Newton's laws function less as a single claim than as a schema for analyzing motion. The second law supplies the form: causes enter as forces, and force equals mass times the second derivative of position. But the choice of second derivative is not neccesarily forced. Suppose we replaced it with F=mdnxdtn F= m \frac{d^nx}{dt^n} holding the other laws fixed and keeping force as the same independently measurable quantity — what a spring balance reads. For each nNn \in \mathbb{N} with n2n \neq 2 , what experiment would expose that this schema is false?