Technology tree · how virtual worlds became possible

Painted scenes (at least 51,200 years ago)

A red-ochre painting in Leang Karampuang cave, Sulawesi, shows human-like figures and a wild pig. Uranium-series dating of the calcite over it puts it at least 51,200 years old. It’s the oldest known scene that tells a story. So people have been painting imagined or remembered worlds for a very long time.

Led to: Linear perspective

Source: Oktaviana et al., ‘Narrative cave art in Indonesia by 51,200 years ago’, Nature 631 (2024)

Address: /trees/technology?n=cave-painting

Camera obscura explained (c. 1011–1021)

China recorded earlier that light through a small hole makes an upside-down image. The Later Mohist Canon (compiled between the late 4th and mid-3rd century BCE) explains the flip by rays crossing at the hole. Shen Kuo’s Dream Pool Essays (1088) said it again, calling the inversion after the small hole a normal principle. Ibn al-Haytham wrote his Kitāb al-Manāẓir (Book of Optics) in Cairo in the early eleventh century. He tested the hole image by experiment. He also argued that we see by receiving light, not by sending it out from the eye. His Optics later fed into Renaissance theories of perspective.

Led to: Linear perspective; Magic lantern; Photography

Source: Encyclopaedia Britannica, ‘Kitab al-manazir’ (and ‘Ibn al-Haytham’)

Address: /trees/technology?n=camera-obscura

Shadow theatre (11th century (securely documented))

In shadow theatre, flat figures behind a lit screen act out stories. It’s documented in Java by the 11th-century poem Arjunawiwaha (c. 1035), which compares the world to a puppet screen. It’s documented in China by Northern Song accounts (960–1127). Earlier claims are legend, or only name a performance without describing it. Examples are the Han story of Emperor Wu and the Jaha and Wukajana inscriptions of c. 840–907. So the earliest date isn’t secure.

Source: Istari, Wukayana inscription of Balitung (907 CE), Berkala Arkeologi (BRIN); Wikipedia, ‘Wayang’ for the Jaha/Arjunawiwaha dates; Hanshu 97A tale as discussed by Gao Cheng

Address: /trees/technology?n=shadow-theatre

Linear perspective (c. 1415–1425)

Filippo Brunelleschi showed a geometric way to paint a scene as it looks from one spot. Alberti wrote the method down in De pictura (1435). The rule is that parallel lines all meet at a vanishing point. Real-time graphics software uses the same projection on every frame.

Built on: Painted scenes; Camera obscura explained

Led to: The panorama; Photography; Stereoscope

Source: Encyclopaedia Britannica, ‘Linear perspective’

Address: /trees/technology?n=perspective

Magic lantern (c. 1659)

In 1659 Christiaan Huygens drew a set of skeleton images to be projected by a lantern with convex lenses. That’s the earliest surviving record of the device. It was the first widely used way to throw a painted or photographic image on a wall for an audience. For over two centuries it was the standard tool for public image shows.

Built on: Camera obscura explained

Led to: Projected moving pictures

Source: Magic Lantern Society (UK), ‘A brief history of the Magic Lantern’

Address: /trees/technology?n=magic-lantern

The panorama (1787–1788)

Robert Barker patented the panorama in 1787 and showed the first one, a view of Edinburgh, in 1788. Later rotundas held round paintings about 18 metres across or more. Viewers stood in the middle of a painted horizon that never broke. It was an early commercial try at swapping a visitor’s surroundings for a built scene.

Built on: Linear perspective

Source: Encyclopaedia Britannica, ‘Robert Barker’ and ‘Panorama’

Address: /trees/technology?n=panorama

Photography (c. 1826–1827)

Nicéphore Niépce made the earliest surviving camera photograph around 1826–27. It was a heliograph on a pewter plate, the view from his window at Le Gras, after an exposure of many hours. It fixed an optical image for good. So for the first time an image resembled the world through a machine, not through a hand.

