Electricity can be created by changing a magnetic field—a phenomenon known as electromagnetic induction.

A changing magnetic field in a transmitter coil causes an electric current to be produced in materials that conduct electricity. This current generates its own magnetic field, which can be detected by a receiver coil and transmitted to a control box, which identifies the presence and depth of an object.

According to the theory, a large magnetic field generator, or dynamo, is created when liquid metal flows through the planet's outer core, producing electric currents that generate a magnetic field. Magnetization patterns in rocks on the surface of planets can serve as evidence for the presence of this internal structure at some point in the celestial object's past.

Based on the concept of electromagnetic induction, when a compatible device is placed on a charging pad with correct alignment, the alternating current flowing through the pad creates a changing magnetic field. This magnetic field induces a current in the device, recharging the battery without a connecting wire.

The technology was developed by Hippolyte Pixii in 1832, almost 25 years before Tesla was born. Other myths about Tesla include that he invented the transformer, radio, and the induction coil, which was invented by Nicholas Callan in 1836.

Instead of a compass needle's movement indicating a magnetic field, an alternating current produces an oscillating magnetic field in a metal bar. An external magnetic field creates an imbalance in the oscillations, which can be measured quantitatively.

Discovered by Thomas Edison, vacuum tubes allow electrical currents to travel through empty space. Later modified into a diode—keeping current flowing in only one direction—vacuum tubes allowed electronics to turn alternating current into direct current.

In 1879, Thomas Edison’s light bulb relied on direct current, but such currents can't efficiently transmit power over long distances. Nikola Tesla introduced alternating current, which feature far fewer energy loses. Despite Edison’s attempts to discredit AC, Tesla proved its efficiency by lighting the 1893 Chicago World’s Fair.

He once electrified himself during a live demonstration to illustrate the safety and power of alternating current, and his presentations often featured arcing coils, glowing lights, and bold claims about a future of wireless power.

Constructed from conductive materials, the cage allows electrons to distribute themselves evenly throughout its surface and travel to ground, keeping the interior neutrally charged and preventing any internal electricity. The same principle blocks electromagnetic waves by redirecting the electric field component, preventing telecommunication signals from entering the apparatus.

The electromagnetic fields produced by the alternating current in transmission lines can induce the motion of charges in nearby objects. This motion yields electric currents that can light up bulbs but are too small to harm humans.

Volcanic rocks can lock in the direction of Earth's magnetic field as they cool, making them natural recorders of magnetism. Dating rocks and seeing the changing orientation of their magnetic field helps construct a timeline of Earth's magnetic field history.

Dubbed the "executioner's current," the device was designed in Thomas Edison's lab by Harold Brown—an opponent of George Westinghouse and Nikola Tesla. The effort aimed at discrediting AC technology and gain favor for Thomas Edison's direct current as part of "The Current War."

J.P. Morgan first backed Thomas Edison's direct current system, seeing electricity's potential to usurp John D. Rockefeller's kerosene empire. Despite the investments and smear campaign against alternating current, alternating current ultimately won public support after lighting the 1893 World's Fair, after which Morgan would fund Tesla's wireless transmission tower.

Since its discovery in 1911, applications of superconductivity have made MRI machines and maglev trains possible due to quantum effects at extreme temperatures. These effects are modeled as electrons cooperating in pairs and flowing more efficiently.

Its magnetosphere emerges from a complex interior process of electrical conduction, heat, and motion known as the geodynamo. The magnetic field shields the Earth from unsafe cosmic radiation, providing one of the many conditions required for life.

While the oxygen atom in water molecules strongly attracts hydrogen's electrons—producing an uneven charge distribution that pulls water toward balloons that have been rubbed against surfaces—the presence of a magnetic field alters the path of these electrons, which produce their own tiny magnetic fields. The interaction of these fields repels water away from magnets, making it diamagnetic.

Alongside his brother, he studied electric fields in crystals and the magnetic properties of substances, which required the construction of delicate electrometers. He would use this apparatus with Marie Curie to measure radioactive emissions and the presence of undiscovered radioactive elements.

Earth's magnetosphere, generated by the movement of molten iron deep within the planet, consists of a magnetic field that deflects charged particles north and south. Some of the particles released by the sun in the solar wind become trapped in this field and are propelled toward the poles, where they produce auroras through collisions with atmospheric particles.

When these beams are emitted into an evacuated tube containing charged plates or a nearby magnet, deflections are observed due to the electron charge. In 1897, J.J. Thomson's calculations of this deflection led to his discovery of the subatomic particle.

While Thomas Edison's thin carbon filament design made light bulbs commercially viable, prior contributions, such as Joseph Swan's development of the first successful incandescent filament electric lamp, made its eventual invention possible.

Journalist Adi Robertson experimented with one of the most accessible biohacks: magnets. Having a tiny magnet in their right ring finger meant they could sense magnetic fields, attract small metal objects, and more. But magnets weaken over time, eroding this new sense. Such implants do more than offer a new way of interacting with the world, they also pose new complications, such as the inability to get an MRI.

Through triboelectric charging, sand and dust on the Martian surface can become electrified when they rub against one another, causing friction to displace electrons and create charged particles. If this matter forms a strong enough electric field, it can overcome atmospheric insulation and produce electrical discharges, resembling lightning on Earth.

After leaving his position working with Thomas Edison, Tesla partnered with George Westinghouse to promote alternating current systems as a more viable, scalable solution to electricity transmission.

By connecting lemons with a piece of zinc on one side and a piece of copper on the other, a team from the Royal Society of Chemistry created a fruit battery with a capacity of 2,307.8 volts.