Disparate Measures presents “six of the coolest scales” devised. Here are three of my favorites:
LAB BIOSAFETY LEVELS
What it measures: Biolab protocols
How it works: Each of the four levels spells out procedures based on the infectiousness of the germs present. BSL-1 covers high school lab rules like hand-washing and no eating. BSL-4, reserved for nasty airborne agents like Ebola, means air locks and X Files-grade hazard suits.
MOHS HARDNESS SCALE
What it measures: Strength of a mineral
How it works: Developed in 1812, Friedrich Mohs’ method rates hardness by staging catfights between minerals, from talc (1) to diamond (10). A rock ranks higher than substances it can scratch and lower than ones that can scratch it. As for real catfights, a finger-nail has a hardness of about 2.5.
TORINO IMPACT HAZARD SCALE
What it measures: Asteroid impact risk
How it works: Named after the Italian city where eggheads ratified it in 1999, a Torino score gauges the odds that a near-Earth object will hit us and the damage it would cause. A space rock that rates a 10 – paging Michael Bay – comes around only once every 100 millennia or so.