The discussion revolves around a misunderstanding of Ampere's Law and the calculation of the magnetic field (B) around a current-carrying wire. The original poster questions whether B is constant within a fixed rectangle. User ehild clarifies that while the direction of B changes, its magnitude remains constant in the rectangle. Additionally, ehild explains that for a long straight wire, the magnetic field strength is inversely proportional to the distance from the wire (B is proportional to 1/r). This highlights the importance of correctly applying Ampere's Law in calculations involving magnetic fields.