Built on: Camera obscura explained; Linear perspective

Led to: Projected moving pictures

Source: Harry Ransom Center, University of Texas, ‘The First Photograph’ (Niépce heliograph)

Address: /trees/technology?n=photography

Motion from stills (1832)

Joseph Plateau in Ghent and Simon Stampfer in Vienna each came up with the phenakistiscope in 1832. It’s a slotted disc of drawings in sequence. Spin it and look in a mirror, and the drawings seem to move. It showed that the eye blends a fast series of still images into smooth motion. That’s the principle behind every film and video frame.

Led to: Projected moving pictures

Source: Encyclopaedia Britannica, ‘Phenakistoscope’

Address: /trees/technology?n=phenakistiscope

Stereoscope (1838)

In 1838 Charles Wheatstone showed that two slightly different flat drawings, one for each eye, merge into a single image with real-looking depth. He built a mirror stereoscope to prove it. The difference between the two eyes’ views became something you could control. Every headset since still uses it.

Built on: Linear perspective

Led to: Stereoscopic film; Sensorama; The Ultimate Display; Telesphere Mask

Source: Wheatstone, ‘Contributions to the physiology of vision, Part I’, Phil. Trans. R. Soc. 128 (1838), 371–394

Address: /trees/technology?n=stereoscope

Stereo sound (1881)

At the 1881 Paris International Exposition of Electricity, Clément Ader’s system sent live performances from the Opera over telephone lines to visitors. It used paired transmitters and receivers, which gave a two-ear, spatial effect. A subscription service followed in 1890. It was an early sign that a sense of place could be sent by electricity to a listener far away.

Led to: Sensorama

Source: Bob’s Old Phones / Telephone Collecting, ‘Clément Ader’

Address: /trees/technology?n=theatrophone

Projected moving pictures (1895)

On 28 December 1895 the Lumière brothers showed the Cinématographe to a paying crowd at the Grand Café in Paris. It was a camera, printer and projector in one. Showing film to a shared audience made recorded motion something people experienced together. That’s the template for later shared screens and rooms.

Built on: Photography; Motion from stills; Magic lantern

Led to: Stereoscopic film; Sensorama; Aspen Movie Map; Telesphere Mask

Source: Encyclopaedia Britannica, ‘Cinématographe’

Address: /trees/technology?n=cinema

Stereoscopic film (1922; boom 1952–54; revival 2009 · Stalled)

Stereoscopic cinema took Wheatstone’s idea and put it on film. Anaglyph features were shown in the early 1920s. The polarised Natural Vision process set off the 1952 boom with Bwana Devil. Audiences lost interest within about a year. The format came back with digital cinema in 2009.

Why it stalled: It stalled because the picture was fixed. Every viewer saw the same two views no matter where they looked. Glasses and projector alignment were annoying. And the image had no way to respond to the viewer.

Built on: Projected moving pictures; Stereoscope

Source: Encyclopaedia Britannica, ‘3-D’ (film process) and ‘Natural Vision’

Address: /trees/technology?n=3d-film

Flight simulator (1929)

Edwin Link built a cockpit driven by air pressure. It pitched, rolled and yawed as the pilot moved the controls, so trainees could practise instrument flying on the ground. The Allies used Link’s Blue Box in the Second World War, and more than 500,000 pilots are reported to have trained on such devices. It showed that a believable feel of flight could stand in for a real aircraft in training.

Source: ASME Landmark #210, ‘Link C-3 Flight Trainer’

Address: /trees/technology?n=link-trainer

Cochlear implant (1957; multichannel 1977–84)

Djourno and Eyries in Paris reported in 1957 that they had electrically stimulated the auditory nerve of a deaf patient. House and Doyle implanted a single-channel device in 1961. Multichannel devices (Hochmair, Clark) were implanted in 1977–78 and approved by the FDA for adults in the mid-1980s. Sound reaches the brain without a working ear. It was the first clinical case of a sense supplied by direct electrical stimulation of the nervous system.

Led to: Brain-computer interface

Source: Lasker Foundation, ‘Modern cochlear implant’ (2013 Clinical Medical Research Award)

Address: /trees/technology?n=cochlear

Telesphere Mask (1960)

Morton Heilig patented a head-worn viewer that gave each eye its own image, with stereo sound. That was years before any computer drove such a display. It played prerecorded film and didn’t track the head.

