What is it that makes natural sunlight difficult to replicate with most artificial lights?

Question

What is it that makes natural sunlight difficult to replicate with most artificial lights?

In: Physics

Answer 1

The sun pumps out EM radiation with wavelengths all up and down the visible spectrum (and well beyond it, everything from radio waves with a wavelength measured in kilometers to gamma rays with a wavelength below 10 picometers). So when you see things illuminated by daylight, you are perceiving all possible wavelengths of light that it can reflect.

Artificial lights are of course much lower energy than the sun and emit light in a far narrower band of wavelengths, so when we use them, typically our surroundings will reflect relatively fewer wavelengths of light back to our eye.