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Engineers Devise Invisibility Shield
GerritHoll points out an article in Nature according to which "researchers at the University of Pennsylvania 'say that a "plasmonic cover" could render objects "nearly invisible to an observer.' Earlier attempts at invisibility worked by colouring a screen to match its background, like a chameleon. The described technique is new, because it works by the concept of reducing light scattering. It is not a 'magic cloak,' however, because it will not work for the full range of visible light and needs to be adjusted precisely for the shape of the object. However, the concept could find an application in stealth technology."
It is not a 'magic cloak,' however.
Like this?
Well, that actually requires a special viewfinder, so it's not quite as cool, but it sure *looks* awesome. Better than the "spot the spaceship" pic, anyway.
How long til I can buy this stuff at Walmart?
What sort of armor class do you get with that?
Making something invisible is easy: all you have to do is generate a Somebody Else's Problem field of sufficient size.
(Seriously, am I the only one who looked at this, saw the word 'plasmonic', and thought "Fucking Slashdot editors, its *March 1st*, not *April 1st*"?)
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Mod me down, you fucking twits. Go ahead. I dare you.
(I read with sigs off.)
I didn't see that one coming.
This technology would only work for microscopic objects (as they must be the same size as the wavelength of light hitting it), and only a single wavelength. So in other words, for you to get a nice, new cloak of invisibility you'll need to be microscopic in size and constantly in environments with only one wavelength of visible light hitting you. =)
Well, back to the drawing board.
-Vendal Thornheart
... to let me sneak undetected into a ladies locker room, then we'll talk.
bash: rtfm: command not found
See, it hides my identity when I post on Slashdot!
I can think of a couple of obvious applications, especially if the technology can be adapted to scatter microwaves. Tanks and mechanized infantry are pretty obvious, but I think we want to avoid battleships unless we want a repeat of the Philadelpha Experiment and the crappy movie versions (though I loved the first one as a kid).
But what about non-military uses? Perhaps a "coat" of plasma on windows to reduce cooling bills in the summer? Or another coat of plasma on TV's to reduce glare? I can't think of anything particularly inspiring.
After all, I am strangely colored.
The object being hidden has to be less than the about the wavelength of the light. So, unless you are nanometers in size, you won't be hidden from visible light.
And it only works on one frequency. Meaning, unless you are nanometers in size, and you are in a room with only red light, you won't be hidden.
This isn't that great. I wouldn't read too much into it.
The radical sect of Islam would either see you dead or "reverted" to Islam.
From the article: "And crucially, the effect only works when the wavelength of the light being scattered is roughly the same size as the object. So shielding from visible light would be possible only for microscopic objects."
OK. So if I have this straight... "You see that thing you can't see because it's too small? Well we just made it invisible! Please send more grant funding. And a few burritos. We're like, totally hungry dude."
Uh huh....
Here is the technique let yourself invisible, try it yourself: http://www.sciforums.com/showthread.php?p=439508
From the article:
...it would be more like the shielding used by the Romulans in the Star Trek episode "Balance of Terror" in 1966, which hid their spaceships at the push of a button.
...it's called a "cloaking device", you insensitive clod!
Really? Invisibility could be used for tasks requiring stealth? No way, that's crazy talk.
This article is like going to a movie after seeing the really great preview, and finding out that the really great preview contains every single really great moment in the movie.
U.S. Air Force scientists looked into generating a field of plasma around an aircraft to reduce aerodynamic drag. One unexpected effect was a reduction of RCS (radar cross section, a rough measure of radar visibility), though to my knowledge the research has not been pursued (it probably continues in classified state, just like the plasma toroid ABM system 7 years ago...). Of course, this is EM radiation in the radio portin of the specturm, not optical.
Russian electrodynamicists are also infamously known for proposing "plasma stealth" devices, which have yet to be demonstrated veritably well. Every few months something pops up about how they've solved high power requirements, reduced weight of the devices, eliminated interferce with the aircraft's EM devices (radar and comm/nav, which critical to everything) and problem Y. And then, you see nothing of it in any journal or trade publication. Just claims, and it seems, nothing more.
Notably, plasma radar stealth has an opposite effect of the optical stealth. The aircraft would glow like a lightbulb, and leave a trail of glowing plasma in its wake. Also notably, aircraft at high hypersonic speeds induce a local plasma air environment, due to the tremendous energy of the aerodynamics.
It's made me invisible to women for 10 years now.
I wish I could turn it off.
Here's an obligatory link to the pre-print research paper and the abstract:
http://arxiv.org/abs/cond-mat/0502336
Achieving transparency with plasmonic coatings
Andrea Alu, Nader Engheta
The possibility of using plasmonic covers to drastically reduce the total scattering cross section of spherical and cylindrical objects is discussed. While it is intuitively expected that increasing the physical size of an object may lead to an increase in its overall scattering cross section, here we see how a proper design of these lossless metamaterial covers near their plasma resonance may induce a dramatic drop in the scattering cross section, making the object nearly invisible to an observer, a phenomenon with obvious applications for low observability and non invasive probe design. Physical insights into this phenomenon and some numerical results are provided.