Built on: Stereoscope; Projected moving pictures

Led to: Head-mounted display

Source: Heilig, US Patent 2,955,156, “Stereoscopic-television apparatus for individual use” (1960)

Address: /trees/technology?n=telesphere

Sensorama (1962 (patent; prototype 1957–62) · Stalled)

Morton Heilig’s Sensorama Simulator (US patent 3,050,870, filed 1961, granted 1962) was an arcade booth. It played pre-filmed stereoscopic colour footage with stereo sound, vibration, wind and scent. It was the first try at engaging several senses at once in one machine. It’s the usual starting point for the history of virtual reality.

Why it stalled: It stalled because everything was pre-recorded on film. No computer made or changed the scene, so the viewer could look but never change anything.

Built on: Projected moving pictures; Stereoscope; Stereo sound

Source: US Patent 3,050,870, M. L. Heilig, ‘Sensorama Simulator’ (filed 10 Jan 1961, granted 28 Aug 1962)

Address: /trees/technology?n=sensorama

First video games (1958; 1962)

William Higinbotham’s Tennis for Two (October 1958, Brookhaven) drew a ball’s flight on an oscilloscope under analog-computer control. Spacewar! (1962) was a two-player space combat game written for MIT’s PDP-1 digital computer. Together they showed that a machine could host a small, shared world with rules that players act in.

Built on: Stored-program computer

Led to: Arcade video game

Source: Computer History Museum, ‘Spacewar!' (see also CHM timeline 1958 for Tennis for Two)

Address: /trees/technology?n=tennis-for-two

Interactive graphics (1963)

Ivan Sutherland’s doctoral thesis at MIT (1963) described Sketchpad. It ran on the TX-2 and let a user draw and edit line diagrams with a light pen, with constraints and reusable master drawings. It made the interactive display a way to work on a model held in a computer.

Built on: Stored-program computer

Led to: The Ultimate Display; First-person networked world; Realistic shading

Source: I. E. Sutherland, ‘Sketchpad: a man-machine graphical communication system’, MIT PhD thesis (1963), University of Cambridge reprint, TR-574

Address: /trees/technology?n=sketchpad

Simulacron-3 (1964 · Idea)

Daniel F. Galouye’s novel Simulacron-3 (1964; UK title Counterfeit World) describes a city simulated on a computer. Its people don’t know they’re programs. It’s one of the earliest novels about a world run inside a computer. It’s also a common reference point in writing on the simulation argument.

Built on: Stored-program computer

Source: The Encyclopedia of Science Fiction, ‘Galouye, Daniel F.'

Address: /trees/technology?n=simulacron

The Ultimate Display (1965 · Idea)

In his 1965 paper to the IFIP Congress, Sutherland proposed a computer-driven display so complete that it could control matter in the room. He wrote that a chair displayed there would be good enough to sit in. It set the goal of virtual reality as a world you couldn’t tell from reality in any sense.

Built on: Interactive graphics; Stereoscope

Led to: Head-mounted display

Source: I. E. Sutherland, ‘The Ultimate Display’, Proc. IFIP Congress 1965, vol. 2, pp. 506–508 (scan)

Address: /trees/technology?n=ultimate

Head-mounted display (1968)

In 1968 Sutherland and Bob Sproull built a head-mounted display. It showed a user simple wireframe 3D graphics, which a computer redrew as the user’s head moved. The optics hung from the ceiling (the ‘Sword of Damocles’). It was the first system to combine a head-worn display, computer-generated images and head tracking.

Built on: The Ultimate Display; Telesphere Mask

Led to: Data glove; “virtual reality”; CAVE; Virtual Boy; Modern VR headset

Source: I. E. Sutherland, ‘A head-mounted three dimensional display’, AFIPS Fall Joint Computer Conference (1968)

Address: /trees/technology?n=damocles

Realistic shading (1971–1980)

Henri Gouraud (1971) and Bui Tuong Phong (1973–75) devised smooth shading and a lighting model for polygon surfaces. Turner Whitted (1980) showed recursive ray tracing with reflection and refraction. Each step moved computer images closer to how light behaves. The techniques became the basis of film and game rendering.

