We humans love to keep track of things (and make lists). Without some type of system of measurement, we wouldn’t be able to conduct business, determine property rights, or perform a variety of everyday functions.

Simple tasks, such as buying items in bulk, which require a retail counter scale, would be impossible to accomplish without some way to measure them.

Our need to monitor and measure also extends to the natural world. How else would we be we able to describe what we are seeing and experiencing in nature? The following are three specific examples.

1. The Danjon Scale for lunar eclipse

If you ever need to describe the brightness of a lunar eclipse, the Danjon Scale will help you nail it down. Named for French astronomer Andre Louis Danjon, it sets the precise measure for the brightness of lunar eclipses. Its values range from L=0 (“very dark eclipse, moon almost invisible”) to L=4 (“very bright copper-red or orange eclipse”).

2. Mercalli earthquake intensity scale

Unlike the Richter Scale, the Mercalli Scale for measuring an earthquake focuses on the effects caused by the event, as opposed to the amount of energy the earthquake releases. With this type of measurement, a I magnitude earthquake may only be noticed by a few people. As the scale moves higher, the level of damage is magnified.

A Level V earthquake will be quite noticeable and awaken many people from sleep. It will break some dishes and windows and may even overturn unstable objects. As the scale increases to the higher numbers (Levels VII-VIII), furniture will be broken and buildings will sustain considerable structural damage.

At Level XI, few structures will be left standing and bridges will be destroyed. Level XII represents total damage under this system of measurement (and there probably wouldn’t be anyone left to record it at that point).

3. Australian tropical cyclone categories

Australian tropical cyclones are measured in categories ranging from 1-5. A Category 1 cyclone produces wind gusts of less than 125 km/h, which will not cause major damage to homes. It could cause some damage to trees and crops.

Mid-category cyclones (2-3) produce winds ranging between 125-225 km/h. At their highest intensity, they may create some roof damage. These levels of storm would also cause power failures.

A category 4 cyclone produces wind gusts of up to 280 km/h, which have the power to cause significant damage. Flying debris would present a serious danger to anyone in its wake, and the storm would trigger widespread power outages.

At the category 5 level, wind gusts of more than 280 km/h may occur. Widespread destruction is likely in this extremely dangerous situation.


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