Resisting the powerful temptation to comment on The City of London spending £92 million a year to change UK government policies, I lift my eyes to the heavens and turn to the most powerful and most mysterious force in the universe, gravity.
Isaac Newton discovered and encoded the Laws of Gravity, which work perfectly for cricket balls, birds, planes, the solar system and interplanetary rockets. All mainstream universal models are based on gravity, the calculations of which wind-back to the Big-Bang. We all experience gravity, all the time; even in “gravity-free” space flight where we know we are balancing the tug of gravity by “falling” towards the Earth (but managing to miss and continue in orbit).
In current theory, “empty” space contains 6 (six) hydrogen atoms (the air around us has millions of billions of hydrogen atoms) per cubic metre; gravity did or will over eons draw them together, find a few more, continue to aggregate atoms and form a star. This is how all life began. But nobody knows what gravity is.
IMAGINE that on the allegedly solid Moon, we dig a 3,475 km tunnel straight through the middle, from South Pole to North Pole. It’s a wide tunnel fitted with a lift /elevator. You and I go down 1,737 km in the elevator from the South Pole, assisted by gravity, to the centre of the Moon. Experience tells us, we will indeed go “down” and Newton’s maths highly accurately inform us that gravity is measured from the centre of masses – from planet centre to centre or from Moon centre to Earth centre. Common sense tells us we will go down to the centre. What next?
At the centre we intuitively know we must climb up to the surface to the North Pole. It’s helpful to have an elevator. But how do we make the transition from “down” to “up”. Is there a weird fuzzy field, a gravitational gateway, we go through head first, heads down, to find on the other side we are heads up? Is the transition abrupt or gradual, in Calculus slices? Do we encounter a gravity-free zone where all the rock and iron in the Moon exert perfectly balanced tugs on us?
Does the force of gravity that we feel on the surface, with 1,737 km of material beneath us, diminish as we near the centre? Imagine having only 5 km of rock and iron between us and the centre and 1,732 km above. It could be thought that the far greater mass above us will draw us up and hinder us from going down.
Discounting any centripetal /centrifugal effect of the spinning Earth, Do Everest climbers experience more or less gravity at the 5 miles high peak – with more “stuff” below them?
Mountaineers, Cavers, MOND, Dark Matter, Dark Energy experts, Solar System and Galactic Astronomers – answers on a postcard please.