Built on: Interactive graphics

Led to: CAVE; Real-time 3D worlds

Source: Gouraud, ‘Continuous shading of curved surfaces’, IEEE Trans. Computers C-20 (1971); also Phong, CACM 18 (1975), and Whitted, CACM 23 (1980)

Address: /trees/technology?n=shading

Arcade video game (1972)

Atari’s Pong was designed by Allan Alcorn from a concept by Nolan Bushnell. It was first placed in a Sunnyvale bar in late 1972 and sold in large numbers. It was built from logic chips, not a microprocessor. It made the video game a commercial public pastime. It also funded the industry that later drove graphics hardware.

Built on: First video games; Integrated circuit

Led to: Cyberspace

Source: The Strong National Museum of Play, ‘Pong’

Address: /trees/technology?n=pong

First-person networked world (1973–74)

Maze was written at NASA Ames in 1973 by Steve Colley, Greg Thompson and Howard Palmer on Imlac PDS-1 computers. It showed the view down corridors from the player’s own position. It started with two linked machines, then added shooting and bots. It was an early first-person shared 3D space. It’s a likely ancestor of the networked first-person shooter.

Built on: Packet network; Interactive graphics

The sources leave this date or claim uncertain.

Source: DigiBarn Computer Museum, Steve Colley, ‘Maze War’ history

Address: /trees/technology?n=maze-war

Colossal Cave Adventure (1975–76)

Will Crowther wrote this text game in 1975, and Don Woods extended it in 1976. A player explored a cave described in prose by typing commands. It set up the explorable, rule-bound world described in text. The first multi-user worlds built on it.

Built on: Stored-program computer

Led to: Shared text world

Source: Encyclopaedia Britannica, “Adventure”

Address: /trees/technology?n=adventure

Shared text world (1978–1980)

Roy Trubshaw began MUD at the University of Essex in autumn 1978, and Richard Bartle joined the work. Once Essex was linked to ARPANET in spring 1980, outsiders could connect. It was a lasting multi-user world of rooms and objects that several people occupied at once. It set the pattern for later online worlds.

Built on: Packet network; Colossal Cave Adventure

Led to: Graphical online world; Persistent online worlds

Source: Richard Bartle, ‘Early MUD history’

Address: /trees/technology?n=mud

Aspen Movie Map (1978–79)

MIT’s Architecture Machine Group filmed Aspen street by street in 1978–79. A user could drive through the stored footage on a touch-screen laserdisc system, turning left, turning right or stopping at will. It was an early interactive, navigable picture of a real place. It was a forerunner of street-level mapping.

Built on: Projected moving pictures; Stored-program computer

Source: MIT Media Lab, ‘The Aspen Movie Map beat Google Street View by 34 years’

Address: /trees/technology?n=aspen

Cyberspace (1982–84 · Idea)

William Gibson coined the word ‘cyberspace’ in the story ‘Burning Chrome’ (Omni, July 1982). He made it popular in the novel Neuromancer (1984), as a shared graphical space of data that you can move around in. It gave a name and an image to the idea of an online world, and engineers later cited it.

Built on: Arcade video game

Led to: The Metaverse

Source: The Encyclopedia of Science Fiction, ‘Cyberspace’

Address: /trees/technology?n=cyberspace

Data glove; “virtual reality” (1985–1987)

Jaron Lanier founded VPL Research in 1985. Its DataGlove (1987) and EyePhone headset were the first commercial VR products. Britannica credits Lanier with coining the term ‘virtual reality’ in 1987. The company put body-tracking input and a head display within reach outside military and academic labs.

Built on: Head-mounted display

Source: Encyclopaedia Britannica, ‘Jaron Lanier’

Address: /trees/technology?n=vpl

Graphical online world (1986–88)

Habitat was built by Chip Morningstar and Randy Farmer at Lucasfilm Games for the Commodore 64, over the Quantum Link service. It ran as a pilot in 1986. Users showed up as cartoon figures called avatars in a shared graphical world. It tested at scale what happens when thousands of people live in a designed virtual place. The builders published the lessons.

