## Monday, 23 February 2009

### G

Forces which oppose gravity interest me, such as magnetic forces found in floating magnets, and the drag forces of a falling object. Another force which can be thought of as opposing gravity is an object's buoyancy in fluid. I'm trying to remember a kids' gadget where a ping-pong ball floated in a stream of air. Drag force and buoyancy created by the air pushing up against the ball, oppose the gravitational forces trying to pull the ball down. More specifically, perhaps, drag force can be thought of as opposing the acceleration force, while buoyancy opposes gravity.

The idea of buoyancy was summed up by Archimedes, in what is known as The Archimedes Principle: any object, wholly or partly immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the object. Our floating ping-pong ball has reached an equilibrium where the three forces of weight, drag, and buoyancy are in perfect balance. I think of floating magnets as buoyant, then I think of a ball out at sea, and then I think of the Earth, bobbing quite merrily, in the fluid that is the aether field.

Normally, the force of weight is always downward. The force of buoyancy is always upward, and is negligible if the object's density is much greater than the density of the medium. A bit like, I guess, dropping a cannon ball into the sea. The Earth seems pretty buoyant in its relationship with the rest of the solar system. If the Earth is a cannonball, then our aether emerges as a fluid like tar. Perhaps, we can also think of the Earth as a little styrofoam ball drifting out at sea. Though we cannot see it, it appears that the aether field is incredibly dense. Far denser than matter.

If Earth does float in a fluid you would imagine there would be a tell-tale sign of it. I think evidence of it is in the wobbles we see in Earth's orbit. There are a number of wobbles. The precession of the equinoxes is actually the movement of the Earth's axis. A complete circuit takes about 25,780 years. Another movement in the earth's axis is a varying in the tilt of the Earth's axis. The tilt changes in a cycle lasting 41,000 years. The Earth's eccentricity also wobbles in a cycle of 92,400 years. Then there is nutation, a tiny wave that repeats itself every 19 years. Cycles and waves, wobbles and nuances, of a ball-all-out-at-sea.

Of note, there is a slight wobble in the way the Earth's orbit changes in the movement of Earth's perihelion. Perihelion means the closest point in an orbit; aphelion means the furthest point in an orbit. The Earth's perihelion moves in a complete circle about the Sun in 21,310 years. Because of this the Earth's orbit can be visualized as a perpetual spiral, never quite visiting the same place twice in space. If you were able to look down upon the Earth, and you had the patience to sit around for 25,000 years or so, then you'd see a signature being drawn-out in the letter 'G'.

Many thanks:
http://www.gateway-to-the-universe.org/brent/tourist/earth0.htm
http://www.ancient-wisdom.co.uk/precession.htm