In Past time era, there is no pollution so the body is much heathy. What-not chemical in the air, water and ground is obselete.
Today however, chemicals are everywhere.. in food, water, air and ground. Turn your water tap you get clorinated water. Go outside you get air pollution.

this is trying to romanticized the ancient world, there are always pollution, when human live in cave live in high level of polution from the smoke of fire due to ventilation problem. air, water and ground contaimination can happen naturally without any human activity.

Because, according to spherical shell dynamic theory, the planets and stars were created out of convection currents between warm and cool regions of space, *snip*

The best scientific argument against that of a hollow Earth or any hollow planet is gravity. Massive objects tend to clump together gravitationally, creating non-hollow spherical objects we call stars and planets. The solid sphere is the best way in which to minimize the gravitational potential energy  of a physical object; having hollowness is unfavorable in the energetic sense. In addition, ordinary matter is not strong enough to support a hollow shape of planetary size against the force of gravity; a planet-sized hollow shell with the known, observed thickness of the Earth's crust, would not be able to achieve hydrostatic equilibrium with its own mass and would collapse.

Someone on the inside of a hollow Earth would not experience a significant outward pull and could not easily stand on the inner surface; rather, the theory of gravity implies that a person on the inside would be nearly weightless. This was first shown by Newton, whose shell theorem mathematically predicts a gravitational force (from the shell) of zero everywhere inside a spherically symmetric hollow shell of matter, regardless of the shell's thickness. A tiny gravitational force would arise from the fact that the Earth does not have a perfectly symmetrical spherical shape, as well as forces from other bodies such as the Moon. The centrifugal force from the Earth's rotation would pull a person (on the inner surface) outwards if the person was traveling at the same velocity as the Earth's interior and was in contact with the ground on the interior, but even the maximum centrifugal force at the equator is only 1/300 of ordinary Earth gravity.

The mass of the planet also indicates that the hollow Earth hypothesis is unfeasible. Should the Earth be largely hollow, its mass would be much lower and thus its gravity on the outer surface would be much lower than it is.

What are the odds of that ?   

We are all still here. Since thousand and thousandsS of year, when the Dinosaurs rule the earth, the Ice Age and when the great flood.