Another point about Bjarne's measurement:
I do hope that when he publishes his scientific paper on the measurement of g in a 30 story building at each story in a peer reviewed journal, that he includes the gravitational influence of the other buildings in the city.
It turns out that he is not actually going to measure g.
He is gong to measure the acceleration due to the
building's acceleration due to gravity according to his "
evidence" web page.
The English is bad but it looks like he expects this quantity (call it g
b) will be constant above the building's center of gravity and g
b will decrease below the center of gravity. Of course this means that the building will have a non-zero g
b at its center of gravity.
The defect in this is easy to see - the top of the building will have a net acceleration into the sky!
Turn the building into an equivalent situation - a satellite in an orbit around the Earth (Bjarne may require it to be geosynchronous). That satellite will then vanish into the Solar System. Someone should tell NASA that they are losing the International Space Station!
Or another equivalent situation - move the same building so that it is in space sitting on a small asteroid. That building will then lift off and vanish into the cosmos.
In this
post, Bjarne states "We have one gravimeter in Denmark that can measure 5/1.000.000.000 of “g” – This should be OK. It’s possible to pay for getting a job done.". I have my doubts that this will be able to detect g
b from the much smaller mass of a buidling, assuming that Bjarne can separate out this from g (from the Earth) and the forces form other sources such as other buildings.
I have probably got the math wrong but 5/1,000,000,000 of g looks like the equivalent g from a rock with the Earth's density with a radius of 15.8 kilometers. That is a fairly large buidling.