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Fatal Flaw Discovered In Invisibility Cloaks
KentuckyFC writes "Carpet cloaks took the world by storm last year because they were the first devices to hide objects at optical frequencies. The idea is that a thin layer of dielectric material placed on a surface can make light look as if it is reflecting off the original surface. In other words, the layer is invisible and anything embedded within it is invisible too. This trick is like hiding something under a carpet, hence the name. Carpet cloaks are relatively easy to make because the dielectric material does not need to be specially constructed to steer light in special ways; physicists call this an isotropic material. Now a group at MIT has shown that isotropic carpet cloaks have a fatal flaw. When viewed at an angle, the carpets don't hide objects at all. Instead, they simply shift their position by about the same distance as they are high. So when viewed from an angle of 45 degrees, an object 0.2 units high is shifted to one side by a distance of 0.15 units, says the team. That's a serious limitation for carpet cloaks."
bummer.
So what they're saying is it's more of a Cloak of Displacement? While less stealthy, I think that's actually better odds of avoiding the hit than the penalty for attacking an invisible opponent.
Yeah - you aren't invisible, but wouldn't that still make the tracking missile miss you?
saw that problem coming.
They DON'T WORK!
When they were creating these cloaks, they didn't think to look at it from other angles than just straight on? Seriously? That's the equivalent of "it works on my machine."
...for making a Wing Commander reference (from the books, not the horrific movie that by coincidence has the same name) in the "department" byline for this story.
"I'd just like to emphasise that taking a million years isn't a metaphor here..." -Rich Bradshaw
From TFA:
Zhang and co go on to prove their assertion by tracing a ray that passes through the kind of isotropic carpet cloak that Pendry suggested. What they've discovered will shock carpet cloakers all over the world.
Yeah, all over the world.... uhm, all three of them. (Emphasis mine)
The three that YOU CAN SEE...
Unfortunately everyone has a mobile phone nowadays, so they -do- stand out (letterboxes too). But if you don't mind the risk of getting blown up for your valuable insides, you could still dress up as an ATM.
offsetting my apparent position could be as useful as making me disappear entirely!
Not when you are trying to use it to sneak around in the women's locker room.
It took a team from MIT to walk to the side of the object, look at the object and report that the object could be seen? I think this cloak managed to hide something other than the object....
And now you are hoping for an +1 informative/funny mod by referring to you post made few weeks ago, that referred to the signature of the GP and asked if it was his or someone elses signature, since you couldnt remember.
Am I right?
I mean, I know we all understand it, but if you're giving an example, why use unitless decimals when you can use integers and tangible concepts? Why not just say it would displace a 4 meter tall truck by 3 meters instead of 0.2 units tall object by 0.15 units?
This sentence no verb.
No. But they considered a sufficiently advanced technology.
That might work. A 6 ft soldier would appear to be displaced by about 4.5', if that ratio holds.
It's kinda sad that the evolving thought on Rules of Engagement is migrating back toward "Leave no witnesses" after a couple of decades of "kill the bad guys, don't even scratch the paint".
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