Built on: Shared text world

Led to: The Metaverse; Persistent online worlds

Source: Morningstar and Farmer, ‘The Lessons of Lucasfilm’s Habitat’ (1990)

Address: /trees/technology?n=habitat

CAVE (1992)

The CAVE was described in 1992 by Cruz-Neira, Sandin, DeFanti and colleagues at the University of Illinois at Chicago. It projected stereo images on the walls and floor of a room. Several people could stand inside a shared virtual scene wearing light glasses. It showed an immersive alternative to the head-worn display.

Built on: Head-mounted display; Realistic shading

Source: Cruz-Neira, Sandin and DeFanti et al., ‘The CAVE: audio visual experience automatic virtual environment’, CACM 35(6) (1992)

Address: /trees/technology?n=cave

The Metaverse (1992 · Idea)

Neal Stephenson’s novel Snow Crash (1992) coined the word ‘metaverse’. It means a shared 3D online world where people appear as avatars. Technology firms revived the term decades later as a name for the next stage of online worlds.

Built on: Cyberspace; Graphical online world

Source: Encyclopaedia Britannica, ‘Snow Crash’

Address: /trees/technology?n=metaverse

Real-time 3D worlds (1993–1996)

Id Software’s Doom (December 1993) put networked players in texture-mapped first-person levels on ordinary PCs. Quake (1996) drew true polygonal 3D with real-time lighting. Fast first-person 3D on consumer hardware created the market and the techniques for later virtual worlds.

Built on: Realistic shading; Microprocessor

Led to: Persistent online worlds

Source: The Strong National Museum of Play, ‘Quake’ (with Encyclopaedia Britannica, ‘Doom’)

Address: /trees/technology?n=doom

Virtual Boy (1995–96 · Stalled)

Nintendo’s Virtual Boy (Japan July 1995, North America August 1995) was a table-mounted stereoscopic console. It showed red, wireframe-style images. It was pulled within a year. Nintendo’s own Iwata later called it a commercial failure.

Why it stalled: It stalled because in 1995 there was no affordable compact full-colour display and no head tracking. The red single-colour image, fixed viewing position and awkward fit tired users quickly.

Built on: Head-mounted display; Integrated circuit

Source: Iwata Asks, ‘Shigeru Miyamoto talks Virtual Boy’, Nintendo

Address: /trees/technology?n=virtualboy

Persistent online worlds (1997–2003)

Ultima Online (1997), EverQuest (1999) and Second Life (2003) put very large numbers of people into lasting graphical worlds. The worlds kept going when any player logged off. They had economies and social structures of their own. They’re the best evidence we have of how people behave in long-lived virtual places.

Built on: Graphical online world; Shared text world; Real-time 3D worlds; World Wide Web

Source: Encyclopaedia Britannica, ‘Ultima Online’ and ‘Online gaming’

Address: /trees/technology?n=mmo

Brain-computer interface (2004–2006)

In 2006 Hochberg and colleagues reported on a man paralysed from the neck down. He could move a computer cursor and run a simple robotic hand using signals from a microelectrode array implanted in his motor cortex. It showed that voluntary neural activity could be read out as a control signal.

Built on: Cochlear implant; Microprocessor

Led to: Full-immersion VR; Whole-brain emulation

Source: Hochberg et al., ‘Neuronal ensemble control of prosthetic devices by a human with tetraplegia’, Nature 442 (2006)

Address: /trees/technology?n=bci

Modern VR headset (2012–13 (developer kit); 2016 (consumer))

Oculus raised $2.4 million on Kickstarter in 2012. It shipped the Rift DK1 developer kit from late March 2013. The consumer Rift followed on 28 March 2016. It paired phone-class displays and sensors with a GPU and low-latency head tracking. That made a wide-view headset cheap enough for developers and consumers.

