[tt] cloaking objects at a distance

[Eugen Leitl]

----- Forwarded message from the physics arXiv blog <howdy at arxivblog.com> -----

From: the physics arXiv blog <howdy at arxivblog.com>
Date: Wed, 5 Nov 2008 14:02:00 -0600 (CST)
To: eugen at leitl.org
Subject: the physics arXiv blog
Reply-To: the physics arXiv blog <howdy at arxivblog.com>


[1]the physics arXiv blog

   [2]Cloaking objects at a distance

   Posted: 05 Nov 2008 07:14 AM CST

   [3]cloaking-at-a-distance.jpg 

   One of the disadvantages of invisibility cloaks is that anything
   placed inside one is automatically blinded, since no light can get in.

   Now Yun Lai and colleagues from The Hong Kong University of Science
   and Technology have come up with a way round this using the remarkable
   idea of cloaking at a distance. This involves using a "complementary
   material" to hide an object outside it.

   Here's the idea: complementary materials are designed to have a
   permittivity and permeability that are complementary to the values in
   a nearby region of space. "Complementary" means that the values cancel
   out the effect that that this region of space has on a plane lightwave
   passing through. To an observer, that region of space simply vanishes.

   Cloaking a region of space is relatively straightforward but cloaking
   an object in that space is another matter. Lai and co say the trick is
   to work out the optical properties of the object and then embed the
   "complementary image" within the cloaking material. So a plane wave
   would be bent by the object but then bent back into a plane as it
   passes through the cloaking material.
   Et voila: cloaking at a distance. And in a way that doesn't leave the
   cloaked object blind.

   Of course , creating the complementary materials necessary to do this
   trick is another matter. And the usual caveats apply: it works only at
   a single frequency in 2D. But cloaking, in theory at least, is looking
   more interesting by the day.

   Ref: [4]arxiv.org/abs/0811.0458: A Complementary Media Invisibility
   Cloak that can Cloak Objects at a Distance Outside the Cloaking Shell

   [5][arXivblog?i=N1IXd9] 
   [6][arXivblog?i=xSF1N] [7][arXivblog?i=KzjbN] [8][arXivblog?i=6rabn]
   [9][arXivblog?i=fARxN] [10][arXivblog?i=SADAn] [11][arXivblog?i=9LeaN]
   [12][arXivblog?i=kTikn] [13][arXivblog?i=nWujN] 
   You are subscribed to email updates from [14]the physics arXiv blog
   To stop receiving these emails, you may [15]unsubscribe now. Email
   Delivery powered by FeedBurner
   Inbox too full? [16](feed) [17]Subscribe to the feed version of the
   physics arXiv blog in a feed reader.
   If you prefer to unsubscribe via postal mail, write to: the physics
   arXiv blog, c/o FeedBurner, 20 W Kinzie, 9th Floor, Chicago IL USA
   60610

References

   1. http://arxivblog.com/
   2. http://feeds.feedburner.com/~r/arXivblog/~3/443220774/
   3. http://arxivblog.com/wp-content/uploads/2008/11/cloaking-at-a-distance.jpg
   4. http://arxiv.org/abs/0811.0458
   5. http://feeds.feedburner.com/~a/arXivblog?a=N1IXd9
   6. http://feeds.feedburner.com/~f/arXivblog?a=xSF1N
   7. http://feeds.feedburner.com/~f/arXivblog?a=KzjbN
   8. http://feeds.feedburner.com/~f/arXivblog?a=6rabn
   9. http://feeds.feedburner.com/~f/arXivblog?a=fARxN
  10. http://feeds.feedburner.com/~f/arXivblog?a=SADAn
  11. http://feeds.feedburner.com/~f/arXivblog?a=9LeaN
  12. http://feeds.feedburner.com/~f/arXivblog?a=kTikn
  13. http://feeds.feedburner.com/~f/arXivblog?a=nWujN
  14. http://arxivblog.com/
  15. http://www.feedburner.com/fb/a/emailunsub?id=8632699&key=kesJ612ZsV
  16. http://feeds.feedburner.com/arXivblog
  17. http://feeds.feedburner.com/arXivblog

----- End forwarded message -----
-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
______________________________________________________________
ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE