Laws are simply observations of phenomena. Gravity is very easily proven. The theories behind WHY it happens, when/where it applies, etc. are not “proven”
If every piece of matter in the universe doesn't obey it consistently 100% it's a pretty lousy law. The devil's always in the details! That's why we have magic stuff like dark matter.
... probably impossible to ever actually observe first hand.
Exactly. That's why the words "prove" and "law" are just not very helpful. As if the universe obeys the slight electrical impulses in a few groups of atoms on one random planet.
It's impossible to say that anything will apply to every "piece of matter". The best we can do is define patterns in what we can observe. Many theories involve phenomena that are...
Most science is not based on observation but on false assumptions and people who believe in books more than in their own ability to think logical. Modern science creates sheeps.
I'm genuinely not sure if you are being satirical or not.
