Predators using meta material

I always thought is was some sort of light-bending thing, but this makes more sense.

I guess it could be, but why would water effect it?

If you check out the director commentary of PREDATOR, John Mctiernan says that the predator techonology bends light to create the invivisble effect.

Lets leave it at that, lol.

Maybe it's like an animal that uses camouflage. All of them depend on still movement, and constant change messes it up.

Water flows constantly, changing light too fast for it to process.

That's what I'm thinking, anyway.

Though that would defeat the purpose of the Predator using it anyway, since they've been seen sprinting while the cloak was under effect, not to mention their ships being cloaked while going high speeds.

Alright, ignore the first half of this post...

Edit: Ignore^

So...

Actually, I'm pretty sure the meta material does bend light, but I still haven't gotten around to looking this up.

Wouldn't the meta material just make their armor invisible, and not the rest of them?

That makes sense, but I'm also open to the idea of them using something similar and more advanced, which could fix that problem.

What we have today would only cover their armor, or whatever area of their body was wearing the material.

I always thought it was something with the netting, not just the armor itself, but as a whole. Armor and netting.

I think i've stated before that bending light is not really as interesting as you guys make it sound. How about the way they can conjure energy in a rather stable ball and send it flying at people? I think that's a bit more interesting.

I have no idea.

Maybe because there's a little more of a real world basis for the stealth?

Meh, I've always found physical projectiles like bullets more interesting than energy balls/weapons (except lightsabers, then again I'm not entirely sure if they count as an energy weapon or not), but that's just me.

That's weird for a fan of sci-fi to admit, maybe. I'm just sayin'.

So, to get back on topic, cloaking devices.

Another type of cloaking they mentioned in the program was this thing a Japanese guy was working on, though that involved a full-body robe made of (once again) a different kind of meta material and a special camera.

From what I remember it didn't work quite as well as the copper one I mentioned earlier but it was still effective. The result was whomever wore the cloak was only transparent and not completely invisible.

If anyone knows more about that, or has any other plausible theory involving the cloak (and not just an 'oooookkkkkaaaayyy') feel free to enlighten us...

"I think i've stated before that bending light is not really as interesting as you guys make it sound. How about the way they can conjure energy in a rather stable ball and send it flying at people? I think that's a bit more interesting"

...Or, like I said before thats how the writers explained the technology, and since the movies are the most canon things you can follow, lets stick with what the movies say.

Yeah, I guess in the end the argument is all for nothing until proven right, but still... sometimes the speculation is fun.

I think what you were thinking of Bloo is Rectro-Reflectum.



"What Tachi has done is create the fabled invisibility cloak through the usage of a camera that records a background image. This Background image is then projected via a device that scientists have dubbed a "Projector" that actually "projects" the background image on to a screen."

Oh, the irony. It seemes the cloaking device that the predators supposedly use was first introduced in the Star Trek series after which the movie i just watched this morning was made.



And here's a picture from wikipedia about how it should work.

I don't know, i've read somewhere that some scientists have been able to make a cloak device that works like this but it's too large to make it portable so far.

hello i am new here but i think i have some answers for you guys it is possable that the preds use the tech and the reason water would short it out would be the fact that water does have some effects on EMF's not sure how much they effect them but they do but i am sure they use a more advanced then what we have now



The news has broken: we are all going to be able to purchase cloaks of invisibility in a few years. Or perhaps not. Some recent research from Berkeley is a big step and will, no doubt, find many applications, but invisibility is not among them. We take a look at what the researchers achieved and use the Ars meta-crystal ballâ„¢ to predict where this will end up being employed.

Over the past few years, there has been a lot of theoretical and experimental work on a class of structures called meta-materials. A meta-material is used to get around the limitations of natural materials by structuring them in special ways. This can best be described using quartz as an example. A single quartz crystal is pretty much transparent to visible light; a few percent of the light is reflected from the crystal surface, but otherwise it all goes through. However, if the wavelength is much shorter (on the order of the spacing between molecules), then the crystal is still transparent, but light is scattered into a pattern. Similarly, if we take a handful of quartz crystals, all the little reflections from the many surfaces scatter even visible light in every direction, resulting in white sand that is no longer possible to see through. If the quartz crystals were all the same size and shape and arranged in an orderly fashion, however, it would be possible to use them to guide visible light down specific paths as well.

