U.S. CitiesCity-Data Forum Index
Covid-19 Information Page
Go Back   City-Data Forum > General Forums > Science and Technology
 [Register]
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
View detailed profile (Advanced) or search
site with Google Custom Search

Search Forums  (Advanced)
 
Old 05-25-2012, 04:31 AM
 
5,660 posts, read 4,504,216 times
Reputation: 5614

Advertisements

Read this article and thought it might interest a few people.

BBC News - 'Cloaking' idea traps a rainbow

"Researchers have trapped a rainbow - slowing light to a near-stop - in an array of 25,000 "invisibility cloaks", each smaller than a hair's breadth.
A report in the New Journal of Physics shows how the quest for an invisibility cloak is leading to cleverer ways to use and manipulate light."
Reply With Quote Quick reply to this message

 
Old 05-25-2012, 03:15 PM
 
28,673 posts, read 41,231,069 times
Reputation: 37417
They need to caption that video. I understood about 10% of what she said so I'm lost....
Reply With Quote Quick reply to this message
 
Old 05-25-2012, 04:03 PM
 
5,660 posts, read 4,504,216 times
Reputation: 5614
Quote:
Originally Posted by Tek_Freek View Post
They need to caption that video. I understood about 10% of what she said so I'm lost....
Me too, i was hoping it would generate some debate so i could try and work out what it all means. I was grappling with the theory and nearly grasped it (in a very basic sense) then it just flew past me and hit the wall...

http://www.bbc.co.uk/news/science-environment-12338447

His explanation was a little more helpful (it's a link from the initial one i posted).
Reply With Quote Quick reply to this message
 
Old 05-25-2012, 08:57 PM
 
2,182 posts, read 4,755,004 times
Reputation: 1206
Hello, my name is Vera Smolyaninova. I'm a professor of physics at Towson University. I will tell you about our latest look on electromagnetic cloaking.

The idea of cloaking is based on so-called "curving" of optical space. Optical properties of materials are characterized by the way they react to external electric and magnetic fields. These properties could be tailored in such a way that light will avoid a particular cloaked region of space. Typically this is done with matter materials.

Recently, we have demonstrated that the same effect may be achieved by much simpler means. When light propagates inside a wave guide, you can literally bend optical wave guide, and achieve the same result. Three years ago, we were able to create a large broadband invisibility cloak. By placing a gold-coated lens on top of a flat gold-coated glass slide. Empty space between the gold surfaces acted as the wave guide we need. The area around the point of contact was cloaked. Light rays propagated around this area.

Now we have extended this look by making tens of thousands of cloaks arrayed in a periodic fashion. Instead of a large single lens, we use the micro lens array. Normally these devices are used in CCD cameras and multi-channel sensors.

In our evoke[?] we have coated the micro lens array with a thin layer of gold and placed it on a gold-coated glass slide. Instead of just one cloak, now we have made tens of thousands of cloaks simultaneously. All these cloaks in the array operate just like the individual cloaks studied earlier, but now we are able to study how all these cloaks may interfere with each other when they are forced into close proximity.

Simple symmetry consideration indicates that arrays of slightly imperfect cloaks, which work well enough individually, will start to scatter lots of light when illuminated at some arbitrary angle. This behavior has become very clear in our experience. Thus, we have demonstrated a very sensitive way to test cloak quality, which could become useful in the future.
Reply With Quote Quick reply to this message
 
Old 05-26-2012, 03:48 AM
 
5,660 posts, read 4,504,216 times
Reputation: 5614
^ Thank you very much for that, the fog has cleared and i cn think clearly again.
Reply With Quote Quick reply to this message
 
Old 05-26-2012, 11:13 AM
 
2,182 posts, read 4,755,004 times
Reputation: 1206
Shows you how bored I was last night
Reply With Quote Quick reply to this message
 
Old 05-26-2012, 11:45 AM
 
28,673 posts, read 41,231,069 times
Reputation: 37417
Those of us with a hearing loss that can't understand anyone with an accent appreciate that "translation". It's frustrating as all get out to not be able to discern the sounds and turn them into words.

When I used to call for tech support and I'd get someone in India it was terrible. If they happened to be someone that talked fast all I heard when they spoke a sentence was one long sound. No words, just sound.
Reply With Quote Quick reply to this message
 
Old 05-27-2012, 04:43 AM
 
5,660 posts, read 4,504,216 times
Reputation: 5614
Quote:
Originally Posted by Tek_Freek View Post
Those of us with a hearing loss that can't understand anyone with an accent appreciate that "translation". It's frustrating as all get out to not be able to discern the sounds and turn them into words.

When I used to call for tech support and I'd get someone in India it was terrible. If they happened to be someone that talked fast all I heard when they spoke a sentence was one long sound. No words, just sound.
In relation to your post (but not the thread) in the UK you have the legal right to request to speak to someone for whom English is the first language. It's one of those "Really? I didn't know that!" laws that's been in place since the 90s.
Reply With Quote Quick reply to this message
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.

Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.


Reply
Please update this thread with any new information or opinions. This open thread is still read by thousands of people, so we encourage all additional points of view.

Quick Reply
Message:

Over $104,000 in prizes was already given out to active posters on our forum and additional giveaways are planned!

Go Back   City-Data Forum > General Forums > Science and Technology
Similar Threads
Follow City-Data.com founder on our Forum or

All times are GMT -6.

© 2005-2020, Advameg, Inc. · Please obey Forum Rules · Terms of Use and Privacy Policy · Bug Bounty

City-Data.com - Archive 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 - Top