TWIL #042 - Pink Doesn't Exist
Pink has no wavelength. It isn't a colour in the electromagnetic spectrum - it's a construct your brain invents to reconcile two signals that don't logically fit together.
- #science
- #physics
- #perception
The visible light spectrum runs from about 380 nm (violet) to 700 nm (red). Every colour you see in a rainbow corresponds to a specific wavelength of light. Pink does not appear anywhere on this spectrum.
Red is at one end. Violet is at the other. In a physical sense, they are as far apart as colours can get - opposite ends of visible light, with no natural meeting point.
But your brain receives signals from three types of cone cells (roughly sensitive to short, medium, and long wavelengths). When red light hits your eye, your long-wavelength cones fire strongly and your short-wavelength cones barely respond. When you see violet, your short-wavelength cones fire and your long-wavelength cones have a secondary response.
When you're simultaneously stimulated by both red and violet light, your brain gets a contradictory signal - high activation at both ends, low in the middle. The spectrum loops around in your brain's colour model, and the colour it constructs to represent "both ends at once" is pink (or magenta, depending on the ratio). It's a colour your visual system generates to fill a conceptual gap that doesn't exist in physics.
This is also why pink can't be produced by a single-frequency LED or laser - it requires mixing. Screens produce pink by simultaneously firing red and blue pixels.
Pastel shades work similarly - they're what happens when you mix coloured light with white (all wavelengths at once), which is why pastels always look slightly washed out: they literally are. There is no single wavelength for baby blue or mint green.
Pink is real to your brain. It just doesn't exist in the universe.