Gravity's Rainbow

Here are some thoughts about gravity that have been keeping me awake for lo these many nights:

- We were somewhat led astray in Physics 101. A bowling ball and a golf ball do NOT fall to Earth from the same height at the same rate. Gravity is a function of the density of opposing masses and the distance between them. Since the bowling ball is more massive than the golf ball, it falls slightly faster, but because the mass of the Earth so overwhelms the mass of these two balls, the difference is so slight as to be almost immeasurable.

- In the U.S., force is measured in poundals (a function of the existing gravitational pull of the Earth). Mass is measured in pounds, ounces, etc. I find it a little strange that the weight of things on Earth (a force) is given in pounds, etc. when they really should be given in poundals (or newtons … or dynes).

- We know a lot about gravity except what it really is? Clearly gravity exists at the celestial level. It even seems to exist at the molecular level. (Isn’t this how dust bunnies come to be?) And I even believe that it exists at the sub-atomic level. Otherwise, how can black holes have such massive gravity when all their atoms have been crushed down to their most elementary particles? Beyond this I cannot speculate except that gravity may, in the very end, be another dimension. (Einstein said that gravity was a “warp in the space-time continuum”. I suspect that, if he were alive today and given the speculation on a 10-dimensional world, he might also label it another “dimension".)

- Speaking of black holes, their massive gravity keeps even light from escaping their grasp. Doesn’t this suggest that photons have at least some mass however minute? Also, Einstein’s “gravity lens” bends light around large stars. This too supports the idea that photons have some minimal mass since their “mass” is clearly influenced by the gravity of these large stars.

- Matter, by its mass, has gravity; energy doesn’t (at least in many scientists’ opinion). Is this the major difference between them? When matter is converted to energy (say through fission), it seems to lose its gravity. And if energy can be converted back into mass (a controversial postulate*), must it re-acquire gravity first?

- Gravity can seem to emanate from empty space. Consider the donut. Its center of gravity, when horizontal is at the center of its whole … so one cannot balance it on a pencil in this orientation. If one had a donut the size of the earth and someone fell from outer space toward its center of gravity, would the faller keep on going through the whole and back into space? If one was walking on the surface of this weird planet toward the hole, at what point would one’s adhesion to the surface become unstable enough to jeopardize one’s safety?

- Gravity seems to act instantaneously across the vastness of space (consider Pluto obediently staying in its orbit), whereas a gravitational wave (a fluctuation in the curvature of space-time which propagates as a wave) is said to travel at the speed of light. If the Sun were to suddenly disappear, how long would it take for the planets in our Solar System to fly off into space? At the same time someone on Pluto saw, after a 4.1 hour delay, the Sun's light go out … or instantly? I propose that, if it would be instantly, then there is more evidence that gravity is indeed another dimension.

- Gravity, it seems, has organized the matter in our universe into planets, planetary systems, solar systems, and galaxies. However, once converted to energy, this same universe tends to dissipate due to entropy. Therefore, entropy’s antithesis (in two different ways) is gravity.

* In 1998 researchers at Stanford University's Linear Accelerator Center successfully converted energy into matter. This feat was accomplished by using lasers and incredibly strong electromagnetic fields to change ordinary light into matter.