• Question: Is it possible that there could be beings on this earth which have the ability to refrect light off of themselves, rendering the invisible to the human eye and any other technology that we have- so far- developed?

    Asked by blueyes to Chris, Dave, David, Fiona, Jack on 24 Jun 2013.
    • Photo: Dave Farmer

      Dave Farmer answered on 24 Jun 2013:


      Dear blueyes,

      Such beings that can reflect light exist… humans! This doesn’t make us invisible though. In fact, it is quite the opposite. The reason that we can be seen at all is because light reflects off us and into the eyes of the observer. To be invisible we would have to allow light to pass through us undisturbed. Currently, as far as I’m aware, there is no being on earth who can do this naturally.

      Invisibility by cleverly directing light around us might be possible by using metamaterials though. I encourage you to check out the discussion on this question:

      What are metamaterials exactly? Can a closed body (body should have separate inner and outer surface areas; imagine a

      Best wishes

      Dave

    • Photo: David Freeborn

      David Freeborn answered on 24 Jun 2013:


      Hi blueyes,

      As Dave says, reflecting light isn’t really the key to invisibility. No animals are really good at being invisible.

      The closest I know of are cuttlefish, a really amazing animal. They are able to make their upper surface look like the surface below them using bags of pigment in their skin, called chromatophores, which they can contract using their muscles, along with a series of reflecting plates.

      The result isn’t invisibility, but it is some pretty impressive camouflage! They also use the colours to communicate with other cuttlefish.

      And here’s a cool mimic-octopus:

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