Gravity
Your Up is My Down | Wrong about Gravity | Gravity a Push Force?
More About Gravity | Low Gravity Experiments | Weight Increases with Depth
Gravity Experiment | Where to 'Get Down'
 Your Up is my Down?
One person's up can be another's down. Imagine yourself in space, looking at the Earth with super vision.  You are viewing two people standing on opposite sides of the Earth, one in Lima, Peru, and one in Bangkok, Thailand. In this case, the first person's "up" is the second person's "down", and vice versa. (see Antipodes below) If one person leaps into the air, aiming for about 50 feet above, he will feel gravity stop him and accelerate him back toward the center of the earth's mass until he is stopped by the ground. No surprises so far.
We Are Wrong About Gravity
On Earth, Newton established laws of gravity and Einstein later made modifications claiming that gravity is the result of mass warping space-time. Today, however, we are finding that our cherished models fail to reflect reality. The spacecraft Pioneer 10 and Pioneer 11 have traveled in opposite directions away from the sun for decades. The problem is, they have both been unexplainably slowing down at the same rate "as if the gravitational pull ... from the sun is growing progressively stronger the farther away" they get. ( CNN ). This is not explainable with our current understanding of gravity.
Is Gravity A Push Force?
Some think gravity is a push force shielded by large masses (and spinning superconductors? 25). In this model, empty space contains a gravity pressure which may be dark energy. 29 In 1917, Albert Einstein imagined a repulsive force pervading space. This later became his "cosmological constant." On September  8th, 1968 Walter Wright predicted "The universe will accelerate and expand forever because gravity is a PUSH between bodies in space." 26 Thirty years later we learned that the universe is indeed expanding at an ever increasing rate. 27 Supporters claim that Wright's push model also accounts for the motion of the earth's 14 tides while the pull model does not explain the high tide on the side of the earth opposite the moon. The push model also explains Saturn's Shepherd Moons. 26
One physicist gave this reasonable argument against gravity being a push force:
1. The push model of gravity does not explain why the more mass you have, the more gravity you have.
More About Gravity
Conventionally, we say gravity is the result of mass. The force of gravity decreases as the square of the distance. At any point in space, gravity is a vector force which has a both a magnitude and a direction. When you are standing on the outside of a sphere, all of the different points pull you toward the center. According to Dr. Fred Duennebier, Professor Department of Geology and Geophysics University of Hawaii, Honolulu "If you are INSIDE a hollow sphere, the force of gravity is zero, no matter how much mass the sphere has." Newton said that "inside a hollow sphere there is no gravitational attraction." 37, 38
If the Earth were a hollow sphere with a shell only 100 miles thick and you tunneled through the shell and dropped into the interior, what would happen? Would you fall to the center of the earth? No. Inside the sphere, all the forces in different directions cancel out. You would be "weightless" but you would not fall unless you pushed off. Here is a mathematical proof at a NASA web site. The force of gravity you feel as your weight is the result of the addition of all the vectors (forces with magnitude and direction) acting upon you. Inside a sphere, there is mass above you as well as below, so you will feel forces both up and down. Calculations show that in a uniform sphere, these forces acting in different directions cancel out.
There is also a gravity balance point between the moon and the earth where you would feel no pull from either, but something about this is odd. In 1960, before the Apollo missions, Encyclopedia Britannica reported the neutral point to be 20,520 miles from the Moon. A Moon with 1/6 Earth's gravity should have a Neutral Point between 22,078 - 25,193 miles from the Moons surface. Yet after the Apollo missions, Time magazine July 25, 1969 said "At a point of 43,495 miles from the moon, lunar gravity exerted a force equal to the gravity of the Earth, then some 200,000 miles distant" In 1973 Encyclopedia Britannica , gave a new neutral point distance of 39,000 miles. The problem with all of this is, a neutral point of 43,495 miles would make the moon with not 1/6th (16%) the Earth's gravity, but 64%.
Low Gravity Experiments?
If the Earth were hollow and weight was lost by descending into the Earth, we conduct low gravity experiments in basses hundreds of miles below the Earth's surface, right? Could the Apollo moon landings have been faked on a sound stage far below the Earth's surface where there is little gravity!?
No. As of July 15, 1985 the deepest hole was on Russia's Kola Peninsula, near the Norwegian border. The hole was over 40,000 feet ( 7.57 miles). A 1994 citation says the deepest was 7.62 miles. No one is going to do anything hundreds of miles below the surface because the crust is only 45 miles thick MAXIMUM. In the Russian hole example, the Mohorovicic discontinuity (or Moho) boundary between the crust and the mantle was 20 miles down. The Moho temperature is 1,110 F and pressure is 6,000 times that of the atmosphere. ( Diamonds form at 1,350 degrees Centigrade and pressure is 57,000 times that of the atmosphere. ) The deeper you go, the more expensive drilling gets. Here's another reason you can do low gravity experiments by drilling into the earth:
Weight Increases with Depth
 Based on Newton's law of gravity, if the Earth was hollow and of uniform density you would weigh less and less as you moved down a mine shaft or elevator. In fact, you would be weightless anywhere "inside" the Earth, not just at the center. In practice, however, weight will actually increase as you descend. Why? Because the Earth's core is more dense than its rocky crust. Your weight increases as you get closer to the dense core with more mass. 1 Even in the model where the Earth has a dense central sun to explain the above observation, inner earthlings would be pulled to the center, not to the shell surface. Their "down" couldn't be our "up".
Your Own Gravity Experiment
QUESTION: How sensitive a scale would you need to verify your change in weight as you moved down a deep mine shaft?
ANSWER: It is about 3,950 miles straight down to the center of the Earth. At the surface, let's say you weigh 170 lbs. At the center, you would weigh 0 lbs. In the simplest ( but wrong ) model you might expect to weight 1/3950th of your current weight 1 mile down. 1/3950th of 170 lbs. is 0.043 lbs, so you would weigh 169.957 lbs. A scientific scale that measured with an accuracy of .001 would do it! I called Arlyn scales (800) 645-4301 to ask if they have a scale that would run on batteries and weigh up to 200 lbs at an accuracy of 1000th of a lb. No, but they do have a 10 lb scale you could use if you modify the experiment slightly and weigh a small weight instead of yourself. Model d620x is $699.00 + battery pack $100 + $23.00 shipping. The scale has no moving parts, comes calibrated, and you should have it calibrated about once a year. It runs for 20 hours on a charge.
Where to 'Get Down'
To conduct the above experiment, I still need to answer this question: Where on Earth can I get down, one mile underground? A mile is 5,280 feet. At Moaning Cavern, you can get 165 feet down to the bottom of the cave. At Carlsbad Caverns you can travel a mile long path that takes you 750 feet into the Earth. Hmm, perhaps man made is the way to go. A web page that mentions the Kidd D Mine says, "Kidd's decision to push into the depths below 10,000 feet is the result of two winning combinations: first, the technological /engineering advances made over the last half century, and second, the unique ground conditions which have made the Kidd ore body a "lucky" lady of wealth." In other words, there are mines almost 2 miles deep! If you happened to live in Ontario, Canada near the Kidd Mine and you had the right connections, you could really get down. If anyone knows of a mile deep mine in California that I could get down in, let me know.
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