Built on: Head-mounted display; Graphics processor; Smartphone

Led to: Room-scale tracking

Source: Road to VR, ‘3 years ago the Oculus Rift DK1 shipped, here’s a quick look back’

Address: /trees/technology?n=rift

Room-scale tracking (2015–2016)

HTC and Valve announced the Vive in March 2015 and shipped it on 5 April 2016. It used Valve’s Lighthouse system, which sweeps infrared lasers across a play area. A headset and two hand controllers could be tracked precisely over about four metres. Walking and reaching inside a virtual space, not just turning your head, became standard.

Built on: Modern VR headset

Led to: Standalone headsets

Source: Road to VR, ‘HTC, Valve and SteamVR: a 2015 retrospective and CES 2016 preview’

Address: /trees/technology?n=roomscale

Standalone headsets (2018–2019)

Oculus Quest (21 May 2019) was a self-contained headset. It used four cameras to track the headset and both controllers from the inside, with no PC or base stations. Earlier standalone units (Oculus Go, Lenovo Mirage Solo, Vive Focus, 2018) tracked at most the head position. The Quest made full tracking portable.

Built on: Room-scale tracking; Smartphone

Led to: Full-immersion VR

Source: Road to VR, ‘Oculus announces Quest, the high-end standalone headset starting at $400’

Address: /trees/technology?n=standalone

Neural rendering (2020–2023)

Mildenhall et al.’s Neural Radiance Fields (2020) learned a scene from photographs and drew new views of it. 3D Gaussian Splatting (Kerbl et al., 2023) did it in real time. Photo-real 3D scenes you can explore can now be captured, not modelled by hand.

Built on: Deep learning on GPUs; Graphics processor

Led to: Generated interactive worlds; Real-time photorealism

Source: Mildenhall et al., ‘NeRF: Representing scenes as neural radiance fields for view synthesis’, ECCV 2020, arXiv:2003.08934

Address: /trees/technology?n=neural-rendering

Generated interactive worlds (2024–2025)

In 2024, research systems such as Google DeepMind’s Genie and the GameNGen diffusion model generated each frame of a playable environment from the player’s input. They had no hand-written game engine. GameNGen simulated the game Doom at over 20 frames per second. By 2025 the demonstrations ran for minutes at interactive speeds. They’re still research prototypes.

Built on: Transformer architecture; Neural rendering; Learned world models; Diffusion models

Source: Valevski et al., ‘Diffusion Models Are Real-Time Game Engines’ (GameNGen), arXiv:2408.14837 (2024)

Address: /trees/technology?n=world-models

Real-time photorealism (2029–2034 · Forecast)

Industry figures have forecast real-time images you can’t tell from photographs. In 2024 one major vendor stated a window of 5 to 10 years. A 2013 forecast of ten years for the same milestone came due in 2023. No one claimed it had been met.

Built on: Neural rendering

Address: /trees/technology?n=photoreal

Full-immersion VR (2029–2030s · Forecast)

One named futurist has published dates for VR that works at the level of the nervous system. He puts it in the late 2020s to the 2030s, by way of nanobots in the brain. We found no expert survey or independent forecast of this milestone. No such system has been demonstrated.

Built on: Brain-computer interface; Standalone headsets; Molecular nanotechnology

Address: /trees/technology?n=fulldive

Whole-brain emulation (2050–2075 · Bridge)

Also in the Simulations tree and Becoming synthetic.

The 2008 FHI roadmap judged that emulation was possible before mid-century only if models at the electrophysiological level are enough. Finer detail would need later dates. A 2014 Monte Carlo model gives a median of 2064, if it arrives at all. The Metaculus community median is about 2073.

Built on: Human-level AI; Brain-computer interface

Address: /trees/technology?n=wbe

Star-scale computer (c. 2250 or later · Forecast)

Dyson (1960) proposed that advanced civilisations would capture starlight. Bradbury (1997–99) extended this to nested shells that run computers on the star’s waste heat. The only dated estimate we found is Bradbury’s. It’s about 2250 if current silicon production trends continued, and within a few thousand years at most.

