Scientists Show How to Make an Invisibility Cloak
Scientists at the University of Rochester have created an optical-illusion device they’re calling a sort of invisibility cloak.
When talking about invisibility cloaks, the Harry Potter series inevitably springs to mind. But this one wouldn’t exactly be useful in aiding Harry and friends’ exploits at Hogwarts.
It’s a stationary trick that bends light around smaller objects — rulers and pens are used as examples by these researchers — so that they seem to have disappeared. Four regular lenses are arranged like this:
For their demonstration cloak, the researchers used 50mm achromatic doublets with focal lengths f1 = 200mm and f2 = 75mm
Image: University of Rochester
If used correctly, you can see beyond the lenses but not what’s between them. Researchers have provided a video to show how it’s done. Physics professor John Howell and grad student Joseph Choi are calling it the first device with three-dimensional, multidirectional cloaking.
“There have been many high-tech approaches to try and achieve cloaking,” Howell said in a video. “We just figured a very simple way of doing that can just be using standard lenses and things that we would normally find in the lab.”
The researchers say the illusion can be replicated with bigger and smaller lenses.
Efforts toward a real-life invisibility cloak have popped up more than a few times over the last several years. None have quite moved beyond the muggle world, but scientists seem keen on bringing a true disappearing cloak to reality.
Here’s more information on how to make your own lens cloaking device.
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