Question

At noon, the sun and the earth pull the objects on the earth's surface in opposite directions. At midnight, the gm and the earth pull these objects in the same direction. Is the weight of an object, as measured by a string balance on the earth's surface, more at midnight as compared to its weight at noon?

Answer 1

1. If we consider only the sun and the moon to be the determining factors, then No, the weight, even though by a negligible amount, would not vary. But, there are a lot of determining factors other than the Sun, and we know that there is no gravitationally neutral point in the universe, as the distance would have to be infinite, for in inverse square law to produce zero gravity.

2. The gravity of the sun is about 0.00589 m/s^2 at the radius of the earth's orbit, or about 0.0006 of the earth's gravity, g = 9.81 m/s^2