PHY.3:9 - Consequences

A useful physical limit can be obtained before the internal mechanism is known. It can reduce unproductive design work, expose an omitted resource, or suggest a different input family or performance requirement. The derivation also gives collaborators a physical question to answer: a needed reference process, a covering law or an unsettled preparation.

The cost is obtaining a physical account whose reach matches the conclusion. Stronger exclusion usually needs broader coverage than failure of a candidate design. A conditional result is often sufficient to guide the next step while that coverage is developed. Near a limiting value, finite time, noise, size and implementation constraints can determine whether pursuing it is useful.