omikeye fatunmb Posted February 1, 2009 Share Posted February 1, 2009 there is a promising new development involving invisibility using an exotic new material called "metamaterial", which may one day render an object truly invisible. ironically, the creation of metamaterials was once thought to be impossible because they violated the laws of optics. but in 2006 researchers at duke university in durham, north carolina, and imperial college in london successfully defied conventional wisdom and used metamaterials to make an object invisible to microwave radiation. although there are still many hurdles to overcome, for the first time in history we now have a blueprint to render ordinary objects invisible. (the pentagons defense advanced research projects agency [DARPA] funded this research.) Link to comment Share on other sites More sharing options...
Xittenn Posted February 2, 2009 Share Posted February 2, 2009 http://science.howstuffworks.com/invisible-tank.htm not quite................................ Link to comment Share on other sites More sharing options...
cameron marical Posted February 2, 2009 Share Posted February 2, 2009 really? thats pretty cool. what is this metamaterial made of? do you know? Link to comment Share on other sites More sharing options...
Xittenn Posted February 2, 2009 Share Posted February 2, 2009 really? thats pretty cool. what is this metamaterial made of? do you know? If you read the article in the link I provided you will know................ Link to comment Share on other sites More sharing options...
cameron marical Posted February 2, 2009 Share Posted February 2, 2009 ohh.:doh:my bad Link to comment Share on other sites More sharing options...
astrosteve Posted February 9, 2009 Share Posted February 9, 2009 The trick currently used with the invisible tanks is different to the technique that would be exploited using the "invisibility cloak" type approach mentioned. Invisible tanks use a projection system to project the view from one side of the tank on to the other side, so that an observer thinks they are just seeing the normal view. The new materials being developed at Imperial actually channel light around an object. This is alluded to in the bottom of the article you mention buttercup, but the article does not state what the metamaterial is made of - I haven't seen any papers on this metamaterial myself but they exist and may mention how the metamaterial is formed. Link to comment Share on other sites More sharing options...
Klaynos Posted February 9, 2009 Share Posted February 9, 2009 Can you provide a citation for when anyone thought metamaterials where thought to be impossible? I ask this as an active researcher in metamaterials. Link to comment Share on other sites More sharing options...
Xittenn Posted February 10, 2009 Share Posted February 10, 2009 The trick currently used with the invisible tanks is different to the technique that would be exploited using the "invisibility cloak" type approach mentioned. Invisible tanks use a projection system to project the view from one side of the tank on to the other side, so that an observer thinks they are just seeing the normal view. The new materials being developed at Imperial actually channel light around an object. This is alluded to in the bottom of the article you mention buttercup, but the article does not state what the metamaterial is made of - I haven't seen any papers on this metamaterial myself but they exist and may mention how the metamaterial is formed. Cool! I just assumed he was talking about the tank as it's been in the media lately.....I'll have to take a boooo. Maybe Klaynos could let us in on some details. I feel silly I didn't actually read the article...........sorry CM! Link to comment Share on other sites More sharing options...
Klaynos Posted February 10, 2009 Share Posted February 10, 2009 Most of the work done in the area of transmission = 1 (invisible) has been done in the microwave regime, so I'll mostly talk about that, some work has been done in other areas though. And we must also make the comment that these devices are currently VERY narrow band. So you've a material, say aluminium, that you can structure in some way, drill holes etc. If these holes are subwavelength you can create phenomena called spoof surface plasmon modes, which look like surface plasmons but are not them. This results in the effective permittivity of the structure changing, this allows you to tune the response of the device, one of the interesting results of this being that you can tune the effective permittivity to give you a negative refractive index and waveguide the light around the centre of the device leaving an area in the middle that cannot be seen from the outside. Link to comment Share on other sites More sharing options...
Xittenn Posted February 12, 2009 Share Posted February 12, 2009 (edited) http://www.sciencemag.org/cgi/content/full/305/5685/847 Cool! So, if the effect is mostly being tested narrow band or in microwave range how is the effect being observed?? Narrow band visible I assume?? Does it look like a colour distortion?? Have you actually seen and/or tested the effect first hand?? Merged post follows: Consecutive posts mergedI always thought Narrow Band meant a select, small, portion of the entire EM spectrum.........good thing I double checked after the fact.........who needs blush! 'Still interested in how the phenomenon is being observed. Edited February 12, 2009 by buttacup Consecutive posts merged. Link to comment Share on other sites More sharing options...
Klaynos Posted February 12, 2009 Share Posted February 12, 2009 You observer it by doing spectroscopy on the sample... Link to comment Share on other sites More sharing options...
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