Magnetic cloaking

The world has gone crazy over metamaterials cos they can be used to build invisibility cloaks, as ya’ll saw just the other week. There’s usually some drawback the media coverage never tells ya which means that we ain’t gonna see no Harry Potter-type invisibility cloaks any time soon. But that hasn’t stopped the living God of metamaterials, John “Now-You-See-Him” Pendry at Imperial College in London UK, from dreamin up ever more ingenious designs.

This week, he and a few pals have gone and built a metamaterial that works for light with zero frequency. That’s egghead-talk for a magnetic field. The material is a thin layer of lead squares pasted onto a cover slip and cooled to superconducting temperatures. This actually prevents a magnetic field from passing through it.

Why would anybody need a metamaterial that screens magnetic fields? There are all kindsa researchers playin around with tiny magnetic fields or with experiments in which they don’t want no magnetism at all. Their work is swamped by larger fields nearby. So a magnetic field cloak might be a useful device to have around.

And unlike other cloaking ideas, the technology is up and running now.

Ref: A DC Magnetic Metamaterial

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