Built on: Moore’s law; Molecular nanotechnology

Address: /trees/technology?n=matrioshka

Abacus (uncertain; Mesopotamian counting boards of the 3rd millennium BC (disputed); oldest surviving board c. 300 BC)

A counting board, or abacus, is a surface where counters stand for place values. By moving them you can add, subtract, multiply and divide. Mesopotamian examples are often claimed, but none survives and the claim is disputed. The oldest surviving board is the Salamis tablet (c. 300 BC), though some see it as a gaming board. It shows that calculation can be moved into a physical state that a mechanism, and later a circuit, can hold.

Led to: Mechanical calculator

The sources leave this date or claim uncertain.

Source: Encyclopaedia Britannica, ‘Abacus’

Address: /trees/technology?n=abacus

Zero as a number (628 CE (Brahmagupta); placeholder dot earlier, date disputed · Idea)

Brahmagupta’s Brāhmasphuṭasiddhānta (628 CE) is the earliest surviving text to treat zero as a number with its own rules. Adding or subtracting zero leaves a number unchanged. A number times zero is zero. His rules for dividing by zero were incomplete, and his 0 ÷ 0 = 0 is wrong. A dot used as a placeholder appears earlier in the Bakhshali manuscript. But radiocarbon dates for its folios run from as early as the 3rd–4th century CE to the 9th–10th. So the date of its zero is disputed.

Led to: Binary arithmetic; Algorithms (al-Khwārizmī)

Source: O’Connor and Robertson, ‘Brahmagupta’, MacTutor History of Mathematics (rules); Bodleian Libraries / University of Oxford, Bakhshali manuscript carbon dating release (2017) (dating caveat)

Address: /trees/technology?n=zero

Algorithms (al-Khwārizmī) (c. 820s CE (Arabic original lost); Latin 12th century · Idea)

In early 9th-century Baghdad, al-Khwārizmī wrote a treatise on the Hindu place-value numerals, including zero, and on calculating with them. The Arabic text is lost. The Latin translation, Algoritmi de numero Indorum, is known to differ a lot from it. Through it, and the later algorismus texts, the Hindu-Arabic numerals and their written arithmetic reached Europe. The word ‘algorithm’ comes from the Latinized form of his name.

Built on: Zero as a number

Led to: Mechanical calculator

Source: O’Connor and Robertson, ‘Abu Ja’far Muhammad ibn Musa Al-Khwarizmi’, MacTutor History of Mathematics (see also Encyclopaedia Britannica, ‘al-Khwarizmi’ and ‘algorismus’)

Address: /trees/technology?n=algorithm

Self-playing flute (Baghdad) (9th century)

The Banū Mūsā brothers wrote their Book of Ingenious Devices in 9th-century Baghdad. It describes a flute that plays by itself. A water-driven mechanism pushes air to sound pipes under a revolving cylinder, and swapping the cylinder changes the tune. Koetsier (2001) counts it among the earliest programmable machines. Al-Jazari’s 1206 book describes later musical automata. But no documented line runs from either work to the European pinned barrel or to the Jacquard loom.

Source: Koetsier, ‘On the prehistory of programmable machines: musical automata, looms, calculators’, Mechanism and Machine Theory 36(5), 2001, pp. 589–603; Hill (transl.), The Book of Ingenious Devices (Reidel, 1979)

Address: /trees/technology?n=banu-musa-flute

Mechanical calculator (1642–1644)

From 1642 Blaise Pascal built a geared adding machine to help his father’s tax work. He made about fifty. Britannica calls it the first calculator made in quantity and actually used. Arithmetic moved from hands to gears.

Built on: Abacus; Algorithms (al-Khwārizmī)

Led to: Analytical Engine; Difference Engine

Source: Encyclopaedia Britannica, ‘Pascaline’

Address: /trees/technology?n=pascaline

Binary arithmetic (1703 (printed 1705) · Idea)

In a manuscript dated 15 March 1679 (De progressione dyadica), Leibniz set out arithmetic in base two. He also sketched a calculating machine without wheels. In it, balls drop through holes that sliding slots open and close, and that does the sums. He never built it, though a working model was made at the Deutsches Museum in the early 2000s. His paper was read to the Paris Academy in 1703 and printed in 1705. It also links the 0–1 notation to the hexagram figures of the Yijing, attributed to Fu Xi, which Joachim Bouvet had sent him from Beijing (received April 1703). An earlier Indian scheme appears in Piṅgala’s Chandaḥśāstra (date uncertain, about the 3rd to 2nd century BCE). It lists metres of short and long syllables in a way later readers analysed as binary.

