Science News

Cloaking device developed, for fish

Thu, 13th Jun 2013

Dave Ansell, Dominic Ford

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The dream of invisibility goes back to at least the Greeks whose god of the underworld, Hades is supposed to have had a helmet of invisibility.

But this week scientists at the Nanyan Technological University in Singapore, unveiled a video of a goldfish and cat disappearing and reappearing behind a new ‘invisibility cloak’ they’d developed. If you haven’t seen it yet you can find a link to the video below but in the meantime here’s the Quickfire Science...

At the moment objects like tanks can only be disguised, using cameras to project the view behind the tank onto screens covering the other side. This was seen on a car in the James Bond movie, Die Another Day.

However this technology only works from one perspective – the angle the camera is facing – so if you spotted the tank from a different angle, it would distort the illusion.

But in 2006, British Researcher Sir John Pendry came up with a way of bending light around an object to create a ‘cloak’, which would make it invisible to the naked eye.

However when light waves are bent around an object they have to travel further than the light unaffected by the cloak. This means the bent light arrives slightly later than it should so the image isn’t perfect.

To correct this, the bent light waves have to appear to move faster than the unaffected light travelling in air, which is impossible with natural materials.

Cloaks like this have been built successfully with artificial ‘metamaterials’, made with carefully designed structures smaller than the wavelength of light. But they’ve only been able to hide objects from view in microwaves rather than visible light.

To disguise large objects in visible light, the team in Singapore decided to see how well they could manage with conventional materials, not worrying about whether the light was delayed.

They used prisms of glass in a hexagon or square which refract the light through one another around the object – so even if your pet moves inside the prisms it looks like it has disappeared!

This can still only be seen from a maximum of six angles but the hope is that they will be able to increase this by changing the layout of the prisms.

They have managed to hide goldfish and even a cat in a real life environment and hope it could be used for both surveillance and entertainment.



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I haven't read the link above as it's taking ten minutes to load a page at the moment due to my slow net connection. What you really want for invisibility is a covering with lots of spherical pits in it acting as pinhole camera/projecters. If the covering is rigid, the equivalent of a retina in each pit would detect light and be able to pass it through to a single pixel in a single pit elsewhere through an unchanging link, and that pixel would then emit as much light of the same colours as hit the original. The more pits used, the better the illusion (or un-illusion, in that you wouldn't see it). At a distance, one centimetre might be sufficient pit resolution, and a person could probably be covered adequately with a couple of square metres, so 20,000 pits be required with perhaps a similar number of pixels each. That would require 400 million connections between pixels, although the wiring could obviously be simplified by timesharing the wires. It strikes me that this should really be quite a trivial thing to build these days. David Cooper, Fri, 14th Jun 2013

Yes the invisibility cloaks are actual and real, ( though they do not make people or objects disappear, they bend light ) and they are being used, and developed further, by Defense Research and Development Canada, one of the companies involved with the program, Hyperstealth Biotechnology Corp., the U.K. and the U.S. as far as the owner of the textiles company has commented on.
It's amazing technology, which the company has termed 'Quantum Stealth'.  Following it in some detail again a few weeks ago, as it was at least back in 2004 and up to and including/ongoing a few years ago it was full on into R&D, well I read into it as much as I could find and as much as there is spoken out to the general public and media, ( without going right on down to the company, based out of an old school in a suburb in lower mainland British Columbia)
Hyperstealth Biotechnology Corp., has been designing the textiles for quite a number countries digital CADPAT, and deceptex transitional camouflages'.

Apparently there are a few methods of the quantum stealth technology, one being electrically circuited and operated, another with the materials in the fabric that bend light around it, other that 'cloak' in other wavelength spectrum's like infrared, thermal, night vision, micro-wave, gamma-wave, through out the spectrum's,  another with ( as mentioned ) billions of pix-elated continous digital photo/video and projection 'cells' (for the lack of the actual term), another using the mentioned "white rabbit" method of mathematical formulated digital pattern disruption algorithms in the textile fabric itself. ReignCzech, Sat, 15th Jun 2013

Well at least they have been fair, not at all one-sided.

I can just imagin the cat sat by the fish bowl.......

Don_1, Sat, 15th Jun 2013

You guys make it really hard to see the invisible cat when the dropbox is denied and this is my third attempt at a comment because the first two were denied and then was unable to 'Go Back'!! Just let me see the video. Please. amber, Tue, 18th Jun 2013

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