Post date: Feb 14, 2017 12:49:24 PM
So yeah. I watched this and had serious misgivings about the science. The one I couldn’t ‘suspend disbelief’ was ‘The Fall’. The freefall gravity train from Britain to Australia.
A quick internet search reveals that many backroom boffs have a problem with this but none seem to see the issue the way I’m coming at it.
The theory is, that gravity pulls the train, ever accelerating towards the centre of the earth. The attained velocity is then sufficient, ever decelerating to reach the other side of the planet. All the sites I read tackle every aspect of this problem apart from what I consider to be the most important one. The fall to the centre of the planet is one of deceleration. How could it be anything other than that ?
This problem is not analogous to a weighted spring or a bouncing ball where one can rule out frictional losses and so on. The weighted spring has a rest point above which is acceleration and below which is deceleration, where gravity is always acting in the same direction.
The Fall is passing through the point where gravity is zero. An object placed there would remain there as the mass attraction in all other directions would be equal.
My simple contention without the need for any demonstration of complicated formulae is the fall to the centre of the earth is a decelerated descent. Any residual inertial momentum would quickly be negated on passing the centre point.
The voice in the wilderness
mark@sovereign-state-fidach.com