• Question: why is the grass green?

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      Asked by Holly to Angus, Catherine, Jenni, Melissa, Waqar on 21 Jun 2016.
      • Photo: Angus Cook

        Angus Cook answered on 21 Jun 2016:

        Grass (and other green plants) get their colour from something called ‘chlorophyll’. It’s a special molecule that helps absorb sunlight, and turn it into energy that the plant can use (it also needs carbon dioxide and water for this to work).

        Interestingly, it’s green because that’s the bit of sunlight that it doesn’t use. Sunlight is made up of a whole load of colours (think of a rainbow, actually see if you can find the rainbow question someone else asked on here…). The chlorophyll takes in lots of the red and blue bits of the light, but it doesn’t take in the green bit, so it reflects that back out, and that’s the light that we can see. This is why we think it’s green.

      • Photo: Melissa Ladyman

        Melissa Ladyman answered on 23 Jun 2016:

        Great answer Angus. It’s the same with everything that we look at. Remember that white light is made up of a rainbow of colours- just like you see when you shine light on a prism, or when the sun comes out after rain (it’s called a spectrum). We see colours because that’s the bit of the spectrum of light that is reflected.

        But, have you ever wondered if the ‘green’ that you see is the same as the ‘green’ that I see? How would we ever know if green looked different to each of us?

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