The limitations of common sense

Gallileo's calculations hold well in air especially if you take into account air resistance. Paning for Gold however probably has more to do with the Brazil Nut Effect than anything else and this is an area of physics that is still not well understood. The Brazil Nut Effect is a perfect example of counterintuitive physics and in fact is so good that nobody knows yet how or why it works in many cases. It is interestingly, also a good example of order from chaos.