The article puts two techniques next to eachother, as if it were alternatives for the same problem. This is false.
The proposed system with plasmonic covering reduces the scattering of light. The lightwaves pass by the object as were the object very small, smaller than it actually is. Hence it only works with objects that are allready very small, because otherwise the object would cast a shadow. (Light passes by, not through)
The system with light detectors and emitters mimics the scene that is behind (bigger) objects with respect to the viewer. You could actualy say that it fills in the shadow cast by the object.
So were the first system reduces the shadow effect, the second replaces the shadow alltogether. I could actualy see these two systems used along side eachother rather than instead of eachother.
"And crucially, the effect only works when the wavelength of the light being scattered is roughly the same size as the object."
Visible light is around 400nm (violet) to 800nm (red). So, this is only effective for sufficiently tiny battleships.
It's not easily possible to hide from any good EW system. They use multiple frequencies, pulse modulation, frequency hopping, staggered pulses, and a hundred other techniques that provide some really fine grained resolution - right out to the MTUR.
You also find RADAR on HF, it's annoying if your day job is to actually listen to the static, sounds a bit like a high pitched fart, transmissions are normally short duration though - less than 30 seconds then the frequency is changed - don't hear it again for a couple of minutes/hours.
I won't believe this 'til I see it.
the effect only works when the wavelength of the light being scattered is roughly the same size as the object
This would make it the perfect for those awkward moments when your nanobots are being attacked by lasers (mounted on sharks?)
The world has changed and we all have become metal men.
I have thought about this few times(when feverish or some other way mentally challenged states) and decided that our technology isn't yet suitable to accomplish this.
Basically it's quite simpple - all you have to do is route every incoming photon around the object without changing it's course.
Fabric made of nano-fibres?
/* If everybody would be like me the world would be much better place to be - at least in my mind. */
The Japanese "invisibility cloak" is nothing more than the front projection technique used in 2001: A SPACE ODYSSEY and many other films. That's like claiming that we have a super weapon that can hit an enemy anywhere -- provided he stands right here on this spot marked X. The alleged surgical and pilotting applications sound equally silly. It is an infinite regression of "if we can fit a camera in front of the surgeon's hands, we can project an image behind them to make a really cool effect that they are invisible!"
I don't think these engineers devised any sort of "invisibility shield"
...match its background, like a chameleon.
Grrr...
Chameleons don't change their colors for this reason. It's a myth. Stop spreading it.
http://www.wsu.edu/DrUniverse/chamel.html
// file: mice.h
#include "frickin_lasers.h"
This technology is really invisibility in the sense that it stops light scattering, but for visible light would only work for microscopic items...
Which must be working because right now I so not see many single microscopic items anyway...
It can't be used to conceal guns from Xrays, which use 0.1nm-20nm wavelegths.
Hiding missiles from radio based radar? Possible?
So shielding from visible light would be possible only for microscopic objects; larger ones could be hidden only to long-wavelength radiation such as microwaves. This means that the technology could not be used to hide people or vehicles from human vision.
Also the 'inventiveness' of the invisibility cloak is much less than its engineering feat.
We all have our own ideas about projecting the view behind your onto the front... from all angles... technically how to do it flexible, and stop illumination / shadow is very hard.
Not impossible, with some very clever technology that can 'feel' its own shape, and sense light conditions, can absorb almost all light (be dark even in bright light, if a shadow is behind you), and shine as bright as the sun on a rock (if you are in the shade, but a bright rock is behind you, and you cannot use the sun on the material to compensate)
This would require some l33t processing skills to handle the data.
#hostfile 0.0.0.0 primidi.com 0.0.0.0 www.primidi.com 0.0.0.0 radio.weblogs.com
I think the device you mean would be a DeBigulator. Of course to return to normal size would require some kind of ReBigulator, which is an idea so patently absurd I can't even begin to comprehend it, ng'hiey!
And crucially, the effect only works when the wavelength of the light being scattered is roughly the same size as the object. So shielding from visible light would be possible only for microscopic objects...
Which are frikkin' microscopic and therefore don't need to be hidden?
Or is it just me that can't see microscopic objects?
IANAL, but I've seen actors play them on TV
Come on, guys! I can't be the first to notice... Okay, I'll spell it out for you -- the correct first reaction to this story is:
(Have none of you kids ever heard of The Philadelphia Experiment ?)
David Gould
main(i){putchar(340056100>>(i-1)*5&31|!!(i<6)<< 6)&&main(++i);}