Watch a timeline of the history of electricity, from observations of static electricity in antiquity to the War of the Currents between Nikola Tesla and Thomas Edison 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.

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.

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.

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

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.

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.

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.

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.

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.

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

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.

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.

Simulate the build-up and discharge of static electricity with 'John Travoltage.'

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

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.

In the photovoltaic effect, light generates electricity by creating a charge imbalance after knocking electrons out of atoms from semiconducting materials.

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.

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.

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.

Watch lightning strike a building at 40,000 frames per second

When the built-up layer of negative charge at the bottom of clouds is sufficiently high, a network of charge filaments will emerge. If one of the filaments meets a rising strand of positively charged particles, a highly conductive path forms, and charges across all filaments move to the path, generating lightning

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.

Learn why electrical substations are needed to provide safe electricity with minimal energy loss

These typically fenced-off facilities with steel boxes or cylinders topped with cone-like caps house circuit breakers, fuses, and switches that can isolate sections of the grid to prevent electrical failures from spreading. Substations use transformers to modify electrical voltage and are customized to the generation, transmission, and distribution networks they interconnect.

View breakdowns of the world's and each nation's electricity comes from

These charts show how the shares of generated electricity sources—solar, wind, hydro, nuclear, bioenergy, oil, gas, and coal—have changed since 1985. Since 2010, an increase in renewable sources has offset the share lost by nuclear and fossil fuels.

The characteristic zigzag of lightning originates from columns of conductive oxygen

Energized electrons from the base of clouds collide with oxygen molecules, placing them in a "singlet delta state," which makes the air conductive. Collisions continue until more than 1% of nearby oxygen is in this state—about 0.00005 seconds—matching the electrical potential of the cloud and propogating electricity in a 50-meter "step."

How brain cells carry information

At any moment, there is an electrical storm coursing through your body. Discover how chemical reactions create an electric current that drives our responses to everything from hot pans to a mother’s caress.

Learn how critical services, infrastructure, and people would be impacted by a US-scale blackout—a nationwide, long-term failure of the electric grid.

Fluorescent bulbs can be illuminated by overhead power lines without making contact

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.

Electricity can flow indefinitely along a ring of superconducting material, which provides zero resistance to the movement of charges due to quantum effects.

A look at how power is restored after an outage on the electric grid

From minor system failures to more widespread blackouts, crews begin by assessing damage done to infrastructure, such as transmission towers and distribution power lines. Prioritizing essential services, such as hospitals, crews then begin restoration, starting with any damage found closest to the power generation and working down the distribution system to customers.

View historical records of solar observations and discoveries, from telescopes in the early 1600s revealing sunspots to NASA's Parker Solar Probe photographing the sun from within its outer corona in 2025.

While gas-powered engines typically have 2,000 moving parts, electric vehicles have about 20.

How cosmic rays and pointed ice shards help generate lightning in clouds

Although clouds generate electric fields as electrons are transferred when currents move past one another—not unlike building up static electricity by rubbing socks against carpet—these fields have been measured to be a tenth of the strength needed to make electricity strong enough to travel through air. However, pointed crystals are estimated to boost fields by factors greater than 10, and particles from outer space may help initiate cascades of displaced electrons.

Radioactive elements can generate electricity, sterilize products, and date artifacts

Since their discovery in the 1890s, these substances have been incorporated throughout our daily lives, from treating food packaging and improving microbial safety to their presence in smoke detectors and gauges for ice cream aeration.

Some scientists hypothesize that stressed rocks can discharge built-up static electricity in the form of lightning—a phenomenon known as fracto-luminescence, or earthquake lights.

Lightning is the sudden flow of electricity in the atmosphere as two oppositely charged regions seek to become balanced via the movement of electrons.

Cathode rays are beams of electrons that emit light when hitting a fluorescent screen

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.

The origins of our fascination with time travel

Humans have been captivated by the prospect of leaping forward and backward in time for thousands of years. Georgia Institute of Technology Science Fiction Studies Professor Lisa Yaszek recounts how the concept has been utilized by storytellers from 400 BCE to modern-day to explore our relationship with the supernatural, technology, and the past. In a way, this historical recounting is a journey through time.

The benefits and risks of smart grids, from improved efficiency to cybersecurity risks

By using a network of devices, including digital meters, sensors, and controllers, smart grids can quickly detect mechanical issues and fluctuations in supply and demand, automatically adjusting electricity flow to prevent cascading failures. While this is important for variable solar and wind power generation, many of these computer systems are designed to be controlled remotely, which increases the risk of malicious access.

Wind energy 101

Learn more about the wind industry, from how a wind turbine works, to the new and exciting research in the field of wind energy.

Explore an interactive timeline of technological inventions and social structures since 1500.

Examining the causes of power outages, from system damage to preventative measures

Stray balloons, contact with trees, malfunctioning equipment, and severe weather are among the causes of failures that can cause widespread, unplanned blackouts. Although contingency options that rely on alternative transmission pathways to deliver electricity from generators to consumers may be possible, some shutoffs, brownouts—available power is reduced—and cycles of repeated outages may be intentionally implemented to protect public safety.

Thunder occurs when fast-flowing electricity heats and pressurizes air, causing it to expand and produce a shockwave at each point along the bolt at multiple frequencies.

Simulate the effects of changing supply and demand on the electric grid

In this application, users can modify the demand of fictional cities and the supply of various generators, including a nuclear power plant and a wind farm, which can be disconnected from the grid. Notice that current may flow into or out of external systems to compensate for available generation. See what it takes to cause a blackout in different cities or shut down the entire grid.

Understanding the power grid and how renewable sources fit in

The power grid is evolving to include ever-higher levels of solar and wind, which don't provide inertia. Should system planners and operators panic?

The 2019 Nobel Prize in Chemistry was awarded for lithium-ion battery development

Stanley Whittingham developed the first functional lithium battery in the early 1970s, while John Goodenough doubled its electrical potential in 1980 by replacing the cathode, thereby enhancing its commercial viability. Five years later, Akira Yoshino developed an anode using carbon material, reducing the risk of flammability.

Faraday cages protect enclosed objects by redirecting electrical currents

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.

Exploring World War I technology on the battlefield

Industrialization brought massive changes to warfare during the Great War. Newly-invented killing machines begat novel defense mechanisms, which, in turn spurred the development of even deadlier technologies. Nearly every aspect of what we would consider modern warfare debuted on World War I battlefields. Starting with soldiers on horseback carrying lances and ending in poison gas, machine guns, and aerial battles, this gallery shows the first tools of modern warfare.

Before discovering cells, life was believed to emerge suddenly from inorganic matter

Popularized by Aristotle in the 4th century BCE, spontaneous generation was used to explain phenomena like mice appearing in seemingly sealed grain storage. The invention of the compound microscope in the late 16th century led to the identification of cells as the basic unit of life, but it was not until 1855 that their origin from preexisting cells was established.