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more on The Economist: How to weave a cloak that makes you invisible
From: David Farber <dave () farber net>
Date: Sat, 27 May 2006 06:58:39 -0400
Begin forwarded message: From: Brad Templeton <btm () templetons com> Date: May 26, 2006 5:37:18 PM EDT To: David Farber <dave () farber net> Cc: ip () v2 listbox comSubject: Re: [IP] more on The Economist: How to weave a cloak that makes you invisible
I believe he is noting that if you have two sensors (such as two eyes, but
further apart) then the light from behind the "invisible" object willreach one eye directly and reach the other eye by going through the object, at the edges. Proper interferometry should show this clearly, I believe.
In general it's unlikely you could make anything so invisible as to hide from somebody with detection equipment designed to find it. Being invisible to the human eye would be amazing enough on its own. However, the technology cited in the article is for narrow wavelengths. It's not indicated, but I suspect it means we would have the cloak be invisible in the blue, but not in the red. Cute, but not invisible to the human eye, except perhaps against a clear blue sky. It is also false to say this would not work (if it worked at all) for spyplanes, because the invisibility need not be two way, nor need it be 100% at all locations. The spyplane could be very visible from above (and thus be absorbing as much light from the ground as it wishes) and invisible from below. Or it could have small circles for camera lenses that absorb 1% of the light and still be an excellent spyplane, invisible to the human eye. The human eye would not see a small slightly dimmed circle against just about any background, even one as simple as sky. Furthermore, planes fly blind all the time, so I can't fathom why the author suggested this as an issue. ------------------------------------- You are subscribed as lists-ip () insecure org To manage your subscription, go to http://v2.listbox.com/member/?listname=ip Archives at: http://www.interesting-people.org/archives/interesting-people/
Current thread:
- more on The Economist: How to weave a cloak that makes you invisible David Farber (May 26)
- <Possible follow-ups>
- more on The Economist: How to weave a cloak that makes you invisible David Farber (May 26)
- more on The Economist: How to weave a cloak that makes you invisible David Farber (May 27)
- more on The Economist: How to weave a cloak that makes you invisible David Farber (May 30)