Charles Platt states in Cryonet Message #10564:
>> From: KlausRei@aol.com >> Disrupted structures can be repaired by an advanced
> Where my life is at stake, I prefer experimental evidence
> to "opinions." <snip> Until cell structures actually have
> been repaired, we are dealing with (possibly well informed)
> speculation.
Alas, all we have is well informed (possibly) speculation. Death is ultimately caused by the failure or incapability of the body's healing mechanisms. The damage caused by freezing is incomparably greater, so a frozen patient is very dead indeed from the viewpoint of contemporary science. Science is concerned with the provable (as it should be) and at present what is provable is that only a few tissues in the human body can survive freezing to cryogenic temperatures.
Ralph Merkle, et al, argue from the viewpoint that there are no 'in principle' barriers to the eventual development of molecular and atomic level nanotechnology (ie, exact placement of molecules and atoms). I can imagine standing in the Parthenon in Athens conversing with Democritus (sorry, I may not have my names and times correct here), the inventor of the Atomic theory, arguing that if we can manipulate atoms with very tiny tweezers, we can build anything we want. (I see a horde of slaves and waldo-tweezers attempting to build something. Can you say "Avogrado's Number"?)
When I was a software engineer, I learned from bitter experience three things:
It is a long, long, long road from principle to product.
> I would find your categorical statements a little easier
> to believe if anyone had done a feasibility study using
> existing macro-scale robots to repair a macro-scale
> simulation of freezing damage. This is a very reasonable
> request, since the predicted onboard computing power of
> nanobots is more modest that the computing power of current
> desktop systems. But no one has a clue how to "train"
> macro-scale robots to repair macro-scale damage. Indeed
> I believe roboticists would tell you that it is impossible
> using this level of processing power.
Some musings: especially the PC. Most solutions to this problem (in principle!) involve combining a standard set of components, a general purpose assembler, and a data tape whose structure as a media is simple. The data tape is read and the assembler executes the instructions. It builds the duplicate assembler, and then duplicates the tape.
I imagine such a device would be rather large. The assembler component on the order of a cubic meter, and a kilometer of so of Lego blocks data tape (if folded or on a spool, about the volume of my house. And it would run verrrrrry slowly, maybe a few years to complete the reproduction).
This would provide a look at the challenges involved, given a an assembler
a priori.
[2] The Trouble with Nanobots and a Solution
We have all seen by now the little video clips of futuristic nanobots
flying like tiny Tie Fighters though the bloodstream, searching for Bad
Biological Blobs and replacing them with Beautiful Beneficent Bits. Here
are a few of the many problems with this dramatic concept:
The first four are obvious enough. Nanobots will be subject to Brownian
motion at non cryogenic temperatures. Flying or swimming through a fluid
medium will always result in this. The fact that you can see Brownian
motion in a light microscope proves the point. At a less visible level,
there's the Heisenberg uncertainty to deal with. The smaller the object,
the more difficult it is to establish the position. The current
Energy source
Locomotion
Orientation
Co-ordination with other Bots
Positional Uncertainty
[3] Warming Up
Another advantage of cryogenic temperatures is that cells could be (in
principle!) constructed in the solid state with every molecule in place. No
ice crystals. No latent heat to complicate warming. If you can get from 77
Deg K to 1 Deg K in a very short time (1 millisecond at the most), warming
from there to body temperature without further damage has been proven (I
recall a hamster at Alcor).
To do this, warming elements must be finely distributed through the body,
close enough that thermal conduction will warm the immediate vicinity
within the millisecond time frame, which implies a distribution of elements
a few cell lengths apart. One idea for this is tiny wires coated with or
comprised of diamondoid material with a conductive center. A 100 Kg body
requires about 8 x 10^5 joules delivered in a 1 ms pulse of 8 x 10^10 watts
(100 gigawatts, approximately).
The wires are assembled into the body during construction, and pulled
Final Comment:
We easily become entrained with unworkable concepts. Nanobots may certainly have their uses in medicine, and extending the idea to reanimation is obvious until looked at critically. We are a long way from knowing what will work, how to do it, or even imagining what the workable options are. Despite all this, I remain an optimist and a signed up cryonicist.
O--------------------------------O | Hara Ra <harara@shamanics.com> | | Box 8334 Santa Cruz, CA 95061 | | | | Death is for animals; | | immortality for gods. | | Technology is the means by |
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