X-Message-Number: 3290
From: Brian Wowk <>
Date: Tue, 18 Oct 94 17:25:21 CDT
Subject: SCI.CRYONICS.Uploading,etc.

Yvan Bozzonett:

(deleted)
> A superficial reader could ask: who is right? Brian or me? The 
> answer is both: Brian solution applies to imaging by X-ray
> absorbtion, my one by X-ray phase shift. Well, there is no
> perfect system and even with a holographic setting, some
> photons will be lost by absorbtion, producing 
> some irradiation, but this is only a residual effect with low
> doses.

	The holographic system you propose for low-dose tissue 
imaging would work-- but only for small tissue samples and soft
x-ray energies of ~1keV where coherent Rayleigh scattering (no 
energy absorption) dominates.  To penetrate the depths of an intact 
brain, x-ray engeries on the order of 100keV are required.  At this 
energy, inelastic photoelectric absorption and Compton scattering 
dominate over all other interactions.  A large portion of the x-ray 
energy would be lost to ionization within the brain.  Any intensity 
of incident x-rays sufficient to encode 10^18 bits of information 
on a photographic plate (even if by phase effects) would 
necessarily cause ~10^18 ionization events within the brain.  
There is no way around this.  


>	May be some readers know about the Aspect's experiment on 
> quantum Bell's inequalities. To reduce everything at some lines, 
> quantum mechanics predicts than, when a photon, in a
> correlated pair or set, is perturbed, the other feels the effect
> instantaneously. Practical experiments strongly 
> suggest this is indeed the way real world applies physics.
(details on Yvan's novel imaging scheme deleted.)

	I am familiar with Aspect's experiment, Bell's inequalites, the 
EPR paradox and all that stuff.  I also know that there is no 
measurement that can be made on a correlated particle that will tell 
you anything at all about what interactations its conjugate has 
undergone some distance away.  Remember that in the Stern-
Gerlach experiment, there is no way to determine the orientation of 
a polarization or spin analyzer from a measurement made at the 
other analyzer.  If it were otherwise, causality would be violated!


> In July 86 or 87, on the cover of the scientific magazine Nature 
> there was the picture of a cell produced by high gradient MRI
> with many details down to micron or less.

	Yes, MRI microscopy is an established field.  It works by 
using rf coils that are hundreds of times smaller than the coil 
required to image an intact brain.  Such small coils only receive 
noise from their immediate neighborhood instead of the entire 
brain (the brain being a million times larger, giving a million times 
more noise).  In theory you could image an intact brain with 
micron resolution using MRI-- if you used nanomachines to 
strategically position thousands of tiny rf coils with microscopic 
preamplifiers and (multiplexed?) connecting wires throughout the 
brain.  Instead of connecting wires you could use on-site 
nanocomputers to acquire and process signal data.  However, as 
you can see once again, we are now many decades into the future.

			--- Brian Wowk   

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