Definition
A metric system of physical measurement that uses the centimeter as the unit of length, the gram as the unit of mass, and the second as the unit of time. All other units in this system, such as those for force and energy, are derived from these three base units.
Plain English
A way of measuring things using centimeters for length, grams for weight, and seconds for time. Every other measurement in the system is built from those three.
Context Anchor
Seen mainly in older aviation maintenance, engineering, or science material when units must be recognized or converted.
Derivation
The name simply lists the three base units the system is built on: centimeter (length), gram (mass), and second (time). It was developed in the 1800s as a standardized scientific measurement system before being largely replaced by the modern SI system, which uses meters and kilograms instead.
Why Pilots Care
Most modern aviation references use either SI units or U.S. customary units. Recognizing CGS helps when reading older technical material so the numbers are not misread or confused with other unit systems.
Intuition Check
Do not read Centimeter-Gram-Second as three separate measurements. It means a measurement system based on those three units.
Example Sentence 1
The older textbook expressed pressure values in the centimeter-gram-second system, so the student converted them before comparing them to the modern chart.
Example Sentence 2
A student comparing unit systems may see density listed in grams per cubic centimeter.