A moving proton does not have its magnetic field naturally align with an external magnetic field; instead, the total magnetic field at a point is the vector sum of all magnetic contributions in the area. The proton's magnetic field can be calculated using Maxwell's equations based on its speed, direction, and charge. While the external magnetic field does not influence the proton's magnetic field, it does affect the proton's movement. In classical physics, alignment does not occur, but in quantum mechanics, measurement along the external magnetic field can cause the proton's spin to align or anti-align with that field. Understanding these interactions is crucial for applications in both classical and quantum physics.