PHY.1:1 - Problem frame

Use this pattern when you want to learn about a physical situation through another arrangement, but changing its size, material, speed or surroundings changes the effects that produce the answer. You may be designing a smaller experiment, comparing observations made under different conditions, or deciding which part of a previous physical result can be reused.

Start with the quantity or behavior you need to infer about the original situation. Then identify one physical effect whose relative importance could change in the proposed comparison. A smaller object has less weight, for example, but its ability to carry that weight changes by a different factor. That difference can determine how the comparison should be built and loaded.

The result is a set of physically compatible comparison conditions, a justified transfer of a selected result, or a conflict that directs the next construction. Here physical similarity means correspondence of the physical behavior needed by the question under stated changes of scale or conditions. Geometric similarity preserves shape under scaling; further conditions can be needed to preserve the relevant behavior.

You need the physical account used in the comparison and the mathematics needed to transform its relations. You can develop that account through B.5.FM and B.5.TU or obtain a missing physical contribution from a collaborator. Algebra and ratios suffice for many first comparisons; fields and time-dependent behavior can require differential equations. A ready comparison whose conditions fit the question can be used directly. If the problem is expressing an already understood account mathematically, MMP.10 supplies that formulation work.