Posted on 09/29/2014 12:38:35 PM PDT by Red Badger
Inspired perhaps by Harry Potter's invisibility cloak, scientists have recently developed several ways—some simple and some involving new technologies—to hide objects from view. The latest effort, developed at the University of Rochester, not only overcomes some of the limitations of previous devices, but it uses inexpensive, readily available materials in a novel configuration.
"There've been many high tech approaches to cloaking and the basic idea behind these is to take light and have it pass around something as if it isn't there, often using high-tech or exotic materials," said John Howell, a professor of physics at the University of Rochester. Forgoing the specialized components, Howell and graduate student Joseph Choi developed a combination of four standard lenses that keeps the object hidden as the viewer moves up to several degrees away from the optimal viewing position.
"This is the first device that we know of that can do three-dimensional, continuously multidirectional cloaking, which works for transmitting rays in the visible spectrum," said Choi, a PhD student at Rochester's Institute of Optics.
Many cloaking designs work fine when you look at an object straight on, but if you move your viewpoint even a little, the object becomes visible, explains Howell. Choi added that previous cloaking devices can also cause the background to shift drastically, making it obvious that the cloaking device is present.
In order to both cloak an object and leave the background undisturbed, the researchers determined the lens type and power needed, as well as the precise distance to separate the four lenses. To test their device, they placed the cloaked object in front of a grid background. As they looked through the lenses and changed their viewing angle by moving from side to side, the grid shifted accordingly as if the cloaking device was not there. There was no discontinuity in the grid lines behind the cloaked object, compared to the background, and the grid sizes (magnification) matched.
The Rochester Cloak can be scaled up as large as the size of the lenses, allowing fairly large objects to be cloaked. And, unlike some other devices, it's broadband so it works for the whole visible spectrum of light, rather than only for specific frequencies.
Their simple configuration improves on other cloaking devices, but it's not perfect. "This cloak bends light and sends it through the center of the device, so the on-axis region cannot be blocked or cloaked," said Choi. This means that the cloaked region is shaped like a doughnut. He added that they have slightly more complicated designs that solve the problem. Also, the cloak has edge effects, but these can be reduced when sufficiently large lenses are used.
In a new paper submitted to the journal Optics Express and available on arXiv.org, Howell and Choi provide a mathematical formalism for this type of cloaking that can work for angles up to 15 degrees, or more. They use a technique called ABCD matrices that describes how light bends when going through lenses, mirrors, or other optical elements.
While their device is not quite like Harry Potter's invisibility cloak, Howell had some thoughts about potential applications, including using cloaking to effectively let a surgeon "look through his hands to what he is actually operating on," he said. The same principles could be applied to a truck to allow drivers to see through blind spots on their vehicles.
Howell became interested in creating simple cloaking devices with off-the-shelf materials while working on a holiday project with his children. Together with his 14 year-old son and Choi, he recently published a paper about some of the possibilities, and also demonstrated simple cloaking with mirrors, like magicians would use, in a brief video.
To build your own Rochester Cloak, follow these simple steps:
Purchase 2 sets of 2 lenses with different focal lengths f1 and f2 (4 lenses total, 2 with f1 focal length, and 2 with f2 focal length) Separate the first 2 lenses by the sum of their focal lengths (So f1 lens is the first lens, f2 is the 2nd lens, and they are separated by t1= f1+ f2). Do the same in Step 2 for the other two lenses. Separate the two sets by t2=2 f2 (f1+ f2) / (f1— f2) apart, so that the two f2 lenses are t2 apart.
A multidirectional `perfect paraxial’ cloak using four lenses. From a continuous range of viewing angles, the hand remains cloaked, and the grids seen through the device match the background on the wall (about 2 m away), in color, spacing, shifts, and magnification. Credit: J. Adam Fenster / University of Rochester
For their demonstration cloak, the researchers used 50mm achromatic doublets with focal lengths f1 = 200mm and f2 = 75mm. Credit: University of Rochester
VIDEO AT LINK............
The Klingons are behind Uranus...............
“It has a reverse gravitational field. The object is actually repelling us, Captain!”
What would Laz do?
I’m confused. I thought the Romulans were the ones with the cloaking device? Did Klingons have it too?
Yes, they did.
I’m confused. I thought the Romulans were the ones with the cloaking device? Did Klingons have it too?
The kingons traded some D7 Battlecruisers with better warp drives than rommies had for cloaking tech from the romulans...
Thank you Mr. Spock.
You have the bridge, I'll be in my quarters with the green chick to recover.................... :^)
Conceptual origins[edit]
Inspired in part by the 1958 film Run Silent, Run Deep, Star Trek screenwriter Paul Schneider imagined cloaking as a space-travel analog of a submarine submerging, and employed it in the 1966 Star Trek episode “Balance of Terror”. Another Star Trek screenwriter, D.C. Fontana, coined the term cloaking device for the 1968 episode “The Enterprise Incident”.
Writers and game designers have since incorporated cloaking devices into many other science-fiction narratives, including Doctor Who, Star Wars, and Stargate.
Source: Wikipedia
Storyline Star Trek episode “Balance of Terror”
The Enterprise answers a distress call from Federation Outpost #4, a monitoring station on the Federation side of the neutral zone with the Romulan Empire. The outposts were established over a century ago and no one has actually seen a Romulan. The Romulan vessel seems to have some type of high energy explosive device as well as a cloaking device to make the ship invisible. When it appears that Romulans bear a strong resemblance to Vulcans, Kirk must deal with a rebellious crew member. He must also engage in a dangerous cat and mouse game with a very intelligent Romulan commander. Written by garykmcd
Source: IMDB
“Ah’m givin’ it all I got, Captain, bu’ ah’m all out of DiLithium crrystals!”
dumbest thing the federation ever did was to promise to not develop cloaking technology. STTNG PEGASUS episode was a very good one. It noted the fed had indeed explored cloaking technology but took it a step further to a molecular shifter. awesome tech.
Must you ask?
You know we luv ya, right Laz?
>>dumbest thing the federation ever did was to promise to not develop cloaking technology. <<
Agreed — that is the same as saying we will disarm all our nukes but let Iran, China and Russia keep theirs.
Th treaty must have been designed by obozo’s great great great grandson. Idiocy is a gene that modern life allows to perpetuate.
Cloaking yes, invisibility no.
[ dumbest thing the federation ever did was to promise to not develop cloaking technology. STTNG PEGASUS episode was a very good one. It noted the fed had indeed explored cloaking technology but took it a step further to a molecular shifter. awesome tech. ]
Oh I am sure Section 31 ALWAYS had cloaking tech.....
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