From: Anders Sandberg (asa@nada.kth.se)
Date: Thu Aug 29 2002 - 10:01:24 MDT
On Thu, Aug 29, 2002 at 04:35:09AM -0700, Robert J. Bradbury wrote:
> :
> On Thu, 29 Aug 2002, gts wrote:
>
> > It is a hard fact of physical science that molecules decompose
> > spontaneously. This spontaneous decomposition happens through a process
> > called "quantum tunneling." Both organic and inorganic molecules are
> > subject to this form of decay.
>
> Ok, lets not go running off into the forrest unless its absolutely
> necessary. I'm not enough of a chemistry expert to know whether
> protein deamidation can be attributed to "quantum tunneling".
> (Anders/Eugene -- comments?).
I don't know, but as Eugene snarled, the quantum effect is probably far
smaller than mere thermal excitation. I don't have my QM textbooks handy
(I want *nonlocal* QM textbooks, but I don't know where to buy them! :-)
but doing the right B^2/A^2 calculation (c.f.
http://www.phys.virginia.edu/CLASSES/252/Barriers/Barriers.html) is
likely relatively easy. The big limiting factor of tunneling is usually
the exponential effect of the barrier width. I guess (handwaving alert)
that this is a few Å for the deamidation scenario, and the mass involved
is at least a hydrogen atom. That sounds like a very low rate.
Personally I would start to worry about this after I got rid of the K40,
C14 and P32 in my body. In the really long term we need to worry about
quantum tunneling into black holes - wait long enough and it could
happen to you! The long run solution for anybody seriously going for
indefinite life is having distributed backups, making the risk of having
them all wiped out exponentially low. If you just increase the number of
backups at a suitable rate the expected lifespan can become infinite.
> Their work has recently resulted in an algorithm that has calculated
> the decay rete of all proteins for which crystal structures are
> currently known (www.deamidation.org & deamidation.entrewave.com).
Cool! Could this be used for dating archeological finds?
-- ----------------------------------------------------------------------- Anders Sandberg Towards Ascension! asa@nada.kth.se http://www.nada.kth.se/~asa/ GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y
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