Why is the Earth round (planets and the sun, too)?
It’s the gravity, of course. Imagine Earth were liquid–consisting, say, only of water. Gravity would of course pull that water towards the center, and if any could flow closer to the center, it would do so. Therefore, if such an Earth were not a sphere–if some points were higher than the average–their water would quickly flow down. Water would also flow into any valley deeper than the average and fill it up. The final shape MUST be a sphere. Only then does every point on the surface have the same distance from the center. Gas planets like Jupiter, Saturn, Uranus and Neptune behave the same way, since gas flows like a fluid. The Sun is gas, too, so it must be spherical. But Earth? The Moon? Why should a planet composed of solid rock have the same shape as one composed of water? Because, dear friend, once you descend a few hundred miles (or kilometers), rocks flow like a fluid, too. A rock 300 miles underground bears the weight of a 300-mile layer of rock, and under such pressure even
