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Glass Invisibility Cloak Shields Infrared
An anonymous reader writes with the latest advance in the quest for a cloak of invisibility (Michigan Tech University's press release). We've been following this research as it develops; here are stories from each of the last four years. "Invisibility cloaks are slowly working their way up to shorter wavelengths — starting at millimeter-long microwaves and working their way to the nanometer wavelengths of visible light. EETimes says we are about half way there — micrometer wavelengths — in this story about using chalcogenide glass to create invisibility cloaks in the infrared. Quoting: 'Invisibility cloaks cast in chalcogenide glass can render objects invisible to infrared frequencies of light, according to researchers at Michigan Technological University... Most other demonstrations of invisibility cloaks have used metamaterials composed of free-space split-ring resonators that were constructed from metal printed-circuit board traces surrounded by traditional dielectric material. The Michigan Tech researchers... claim that by substituting nonmetallic glass resonators made from chalcogenide glass, infrared cloaks are possible too...'"
I so totally didn't see this story coming this morning...
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is not halfway there
Once you can cloak infrared, then you have a genuine military grade cloak with true stealth capability and applications. Expect most of the real breakthroughs to never see the front page of /. or any other news source. Except maybe Wikileaks.
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Calling these things "invisibility cloaks" is being very, very generous.
They are fundamentally flawed in the specs: percent transmission, angle, bandwidth, and refraction.
They're more of a laboratory curiosity than anything that would fool anybody.
but can't see the story. What gives?
Anything you say will be held against you.
Does this really mean that visible light invisibility shielding is actually possible? Over the years, whenever I saw an article on this, I just yawned and assumed that the laws of physics wouldn't really allow someone to make a real device that could not be detected by some wavelengths of light.
However, I'm going to assume that a practical real world application of the technology will require another tech called 'molecular manufacturing' as a prerequisite. I'm guessing that to cloak a macroscopic object from visible light you'll need to create a shield with atomic level precision. And forget cloaking a person, probably - a shield would need to be a rigid object and there's probably an upper limit to how large it could be. I'm thinking that the insect sized spy drones of the future could be made totally invisible to the naked eye, however.
Didn't they do this on Mythbusters?
Glass Invisibility Cloak Shields Infrared
You know you've been coding too much when the brain reads that as "noun noun noun noun noun" and throws a parse error expecting a verb...
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When the Predators invade, we'll be ready!
This can bypass infrared security systems?
TSA screener: "nothing for me to see here, move her right along"
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Anyone using infra red detection goggles/devices will see a very unusual cool spot that stands out against the background (try out some first or second gen goggles some time). And it will be especially noticeable if this cool spot is moving. Good milspec devices like this, to be really stealthy, would detect and measure the surrounding background heat levels and *match them*, like a chameleon matches background visual colors.
I know it is premature speculation on lab technologies but, well Infra-reds invisibility could mean improved heat isolating glasses windows for buildings. Keep visible light enter the building, let infra-reds refract though the other side and keep inside radiating heat bouncing the glass with perfect reflection. Would be a boon for vehicles where most windows face side to side. Would this be more efficient or combinable with athermic design?
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If this can be made to work at the frequencies used by infrared targeting sensors it could be extremely useful. It doesn't have to 'match' anything. All it has to do is make the platform not emit in the expected direction, but in a direction that will make tracking difficult. Remember that these kind of meta-materials have a negative index of reflection, so they can act like unusual lenses. It doesn't even have to do this for the entire vehicle, just the hot parts used for targeting. For example, this could be a big winner for UAV platforms.
Why is Snark Required?
No 'predator' tag?
I'm talking about the garage type with a beam?
Ok, I'm not up on materials science and had to look this up--thought others might be curious, too: chalcogenide glass
Does it mean you can hide at all?
I haven't RTFA but "cloaking IR" and talking about wavelengths for me sounds rather like it absorbs any IR thrown at it (so it would look "dark" if that was all you where looking for, hence invisible) or block IR from the object to be seen (wouldn't that need cooling/heat distribution to?) but then it would still be darker then the surroundings, or?
Regardless of how it works unless the object emits the same energy waves/particles that is on the opposite side of the object for the observer it's not really invisible at all is it?
I don't see how blocking or not reflecting anything is "invisibility"?
Science needs to get working on my Gauntlets of Ogre Power.
You neither block nor reflect, you cause the light to bend around you.
Imagine a smoothly-flowing stream: If you put a rock in it, the flow will be disturbed. If the rock is irregularly shaped, some of the water will "bounce" back(because this is water, and not photons, it will only cause some turbulence, not actually be reflected; but such is the weakness of analogies...). If the rock has a nice, smooth, hydrodynamic sort of shape, the water will part smoothly when it hits the rock and then come back together behind the rock, with minimal disruption to the flow. The rock exists; but for a hypothetical organism that can only detect water currents(say a water bug with sensory hairs, sitting downstream), it will be invisible.
It turns out that, on small scales, under laboratory conditions(and often only in two dimensions), with exotic materials, you can cause photons to "bend around" an object, thus rendering the object effectively invisible. They don't get absorbed, so you can't detect the object by their absence, and they don't get reflected, so you can't see the object, they just take a circuitous path around the object, and continue on their merry way as though nothing was there(though, since a semicircular path is slightly longer than the straight path would have been, I suppose a sufficiently sensitive travel-time comparison system could still detect the cloaked object...)
Where does the heat go?
Have you fscked your local propeller head today?
The only way this will work to evade military grade infra red detection is if 1) you are not moving - people tend to notice a "cold patch" moving against a background - it's almost as good as a hot one; and 2)if you can manage to match the background heat exactly, thus masking your shape. Unfortunately if you're being viewed by something that's moving (like a helicopter or drone), you have no idea at what angle you are being viewed from at any point in time. This complicates matters.
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you can't see a predator, but he shows up on infrared
with this tech, you don't show up on infrared, but you can still be seen
maybe this tech will finally allow for a lasting peace with the predator alien race via mutual incomprehension
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Didn't the mythbusters already prove you can foil a heat-sensing alarm by holding a pane of glass in front of you?
Now we're set in case of Predator attack.
Cloaking uses metamaterials which have a negative refractive index- these bend light rays around the object being cloaked. Very recently, physicists and engineers realised that a similar principle can be applied to pressure waves caused by earthquakes. With the right design, the shockwaves might be bent around a building, rendering it "invisible" to an earthquake.
This was previously thought impossible due to mistakes in some engineering research articles.
Link here:
http://www.sciencedaily.com/releases/2009/07/090720105125.htm
More techncial articles can be found by googling "elastic cloaking".
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