Often times we find a very specific theory, law or observation generalised. For instance, Heisenberg's uncertainty principle was about detecting an electron using a photon, however, it was then generalised to be a true property of particles no matter what you use to identify their positions or momenta, not just when detecting electrons with photons. How are those leaps made? What kind of evidence is enough to show that something is an inherent property of nature, such as conservation of energy or charge for instance. I know these phenomena have a ton of evidence to support them, but when they were first proposed to be inherent traits of nature, what kind of evidence does one have to produce to make such claim?