[Dixieme]

I read a mighty interesting article today how some scientists managed to ‘trap’ a rainbow. In short, this is what they did:

‘They etched grooves into a tiny piece of silver, each groove slightly deeper than the last. They then shone light over the surface, letting some of it interact with the plasmons on the silver. They found that the grooves trapped different wavelengths of light from 500-700 nanometers.’

Whoa… can you just imagine you get to have some rainbow creator in your garden or living room WANT!


Link: http://io9.com/#!578...inbow-in-a-cage

[coastie65]

I'm wondering if that is productive or just another example of somebody with too much time on their hands. Pretty neat though.

[mjd420nova]

Most probably a scientist trying out some way of capturing wavelengths of light. Might have been laser research or even microwaves. This certainly gives me something to think about along the lines of adaptive optics. If the depth of the grooves could be manipulated in the NANO sense, it might be used to "cloak" an aircraft. Much like radar that relies upon the reflectived signals, manipulation of a panel to capture light waves could be changed to absorb certain wavelengths of light and prevent their reflection back to their source.

[coastie65]

mjd420nova, on 19 April 2011 - 07:52 PM, said:

Most probably a scientist trying out some way of capturing wavelengths of light. Might have been laser research or even microwaves. This certainly gives me something to think about along the lines of adaptive optics. If the depth of the grooves could be manipulated in the NANO sense, it might be used to "cloak" an aircraft. Much like radar that relies upon the reflectived signals, manipulation of a panel to capture light waves could be changed to absorb certain wavelengths of light and prevent their reflection back to their source.

That is why they used to drop all the shredded tin foil ( chaff ), to mess up the radar return ( an it did ). There was some government facility outside of Hertford, N.C. that was messing with that stuff. When they were done, my Grandmother had shredded tin foil all over the place on her farm ( she was about 20 Miles or so from the facility, which is still there ).

[mjd420nova]

Rope, chaff and window is the terms used for the passive type of jamming radar. Strips of foil cut to dimensions that coincide with the frequency of the radar they are trying to jam. Today, active type jamming is employed that can cause all sorts of malfunctions in radars and infra-red seeker heads on missles and rockets. Stealth is the process of preventing radar signals from being bounced back to the sending radar but a network of recievers with only one transmitting unit defeats that type of stealth. Radar absorbing materials have become the new cutting edge, preventing any signal from being reflected at all. The "cloaking" technology is only applicable to visual type of detection by routing light in the background around an object and presenting it in the foreground. Active jamming can cause offensive weapons to lose their return signals, changing the return signals in a way that would make the weapons overshoot a target or undershoot or even turn to a different heading. Unforunately, todays weapons can be programmed to lock unto the signal source, regardless of its effect it may have on a reflected signal. This was pretty effective in Viet Nam and is still used today, especially with the new drones that can linger in a target area for over twelve hours, just waiting for that radar signal to come back on the air and then attack. For every method of evasion there is a counter-measure. Development is striving to stay ahead of the newest defenses with new offensive detection methods.

[coastie65]

Yep. That was a long time ago when they were testing that stuff. As I said, that place is still there and is some kind of government testing / research site. During WWII it was a Navy Seaplane base that they used for ASW. I remember going out there once when I was real young and the place had been closed. The buildings had either fallen or were falling down and grass was growing up through the tarmac. The last time I was out there ( after I had left the service ), they had a gate and armed guards, so sightseeing was not an option. I have checked out the satelitte pics of the place though ( Harvey's Point east of Hertford, N.C. ).