A colour that’s truly in the pink

QUESTION I recently saw a headline claiming that the colour pink does not exist. If not, why can I see it? In PHYSICS, a colour is visible light with a specific wavelength. Light is made of particles called photons and each photon has its own wavelength which the eye perceives as colour.

It is widely accepted that black and white are not colours because they don’t have specific wavelengths — white is the reflection of all colours and black is the reflection of none (or black is nothing) — while what we do have in the visible light spectrum is the old rainbow mnemonic ROYGBIV.

The light we see zips in at about 400 million, million times per second depending on the colour. R (red) is slowest, while at the other end V (violet) is the quickest, as far as it can get from red. Pink happens when red and violet get together, yet they don’t get together.

Pink doesn’t have a particular frequency, as shown by Robert Krulwich in a 63-second online video by Minute Physics: ‘There is no pink light. There is no such thing as a band of wavelengths that mix red and violet. Hence it doesn’t exist.’

This is misleading and many experts refute it. Jill Morton, former professor at the University of Hawaii, explains that because pink isn’t part of the light spectrum, ‘it’s an extra-spectral colour, and has to be mixed to generate it’.

In an online post Stop This Absurd War On The Colour Pink, U.S. scientific blogger Michael Moyer points to research that indicates all colour, whether in the rainbow or not, is a fabrication of our brains. ‘Pink is real’, he concludes, ‘or it is not — but it is just as real or notreal as red, orange, yellow, green, blue and violet.’

Emilie Lamplough, Trowbridge, Wiltshire.

QUESTION Do fungi have any commercial use other than as food? FURTHeR to the earlier answer, the pulp and paper industry benefits from the enzyme production capabilities of certain fungi (mainly ascomycetes and basidiomycetes) to soften wood fibres and provide an ecologically sound alternative to chemical bleaching.

Pete Dunn, Exeter.