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

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.

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.

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.

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.

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 flow of electricity in AC circuits flips back and forth, unlike DC circuits

Alternating currents in the US change the flow direction 120 times every second, allowing for efficient transformation and transmission of energy across power grids by sending energy at lower currents. This is changed into one-way direct currents when powering electronics.

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.

How electricity is generated by heating water into steam, which rotates magnets

Electrical current—the flow of electrons in a wire—can be produced when exposing a wire to a changing magnetic field. By rotating the magnets, as occurs in a turbine-generator system, the field changes become cyclical. This produces alternating current—flow that moves forward and backward—converting mechanical energy into electrical energy.

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

The inventor was interested in developing a scientific method for communicating with the dead. He was not interested, though, in the occult figures who believed the dead could be reached through Spiritualism, which he found childish. He believed those kinds of people "permit themselves to become, in a sense, hypnotized into thinking that their imaginings are actualities."

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.

The speed of electricity may refer to the movement of electrons or energy

In the 18th century, various experiments, including one in which monks holding an iron wire were shocked, suggested that electricity traveled at infinite speed. Advancements in technology, recognizing that electric currents were moving electrons, and the development of the theory of electromagnetism showed that electric signals can travel at near light speed, despite electrons moving much slower.

The world's first geothermal power plant was built in 1913 in Devil's Valley

In Tuscany, Italy, Prince Piero Ginori-Conti of Trevignano established the plant nine years after creating a generator that powered five light bulbs using steam vents in the area. Within three years, a second plant was built with two generators, each with 10 times the energy output of the first.

The treadmill was invented as a machine for prison labor

William Cubitt invented the machine in the early 1800s, imagining prisoners, usually two at a time, would use it to grind grain or pump water.

The first computers performed calculations using lightbulb-like tubes

Before transistors, the first electronic computers relied on vacuum tubes—components that switched signals on and off. Despite machines like ENIAC—the first programmable, general-purpose, electronic computer—utilizing nearly 18,000 tubes that generated massive amounts of heat and frequent failures, they laid the foundation for modern computing hardware.

No proof of Nikola Tesla developing a working 'death ray' exists

He described his "teleforce" weapon as generating beams of concentrated particles that could destroy targets from 250 miles away with unparalleled precision. Analysis of Tesla's papers on the subject by an expert after his death revealed the work to be mostly speculative.

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.

Samuel O’Reilly patented the tattoo gun in 1891

Before the tattoo gun's invention, recipients sweated while artists slowly tapped or sliced designs into their flesh. The tattoo gun changed the field, helping artists ink clients’ skin at incredible speeds. Inventor Samuel O’Reilly applied the basic idea of an electric pen invented by Thomas Edison to his tattoo gun.

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.

Explore jury nullification, the little-known power that lets jurors ignore the law and acquit anyway

When jurors disagree with a law, they can simply vote to acquit regardless of the evidence; however, this practice is rare, and the legal system actively discourages it. This podcast traces its history from a Quaker prayer meeting in London to the LA riots.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

The Electoral College was shaped in part to balance North–South power

This article examines how the Electoral College emerged from political compromise, including efforts to placate slave-owning Southern states and concerns that Northern states would dominate a direct national presidential vote.

The Wrights battled inventor Glenn Curtiss for market dominance, ultimately losing

Their 1903 flights were met with skepticism, and the pair were hesitant to conduct public demonstrations. By 1908, Curtiss developed his own airplane, successfully flying a mile in front of judges and winning the nation’s first pilot license. The Wrights sued for patent infringement, sparking a business war.

The story of serial killer Ed Gein who inspired pop culture

The creators of antagonists from "Silence of the Lambs" and "Texas Chainsaw Massacre" took notes from this horrifying Wisconsinite's story, known for body-snatching and creating keepsakes from corpses.

An LSD scientist's role in a US mind control project

Within a decade of LSD's discovery, the US government had launched a secret initiative involving hypnosis and hallucinogens. LSD researcher Louis Jolyon West conducted experiments for the CIA's MKUltra project, which focused on the potential of mind control. He later took part in a criminal trial that hinged on testimony whose sourcing was seemingly inspired by MKUltra experiments. This article explores light shed by West's personal archive.

Particle accelerators allow physicists to create controlled nuclear experiments

Before the 1930s, scientists relied on naturally radioactive substances to learn about atomic nuclei. The first atom was split in 1932 when John Cockcroft and Ernest Walton fired a beam of accelerated protons at a lithium atom, producing alpha radiation.

The Civil War introduced many technological advances to both society and warfare

The conflict accelerated innovations—including railroads, telegraphs, ironclad ships, and mass-produced weapons—while advances in photography, medicine, and manufacturing transformed how Americans communicated, healed, and built after the war.

The magazine competition that pitted Houdini against the author of 'Sherlock Holmes'

In 1922, Scientific American magazine launched a contest to prove, or disprove, the existence of ghosts and define the limits of Spiritualism. This article details how this competition furthered the growing ideological split between escapologist...

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

After her fellow cult members tried to kill her with an LSD-infused hamburger, one member of the Manson Family, the murderous cult led by Charles Manson, decided to testify against the group's leader.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

After the Boston Tea Party, colonists switched to coffee, which became the main morning drink for revolutionaries.

The concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

Dirty lightning is a thunderstorm created from friction between rising and falling flows of ash and smoke during volcanic eruptions.

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

The rivalry between Alexander Hamilton and Thomas Jefferson centered on federalism—the question of how much power the federal government should hold relative to the states.

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

Walt Disney's early film 'Alice's Wonderland' was a groundbreaking innovation in the silent film era

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

See a ranking of the best (and worst) Federal Reserve Chairs since 1914 out of the 16 men and women who have held the office since.

Legendary architect Frank Lloyd Wright designed the SC Johnson headquarters in Wisconsin, aiming to make a cathedral-like workplace

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

The Beatles' US label rejected the band's first two singles, 'Please Please Me' and 'From Me to You,' with one executive calling the band 'dead in the water.'