They are ‘constant’ in the fact they facilitate global interactions. For me as an engineer that good enough to build stuff on. I leave the uncertainty to the quantum physicists.
Discussion
Same. Constant enough to be worth building on :Check:
Like with Bitcoin, those scientists could do with a little bit more "Verifying" and a little less "Trusting": https://www.sheldrake.org/essays/how-the-universal-gravitational-constant-varies
I generally work within the Newtonian Frame of Reference. Good enough for me.