Okay, first I explain what I think I understand, then what my problem is. As I understand it, if you have two massive bodies connected by a perfect frictionless spring, so that they fall towards each other by gravity and then bounce back from the spring, they will eventually come to rest with the energy carried off by gravity waves. This is because information can't travel faster than light, so that at any given moment while they are falling towards each other, they "feel" like they are farther apart and thus have less pull than they "should" (and so the spring stores up less energy) and as they are moving away, they "feel" like they are closer, and so the spring requires more energy to separate them, and all this lost energy is carried away as said by gravity waves. Assuming I understand that much correctly, what happens then if you drill a hole through a massive body and drop something through. Without relativity you would think it would pendulum back and forth forever, being braked as it passes the center as much as it accelerates on the way down, reaching the same height on the other side that it was dropped from. However, if we use relativity this is seems analogous yet opposite to the spring problem. As you approach the the center of the massive body, the gravitational force is constantly reduced. This means that at any given point, the object will "feel" more pull, which means it will arrive at the center will more speed than you would have assumed without relativity, and seemingly have gained energy. What's worse, the problem continues on the way past the center as it goes "up" the other side. At any given moment it will "feel" less gravity on and breaking it, so it seems it should reach a higher point on the other side than it was dropped from, and have gained energy, and this should continue on each swing. What am I missing here?