An excerpt from at the earth’s core
edgar rice burroughs
1 “let’s have a look beyond that door, david,” he cried.
2 together we stepped out to stand in silent contemplation of a landscape at once weird and beautiful. before us a low and level shore stretched down to a silent sea. as far as the eye could reach the surface of the water was dotted with countless tiny isles—some of towering, barren, granitic rock—others resplendent in gorgeous trappings of tropical vegetation, myriad starred with the magnificent splendor of vivid blooms.
3 behind us rose a dark and forbidding wood of giant arborescent ferns intermingled with the commoner types of a primeval tropical forest. huge creepers depended in great loops from tree to tree, dense under-brush overgrew a tangled mass of fallen trunks and branches. upon the outer verge we could see the same splendid coloring of countless blossoms that glorified the islands, but within the dense shadows all seemed dark and gloomy as the grave.
4 and upon all the noonday sun poured its torrid rays out of a cloudless sky.
5 “where on earth can we be? ” i asked, turning to perry.
6 for some moments the old man did not reply. he stood with bowed head, buried in deep thought. but at last he spoke.
7“david,” he said, “i am not so sure that we are on earth.”
8 “what do you mean, perry? ” i cried. “do you think that we are dead, and this is heaven? ” he smiled, and turning, pointing to the nose of the prospector protruding from the ground at our backs.
9 “but for that, david, i might believe that we were indeed come to the country beyond the styx. the prospector renders that theory untenable—it, certainly, could never have gone to heaven. however i am willing to concede that we actually may be in another world from that which we have always known. if we are not on earth, there is every reason to believe that we may be in it.”
question: why does perry believe that he and david are the earth's core? use details from the passage to support your answer.