Tag: John Howell
We’re still a long way from donning real invisibility cloaks, but by working out a better way to bend light, scientists from the University of Rochester can make movable objects invisible to the viewer — multi-directionally, and in three dimensions.
BBC Click’s Spencer Kelly looks at some of the best of the week’s technology – including how scientists at the University of Rochester are using a series of lenses to create a form of invisibility and plans to turn the game Tetris into a film.
Could this be the invention that every Harry Potter fan has been waiting for? Nerds the world over are going gaga for a so called invisibility cloak. It uses lenses to make light pass around an object so it looks like it isn’t there. To tell us about the breakthrough we have the creator of the invisibility cloak, Professor John Howell with the University of Rochester. Can you talk us through how this works?
Everyone from Harry Potter to working physicists are fascinated with cloaking devices. Now, researchers at at the University of Rochester have used simple, inexpensive, off-the-shelf components to hide objects in the visible spectrum of light. In other words, now you see it; now you don’t.
It’s like a very small invisibility cloak made of glass. Researchers at the University of Rochester seem to be taking the words of science fiction writer Arthur C. Clarke’s to heart: “any sufficiently advanced technology is indistinguishable from magic.”
Scientists have recently developed several ways—some simple and some involving new technologies—to hide objects from view. The latest effort, developed by physics professor John Howell and graduate student Joseph Choi, not only overcomes some limitations of previous devices, but uses inexpensive, readily available materials in a new way. “This is the first device that we know of that can do three-dimensional, continuously multidirectional cloaking,” said Choi.
Physicists have figured out the optical parameters for a magic trick they characterize as a kind of “invisibility cloak” — and unlike most magicians, they’re only too willing to show you how it’s done. “We just figured a very simple way of doing that can just be using standard lenses, and things that we normally find in the lab,” physics professor John Howell said in a video explaining the setup.
Quantum mechanics imposes a limit on what we can know about subatomic particles. If physicists measure a particle’s position, they cannot also measure its momentum, so the theory goes. But a new experiment has managed to circumvent this rule—the so-called uncertainty principle—by ascertaining just a little bit about a particle’s position, thus retaining the ability to measure its momentum, too.
Physicists have shown that a technique called compressive sensing offers a way to measure both variables at the same time, without violating the Uncertainty Principle.