LEGEND has it that there’s a pot of gold at the end of every rainbow.
But you’d need more than the luck of the Irish to find it – and not just because you can only see the colours from a distance.
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The rainbow we see is a semi-circle but that is not the full pictureCredit: Getty Images
It turns out that the arched semi-circle of a perfect rainbow is not the whole thing – and they’re actually CIRCULAR.
So what we are seeing is only half the story, and this is why.
Rainbows are caused by sunlight being refracted, or split into different colours, as it gets reflected by raindrops.
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Rainbows are not an arch but a full circle, if seen from the airCredit: Alamy
When we are on the ground, we can only see the light that bounces back above the horizon, which seems to form a perfect arch.
The other half of the rainbow is hidden, unless you are up in the air, and together they make a full circle.
So if you are lucky enough to be flying or even climbing a mountain when a rainbow occurs, you should see the full circle.
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An aeroplane is framed by a circular rainbow in AlaskaCredit: Getty Images
Since a circle has no end, this means there is no such thing as the end of a rainbow.
Another reason you can’t reach the end of a rainbow is that they move with you.
This is because the refracted light is always the same distance and angle – 42 degrees – from you when you see it.
If you travel a mile towards it, you may think you are seeing the same rainbow but you are actually seeing the light reflected on droplets a mile past the initial rainbow.
All of which means that the rainbow is nature’s ultimate optical illusion.
Categories: Optical Illusion
Source: HIS Education