Utter nonsense and idle speculation.
I think it's time for a little sanity check. How did they make the Greenland bore-hole measurements? How did DTU measure gravity in Domus Vista for Bjarne?
Answer: They had some very sophisticated gravimeter instruments. And expensive.
Where did those instruments come from?
Answer: They were constructed, manufactured and sold.
Why would anyone construct, manufacture, not to mention buy, such strange and expensive instruments?
Answer: Because extensive research is going on, worldwide, on gravity anomalies.
Why are gravity anomalies so interesting?
Answer: Because they can tell us a lot of how Earth's crust is put together and help us find oil and precious minerals.
What has this to do with Bjarnes' alternative gravity thesis?
Answer: A lot! You see, to find those anomalies that may tell us where there is oil and minerals, we have to know the ideal scenario. We have to know
exactly which gravity would be expected in a homogenous mass. When we subtract that from what we measure, we can see the anomalies.
If we actually measured something quite different, we would immidiately discover it.
Out of curiosity, I found and read a few articles on the matter, and there has been extensive research in borehole gravity, gravity inside mountains and large buildings, gravity measured from sattelites, etc., so when Bjarne claims it has never been researched, he is speaking out of ignorance.
I won't reference the articles here; they are only a Google search away. Most of it is quite sophisticated and will be way over Bjarne's head, and he will continue inserting his own fantasies instead, anyway.
Hans