Certainly, rainbows occur quite often but the scale of rainbows in Bude on Tuesday had photographers snapping and people stopping in the streets to capture images. Somehow, even if there is no pot of gold at the end, they cheer us up!
The National Geographic tells us how they are an optical illusion; it’s all about refraction and reflection of light:
The most familiar type rainbow is produced when sunlight strikes raindrops in front of a viewer at a precise angle (42 degrees). Rainbows can also be viewed around fog, sea spray, or waterfalls.A rainbow is an optical illusion—it does not actually exist in a specific spot in the sky. The appearance of a rainbow depends on where you’re standing and where the sun (or other source of light) is shining.