History
Measurement has been important ever since man settled from his nomadic lifestyle and started using building materials; occupying land and trading with his neighbours. As society has become more technologically oriented much higher accuracies of measurement are required in an increasingly diverse set of fields, from micro-electronics to interplanetary ranging.
One of the oldest units of length measurement used in the ancient world was the 'cubit' which was the length of the arm from the tip of the finger to the elbow. This could then be subdivided into shorter units like the foot, hand (which at 4 inches is still used today for expressing the height of horses) or finger, or added together to make longer units like the stride. The cubit could vary considerably due to the different sizes of people.
After Albert Einstein's Special Relativity, length can no longer be thought of being constant in all reference frames. Thus a ruler that is one meter long in one frame of reference will not be one meter long in a reference frame that is travelling at a velocity relative to the first frame. This means length of an object is variable depending on the observer.
Read more about this topic: Length
Famous quotes containing the word history:
“A great proportion of the inhabitants of the Cape are always thus abroad about their teaming on some ocean highway or other, and the history of one of their ordinary trips would cast the Argonautic expedition into the shade.”
—Henry David Thoreau (1817–1862)
“The history of his present majesty, is a history of unremitting injuries and usurpations ... all of which have in direct object the establishment of an absolute tyranny over these states. To prove this, let facts be submitted to a candid world, for the truth of which we pledge a faith yet unsullied by falsehood.”
—Thomas Jefferson (1743–1826)
“Don’t you realize that this is a new empire? Why, folks, there’s never been anything like this since creation. Creation, huh, that took six days, this was done in one. History made in an hour. Why it’s a miracle out of the Old Testament!”
—Howard Estabrook (1884–1978)