X-Message-Number: 4826
From: Garret Smyth <>
Newsgroups: sci.cryonics
Subject: Re: Blue Blood
Date: Mon, 21 Aug 95 00:38:29 GMT
Message-ID: <>
References: <40sc33$>

> > The cracking in large tissue samples is usually attributed to
> > mechanical strain because of a temperature gradient. One part of the
> > patient has contracted more than the rest and stress is built up.
> 
> Is it known for sure that this is the cause, rather than the different
> constituents of flesh having different coefficients of expansion?

Dr Johnson, best known for writing the first dictionary and for leaving a lot
of quotes, was once at a dinner party. A woman at the table pointed out to him
a rather simple mistake he had made in his dictionary, which he acknowledged. 
She added that she was surprised by his being tripped up by such a simple error
when she, not known for great intelligence, spotted at once. How could this
be?

"Sheer ignorance, ma'am, sheer ignorance."

Okay, you've guessed it, I don't know whether cracking is due to different
coefficients of expansion or the same one at different temperatures. CI's 
recent work suggests that very slow cooling avoids cracking which would weigh

in on the gradient theory. Perhaps others better equipped than me to answer this
could come in. 

> 
> > ... clean cracks that occur in solids should allow us (or our friends
> > in the future) to map both surfaces and work out where they fitted
> > together, and then knit up the molecules.
> 
> Maybe.  On the other hand, where does the released strain energy go
> when a crack happens?  If it goes into extremely localized heating,
> it could thoroughly scramble the structure for several microns on both
> sides of the crack.

Yes, I admit to being overly positive. I've heard this suggestion before and
can't give an answer off the top of my head. Scary thought, eh?

In reply to Y. Bonnozzetti's posting, I still don't think that it is the
expansion of ice that causes problems but in saying that don't get the
impression I am trivialising the problems. As I mentioned above, the cracking 
problem is scary, fine physiological damage problems are scary, just getting
suspended (and then staying in long enough) is scary. All the reasons why 
cryonics might not work, at least for those frozen today, add up to an 
awful lot of scaryness.

The upside is that your chances of revival are far better with cryonics than 
with anything else, such as burial or being put on a disc.

It occurs to me that the form of the cracks might give some info about their 
cause. Differences in the rate of contraction of different tissues might lead
to changes in the fracture patterns at junctions between tissues, but fractures
solely due to strain from a temperature gradient should go clean across 
different tissues.

Anyone got any pictures?

TTFN

Garret

-- 
Garret Smyth

Phone:  0181 789 1045 or +44 181 789 1045

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