Star Trek Cloaking - May Soon Be Real

The days of cloaking found in science fiction movies may not be so far away according to Nader Engheta and Andrea Alu of the University of Pennsylvania.

The proposal uses plasmons or "plasmonic cover", tiny electronic excitations on some metal surfaces to cancel out the visible light or other radiation coming from that object.

Here's a brief excerp, but read the 2 articles from 2 sources, its very interesting.
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www.livescience.com...

"A proper design … may induce a dramatic drop in the scattering cross-section, making the object nearly invisible to an observer," Nader and Alu write in a scientific paper that was made available to the public Feb. 14.

But cloaking ability would depend on an object's size, so that only with very small things -- items that are already microscopic or nearly so -- could the visible light be rendered null. A human could be made impossible to detect in longer-wavelength radiation such as microwaves, but not from visible light.

A spaceship might be made transparent to radio waves or some other long-wavelength detector.

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www.nature.com...

It is a self-contained structure that would reduce visibility from all viewing angles..........
The key to the concept is to reduce light scattering. We see objects because light bounces off them; if this scattering of light could be prevented (and if the objects didn't absorb any light) they would become invisible. Alù and Engheta's plasmonic screen suppresses scattering by resonating in tune with the illuminating light.

Plasmons are waves of electron density, caused when the electrons on the surface of a metallic material move in rhythm. The researchers say that a shell of plasmonic material will scatter light negligibly if the light's frequency is close to the resonant frequency of the plasmons. The scattering from the shell effectively cancels out the scattering from the object.

For visible-light shielding, says Engheta, nature has already provided suitable plasmonic materials: silver and gold. To reduce the scattering of longer-wavelength radiation such as microwaves, one could make the shield from a 'metamaterial': a large-scale structure with unusual electromagnetic properties, typically constructed from arrays of wire loops and coils.

Alù and Engheta's calculations show that spherical or cylindrical objects coated with such plasmonic shields do indeed produce very little light scattering. It is as though, when lit by light of the right wavelength, the objects become extremely small, so small that they cannot be seen.
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I suggest reading the Nature article for the best overall discription.

Now, this brings me to an opinion based on this type of technology which appears very very possible. If an advanced race was visiting Earth, they would most likely have these abilities as well...? And if they do, why do they choose not to use them, or are we only seeing a fraction of whats really out there?


[edit on 3/1/2005 by infinite8]

Thanks for the links! I have been interested for some time in the cloaking, or active camoflauge technologies being developed.

Very interesting. If the aliens do have such tech, we would be in some trouble if they're hostile.

The proposal uses plasmons or "plasmonic cover", tiny electronic excitations on some metal surfaces to cancel out the visible light or other radiation coming from that object.



"A proper design … may induce a dramatic drop in the scattering cross-section, making the object nearly invisible to an observer,"

Hi
I think this is a clear case of the 'Invisibility Fallacy'. True invisibility requires light to travel through the object, so that anything behind the object can be seen. Cancelling out visible light, or eliminating scattering will not have this effect, therefore ithe object will not be invisible. It may be invisible to radar which relies on a return signal, but not visually invisible as in Star Trek 'cloaking'.

The Farseer

[edit on 3-3-2005 by The_Farseer]

This got me thinking about a coupla things. Check out this link for Wikipedia about mirages . . .

en.wikipedia.org...

I was thinking about how mirages are created the other day, and wondering if there is some way to utilize the same effect to bend images behind an object around that object so that it would appear that the object isn't even there. Natural mirages work because of warm air. I wonder if it would be possible to achieve the same effect by manipulating the air around an object in some way. Just an idea.

-P

That is quite interesting.

Originally posted by postings
I wonder if it would be possible to achieve the same effect by manipulating the air around an object in some way. Just an idea.

-P

Actually, take a close look at the second picture, and how the trees are almost completely obscured by the mirage. If the effect was complete, you would not even see them at all!

-P