Cloaking Device Planned by Engineers

7 Mar, 2005 at 2:57pm ET Article published in Tech

In popular science fiction, the power of invisibility is readily apparent. Star Trek fans, for example, know that Romulan and Klingon spaceships have the ability so suddenly vanish. According to engineers at the University of Pennsylvania, that idea isn’t as implausible as people might initially think.

Electronic engineers at the University of Pennsylvania in Philadelphia are researching a device they say could make objects “nearly invisible to an observer.” The contrivance works by preventing light from bouncing off the surface of an object, causing the object to appear so small it all but disappears.

Light manipulation… it’s the spice of life!

Source: National Geographic

Comments

7 Mar 2005 ~ 3:03pm GHoosdum Oh no! Now women can start wearing these cloaking devices to hide their extra flab, and we unsuspecting men just won't know what it is we're taking home from the bar! :bawling:
7 Mar 2005 ~ 3:12pm Garg Combined with beer goggles, we'd be screwed.
7 Mar 2005 ~ 3:20pm Thrax ****, when I saw the title of this thread, the first thing I thought was "KHAAAAAAAAAAAAN!!"
7 Mar 2005 ~ 4:05pm a2jfreak OK, so light doesn't bounce off it, but what about "through" it?

On Star Trek you see the starship and 2 seconds later (after it "melts" into the backdrop of black and stars) you see everything behind it. So what if the light from my flashlight doesn't bounce off it, I'm going to know something is there because were I used to see an off-white wall, now all I see is this light-eating void.
7 Mar 2005 ~ 4:11pm primesuspect Light does bounce off of it, but it makes the object appear so small that you can barely see it.

At least, that's what I got out of the article.
7 Mar 2005 ~ 4:15pm RWB

primesuspect wrote:

Light does bounce off of it, but it makes the object appear so small that you can barely see it.

At least, that's what I got out of the article.

Same here, like stealth technology.... it doesn't dissapear, it just gets too small to notice or is just another birdy
7 Mar 2005 ~ 5:01pm a2jfreak It's not what I got out of the article.

Electronic engineers at the University of Pennsylvania in Philadelphia are researching a device they say could make objects "nearly invisible to an observer." The contrivance works by preventing light from bouncing off the surface of an object, causing the object to appear so small it all but disappears.

The concept is based on a "plasmonic cover," which is a means to prevent light from scattering. (It is light bouncing off an object that makes it visible to an observer).

The cover would stop light from scattering by resonating at the same frequency as the light striking it. If such a device could cope with different wavelengths of electromagnetic radiation (including visible light), in theory, the object would vanish into thin air.

When light strikes a metallic material, waves of electrons, called plasmons, are generated. The engineers found that when the frequency of the light striking the material matched the frequency of the plasmons, the two frequencies act to cancel each other out.

Under such conditions, the metallic object scattered only negligible amounts of light.

The researchers' studies show that spherical and cylindrical objects coated with plasmonic shielding material produce very little light scattering. These objects, when hit by the right wavelength of light, were seen to become so small that they were almost invisible.

Seems like it prevents light from bouncing off objects, or prevents all but negligable amounts from bouncing.

primesuspect wrote:

Light does bounce off of it, but it makes the object appear so small that you can barely see it.

At least, that's what I got out of the article.
7 Mar 2005 ~ 5:20pm Private_Snoball Who cares why it works, all that matters is that it is cool. Then when someone creates a neat little tutorial on how we can all do this ourselves and puts it on the internet, then we can all have fun.

Until then it sounds like a bunch of jibber jabber...but very intelligent jibber jabber
7 Mar 2005 ~ 5:56pm Cyclonite Obviously a lot of people cared. If no one cared, then this would not have a discussion in the first place. Personally, I'm enjoying learning about how it works.
7 Mar 2005 ~ 7:09pm RADA

Gargoyle wrote:

Combined with beer goggles, we'd be screwed.

*RADA fires up his new Plasmonic 3000 body suit, and heads for the University of Arizona Cheerleaders locker room!

I KNOW, I KNOW! .....BAD RADA,, BAD!
7 Mar 2005 ~ 7:46pm drasnor This is similar in concept to the active stealth technologies currently employed on the latest generation of fighters. When the fighter's ECM suite detects an active radar signal, it broadcasts the original signal back at the source with a 180 degree phase shift. The addition of the two waves cancels it out and the radar thinks it's seeing empty air. Without this technology, the radio waves would be scattered and reflected back to their source (early stealth technologies focused on having the radio waves reflected to any direction except the source).

These guys have figured out how to get around the whole mess by not letting light be reflected or scattered at all. They have another big challenge ahead of them though, as best stated in the article:

It would be still more difficult to devise shields that could cope with all wavelengths of the visible spectrum—from red to violet light—and not just a single color.

Getting the material to resonate at multiple frequencies without interference seems impossible to me.

-drasnor
7 Mar 2005 ~ 11:49pm RWB

RADA wrote:

*RADA fires up his new Plasmonic 3000 body suit, and heads for the University of Arizona Cheerleaders locker room!

I KNOW, I KNOW! .....BAD RADA,, BAD!

NO!!!!!

GOOD RADA,, GOOD!!! Here....

TAKE MY CAMCORDER!!!
8 Mar 2005 ~ 1:33am W4R-H1LD

Thrax wrote:

****, when I saw the title of this thread, the first thing I thought was "KHAAAAAAAAAAAAN!!"

Here ya go Thrax lol

http://www.khaaan.com/
9 Mar 2005 ~ 1:04am qparadox Unfortunately National Geographic people don't seem to understand science or be able to properly read and quote papers. The method only works for objects on the same order of magnitude as the wavelength (ie nanometers for visible light) and also only works at one wavelength. The effect is in no way scalable to large objects (unless for some reason your tank to be invisible to AM radio :P). You'd be better off painting yourself black and sticking your head in the sand. Stories like this give science a bad name.

The real story is available on Nature here:
http://www.nature.com/news/2005/050228/full/050228-1.html
9 Mar 2005 ~ 3:46pm Omega65 Shades of Tesla and the Philadelphia Experiment....
9 Mar 2005 ~ 8:27pm gcl another way for the police to abuse their power!
9 Mar 2005 ~ 8:31pm Thrax Yeah, those microscopic police are a bitch.