A Canadian company called Hyperstealth is reporting that it has developed Quantum Stealth, a material that renders the target “completely invisible by bending light waves around the target.” If the mock-up photos are to be believed, Quantum Stealth basically works like Harry Potter’s invisibility cloak.
Apparently his invention also negates the second law of thermodynamics.
I'm calling BS on his claim here.
If it's bending visible light, isn't it also plausible it could bend infrared light? In fact, the longer wavelength in the IR portion of the electromagnetic spectrum should make it easier to refract than visible light. How does the 2nd law of thermodynamics even apply here? The cloak doesn't stop an object from radiating heat into its environment, it simply bends the electromagnetic radiation (light, whether in the visible or infrared spectrum).
If it's bending visible light, isn't it also plausible it could bend infrared light? In fact, the longer wavelength in the IR portion of the electromagnetic spectrum should make it easier to refract than visible light. How does the 2nd law of thermodynamics even apply here? The cloak doesn't stop an object from radiating heat into its environment, it simply bends the electromagnetic radiation (light, whether in the visible or infrared spectrum).
The 2nd law applies because of entropy - what is under the cloak is not a closed system.
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Following the second law of thermodynamics, entropy of a closed system always increases and in heat transfer situations, heat energy is transferred from higher temperature components to lower temperature components.
Despite the bending of the immediate area, the entire area is the system. The cloak cannot prevent object surrounding the cloak from soaking up heat - it can bend all the light it wants but a highly sensitive thermal imaging system (read military grade) will pick up the thermal footprint of the surrounding area as well. The cloak can only hide what is directly under it, not what surrounds it. Just like how a thermal camera will see your footprints long after you've walked on by, it will pick up reflected heat from the ground, rocks, trees, etc. Go jump under your bedsheet and see how much that intensifies your temperature and then tell me it doesn't amplify the heat as it builds up. That heat is going to leech beyond the cloak.
Now if you tell me the requirements to defeat thermal imaging require a 98 degree desert, the user wearing a scuba suit and such, ok... I will concede the point but I find it far from practical to have a sheet of fabric much like the emergency thermal blanket as the inventor already cites be able to thermally absorb enough energy to prevent leeching to the point it extends beyond the field light that is being bent and thus hidden. It's a blanket, not a black hole.
It's advertising and PR, naturally they're going to tend to exaggerate its features. I think they were merely pointing out the ability to refract IR light from the wearer.
Also, footsteps aren't an issue if the soldier has been in place for an extended period of time. Like a sniper.
If it's bending visible light, isn't it also plausible it could bend infrared light? In fact, the longer wavelength in the IR portion of the electromagnetic spectrum should make it easier to refract than visible light. How does the 2nd law of thermodynamics even apply here? The cloak doesn't stop an object from radiating heat into its environment, it simply bends the electromagnetic radiation (light, whether in the visible or infrared spectrum).
Most (all?) IR scopes are passive. Imagine it's a camera or viewhole that only sees IR.
If they were active (ie: they shoot IR at a target and wait for it to bounce back and hit a receiver), then bending IR would matter.
Bending IR absolutely matters. The IR is radiating from the heat source. The heat source is beneath the blanket. The IR refracts back towards the heat source when it hits the blanket. The IR never reaches the scope.
If the blanket isn't thermally insulated, then the heat source may heat the blanket and cause it to radiate as well. That would obviously be visible to the scope. But that's an easy problem to fix.
Bending IR absolutely matters. The IR is radiating from the heat source. The heat source is beneath the blanket. The IR refracts back towards the heat source when it hits the blanket. The IR never reaches the scope.
I was going to talk about "refracting backwards".
The problem is that I really don't know how the hell they orient the NIM cloak structure, and have serious issues wrapping my head around negative n.
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Originally Posted by Mystlyfe
If the blanket isn't thermally insulated, then the heat source may heat the blanket and cause it to radiate as well. That would obviously be visible to the scope. But that's an easy problem to fix.
Ok well I often post images without any context in a science thread and expect everyone to instantly recognize factual evidence from faked concepts.
If only you had included that simple line of text along with your photo only post...
He was replying to my post, which was talking about negative refractive indices.
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Originally Posted by Unaffiliated
The problem is that I really don't know how the hell they orient the NIM cloak structure, and have serious issues wrapping my head around negative n.
The context is there.
Now as I've said, those kinds of pictures don't help me understand how the waves propagate near/around the cloak, but that doesn't mean the post was totally out of the blue.
If there was any truth to this the military would be all over it. It does sound fishy because we would be getting more info about it, 'top secret' or not. As a hunter, I can tell you that deer can't see alot of things except primarily movement. You can be in full camo or blaze orange, and if you're still and the deer don't smell you, they don't know you are there. I've had deer walk right up to me by just staying perfectly still. It would be great for our troops if this stuff does pan out though.
If there was any truth to this the military would be all over it. It does sound fishy because we would be getting more info about it, 'top secret' or not. As a hunter, I can tell you that deer can't see alot of things except primarily movement. You can be in full camo or blaze orange, and if you're still and the deer don't smell you, they don't know you are there. I've had deer walk right up to me by just staying perfectly still. It would be great for our troops if this stuff does pan out though.
So this technology is being developed to battle the upcoming Deer invasion?
