Logarithms abound in nature, and nowhere more so than in the human senses. I was boggled the other day to discover that the human eye has a sensitivity to light of around 1,000,000 : 1. This means that we can see things that are a million times brighter than something else. And it does this instantly and automatically, making it way better than most cameras out there. Never mind that with around 130,000,000 individual sensor cells they beat out my 12MP Nikon by a fair shot.
It reminds me of human hearing. You might have heard that humans can hear things from 20Hz to 20KHz, in relation to frequency. What is kind of insane is that a doubling of frequency is about the same as an octave of a keyboard. This means that the human ear can hear a whopping eleven octaves. Sensitivity to loudness is even crazier – a rise of 6dB is equivalent to about a doubling of sound, which means that a doubling from 30dB to 60dB is the difference between a whisper and a conversation, but a doubling from 60dB to 120dB means your ears will start to bleed.
Isn’t the human body awesomely bizarre?