutron
loose which hits a nitrogen atom, etc.), but the key word is
"tiny." And since a big impact's plasma can produce x-rays,
other energetic photons, and lots of bouncy electrons, some
C14 will be produced in the air around the impact, more than
lightning could produce, but I doubt anybody has calculated
the amount (if possible) and I sure not going to try.

    However, material from the impactor, depending entirely
on the carbon content of the impactor (comet or some other
carbonaceous body), could be distributed as debris from
the impact (or especially in an airburst). This could greatly
enrich the local stock of C14 in the area of the impact. This
C14 enrichment might well be, not worldwide, but continental or
even be restricted to a smaller area. Carbon in a meteoric body
would be greatly enriched in C14 as its exposure to energetic
radiation would be greater and longer than terrestrial carbon.

    So, ya see, it ain't so simple... And you guys are simplifying
way too much, in the urge to bash each other.


Sterling K. Webb
----------------------------------------------------------------------
----- Original Message -----
From: "E.P. Grondine" <epgrondine at yahoo.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Friday, December 21, 2007 12:32 PM
Subject: Re: [meteorite-list] Mammoth Stew,shooing nuisances away from the
fire


Jason wrote:

>The only person in denial here is you, who refuses to
>accept the fact that he can't possibly know with any
>certainty what sort of cosmic cataclysms caused
either >dust layer.

And Darren chimed in:

>Sure he can. 200 years ago, between sips of
>firewater, some indian told some trader something
that >he roughly translated as "great snake eat
>firebird's moccasans, rain death on Great Ancestors"

That is a deliberate lie as well as a slander on every
Native American.

"And if you don't agree with what he says, you don't
"understand him and are stupid, you European,
"forked-tounge-speaking invader.

Actually, the evidence is what it is. Insulting me is
not going to change it, and in doing so you only
demonstrate yourself to be a fool.

Darren also wrote:

>And don't forget (only seen because someone quoted
>him--originals go bye bye) the gem that the Canyon
>Diablo impact "might have generated neutrons",
>synthesizing C14 and skewing C14 data. Hy-larious.

Actually, Darren, that's creating C14, not
"synthesizing" it, and yes the radio-dating
calibration charts seem to indicate that neutrons may
be released in hyper-velocity impacts.

E.P. Grondine
Man and Impact in the Americas




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Received on Fri 21 Dec 2007 07:13:59 PM PST