PHY.4:1 - Problem frame

Use this pattern when an observed or proposed physical effect needs an account, but the interaction law is not supplied. A detailed mechanism may be unresolved and a familiar analogue may be inadequate. You can still ask how the situation could be changed, what would remain physically equivalent, and which responses those comparisons allow.

Start with one physical response or relation needed by the work. Describe its participants, preparation and relevant surroundings. Construct one comparison that could rule out a proposed dependence or restrict its form. A conditional restriction, together with the dependence it leaves unresolved, is a useful first result.

The method uses transformations justified for the physical situation: changes of position, orientation, scale, preparation, participant assignment or other relevant conditions. It combines their consequences with applicable dimensions, balances and dissipation. The question selects which of these contributions is useful.

You need enough physical understanding to propose the comparison and explain its conditions. Obtain an unfamiliar physical premise from a suitable account or collaborator. A qualitative comparison can already change the next move. The vector example additionally uses rotations and dot products; the chamber example uses elementary algebra and particle balance. Their branch-specific preparation belongs to those examples.

If an established interaction law already answers the question under the intended conditions, apply it. PHY.1 develops physical similarity across changed conditions, PHY.2 constructs a physical analogue, and PHY.3 derives a performance limit from permitted transformations. Return here when the unresolved contribution is the form of the interaction law itself.