Folks , I found some great insights for our concept of Hollow Planets , from this online tutorial on Dyson Sphere . This kept reminding me of Darth Vader's Battle Star from the Star Wars Trilogy :))
I do suspect that George Lucas and the makers of the original Star Wars Trilogy , knew about the Hollow Planet/Dyson Sphere concept . I also read somewhere that in future , when humans build permanent settlements in space , a Hollow spherical metallic shell (Dyson sphere) could be one of the preferred designs .
I personally think all Hollow Planet researchers need to familiarise themselves with the Dyson Sphere idea . Earth's Hollow (maybe artificial) moon may well be a good example of a Dyson sphere :-
Regards