Perfect measurements are limited to counting. The number of people in your office can be measured exactly. Your weight cannot. There is always another decimal point of accuracy.
You might argue, “What if the scale says my weight is exactly 150 pounds and it really is?” Yes, I’d counter, it could happen, but there's no way for you to know if it did happen because there are no perfect scales.
Measurement precision is the root of chaos, the reason that predictions of nonlinear systems like weather, economies, the result of climbing sea levels, the final position of a gas molecule after escaping a popped balloon, even consciousness itself, are one step beyond predictable.
Click to read the rest of this article on Test and Measurement World.