Quartz demonstrates how order and scale matter in how light propagates through a material. Meta-materials take advantage of this by deliberately engineering materials to have order on scales comparable to the wavelength of light that they want to influence. This can be done by alternating layers of materials (as in antireflection coatings), by crafting arrays of holes in an otherwise solid material, or by building crystal-like structures composed of small spheres.

In certain circumstances, a meta-material can exhibit a negative refractive index (in nature, the refractive index is always positive), which causes light to bend in unexpected directions. This has proven to be difficult to achieve at visible wavelengths due to a number of challenges. A negative refractive index has to have the appropriate scale (~30nm features), which is difficult, but not impossible.

However, the electric field phase of the light also needs to be controlled. To do that, the material must respond to the light's electric field with a large opposing field that can slows the light's advance. In effect, this requires metallic structures that allow the electrons to resonate with the light field, allowing a large opposing field to build up. Making a single layer of these structures has been done before, but it's really hard to define the bulk properties of a meta-material when it's only a single layer thick.

That is what makes the new research so important. For the first time, researchers have managed to make a negative index meta-material* that is more than a single layer thick. This allowed them to directly measure its bulk properties and confirm some of the predictions for these materials.




Nature, J.Valentine et al To construct their negative index material, the researchers grew alternating layers of silver and magnesium fluoride. This provides the bulk periodicity required, but it doesn't provide a resonant structure that will slow the light. To obtain that, the researchers drilled holes through the structure, creating a series of silver rings. Each ring acts like an electrical inductor, retarding the phase of the light's electric field locally. The inductors in adjacent layers all couple together, creating one giant inductor. This has the effect of reducing the retardation per inductor, but increasing the range of light colors that the rings will retard.


The meta-material used in this demonstration had 21 layers (ten of magnesium fluoride and 11 of silver) with 484 holes drilled through it. The holes are about 500nm in diameter, and the whole structure has a face of just 5 micrometers on a side. One face was angled so that the material acted like a prism. The researchers' measurements showed that the prism did indeed have a negative refractive index over about one-third of the near-infrared spectrum (1.45 to 1.8 micrometers, to be precise).

Although this is quite small scale, it is a very important achievement. Let's deal with what it isn't first. It will not act as a cloaking material because of absorption. There is a lot of silver in it, and silver absorbs and reflects radiation quite efficiently, meaning that not much light makes it through the materialâ€â€the sample described in Nature, which was less than one micrometer thick, absorbed 35 percent of the incident radiation.

Under ideal fabrication conditions, this might be reduced to as little as six percent per micrometer. Nevertheless, when you consider that a windowpane reflects about four percent of the incident radiation, you can see why even six percent is too high to render anything invisible. If anything, it will be easy to spot, as humans pick out reflections and flashes, meaning that this would probably draw more attention than good camouflage.

So, if this isn't a material for making you invisible what is it good for? It's the basic material we need for beating the diffraction limit. Negative index materials are not subject to the diffraction limit, meaning that light can be focused to smaller volumes. This implies that we would be able to illuminate cellular machinery at the level of individual molecules or perhaps even individual atoms. It would even be possible to use direct chemical imaging, instead of relying on fluorescent labels. This one application, which may well be attainable with the technology the authors used in their demonstration, should be enough for anyone to get excited about.

I actually meant to post what I've learned through whatever amount of internet research I've done on this subject but never did (see first post), so I actually need to thank you. And welcome to the site.

I'd expect a much better reply coming from me in a topic that I started but at the moment I don't think I can add anything worth contributing. It's been a while since I've touched this subject so I think I'll read more and get back to you on that.

it is all good and thanks it is just happens that i had already been doing some reserch on the subject that i had the info that i had but i am glade i found this sight.

i also found a site that had some more stuff on it and a pic that i am not sure is a real pic or one just the visualy show the idea behind the research


http://www.nextenergynews.com/news08/next-energy-news8.11.08b.html