[meteorite-list] Astrobiologists Find Stuff

[Garry Stewart]

Life as we know it is based upon the elements of carbon and oxygen. Now a team of physicists, 
including one from North Carolina State University, is looking at the 
conditions necessary to the formation of those two elements in the 
universe. They've found that when it comes to supporting life, the 
universe leaves very little margin for error. Both carbon and oxygen are produced when helium burns inside of giant 
red stars. Carbon-12, an essential element we're all made of, can only 
form when three alpha particles, or helium-4 nuclei, combine in a very 
specific way. The key to formation is an excited state of carbon-12 
known as the Hoyle state, and it has a very specific energy – measured 
at 379 keV (or 379,000 electron volts) above the energy of three alpha 
particles. Oxygen is produced by the combination of another alpha 
particle and carbon. NC State physicist Dean Lee and German colleagues Evgeny Epelbaum, 
Hermann Krebs, Timo Laehde and Ulf-G. Meissner had previously confirmed 
the existence and structure of the Hoyle state with a numerical lattice 
that allowed the researchers to simulate how protons and neutrons 
interact. These protons and neutrons are made up of elementary particles called quarks. The light quark mass is one of the fundamental 
parameters of nature, and this mass affects particles' energies. In new lattice calculations done at the Juelich Supercomputer Centre the physicists found that just a slight variation in the light quark mass 
will change the energy of the Hoyle state, and this in turn would affect the production of carbon and oxygen in such a way that life as we know 
it wouldn't exist. "The Hoyle state of carbon is key," Lee says. "If the Hoyle state energy was at 479 keV or more above the three alpha particles, then the amount of carbon produced would be too low for carbon-based life. "The same holds true for oxygen," he adds. "If the Hoyle state energy 
were instead within 279 keV of the three alphas, then there would be 
plenty of carbon. But the stars would burn their helium into carbon much earlier in their life cycle. As a consequence, the stars would not be 
hot enough to produce sufficient oxygen for life. In our lattice 
simulations, we find that more than a 2 or 3 percent change in the light quark mass would lead to problems with the abundance of either carbon 
or oxygen in the universe." The researchers' findings appear in Physical Review Letters.

Read more at: http://phys.org/news/2013-03-foundations-carbon-based-life-room-error.html#jCpLife as we know it is based upon the elements of carbon and oxygen. Now a team of physicists, including one from North Carolina State University, is looking at the conditions necessary to the formation of those two elements in the universe. They've found that when it comes to supporting life, the universe leaves very little margin for error. Both carbon and oxygen are produced when helium burns inside of giant red stars. Carbon-12, an essential element we're all made of, can only 

form when three alpha particles, or helium-4 nuclei, combine in a very specific way. The key to formation is an excited state of carbon-12 known as the Hoyle state, and it has a very specific energy – measured at 379 keV (or 379,000 electron volts) above the energy of three alpha particles. Oxygen is produced by the combination of another alpha particle and carbon. NC State physicist Dean Lee and German colleagues Evgeny Epelbaum, Hermann Krebs, Timo Laehde and Ulf-G. Meissner had previously confirmed the existence and structure of the Hoyle state with a numerical lattice that allowed the researchers to simulate how protons and neutrons interact. These protons and neutrons are made up of elementary particles called quarks. The light quark mass is one of the fundamental parameters of nature, and this mass affects particles' energies. In new lattice calculations done at the Juelich Supercomputer Centre the physicists found that just a slight variation in
 the light quark mass will change the energy of the Hoyle state, and this in turn would affect the production of carbon and oxygen in such a way that life as we know it wouldn't exist. 


"The Hoyle state of carbon is key," Lee says. "If the Hoyle state energy was at 479 keV or more above the three alpha particles, then the amount of carbon produced would be too low for carbon-based life. "The same holds true for oxygen," he adds. "If the Hoyle state energy were instead within 279 keV of the three alphas, then there would be plenty of carbon. But the stars would burn their helium into carbon much earlier in their life cycle. As a consequence, the stars would not be hot enough to produce sufficient oxygen for life. In our lattice simulations, we find that more than a 2 or 3 percent change in the light quark mass would lead to problems with the abundance of either carbon or oxygen in the universe." 

The researchers' findings appear in Physical Review Letters.

Read more at: http://phys.org/news/2013-03-foundations-carbon-based-life-room-error.html#jCp



>________________________________
> From: Richard Montgomery <rickmont at earthlink.net>
>To: Michael Mulgrew <mikestang at gmail.com>; Mark Ford <mark.ford at southernscientific.co.uk>; Meteorite List <meteorite-list at meteoritecentral.com> 
>Sent: Wednesday, March 13, 2013 7:16 PM
>Subject: [meteorite-list] Astrobiologists Find Stuff
> 
>Michael M and List,
>
>First, apologies to be so Sci-Fi...not the intention.  If I had a better rocker I'd probably be knocked off of it for remotely, even slightltly suggesting this, especially to this credentialed List; best a slap upside-the-head to get me back to reality...
>
>Meanwhile, here goes....it falls into the X-curiousity factor of all equations: how can we rule out everything that hasn't already been ruled in? To wit: given what we know about Life-to-develop-needs-100%-water, what don't we know?  Is our silly-human insignificance bound only by what we currently know and entertain as possibilities?
>
>This is NOT an endoresment for rice-paddy science; nor a support for the previous thread.  I've just always wondered why we assume that all elemental progressions are known.
>
>Big stew out there! I really would like to hear from you heavy-weights...it'll rest better when I read.
>
>Sincerely, and good thing I'm not a B-movie producer,
>Richard Montgomery
>
>
>----- Original Message ----- From: "Michael Mulgrew" <mikestang at gmail.com>
>To: "Mark Ford" <mark.ford at southernscientific.co.uk>; "Meteorite List" <meteorite-list at meteoritecentral.com>
>Sent: Wednesday, March 13, 2013 9:28 AM
>Subject: Re: [meteorite-list] Astrobiologists Find Ancient FossilsinFireballFragments
>
>
>> Considering our current understanding of what it takes for life to
>> develop, i.e. water is 100% absolutely necessary, I would say the
>> recent evidence of Mars' wet past increases the chances of
>> extraterrestrial life discovery by much, much more than "a tiny tiny
>> amount".
>> 
>> Michael in so. Cal.
>> 
>> On Wed, Mar 13, 2013 at 9:03 AM, Mark Ford
>> <mark.ford at southernscientific.co.uk> wrote:
>>> 
>>> Sure and I don't deny finding water or evidence of it is very exciting, but what I question, is 'the building blocks of life claim'. This is pure hype. Sure water and amino acids are essential for life, but I would question exactly how certain life is to evolve when water alone is present. The answer is it's massively more complex than just having flowing water. So finding water does not immediately mean there is any life. From some of the recent press and Nasa coverage, you would get the impression that finding water on Mars automatically means the hunt for extraterrestrial life is nearly over, but the truth is very far from it! It just makes it a tiny tiny amount more likely..
>>> 
>>> Mark
>> ______________________________________________
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