Space measurement {length measurement} {distance measurement} uses distance units. The MKS system has a fundamental length unit {meter, length} (m). Derived length units include 10^-2 meters {centimeter}, 10^-6 meters {micron}, and 10^-10 meters {Angstrom}.
English measure
0.001 inches (mil) measures wire diameter. 2.54 centimeters {inch} (in). 39.37 inch = 1 meter. 0.66 feet {li, length unit}. 3 inches {palm, length}. 4 inches {hand}. 7 to 9 inches {span}. 12 inches {foot, length} (ft). {board foot}. 18 inches to 22 inches {cubit}. 2.5 feet {pace, length}. 3 feet {yard, length} (yd). 6 feet {fathom}. 16.5 feet {rod, measure}. 100 links or 66 feet {chain, length} {Gunter's chain} {surveyor's chain}. 100 feet or 100 links {chain} {engineer's chain}. 625 Greek feet or 0.1196 mile {stade}. 220 yards {furlong}. 5280 ft, 1760 yards, 8 furlongs, or 1.609 kilometers {mile} {statute mile}. 1 arc-minute on great circle of sphere with area equal to Earth area is 6080 feet {nautical mile}. 1 arc-minute at equator is 6087 feet {geographic mile}. 3 miles, or 2.4 to 4.6 miles {league}.
railroad
Railroad track {railroad measurement} has width {standard gauge} {narrow gauge} {HO guage}.
wire gauge
Wires have diameters {wire gauge}, such as American or Brown and Sharpe system.
minimum
By quantum mechanics, minimum length is Planck length, 1.6 * 10^-35 meters, where length becomes quantized.
maximum
Maximum length is circumference of universe, 10^30 meters.
Length, in meters, divided by time, in seconds {meters/second}, is velocity {speed measurement}. In English measure, velocity is miles per hour (mph) or nautical miles per hour {knot, speed}. Velocity divided by time, in seconds {meters/second squared}, is acceleration. Earth-gravity acceleration is 9.8 m/s^2. Car acceleration is 3 m/s^2 or 1/3 gravity.
Surface measurement {area measurement} is length squared or square meters (m^2). Area measure can be 1000 m^2 {hectare}, which is 2.5 acres. In English measure, area can be 10 square chains, 160 square rods, or 0.4047 hectare {acre} or can be 36 square miles {township}. 640 acres equals 1 square mile. For cross-sections {cross-sectional area}, 1 barn is 10^-28 cm^2.
Space measurement {volume measurement} depends on length measurement. Length cubed is in cubic meters. Volume measure is 1000 cm^3 or 0.001 m^3 {liter} (L).
English measure
1/360 fluid ounce {minim}. 1/6 fluid ounce {teaspoon} (tsp). 3 teaspoons {tablespoon} (tbsp). 2 tbsp {fluid ounce} (fl oz). 1 1/2 fl oz {jigger}. 0.25 pint or 4 fluid ounces {gill, volume}. 8 fluid ounces {cup}. 2 cups or 16 fluid ounces {pint}. 1/16 peck {dry pint}. 2 pints or 1.1 liter {quart, volume}. 1/8 peck {dry quart}. 4 quarts {gallon}. gallon slightly larger than regular gallon {Imperial gallon}. {stere}. 0.25 bushel {peck}. 0.3524 hektaliter {bushel}. 1/4 barrel or 9 gallons {firkin}. 31.5 gallon {barrel, volume unit}. {demijohn}. 2 barrels {hogshead}. 3000 ml or four-fifths gallon {double-magnum} {jeroboam}, for wine. two-wine-bottle or 1500 ml {magnum, champagne}. {split}. {trencher}. 128 ft^3 {cord, volume}. hay {bale}.
Two intersecting lines have opening amount {angle measurement} at intersection. If lines are the same, angle between them is 0 degrees, and angle around them is 360 degrees, two times pi radians. If lines are parallel and meet at center, angle between them is 180 degrees, pi radians. If lines are perpendicular, angle between them is 90 degrees, pi/2 radians. Angle measure can use larger unit {rhumb}, which is 11.25 degrees, 1/16 of reverse turn, or one point on mariner's compass.
Metal wires have diameters {gauge, measurement}. Smaller numbers are larger diameters.
Aperture size {opening measurement}, as for camera lens, has units {f number} {f stop}. f stops are numbers 2 for wide open, 2.8, 4, 5.6, 8, 11, 16, 22, and 32 for almost closed.
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225