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 multi-directional cloaking, which works for transmitting rays in the visible spectrum,” said Choi, a PhD student at Rochester’s Institute of Optics.
(Score: 3, Insightful) by bob_super on Monday September 29 2014, @08:04PM
They filed a patent for using lenses to direct light rays coming from a narrow region of space around another region of space and then back along the original path.
I'm pretty sure we covered that math in high school. the "range of angles" is probably pretty darn narrow.
I'm glad they didn't use mirrors, can you imagine the number of magicians filing a lawsuit?
(Score: 2) by JeanCroix on Monday September 29 2014, @09:01PM
(Score: 0) by Anonymous Coward on Tuesday September 30 2014, @09:56AM
Indeed, their "invisibility cloak" is itself very visible. The point of an invisibility cloak is that you see nothing special. If I were to hide behind this "invisibility cloak" I could just as well hide behind an opaque object. Yes, you wouldn't see what's behind me, but hey, I would be invisible!
Maybe I should patent my invisibility cloak made out of cardboard. ;-)
BTW, magicians for a long time used "invisibility cloaks" which didn't even need fancy lenses, but worked with simple mirrors!
(Score: 3, Insightful) by bziman on Monday September 29 2014, @08:35PM
I read an article about this the other day, and the really cool part was the application. One proposed application allows a surgeon to have an unobstructed view of his working area, despite having his hands and instruments there. The other was for rearward visibility in large vehicles. This would definitely be better than a camera for things like depth perception as well as field of view.
(Score: 2) by MrGuy on Monday September 29 2014, @08:46PM
I'm not clear how this would be reasonably possible.
As I understand it, the object to be cloaked needs to be placed between lenses 2 and 3 of a 4 lens system (i.e. there must be 2 lenses BEHIND the object to be cloaked, and they need to be at precise distances (depending on the focal length of the lenses).
If you're a surgeon, you might be able to cloak your own hands, but there are 2 pieces of glass and metal between your hand and the thing you're trying to cut. If you're trying to use this to cloak part of the back of a vehicle, you need some lenses sticking out behind the vehicle.
I can see why in both cases some way to "cloak" the objects in question is valuable. I'm just missing how this technology would work in those specific cases.
(Score: 2) by Alfred on Monday September 29 2014, @09:20PM
I'm with you and it seems this is of little worth in practice. Like your car example, you would need two more vehicles to haul the necessary lenses just to hide the car from observers in the same lane. Nope, that wouldn't raise suspicion.
I'm sure some magician figured this out and used it for some forced perspective trick years ago and is long since dead.
NotImpressed.jpg
(Score: 0) by Anonymous Coward on Monday October 06 2014, @04:00AM
So what you're saying is that the alleged practical applications of this are a bunch of smoke and mirrors.
(Score: 1, Informative) by Anonymous Coward on Monday September 29 2014, @09:04PM
Riflescopes are narrow in the middle, so a 1X riflescope cloaks in the same way this device does.
(Score: 2) by Dunbal on Tuesday September 30 2014, @02:30AM
Only problem is that for it to work, you have to stand exactly here. Don't move!
(Score: 3, Interesting) by JNCF on Tuesday September 30 2014, @02:35AM
Emphasis mine, obviously. I love that quote. Maybe it's just poor phrasing on his part, or maybe he's leaving open the possibility of extraterrestrial technology or something, but to me this reads "this is the first continuosly three-dimensional cloaking device that wasn't developed by a military with a huge black budget."
(Score: 1) by axsdenied on Tuesday September 30 2014, @08:49AM
Phrases like this are common in the scientific literature.
You can search but you may miss a similar application/research/prior work, especially if it is in some obscure journal. So putting words like "to the best of knowledge" or "that we know of" takes care of that.
(Score: 1) by JNCF on Tuesday September 30 2014, @01:39PM
I see what you're saying, that seems like a more likely reason for the phrasing.
(Score: 0) by Anonymous Coward on Wednesday October 01 2014, @08:14AM
Did we really need the reference to Harry Potter's invisibility cloak? Why not one of a thousand other fictional invisibility devices? It is the sort of silly spurious link to pop culture you'd expect from a tabloid not on a site for geeks/nerds. It might have been worth mentioning had it actually been inspired by Harry Potter's cloak, but it most likely wasn't, it doesn't even work in a similar fashion to Harry Potter's invisibility cloak.