A non-destructive brain scan for uploading?

John K Clark (johnkc@well.com)
Sat, 15 Mar 1997 21:23:34 -0800 (PST)


A few years ago I read about a technique for seeing through opaque objects
with optical LASER pulses of astronomical intensity but modest energy,
I remember seeing a picture of a newspaper taken through several inches of
milk, you could still read it. I wonder if a device working on a similar
principle could be used to obtain enough information from a non-destructive
brain scan to upload a mind.

When most photons that make up an image enter milk they are refracted off the
many fat globules in solution, if any photons come out the other side of the
milk container they have been bounced around so much that the information on
where they originated is hopelessly scrambled, all you would see is a diffuse
glow, not an image. However, a few very lucky photons, perhaps one in a
billion trillion, perhaps less, can make it through the milk without
interacting with anything. Because these rare photons don't get bounced
around but take a shorter direct path, they are the first photons to emerge
from the milk. If you only looked at those early photons and ignored the much
more numerous later ones, you could see an image and not just a general glow.

I don't remember the researcher's name or the exact specifications of his
LASER, but I do know that intensities as high as 10^18 watts per square
centimeter and pulses as short as 10-14 seconds have been achieved with table
top LASERS. You'd want to squeeze every bit of information out of the rare
photons that make up the image, so just recording their amplitude, as in
photography, would not be good enough, you'd want to know their phase too,
and that means Holography. As a bonus, you wouldn't have to worry about depth
of field focusing problems, and the reference beam for the Hologram could act
as a super fast camera shutter, use a different frequency for the reference
beam pulse and put in a filter for the original frequency.

10^14 seconds might be too long for a safe brain scan at the enormous
intensities required, and light can travel about a tenth of a millimeter in
that time, but I'll bet a soft X ray LASER could be built with a lot shorter
pulse than that, I just hope it can be made short enough that the brain is
not vaporized. Anyway it's just a thought.

John K Clark johnkc@well.com

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