Empirical evidence is gathered from experiments when you do research. You might notice in chemistry or mathematics, that some correlation have empirical constants already. They have already established these values through experiments and approved by the scientists. Examples of empirical values are the Avogadro's number which is 6.022 x 10^23 particles/mole and the speed of light which is around 300 million m/s.
<span>The Royal Road decreased the travel time between Persepolis and Anatolia [Turkey} from months to days, making transportation easier and faster.</span>
