We can test everything. Aynthign and still not be 100% sure, we can be 99.9 percent sure. And then claim it's a law because we see no different.

But just because we soo no different doest mean there isnt. Scientific community sems to agree that nothing is %100.

We say things are law, but what if in a 99.9 percent probability that gravity is the was we've worked it out to be, isnt the way.
We can just speculate what little we know in this short lived civilization. Mabein a couple melenia. Right now gwe should concentrate on surviving for another couple hundreed years, forget a couple thousand or even 1 melenia.