Uniformity principle (E.P. Hubble):
The principle that the laws of physics here & now are not distinct, at least qualitatively, from the laws of physics in previous or future epochs of time, or elsewhere into the Universe. This principle was scoffed at through the ancients who supposed that the laws that governed the Earth & those that governed the heavens were totally divorced; now it is utilized routinely in cosmology to define the structure & evolution of the Universe.