“Is it possible to stack blocks so that no part of the bottom block is below the top block? In general, how much horizontal distance can there be between the top block and the bottom block? This is a good kind of math question to ask. If there’s a limit to how distant the top block can be from the bottom block it will be interesting to know what it is. It would also be interesting to discover that there’s no limit to this distance. In the end, this becomes a question of whether the top block’s position converges or diverges.”

The topmost block has to cover at least half of the block below it or else it will fall.