The guy wrote the series wrong! The actual series should have been 1/2+1/4+1/8+1/16... And he cannot go any further than double the length of one block, measured from left end of the top block to the right end of the bottom block. And this means he would actually need infinitely many blocks to align the ends of the top and bottom blocks. So the guy actually couldn't pass the bottom block, it just seems like it from that angle. (Trust me, I solved this question in physics class in high school.)####[['NULL', 'Instructor', 'NEG'], ['NULL', 'Instructor', 'NEG']]