Why are rainbows upside down?

I thought it was from left to right

Rainbows were always like that

Yes, the mnemonic was always ROYGBIV (Richard Of York Gave Battle In Vain), but that's just an easy way to remember it - an actual rainbow has always had the red on the outside.

When you realise how a rainbow is formed, it SHOULD have the red on the outside.
Light is slowed when it goes through something transparent or semi-transparent like glass or water (or even air), it's only a constant in a vacuum - and different mediums affect the speed more, or less.
That's how a prism or lens works, by bending light as it goes through.
Red light has a longer wavelength, and travels slightly faster through a transparent medium than violet, so it doesn't get bent as much as violet.

Take a look at any photo of light through a prism, the violet is bent more.

Heck, even take a look at the cover of Pink Floyd's 'Dark Side of the Moon' album cover from the 70s.
The red is bent less, and is on the top.
Even further back...? - Check out John Constables painting 'Salisbury Cathedral on the Meadow', or 'Arctic Sunset with Rainbow' by William Bradford, both from the 1800s

Last Edited by Karlos on 05/19/2022 05:40 AM

Mandela effect

Nah! - Just flawed memory.

if the earth is flat, shouldn't rainbows also be flat?

Why are there no rainbows in cave drawings or ancient paintings.

Only if raindrops are flat...

They had the sense to get out of the rain...