Size

### Size - Names, Numbers, Signs

The hand leads to things about location, size and number. Fingers point but they also help to count. The distance between two joints of a finger is a useful length. Words name lengths by using parts of a finger - or a hand, or an arm. A portion of food could be the amount a hand can grasp.

Inch*, centimeter, yard**, and pint, describe how big some things may be. A few started as parts of the human body.

Human tools include things hands hold, eyes look through, but also signs and symbols, marks showing thought. Lenses make stars and bacteria visible. The distances of stars and size of bacteria led to a new way to write numbers. That way is called scientific notation***.
*The word inch describes a length. When two lines are an inch apart they are about as far from one another as the first and second joints on a forefinger. That same spacing is about 2.54 centimeters.

**An encyclopedia entry for yard also mentions cubit, and older measure based on parts of the body: Yard and Other Lengths. The Egyptians measured a cubit as the length of arm from elbow to outstretched finger tips. The meter is similar to a yard in size. It is based on how light travels in a vacuum: one meter takes 1/299792458th (nearly 1/300000000th) of a second.

***Exercises and explanations are at Math & Physics, Practice Converting, and Encyclopedia Entry.

A word for a thousand million, billion, related symbols for those and other size words, as well as language for very large and extremely small numbers, follows below. This table gives scientific notations for sizes technology has made meaningful.
 yotta [Y] 1 000 000 000 000 000 000 000 000 = 1024 zetta [Z] 1 000 000 000 000 000 000 000 = 1021 exa [E] 1 000 000 000 000 000 000 = 1018 (a quintillion) peta [P] 1 000 000 000 000 000 = 1015 tera [T] 1 000 000 000 000 = 1012 giga [G] 1 000 000 000 = 109 (a thousand millions = a billion) mega [M] 1 000 000 = 106 (a million) kilo [k] 1 000 = 103 (a thousand) hecto [h] 100 (a hundred) deca [da] 10 (ten) deci [d] 0.1 (a tenth) centi [c] 0.01 (a hundredth) milli [m] 0.001 (a thousandth) micro [&mu] 0.000001 (a millionth) nano [n] 0.000 000 001 (a thousand millionth) pico [p] 0.000 000 000 001 = 10-12 femto [f] 0.000 000 000 000 001 = 10-15 atto [a] 0.000 000 000 000 000 001 = 10-18 zepto [z] 0.000 000 000 000 000 000 001 = 10-21 yocto [y] 0.000 000 000 000 000 000 000 001 = 10-24

Go beyond the names and definitions of numbers by continuing at Large Numbers.
Look at number words visually by continuing at Prefixes. Thorough information of this sort also appears at Rowlett and Conventions.
 29 July 2007 Version http://www.cs.ucla.edu/~klinger/sizE.html ©2007 Allen Klinger