During the Renaissance (and before), many reasonable people scoffed at the idea that the Earth is spinning.
The main (non-religious) objections were: 1) If the Earth is spinning then why doesn't the Earth move below a stone thrown straight up. 2) A body that is not anchored to the ground should fly off. These criticisms were quite reasonable and really couldn't be adequately answered until the concept of inertia was introduced into the science of motion. The answer to the first the question was that our inertia carries us along with the spinning earth. The answered to the second question depends on the answer to the first question. According to the principle of inertia any body that is not secured to the earth should fly off, but since this is not the case it must be because gravity is a force which is strong enough to overcome a body's inertia. Harry
