Is there any evidence that the gravitational constant is static?
How do we know the gravitational constant does not change with time? For example, it is adjusted by a powerful intelligent being (i.e. God) with a slower clock rate than us, in accordance with his will? Or maybe it just fluctuates for various reasons. This would throw the age estimate of the universe out the window.
Re: Is there any evidence that the gravitational constant is static?
There is no reason to think such a thing even exists. Interestingly there is reason to think the speed of light changes over time from data earlier last century. This would contradict mainstream theories, so perhaps that was why they redefined a meter in terms of how far light travels in a certain fraction of a second, so it is not possible to notice variations of speed.
By inductive reasoning. One may question inductive reasoning like in the problem of induction. The answer is either to accept it axiomatically or to say that God is one which implies that God is consistent which implies that inductive reasoning generally works.