• Question: I am confused, if light is reflected and that white is made up of the main 'rainbow colours' so the primary ones make secondary colours like magenta cyan etc. but does that then mean that everything is actually white?

    Asked by ALOrona to John, Laura, Luke, Rob, Ruth on 16 Jun 2016.
    • Photo: John Fossey

      John Fossey answered on 16 Jun 2016:

      No a rainbow is actually all colours.
      Absorption, reflection and refraction are not the same.

      Take all the colours of paint you can and mix them together you’ll end up with black – something that absorbs all wavelengths.

      thinks about a leaf – it looks green, but this means that when white light hits it all the colours accept green are absorbed, only green light is reflected, the other light is used in photsynthesis

    • Photo: Laura Finney

      Laura Finney answered on 16 Jun 2016:

      Different things of different colours absorb different wavelengths of light. So if it absorbs everything but reflects green then it looks green to you. The same with red, if it reflects red but absobs all the rest, the red light reaches your eye and so you see it as red.

      The reason a rainbow looks all colours is because the light refracts from water and is split into all the different colours, meaning that at different points, and different refraction angles front he water, a different colour is reflected and so that is what you see – different colours at slightly different position.

      Something that is white reflects all of the colours and so has no colour i.e. is white.
      But black reflects no colours, i.e. it absorbs them all and like in paint if you mix all the colours you end up with something very dark and black.

      Does that make more sense?

    • Photo: Luke Williams

      Luke Williams answered on 17 Jun 2016:

      John and Laura have it spot on – but as I keep putting the mantis shrimp everywhere in questions, and it actually has relevance here, I shall sneak it into this question as well.

      http://theoatmeal.com/comics/mantis_shrimp

      The point I am trying to make is that we can only see what we see because of our natural abilities – i.e. how good our eyes actually are at seeing colour. There are other organisms which can see colour in a completely different manner.

Comments