Watch a timeline of the history of electricity, from observations of static electricity in antiquity to the War of the Currents—a rivalry to establish the ideal system for electric grids.

Tesla's alternating current power's most of the world's electric grids

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.

A dispute about the origin of twitching frog legs led to the invention of the first battery

Experiments by Luigi Galvani on exposed frog leg nerves showed activity when they were hung from iron railings and brass hooks, suggesting the existence of "animal electricity" that discharged when connected to metals. Alessandro Volta's voltaic pile, which stacked metals with an inorganic electrolyte, showed that electricity originates from chemical reactions.

Thomas Edison publicly executed animals with AC to convince the public of its dangers

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.

The speed of electricity may refer to the movement of electrons, which is on the order of a fraction of a millimeter per second, or energy, which is near the speed of light.

Electromagnetic induction creates electricity from a changing magnetic field

The phenomenon was discovered in 1831 by Michael Faraday when an electric current was induced in a wire wrapped around an iron ring after a second wrapped wire not connected to the first was connected or disconnected from a battery.

Named after Nikola Tesla, who pioneered alternating current power systems, the Tesla coil was the first device to wirelessly transmit electricity.

The engineering underlying the electric grid and why it needs to be modernized

The system includes generators for producing electricity and millions of miles of transmission and distribution lines to transport the energy. The substantial increase in the number of electronic devices and electrical demand since the construction of much of the grid in the mid-1900s has strained infrastructure, requiring continuous upgrades and massive investments in new construction.

Niagara Falls helped decide the battle between AC and DC power

In the 1890s, Niagara Falls became the proving ground for alternating current (AC) when Tesla and Westinghouse built the first large-scale AC hydroelectric plant—defeating Edison’s push for direct current (DC) in the US electrical system.

Nikola Tesla embraced showmanship when promoting ideas ahead of their time

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.

Visualize how alternating currents—electricity that periodically changes direction—are generated by rotating magnetic fields, as occurs in turbine-generator systems.

The history of the North American power grid, which is composed of five major grids

Thomas Edison's Pearl Street Station was the first US commercial power plant, burning coal to power lamps for some Manhattan residents. Over time, local power plants would be bought out by larger ones, forming interconnected systems spanning multiple states. Today, the Eastern Interconnection and Western Interconnection are the largest of these systems.

Before the invention of transistors, vacuum tubes made radio possible

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.

Alternating current was used to commit the first execution by electric chair

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."

Despite promoting alternative current, Nikola Tesla did not invent it

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.

Benjamin Franklin described a series of static electricity storage jars as 'batteries'

Discovered over 50 years before the first electrochemical cell was invented, Leyden jars stored electric charge between the metals inside and outside a liquid-filled container. Franklin was the first to use the term "battery" in an electrical sense, though his multiple-jar device—lacking chemical reactions—was actually a series of capacitors.

Niagara power helped electrify early New York City

Tesla's AC system at Niagara Falls was so successful that electricity generated there lit up Broadway theaters and powered NYC's subway system in the early 1900s.

Explore a gallery of electric vehicles from before 1920

In 1884, Thomas Parker invented the first practical electric car in London. By the turn of the century, early EVs were seen on the streets of Washington, DC. Automaker promotional materials included photographs of cars on mountain roads and other terrains.

A collective effort from multiple scientists and inventors led to the light bulb

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.

Ray Bradbury said he was inspired to pursue writing after meeting a magician named Mr. Electrico, but scholars have never been able to confirm the story.

Discoveries in electromagnetism, which suggested that light traveled at a single speed, became the catalyst for overturning Isaac Newton's view that all speeds are relative and could appear to change based on one's perspective.

In 1880, Jacques and Pierre Curie discovered that electricity could be produced by striking certain materials—the piezoelectric effect—a phenomenon that is seen in barbecue lighters.

Electricity is produced when the ends of a battery are connected by a conducting wire, triggering chemical reactions that release the energy stored in chemical bonds.

Thomas Edison created the first strand of electric Christmas lights in 1880

Edison strung electric bulbs outside his laboratory in 1880, and his business partner Edward H. Johnson first wrapped a tree in lights in 1882. It wasn’t until the lights were commercialized in 1917 that they became common in household Christmas decorations.

Transformers change the current and voltage across a set of wires by wrapping them around a magnetic core and using the magnetic field of one wire to induce a current in the other.

Electricity can be lethal because it can disrupt the nervous system, which controls critical bodily functions that rely on electrical signals between cells, such as breathing and heart rate.

Before transistors, which regulate the flow of electricity, vacuum tubes—glass tubes containing no gas that resemble light bulbs—served as the electronic switches in computers.

Nikola Tesla was born in modern-day Croatia and moved to the US in 1884

His interest in electricity came from his mother, who invented small household appliances during Tesla's upbringing. Upon arriving in America, he began working for and improving upon the electrical inventions made in Thomas Edison's lab.

