Metamaterial Electromagnetic Cloak at Microwave Frequencies
D. Schurig¹, J. J. Mock¹, B. J. Justice¹, S. A. Cummer¹, J. B. Pendry², A. F. Starr³, D. R. Smith<sup>1*

1</sup> Department of Electrical and Computer Engineering, Duke University, Box 90291, Durham, NC 27708, USA.
² Department of Physics, The Blacket Laboratory, Imperial College, London SW7 2AZ, UK.
³ SensorMetrix, San Diego, CA, USA.

Recently published theory has suggested that a cloak of invisibility is in principle possible, at least over a narrow frequency band. We present here the first practical realization of such a cloak: in our demonstration, a copper cylinder is 'hidden' inside a cloak constructed according to the previous theoretical prescription. The cloak is constructed using artificially structured metamaterials, designed for operation over a band of microwave frequencies. The cloak decreases scattering from the hidden object whilst at the same time reducing its shadow, so that the cloak and object combined begin to resemble free space.

The first cloak only works with microwaves in two dimensions and it still reflects a little light and casts a small shadow. The effect is that the background is visible, but it is slightly darker in color due to the shadow and reflectivity.

It is believed the concept can be extrapolated to working with visible light in three dimensions, so that it would not reflect light or cast a shadow. In the picture above, the dark lines represent the path that light would take around a cloaked sphere, rendering it invisible because the light was not reflected back to the viewer.

If this can be made to work with microwaves and visible light, I have a REALLY. BIG. QUESTION.


Can we do the same with GRAVITY WAVES?


In the past, many anti-gravity device concepts relied on the idea of repelling gravity. The usual suspect in this scheme was some method of using a singularity (small black hole) contained within a magnetic field.

Never mind the difficulties of finding (making?), containing, and directing the energies of miniature black holes. Consider the consequences of one of those little monsters escaping it's containment field. I shudder to think of a failure in a system of this type. The magnitude of the disaster would compare favorably to any of those attributed (wrongly of course) to the WWWA’s Lovely Angels (Dirty Pair).

If we could just bend gravity waves instead of trying to repel them, cheap access to space and the long-awaited, much maligned air-car concept could become reality.

Imagine the object in the center of the field were a spaceship or an air-car - gravity waves would simply have no affect, and propulsion would become a simple matter of current engine/motor technology, be it air-breathing or space-capable.

And our new gravity-bending ship will work just as well on Mars as it does on Earth. Or any other planet in our solar system. Or any other solar system, for that matter.

Suddenly, real space exploration becomes not only possible, but relatively cheap. The gravity well ceases to be our prison, and exploration of other planets no longer requires carrying the massive loads of propellant necessary to descend to and escape from another planet’s gravity well. Descending to, and leaving a planet would require only minimal propulsion, and the main purpose of propulsion becomes interplanetary travel. Hello, Ion engines.

And since gravity is no longer an issue, spacecraft size becomes a lot less important. Spacecraft size is currently limited by the energy required to escape from the gravity well. Remove that limitation, and truly large spaceships become possible, limited only by the strength requirements of a pressurized atmosphere.

In addition, if the gravity-bender can be controlled, might it be possible to direct gravity waves back in the direction they came from, so as to use them to slow down when approaching a planet?

One would first go past the planet. Once past, bend the waves back at the planet, effectively doubling the gravitational pull in the direction of the planet. Then gradually dial the “bending” effect down, so as to control the approach. When a proper approach vector and position has been achieved, one could revert to “anti-gravity” bending again.

This could happen in my lifetime. And getting to space would no longer require high-G force rocket launches, so even old people could go into space (although the loss of bone calcium would make it un-wise for extended periods).

Woo-hoo!