Unfortunately, the article doesn’t have much explanation. Does anyone know anything about current research? What are they using to bend the light? What are the mechanics involved. How far have they actually come?
Did something really happen recently that makes this news worthy? Some breakthrough in materials science or technique? Or is the journalist just being led on. He really doesn’t seem to know what he’s talking about.
The article seems to suggest that being able to “curve light waves completely around an object” is still decades away. Ummmmm so then what is the big deal? They bent light a little bit? Shit, I can do that with my fancy material called a mirror.
How much “bending” are they capable of? What is this new material scientists recently engineered?
Here is earlier BBC article that relates to the same thing. There is some more explanations there. The idea is to make light “flow” around object. Sure, prestidigitators can do that using mirrors, but you need a lot of setup for that and it only works from one direction. These metamaterials might work all-around.
I don’t know what the advances in optics are like, and that news story contains zero usable information to go on. But geometrically speaking, the Hairy Ball Theorem guarantees that this can’t be used to make something invisible from literally all directions: There will have to be defect points where the light doesn’t bend properly.
Color me skeptical. This isn’t the first time I’ve heard of metamaterials, and while they may have some interesting potential, right now their uses are pretty drastically limited. Besides the problem of scale, I seem to recall that their ability to bend light is pretty strongly wavelength dependent, and each given material only exhibits its interesting properties over a pretty narrow range of wavelengths.
Of course, there may have been new developments that I don’t know about, but I’ll believe it when I see it. (…or not, as the case may be.)
I too am highly skeptical. The technology required to create an invisibility cloak as people envision them would be astronomically advanced. When I see headlines like that I feel like I’m looking at a flying aircraft carrier on the cover of Popular Mechanics.
Obligatory Hitchhiker’s reference:The Somebody Else’s Problem field is much simpler and more effective, and what’s more can be run for over a hundred years on a single torch battery. This is because it relies on people’s natural disposition not to see anything they don’t want to, weren’t expecting, or can’t explain. If Effrafax had painted the mountain pink and erected a cheap and simple Somebody Else’s Problem field on it, then people would have walked past the mountain, round it, even over it, and simply never have noticed that the thing was there.
[right]–Life, The Universe, and Everything[/right]
As far as I know, it’s only the two-dimensional case that’s being talked about, i.e. making something ‘invisible’ with regards to a given line of sight, so they’re only thinking about circles, which are quite easily combed.
The mechanism for this invisibility is actually rather easy: using a metamaterial (a material that derives its properties from its structure rather than its molecular composition) with a negative refractive index (which refracts the light on the same side of the normal the incident beam is on), the ‘light’ (as far as I know, the only success so far was in the microwave spectrum, with rather small objects) can be brought to interference in such a way that it looks the same behind the object as it did in front of it – essentially the same way a Romulan cloaking device works.
Some 25 years ago a bunch at the Institute of Optics in Rochester was talking about doing this using gradient index optics. They eventually gave up on it, saying it was too complex for a trivial end. I have no idea what new theories and materials are being used for this, or why metamaterials with negative refractive indices are needed – back themn gradient index optics looked as if it might be sufficient.
I’ll have to look into this further.
I don’t see how the Hairy Ball Theorem ( Hairy ball theorem - Wikipedia ) is going to be a practical problem (the hairy ball theorem states that, if you try to comb the hair on, say, a tennis ball into a nce and smooth pattern, there’s going to be someplace where you get an ugly-looking signuarity. a “cowlick”. As someone once put it, the winds try to do this on the Earth, so there’s always a cyclone somewhere). It just means that there’s going to be a probably small error somewhere.
