[ckissick]

Astronauts orbiting earth are weightless because they are in free-fall while orbiting earth. The spaceship is also weightless for the same reason. Earth is orbiting the sun, just as a spaceship orbits earth. Therefore, Earth is weightless. So if you can be at the exact center of Earth's mass, you are weightless. I'm ignoring other gravitational "forces" - gravity is not a force - like the pull between Earth and Moon, and the fact that orbits decay.

Is this correct? I just came up with this theory. But it makes sense to me.