Re: [cdn-nucl-l] " Life on Earth 'began on a radioactive beach' "

[Bill Garland <garlandw@mcmaster.ca>]

Well, radioactivity is apparently partially responsible for
the internal heat generation of the earth's core and part of the driving
force for building mountains but I rather doubt that it is the prime
engine for life in the sense that it is the mechanism behind the
formation of  complex, replicating molecules.  Yes, it may have
created some of the energy stores but what we really need is a machine
that takes advantage of those energy stores.  I was taught growing
up that life likely began when lightening struck a primordial soup of
proteins.  To me that seems unlikely.  On a molecular level,
sparking or radioactivy is much more disruptive than it is
creative.  It may create complex molecules but it is more likely to
split them.  Kind of like building a house with explosive
charges.  High voltage may get a beating heat restarted but I think
it does so by disrupting the current state of the heart so that the heart
can restart itself.  So a shock (of electricity or radioactivity) is
not a good mental model for the beginning of life.  

I much prefer chapter
12 of “The Bottomless Well” by Huber and Mills.  That chapter is
very out of place in that book (Mills told me that Huber insisted it be
kept in - and I am glad that he did).  Huber writes of the notion of
the daily thermal cycle caused by the rotation of the earth as the basis
for the heat engine that unzips and zips DNA which are helical sugar -
phosphorous strands (the energy stores) joined by cross-link bars (the
genes, the information stores).  So we (meaning all living things)
are thermodynamic heat engines.  We are energy seeking
machines.  We have evolved sensors to find and exploit sources of
energy.  Small wonder that we function on a 24 hour cycle.  In
my little mind, I can imagine the first proto-life molecules expanding
and contracting, following the daily heat cycle.  This gives
direction, or bias if you will, to the process.  I imagine life
starting more by gentle insistence than by a shock. 

I will take the opportunity to take this a bit further (and away from the
thread of the initial post, sorry).  If we are indeed heat engines,
the more successful of us were/are the ones that can find
heat/energy  sources. Pattern recognition is, thus, fundamental to
what we are and how we survive.  We thus have evolved to recognize
patterns that lead to the satisfaction of needs.  Thus, the feelings
(sensors and emotional) we have are part of our control and regulation of
our actions that seek to optimize success.  Good and Bad are thus
defined.  Rational thought extends the complexity of interpretation
of what is Good and what is Bad.  Even passion fits in to this
picture.  I say that our passion for music, for a hobby, .... for
life is really 'just' a manifestation of the quest for Good and the
avoidance of Bad.  Passion is the reflection of your inner voice
(inner engine).

So there you have it, a 1 minute explanation of the meaning of
life.  Stay tuned for the next in this 'explanation' series wherein
politics of nuclear regulation is explained.  This turns out to be a
simpler energy (read power) engine mechanism than the mechanism mentioned
above because rational thought is not involved. :-)

Bill

At 07:05 AM 10/01/2008, Jaro wrote:

> http://www.telegraph.co.uk/earth/main.jhtml;jsessionid=M1PDFUOI4C04HQFIQMGSFFWAVCBQWIV0?xml=/earth/2008/01/09/scibeach109.xml
>  
>
> Life on Earth 'began on a radioactive beach'
>
> By Nic Fleming, Science Correspondent
>
> Last Updated: 6:01pm GMT 09/01/2008
>
> Life on Earth began on a radioactive beach, a scientist claimed
> today.
>
> The sifting and collection of radioactive material by powerful tides
> could have generated the complex molecules that led to the evolution of
> carbon-based life forms - including plants, animals and humans. 
>
> While radiation may seem an unlikely candidate to kick-start life because
> it breaks chemical bonds and splits large molecules, it also crucially
> provides chemical energy needed to generate some of the basic building
> blocks of life.
>
> Zachary Adam, an astrobiologist at the University of Washington in
> Seattle, has suggested the collection of radioactive material on a beach
> as a new theory for the origins of life - to be added to the existing
> long and varied list of hypotheses.
>
> One is its emergence from a "primordial soup" of simple organic
> chemicals accumulated on the surface of bodies of water within the
> hydrogen-rich early atmosphere - formulated in the 1920's by English
> geneticist J. B. S. Haldane and Russian biochemist Alexander
> Oparin.
>
> Others include early life forming in inorganic clay, the initial energy
> coming not from chemical reactions but from sunlight or lightening and
> the arrival of microscopic seeds of terrestrial life on chunks of
> meteorites or comets, and the intervention of a divine, intelligent
> designer.
>
> In work highlighted in this week's New Scientist magazine, Mr Adam
> suggests the more powerful tides generated by the moon's closer orbit
> billions of years ago compared to today could have sorted radioactive
> material from other sediment.
>
> According to his computer models,
> deposits could collect at a beach's
> high tide mark in sufficient quantity to trigger the self-sustaining
> fission reactions - as occur in natural seams of
> uranium.
>
> Mr Adam demonstrated in laboratory experiments that such a deposit could
> produce the chemical energy to generate some of the molecules in water
> which produce amino acids and sugars - key building blocks of life - when
> irradiated.
>
> A deposit of a radioactive material called monazite would also release
> soluble phosphate, another important ingredient for life, into the gaps
> between sand grains - making it accessible to react in water.
>
> Mr Adam told the New Scientist: "Amino acids, sugars and [soluble]
> phosphate can all be produced simultaneously in a radioactive beach
> environment."
>
>
>
>
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