[ExI] Quantum Radar

[John Clark]

On Mon, Sep 2, 2019 at 11:28 AM Stuart LaForge via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

* > Does PDC to x-ray wavelengths require a particle accelerator
> to generate the input beam? Something like a free-electron laser? *


Yes, they need to make them a lot smaller and cheaper before medicare will
pay for such a scan.


> *> Are  x-rays the best wavelength to map the brain? Isn't
> brain-tissue largely transparent to x-rays?*


Yes but with this technique a X-ray photon wouldn't have to be absorbed by
a atom for us to figure out there was matter there as it is with
conventional X ray photographs. The photon wouldn't have to be destroyed,
if it was just perturbed in even a tiny way we would know the photon must
have had a slight glancing encounter with an atom.

A somewhat analogous idea was used to make the world's smallest neutrino
detector. A neutrino needs to pass through several light years worth of
lead before there is a 50% chance of it being absorbed, but a vastly
smaller amount of matter can disturb them, it's very slight but detectable.
In this case the detector only weighed 14.6 kilograms:
Milk jug–sized detector captures neutrinos in a whole new way
<https://www.sciencemag.org/news/2017/08/milk-jug-sized-detector-captures-neutrinos-whole-new-way>


>
> *> I mean if you get refraction off an  atomic nucleus here and there,
> that's great and all but if the  radiative flux is near background, then is
> that going to be enough  photons to make a complete image?*
>

They say even without attosecond precision they've improved the signal to
noise ratio by many orders of magnitude in a noisy background environment.


> >>  the optical nuclear clock
>
> * > I imagine something like this would revolutionize
> x-ray crystallography of proteins and what not.*
>

I think such a clock would revolutionize a lot of things, in one attosecond
light can move a distance of only about 2 hydrogen atoms, and a Thorium
Nuclear Clock (not to be confused with an atomic clock) could time things
to a tenth of a attosecond. The science is there, now we just need to
figure out how to engineer one.

*> *
>
>
> *I wonder if something similar could be done with ultrasound using
> phonons. Ultrasound might be a better approach to imaging the brain  then
> x-rays provided you figure out a way to get the sound waves  through the
> skull.*


That is a very interesting idea!

John K Clark
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