The principle is based on the unity of knowledge; measuring the same result by several different methods should lead to the same answer. For example, it should not matter whether one measures the distance between the Giza pyramid complex by laser rangefinding, by satellite imaging, or with a meter stick – in all three cases, the answer should be approximately the same. For the same reason, different dating methods in geochronology should concur, a result in chemistry should not contradict a result in geology, etc.