“When you can measure what you are speaking about, and express it in numbers, you know something about it. When you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science.” Lord Kelvin
The measurement that Lord Kelvin refers to requires the presence of something stable. You cannot measure length with a rubber band because its own length is not stable. In the same manner, you cannot measure value with a value that is not stable – i.e. you cannot measure the value of real money, Gold, with paper pseudo money.
From where is Gold’s stability of value derived? From HERE.
When you see a graph of the dollar price of Gold, you will be misled if you fail to realize which it is that is really being measured.
According to Monetary Metals, the current price of the dollar is 17.4 milligrams