Have you ever been asked for your height in centimeters, your weight in kilograms, or
the speed limit in kilometers per hour? These measurements may seem a bit odd to
those folks who are used to feet, pounds, and miles per hour, but the truth is that scientists
sneer at feet, pounds, and miles. Because scientists around the globe constantly communicate
numbers to each other,they prefer a highly systematic, standardized system. The International System of Units, abbreviated SI from the French term Système International, is the unit system of choice in the scientific community.
In this chapter, you find that the SI system offers a very logical and well-organized set of
units. Scientists, despite what many of their hairstyles may imply, love logic and order, so SI
is their system of choice.
As you work with SI units, try to develop a good sense for how big or small the various units
are. That way, as you’re doing problems, you’ll have a sense for whether your answer is