"Light is measured in candelas. Sound in decibels. If you’re running a pneumatic drill, chances are you’re generating 80 decibels of ear-piercing noise."
"But ask a scientist how bad the pig farm down the road smells, and you’ll probably get a quizzical look and a vague answer. When it comes down to odor, the nose knows when something stinks, but there’s no olfactory equivalent to decibels."