Just a reminder of this critically important and fantastic book that should be on EVERYONE's bookshelf:
Hollow Planets: A Feasibility Study of Possible Hollow Worlds - Could the Planets Mercury, Venus and Earth Possibly be Hollow? by Jan Lamprecht
If you find yourself unable to purchase, you might drop a note and we can see if perhaps there are other ways to buy the book from Jan Lamprecht. There was a cache of these books that was published and put into "storage" in the USA many years ago and it would be nice if they could be liberated somehow.