From: "Erica VD Ginter" <eginter at klgai.com>
To: "'WSFA members'" <WSFAlist at keithlynch.net>
Subject: [WSFA] Re: invisibility cloak
Date: Fri, 7 Feb 2003 20:09:22 -0500
Reply-To: WSFA members <WSFAlist at keithlynch.net>

And here I thought we would be talking about Harry Potter's cloak...

Erica

-----Original Message-----
From: ronkean at juno.com [mailto:ronkean at juno.com]
Sent: Friday, February 07, 2003 6:40 PM
To: WSFAlist at keithlynch.net
Subject: [WSFA] Re: invisibility cloak

On Fri, 7 Feb 2003 17:43:19 -0500 "Ted White" <twhite8 at cox.net> writes:
>
> ----- Original Message -----
> From: <ronkean at juno.com>
... It works by
> > projecting a video image shot from
> > the back of the coat onto the front....
> >

> And for those of us standing to the side...?
>
> --Ted White

>From the description, it sounds like it only works in one general
direction.  I imagine the principle could be extended to all-round
protection by having the entire cloak be an active display, with each
segment of the cloak reproducing the view on the far side of the cloak.
That would require a number of cameras, each aimed in a different
direction.  The cloak would probably have to be a semi-rigid cylinder for
that to work well.

In practice, with existing technology, a man-sized camera/display
invisibility cloak at best would be a sort of smart, real-time adaptive
camouflage, and an observer would have to be 100 feet or more away for
there to be much hope of actually fooling the observer in ordinary
lighting conditions, and the observer would have to not be paying close
attention.

Another imaginable type of invisibility cloak would have many optical
fibers, with each fiber joining two horizontally opposite points on the
cloaking cylinder.  The fibers would be routed along the inner surface of
the cylinder, to allow space for someone to stand within the cylinder.

Keith, would that implementation require a collimating lens at each end
of each fiber?

Ron Kean