There are always constraints in product development and what is actually possible. While many times, an idea may be profound, it may not be physically possible in the real world. First and foremost, the actual materials to make the idea work need to exist. The idea of a floating transportation board that is non-powered since it is made of a gravity defying element that can bear weight and will not float away may sound great. This idea falls apart when you take into account that an element doesn’t exist. Other times, your idea may step on a patent and may not be legally viable as a result, or at least not financially viable after paying royalties to the patent holder.