Chinese magnetic sensor breakthrough may help smartwatch detect submarine 500 metres deep

Picture a fisherman hauling in his nets on a calm morning at sea, when his smartwatch suddenly vibrates with an alert: “Magnetic anomaly detected – possible submarine passing 500 metres below.” Far‑fetched as it sounds, Chinese scientists have just taken a decisive step towards making that scenario real. A team from the Hefei Institutes of Physical Science and the Ningbo Institute of Materials Tec