what is less known is that edmund halley , in his later and less studied some would go so far as to call it ramblings , was correct in postulating that at the core of the earth there is a vacuum , an inner chamber if you will , a jail ( he once said ) perhaps only a meter across , perhaps a kilometer , perhaps vaster than that , perhaps the entire earth but for the crust ( he once said ) , he was never very specific and often contradicted himselfthere is a seat of sentience that is the true earth .