Magnetic fields

A magnetic field is an invisible force that surrounds magnets and moving electric charges, describing the space in which magnetic forces act. Unlike gravity, which only attracts, magnetic fields have two poles—north and south—that both attract and repel. They're fundamental to how electromagnetic phenomena work, from the compass needle pointing north to electric motors spinning.

Earth itself generates a vast magnetic field, likely from churning molten iron in its core. This planetary shield protects our Atmosphere from harmful Solar wind, making life possible. Migrating birds and sea turtles navigate using it; some organisms may sense it directly through specialized proteins.

Magnetic fields surround any wire carrying current and coil tightly around electromagnets. Scientists study them using gravitational wave detectors and Brain imaging equipment like MRI machines, which exploit magnetic fields' ability to align atomic nuclei. At subatomic scales, quantum effects create intrinsic magnetism in electrons themselves.

The Newtonian framework describes magnetic forces mathematically through Maxwell's equations, though Quantum field theory reveals deeper truths: magnetism and electricity are two faces of one unified force. Understanding magnetic fields unlocked the Industrial Revolution's motors and today's entire digital infrastructure.

Related

Electromagnetism, Earth's core, Quantum mechanics, Magnetic resonance, Magnetite, Electromagnetic spectrum