Shazzam!

[Miulang]

Wanna play like Harry Potter? Scientists have come up with a way that may help to make people "disappear" by rearranging molecules. Called "invisibility cloaks", the device deflects electromagnetic waves so that they flow around an object.

I can see all kinds of interesting uses for this technology, once it is perfected. Like making all our troops "invisible" to the enemy to make them harder to hit!

Their device, reported in today's online version of the journal Science, works only with waves of a certain frequency — microwaves — and only in two dimensions. And it does not yet provide complete invisibility, producing a small shadow that can be detected.
...
The current device cloaks a copper cylinder about half an inch tall. The team is now building one that it says will cloak an object the size of a toaster in all three dimensions.

The technique is different from stealth technology, which uses unusual shapes and radar-absorbing materials to reduce reflections back to the source. That technology can reduce the radar image of a plane to a size similar to that of a bird.
...
The key to the cloaking device is a new family of materials called "metamaterials." In essence, they are metal patterns laid onto the surface of materials that are commonly used in making circuit boards, such as ceramics and fiber composites.

If the right metals are used in the right configuration, incoming electromagnetic waves interact with electrons in the metals and are bent around the object. Electromagnetic radiation includes visible light as well as radio waves, microwaves, infrared radiation, ultraviolet radiation, X-rays and gamma rays.

Miulang

[Palolo Joe]

Re: Shazzam!

I can see all kinds of interesting uses for this technology, once it is perfected.

That's extremely wishful thinking.

From the same story:

A key consideration is that the metal shapes must be significantly smaller than the wavelength of the radiation, which is why Smith and post-doctoral fellow David Schurig used microwaves, which have a long wavelength.

Bending visible light waves would require much smaller metal patterns.

And because a different set of materials is required for each wavelength of light, producing a device that could block visible light could be extremely challenging, Smith said.

And this:

But cloaking a Romulan spaceship, a tank, or even a human would produce a serious limitation.

Because all the incoming light is bent around the cloaked object, anyone inside would be left, quite literally, in the dark and would not be able to see where he was going. Any device used to provide vision for the occupant would itself be visible, Smith said.

[craigwatanabe]

Re: Shazzam!

Ha the Air Force has been doing that since 1980. We were doing phase relationship experiments which ultimately led to the development of what is now known as Stealth technology.

It's all about frequency. Send an equal amplitude but 180-degree out of phase signal back at the object and Shazzam, it's gone.

Problem back in the early 80's was the ability to create an oscillator that could generate light frequencies and a processor that could vary that frequency as the object moved. Every fraction of a second required the frequency shift to follow the source and send the phase shifted signal back.

Using a broadband laser to scan the object, the reflected laser emission was then shot back with the same light frequency but out of phase rendering that object invisible at least that was the theory. It worked with sound, it worked with radar emissions, theoretically back then it could work with light.

We just lacked the technology back then to prove that theory with light emission in a practical way meaning in a self-contained apparatus not some big science lab.

[MadAzza]

Re: Shazzam!

I can see all kinds of interesting uses for this technology, once it is perfected. Like making all our troops "invisible" to the enemy to make them harder to hit!

Better we should make them invisible to the Bush administration!