[extropy-chat] PRIVACY: GPS darts

Mike Lorrey mlorrey at yahoo.com
Wed Apr 21 16:49:53 UTC 2004

--- Daniel Matthews <dan at 3-e.net> wrote:
> Anyone want to do the physics on this? What energy is required to
> give such an object the required penetration of 
> human flesh at such a range? How is this kinetic energy transfered to
> the target to slow the projectile to a stop without the target
> like they just got kicked by a horse?

Human flesh can be penetrated, even through clothing, at subsonic
velocities (i.e. less than 900 fps) by bullets as large as .30 caliber
or more. A 9mm bullet can penetrate human flesh over 2 inches at
600-800 fps. The smaller your caliber, the easier it will penetrate at
lower velocities, especially given the profile of the darts have a much
larger length/diameter ratio than bullets.

As the projectile is travelling at subsonic velocities, it transfers
energy by simple friction.

> Then there is the physiology, what percent of the body has provision
> to absorb such an impact and then host the projectile without
> subsequent complications such as hemorrhaging or infection. 

As the artists website stated in his log of his experience at the China
show, an attendee suggested the buttocks.

> Mike, I suggest you ram a 2x40mm needle into your bum and leave it
> there for a few days if you still think such a device is realistic.
> Don't forget you can't sterilise it and it must go through a full
> layer of clothing.
> Having just had a round of immunisation injections I know that even a
> small needle in skilled hands will leave you with painful area for
> several days.

The pain and discomfort with an immunization shot is the immune
reaction of the body to the proteins one is being injected with. A
hypoallergenic package would not entice such a reaction, though there
would be some hemmorhaging. Nor was I proposing that current tech met
the needs of this proposed device. It is realitically going to need to
be reduced to a fraction of a mm in diameter to acheive the desired
penetration without sigificant hemmoraging.

> Others have already pointed out that no device is that small and that
> such a small device would not work as a transmitter.

You apparently weren't paying attention to my later posts, with links
which illustrated a 2mm x 10mm device and a 3x23mm device.

> The image of the gun is clearly a computer rendering and not a very
> good one either. No HDRI based GI etc.

Sure it is clearly a computer rendering. Did you even read into the
fellows website? The whole point of his exercise was to illustrate,
through performance art, of how enthusiastic the state is for such
technology, and how close we are to achieving it that interested buyers
totally bought into the idea that the tech was available today as a
cutting edge breakthrough.

Please take your own advice.

Mike Lorrey
Chairman, Free Town Land Development
"Live Free or Die, Death is not the Worst of Evils."
                                       - Gen. John Stark
Sado-Mikeyism: http://mikeysoft.zblogger.com

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