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Saturday, 11 March 2017

Origin of life science tosses up yet another Just so story

Cranky young sun kickstarted life? No.

Unless you believe New Scientist::

Giant flare-ups from the young sun might have kept early Earth warm – and any life nicely fertilised. By splitting inert nitrogen molecules in the atmosphere, charged particles from the sun could have sparked chemical reactions that heated the planet and could be the precursor for life.

This suggestion is the latest attempt to solve a famous paradox known as the “faint young sun” problem. About 4 billion years ago, the sun was only 70 per cent as bright as it is today, which should have made the Earth a frozen snowball. But geological evidence shows that ancient Earth was warm enough for liquid water. The same holds true for Mars.

Now, Vladimir Airapetian of NASA’s Goddard Space Flight Center in Maryland suggests that blasts of protons from the hyperactive young sun could be the answer .More.

Physicist  Rob Sheldon writes to say,

This is a bit close to my field: magnetospheric particles, flares, etc. But its claim is rubbish:

a) The number of nitrogen molecules “split” by solar protons is miniscule, because we’re talking maybe 10 protons/cubic centimeter. This is ultra-high vacuum in any other location on the surface of the planet. And all that split nitrogen is high up in the ionosphere–unlikely to ever diffuse down to sea level.

b) Sea-level lightning splits nitrogen and generates the majority of the NOx in the Earth, which is gratefully used by life, the density of nitrogen being some 17 orders of magnitude larger here than in solar flares.

c) But to sustain life, neither flares nor lightning is important, life does it alone from nitrogen fixing cyanobacteria in the oceans or root-nodules of legumes. Nitrogen fixation is then one of those “irreducibly complex” problems for evolution.

But what this article does reveal–like so many Darwinian “breakthroughs”–is that nitrogen is a real problem for Origin-of-life (OOL). Every protein and nucleobase has nitrogen in it, which needs to be “fixed” or chemically bound for life to start, because fixed nitrogen is unstable. That is because the N2 gas that fills our atmosphere (“unfixed”) is so extremely stable, as organic matter decomposes in our garden, it loses nitrogen to the atmosphere, which never comes back. That’s why coal has no nitrogen content. Other than fresh organic stuff, (or mined organic stuff such as guano) farmers have to put (fixed) nitrogen back in the soil as “nitrates”, a popular version being “ammonium nitrate”, which is now made synthetically using the Nobel-prize winning “Haber-Bosch” high-temperature catalyst process.

So what OOL needs, in addition to energy sources, entropy barriers, miscible membranes, hot-springs etc, is some way to get fixed nitrogen in the environment as well. This article wants to tie it into solar flares and thence to a young sun to make OOL on Earth more likely. In contrast, Miller-Urey argued for lightning, which is indeed, far more efficient than solar protons. This fellow is either cheerleading for Darwin, or advertising his (overly-simplistic) 2-D computer modeling codes (having done some 3-D magnetosphere models ~20 years ago.) But that’s the way this

game is played–no matter how insignificant your result, if you want the media to notice your press release, claim it either supports Darwin or global warming or both.

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