The first computers performed calculations using lightbulb-like tubes

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.

A timeline of computer history

The earliest computers bear little resemblance to the computing devices that most people rely on today. This timeline graphic from the Computer History Museum tracks their evolution, from the early days of bulky mainframes that only experts generally used through to the personal computing revolution and on to the modern mobile era. Readers will learn important context ahead of the next major computing platform shift.

Transistors in traditional computers are physically limited to atomic scales

As computer parts shrink, transistors—tiny switches that control the path of electrical signals—become obsolete because electrons can quantum tunnel through switch barriers. This makes quantum computers, which take advantage of quantum effects, an enticing alternative.

All computers are defined by their ability to input, store, process, and output data

From wooden machines to wearable tech, computers have changed a lot in appearance, but they all still perform the same essential tasks. Early computers were made of wood and metal—some were so big that they filled entire rooms just to solve simple math problems.

An explanation of Turing machines—the foundations of digital algorithms and computers

The device reads data, overwrites or ignores it, and then moves on to the next piece of data based on a set of programmed rules. By imagining this data as zeros and ones—binary that makes up computer code—Turing machines became the theoretical models for how any algorithm could be run on a computer if the procedure could be coded into a set of digital rules.

FLOW-MATIC was the first programming language resembling the English language

As part of the team working on UNIVAC—the first commercially produced electronic digital computer in the US—Grace Hopper helped develop the system that enabled nonprogrammers and businesspeople without a strong mathematics background to use the machine effectively, thereby enhancing the computer's commercial viability.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

CES debuted in 1967 amid a wave of miniaturization in at-home electronics

The rapid development of integrated circuits—the basis of computing power—in the 1960s catalyzed an industrial shift toward miniature devices, including pocket transistor radios, smaller TVs, and more. This first consumer electronics trade show (with a slate of 117 exhibitors and 17,000 attendees) sought to make everyday electronics accessible and portable. See a timeline of early consumer tech with photos.

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.

The first computer virus was created by a USC doctoral candidate in 1983

A year after creating malware in a controlled experiment that multiplied until it took over all of a computer's memory, Fred Cohen went public with his research and its risks. He called the self-replicating software a "computer virus," a term Cohen's advisor, Leonard Adleman, coined to describe its infectious behavior. (Some readers may experience a paywall.)

The first algorithmic random number generator was developed in 1946

Although previous methods of randomness involved physical tools with limited outcomes, such as dice, or relied on chaotic variables for number generation, such as electronic noise, John Von Neumann's middle-square method turned the problem into a mathematical computation. It has since been replaced by methods that generate numbers from unique initial values, such as the time on a clock.

The terms 'bug' and 'debugging' were popularized by Grace Hopper's team

Engineers working on the Mark II computer at Harvard University identified a moth in one of its components in 1947, which caused it to malfunction. Describing the incident as the "first actual case of bug being found," the term first used by Thomas Edison in 1878 to describe faults in an apparatus caught on.

VisiCalc was the first electronic spreadsheet, released with Apple II's personal computer in 1979

Before 1979, managers were essentially information processors working off paper ledgers. Scenario modeling was slow, manual, and expensive. Companies were understood as organizations that built things with financial analysis as secondary. VisiCalc made calculation so cheap that you could work iteratively, setting out forecasts and tweaking assumptions until you got the answer you wanted. Oks argues It created a new way of seeing the world.

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.

The first practical silicon solar cell was developed at Bell Labs

In 1953, scientists at Bell Labs attempted to develop a power source for phone systems in remote locations, as the dry battery cells lacked the necessary longevity. They experimented with solar power, but the selenium solar cells of the time were too inefficient, eventually leading to the usage of silicon.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

The first ATM—dubbed a 'cash dispenser'—was installed in 1967 in London

Specifically, the first ATM (which stands for “automatic teller machine”) made its debut at a Barclays bank in London. A timeline of ATM history can help illustrate and visualize other key events in ATM history.

An integrated circuit combines major circuit components onto a single device

Before 1958, these components were fabricated separately before manual assembly, introducing human error, delays, and higher costs. The invention of the IC laid the foundation for automated manufacturing, miniaturization, and improvements to speed and energy efficiency.

The world spent up to $600B to avert the Y2K computer glitch

Early computer programmers used a two-digit code to record years rather than four. With the switch in the year 2000 from '99 to '00, analysts feared databases might fail and prompt outages and financial catastrophe. To prepare, governments and businesses spent an estimated $300B to $600B to mitigate the glitch.

The hardware powering AI was originally designed for video game graphics processing

Graphics processing units are specialized computer chips that can process multiple data streams in parallel, including pixel colors for a display. Such processing is required to find connections across text data and generate outputs quickly.

Before electric lights, Christmas trees were lit with real candles

The practice of lighting Christmas trees with electricity didn’t begin until the late 1800s. Before that, families used wax candles on branches—a dangerous tradition that originated in 16th-century Germany.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

The first portable laptop had a 5-inch screen and weighed 24.5 pounds

Introduced in 1981 for $1795, the Osborne 1 had no battery but came bundled with almost $1,500 worth of software. Early announcement of a future model stalled sales and bankrupted the company as users waited for the more advanced version, a phenomenon now called the Osborne effect.

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.

Why were tanks invented?

Tanks first appeared in warfare in World War I. As old methods of conducting battles proved ineffective, the idea of an armored vehicle that could traverse almost any terrain and carry a cannon came to fruition. World War I provided the impetus and finances to develop the modern tank. Learn more in this short but detailed article.

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.

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

Building the first atomic bomb required unprecedented coordination

Creating the first atomic bombs demanded breakthroughs in physics, engineering, and logistics—uniting elite scientists with tens of thousands of workers across the US. This in-depth history explains how the Manhattan Project overcame those challenges.

Particle accelerators propel matter toward small targets at high speed

Devices like cathode-ray tube televisions were once basic particle accelerators, but modern ones, such as the Large Hadron Collider, use massive magnetic fields and circular tunnels to achieve energies high enough to recreate the conditions just after the big bang.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

The first robot in literature may have been a 'mechanical man' in 1907's 'Ozma of Oz,' a book in L Frank Baum's 'Wizard of Oz' series.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

Learn more about the history of fireworks, which dates back to an accidental invention during an alchemist's quest for information about immortality.

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

A vending machine run with Anthropic's AI went out of business after it was convinced to give away items for free and sell a video game console.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

The animatronic shark from Steven Spielberg's 'Jaws,' the first modern blockbuster, was a complex underwater apparatus called 'Bruce.'

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Sears sold DIY house kits starting at $600 in its famous catalog from 1908 through the 1940s, resulting in roughly 10,000 'Sears and Roebuck houses' being built.

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

A century of Billboard issues documenting the evolution of popular music.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

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.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight