MRI machines generate extraordinarily powerful magnetic fields (60,000 times Earth's magnetic field) using 20 miles of electromagnetic coil wiring, making them both dangerous and capable of dramatic demonstrations like attracting metal objects with extreme force.
MRI machines use superconducting magnets ranging from 0.5 Tesla to 3.0 Tesla (5,000 to 30,000 gauss) in clinical settings, with research magnets reaching up to 60 Tesla. Compared with Earth's 0.5-gauss magnetic field, a standard 1.5T clinical MRI is approximately 21,000 times greater than the earth's natural field, while a 7T magnet generates a field 140,000 times stronger than Earth's magnetic field. The "60,000 times" claim in the video appears to be a rough approximation for a 3T scanner. Regarding wire length, the length of superconducting wire in the magnet is typically several miles, and a 7T magnet uses about 10 times more wire than a 3T magnet. For ultra-high field research magnets, 11.7T systems use approximately 600 km of NbTi wire (about 373 miles). The "20 miles" claim is plausible for standard clinical MRI systems.
The danger is real and well-documented. Metal objects in the MRI suite can become dangerous projectiles due to the magnetic force, with small objects such as paper clips and hairpins having a terminal velocity of 40mph when pulled into a 1.5T magnet. From 104,659 accident reports over nine years in Japan, 172 involved ferromagnetic objects brought into MRI rooms. Fatal accidents have occurred: in July 2001, 6-year-old Michael Columbini was tragically killed when a ferrous oxygen tank became a lethal projectile, and in July 2025, a 61-year-old man died after being pulled into an MRI machine by a large metallic chain around his neck. The MRI machine is always magnetized—it's always on, making constant vigilance essential. A recent study found that 74% of MRI incidents could have been prevented by following standard safety practices.
Clinical MRI machines use several miles of superconducting wire to generate magnetic fields 21,000-140,000 times stronger than Earth's, creating powerful forces that can violently attract metal objects.