Interview By Nicola Davis The Observer
So how can we make objects seem almost invisible?
You need to have a material that bends light around an object. All transparent materials bend light. You can do that in a clever way so that the lightwaves that go around an object then go straight again so you are guiding light around the object as if the object isn't there. This is possible to do in principle, but in practice it's difficult to create these materials. So far it only works for very small objects.
o how can we make objects seem almost invisible?
You need to have a material that bends light around an object. All transparent materials bend light. You can do that in a clever way so that the lightwaves that go around an object then go straight again so you are guiding light around the object as if the object isn't there. This is possible to do in principle, but in practice it's difficult to create these materials. So far it only works for very small objects.
How will Tower Infinity achieve invisibility?
This is a much simpler idea and an idea that is used by nature in many examples - it is camouflage. What happens is they record the image of the background scenery with detectors and then have light-emitting diodes on the other side that project that image onto the skyscraper.
What's the advantage of the light-bending approach?
There is something those devices could do that the skyscraper cannot do, and that is to really transmit a stereo-image. If you record the background scenery then you would lose the sense of depth and so if you look very carefully at the invisible skyscraper you would essentially just see the picture on the wall. If you were to look from the side or so, you would notice that it's just a picture.
There are also fish in the ocean that hide from predators coming from the depths. If you look from the depths, normally you would see the black shapes of the fish against the light coming from the sky. These fish have sensors on their backs and bioluminescent bacteria in their bellies and switch these bacteria on to give the same amount of light that the fish receive on their back. So they become invisible. They are no longer black, they are as light and blue as the sky looks from the deep.
Source: theguardian
