Amanda Goram got me thinking about light yesterday and I came to this idea inspired by her poem especially where she exhorts us to be the light. I can’t praise her highly enough. We are so fortunate to have inspiring and accomplished people such as her representing us right now.

Not sure if this is a conjecture or just an art project but here goes: Most ‘light’ is ‘black’. When we examine the wave nature of light we find visible light is modelled successfully by a certain set of frequencies or wavelengths of electromagnetic wave from about 10^12 to 10^16 Hz (you’ll have to do the wavelength conversions yourself λν = c.) That’s a rough difference of about 10^4, or 10,000.

The rest of the spectrum frequencies are from 10^4 to 10^12 Hz and from 10^16 to 10^20 Hz. These parts of the spectrum are not visible electromagnetic radiation, they are ‘black’ or not perceptible to human eyes. Imagine a world where we could see the full electromagnetic spectrum; that’s a different thought experiment but a worthy one. These two parts of the EM spectrum represent differences of approximately 10^8 and 10^4 which together sum to about 100,010,000 or about a range of one hundred million Hertz for invisible light. That is four orders of magnitude greater than the difference of ten thousand Hertz we get for visible light.

This very coarse math shows that the vast majority of light (electromagnetic radiation) is beyond the ability of our eyes to perceive so “most light is black”. Is this just an artifact of our biology? Yes. You can see the EM spectrum represented visually, though as a logarithmic scale, here: