A universal gravitational constant can not be measure by any means available to the general public

The mass of the walls in buildings and the observer's body is ignored in experiments that try to measure it on earth

Experiments in outer space can not be performed by the general public

Local gravitational constants can be measured by dropping a ball and filming it

Most astronomy is fake

This does not mean the world is flat or round

I am simply talking about what you can and can not know