Nearly 40% of American cars were electric in 1899

They were most common in cities, where battery swap stations allowed drivers to "refuel" their vehicles reliably. Innovations in combustion engines caused electric cars to lose ground until environmental policies and advances in battery technology revitalized interest.

Tesla's first successful AC prototype used a metal shoe polish tin for a rotor

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.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

Nikola Tesla's biggest dream was a worldwide network of wireless power transmission

He built the Wardenclyffe lab and a massive prototype transmission tower to develop trans-Atlantic transmission, but it was never operational. The concept was based on incorrect assumptions about Earth's conductivity, but it inspired subsequent efforts for wireless systems.

George Westinghouse purchased Tesla's AC technology patents for $60,000

The seven patents in alternating current motors and power transmission formed the basis for a system of technologies including generators, transformers, and lighting. Nikola Tesla spent half the funds on a new laboratory to develop new inventions.

The world's first AC hydroelectric power plant incorporated Tesla's engineering

Built at Niagara Falls, New York, the plant alternating current electricity was hailed as the future of power generation. Tesla's fascination with Niagara Falls is traced to his seeing a photo of the waterfalls when he was still a child.

Simulate the buildup and discharge of static electricity through friction by dragging the arm and leg of 'John Travoltage' along surfaces.

In 1898, Nikola Tesla wowed a crowd by controlling a boat with no visible connection

Some onlookers thought it was a trick, such a a monkey being inside the boat, rather than mind control or some other metaphysical phenomenon. In reality, Tesla was pioneering radio waves, proving wireless control was possible.

Electric vehicles have been around since the 19th century

The first EVs ran on rechargeable lead-acid batteries, which could travel 60 to 80 miles on a single charge. Women preferred these vehicles, which were quieter, less smelly, and did not require turning a hand crank to start the engine.

The unpredictability and brevity of lightning make lightning power impractical

While a typical lightning strike provides 30,000 amps at 300 million volts, the bolt only lasts about 30 microseconds. If the electrical surge could be captured—assuming one knew beforehand where it would strike—it would only provide enough electricity to power one home for about 6.4 hours.

Explore how excitatory cells, such as neurons and muscle cells, transmit information in the body via electrochemical signals, which can travel up to 120 meters (390 feet) per second.

If two strands of conducting materials are connected at two junctions, electricity can be generated if one junction is heated while the other is cooled—a phenomenon known as the Seebeck effect.

Thomas Edison, eager to communicate with ghosts, tinkered with an apparatus called the 'spirit phone.'

Electrogenic animals generate their own electricity within an electric organ by changing the pattern of electrical charges in disc-shaped cells called electrocytes.

While charges consistently move in the same direction in a direct current, the flow of charges changes multiple times per second in an alternating current.

Guglielmo Marconi overshadowed Nikola Tesla through commercialization

Despite Tesla envisioning wireless power and communication earlier, Marconi developed practical implementations of wireless communication, including transmitting the first transatlantic radio signal. The technology, which facilitated telegraphy critical for warships and navies, earned Marconi the 1909 Nobel Prize in physics.

On average, the human body produces about 100 watts of electricity—enough to power a light bulb—but some people can produce over 2,000 watts in short bursts, such as when sprinting.

Lightning rods provide a conductive pathway to safely steer massive electric currents

The device is positioned higher above the ground to "catch" one of the many branching filaments of electrons from clouds before they make contact with other surface structures, which have been induced to have a positive charge by overhead storm clouds. The current is then sent to a conductive grid buried underground.

Around 380 underwater cables power the Internet across the world.

On July 29, 1858, two steam-powered battleships met in the middle of the Atlantic Ocean. There, they connected two ends of a 4,000 kilometer (2,500 mile) long, 1.5 centimeter (0.6 inch) wide cable, linking for the first time the European and North American continents by telegraph.

19th-century Americans used technology to try to prove the existence of ghosts

In the 19th century, following technological advancements like the telegraph, phonograph, and others, efforts were made to capture proof of ghosts. These technologies seemed supernatural in their own right and emerged at the same time Spiritualism took off in the US, resulting in new approaches to connecting with the dead.

The dynamo theory explains how planets generate their own magnetic fields

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.

View the various types of lightning

The most common form of lightning involves channels of electricity between oppositely charged regions within a cloud or between two clouds to reestablish electrostatic equilibrium. While cloud-to-ground lightning is understood best, research is ongoing to fully model the mechanisms behind rarer forms of lightning, such as transient luminous events.

Lightning forms when streams of rising and falling charged particles connect

In cloud-to-ground lightning, a buildup of negative charge at the bottom of clouds repels electrons on Earth's surface, leaving behind positively charged particles. When descending negatively charged air—the stepped leader—meets rising positively charged particles—the upward streamer—brightening runs up the connection, producing intense flashes known as return strokes.