That's a good definition, but you should include duration as well as position.
Thanks. Duration is the
measure of the change in position. Normally, we take step function positions, by default, rather than continuous functions. For example, while the sun's movement across the sky is continuous, we tend to measure discreet step functions, such as rise, noon and set. Before the advent of railroads, noon was defined as the time when the sun was directly overhead (or not rising or setting).
An often difficult concept to separate is a thing from a
measure or
source of a thing. For instance, lakes and rivers are
sources of water but they are not water. Temperature is a
measure of heat but it is not heat.
Another example from politics is income. Sales and wages are
source of income but they are not income, which is a gain. Inflation is defined as an increase in the money supply (relative to economic activity) but is
measured by a change in the price of a basket of goods. In the book,
End the Fed by Ron Paul, he analyzed business cycles and found people focus on the bust not not the cause of the boom.
The boom was often artifically created by inflation, an increase in the money supply. For instance, there was a movement in the housing market to lend to minorities on the grounds that they were discriminated against. This caused the boom. When the individuals with bad credit acted as bad money managers, not paying their bills, it lead to the bust in the early part of this century. (I know this is deviating from the main topic but is still fascinating.)
