In the context of electromagnetism and reference frames, observer A, who is at rest relative to a stationary charge, will not detect a magnetic field, while observer B, who sees the charge moving at a constant velocity, will detect a magnetic field. This discrepancy arises from the principles of relativistic electromagnetic theory, as outlined in Einstein's original paper on special relativity. The transformation laws for electromagnetic fields between different reference frames explain this phenomenon. The discussion emphasizes the importance of the observer's frame of reference in detecting electromagnetic fields. Understanding these concepts is crucial for grasping the implications of relativity in electromagnetism.