Built on: Zero as a number

Led to: Zuse Z3

Source: Leibniz, ‘Explanation of Binary Arithmetic’ (1703), English translation

Address: /trees/technology?n=binary

Punched-card loom (1804)

Joseph Marie Jacquard’s 1804 loom used a chain of punched cards to pick which warp threads to lift. To change the pattern, you changed the cards. Bouchon (1725) and Falcon (1728) had used punched paper or cards before him. But Jacquard’s version was widely adopted, and Babbage borrowed its card-reading idea.

Led to: Analytical Engine

Source: Science Museum Group, ‘Model of Falcon’s loom’ (Jacquard refined Falcon’s method in 1804)

Address: /trees/technology?n=jacquard

Difference Engine (1822 (proposed); built 1991 · Stalled)

Babbage designed a machine to compute and print mathematical tables by the method of finite differences. It would take human error out of the arithmetic. A small working section was shown. The full engine wasn’t built in his lifetime.

Why it stalled: Work halted in 1833 after a dispute with his engineer, Joseph Clement. The Science Museum finished Difference Engine No. 2 from his drawings in 1991. That showed the design itself was sound.

Built on: Mechanical calculator

Led to: Analytical Engine

Source: Science Museum, “Charles Babbage’s Difference Engines and the Science Museum”

Address: /trees/technology?n=difference-engine

Analytical Engine (1837 (conceived 1834) · Stalled)

Charles Babbage designed a programmable mechanical computer. It had a store, an arithmetic mill, conditional branching and instructions on punched cards. It anticipated the layout of later computers by a century. Only a trial piece was built before he died in 1871.

Why it stalled: It stalled because it needed thousands of parts, and 1840s Britain couldn’t supply the precision engineering, steady funding and settled design that took. The Computer History Museum lists runaway costs, high precision demands, a dispute with his engineer and patchy financing.

Built on: Punched-card loom; Mechanical calculator; Difference Engine

Led to: Note G

Source: Computer History Museum, ‘Babbage: a brief history’

Address: /trees/technology?n=analytical-engine

Note G (1843 · Idea)

Ada Lovelace translated Menabrea’s paper and added notes. Note G is a worked table of operations for computing Bernoulli numbers on the Analytical Engine. She also remarked that the engine might act on things other than number, such as musical composition, if their relations could be expressed. That second claim is the first clear statement that a computing machine handles symbols, not just quantities.

Built on: Analytical Engine

Source: Menabrea and Lovelace, ‘Sketch of the Analytical Engine’, Taylor’s Scientific Memoirs (1843), text at Fourmilab

Address: /trees/technology?n=lovelace

Boolean logic (1847; 1854 · Idea)

George Boole’s Mathematical Analysis of Logic (1847) and An Investigation of the Laws of Thought (1854) treated logical statements as an algebra with two values. That meant reasoning could be calculated. Shannon later showed that circuits carry out this algebra. So Boole’s system became the logical basis of digital hardware.

Led to: Universal machine; Logic in circuits

Source: George Boole, An Investigation of the Laws of Thought (1854), Project Gutenberg

Address: /trees/technology?n=boole

Vacuum tube (1904–1907)

John Ambrose Fleming’s two-electrode valve (1904) turned radio signals into a usable form. Lee de Forest added a grid to make the three-electrode Audion (1906–07), which could amplify and switch electrical signals. The triode was the working part of radio, telephony and the first electronic computers.

Led to: Electronic computer; Transistor; Colossus

Source: Encyclopaedia Britannica, ‘Thermionic valve’

Address: /trees/technology?n=vacuum-tube

Universal machine (1936–37 · Idea)

Alan Turing’s ‘On Computable Numbers’ (read in 1936, published 1936–37) defined an abstract machine. It showed that one universal machine can do the work of any other, given that other’s description as input. That’s the theoretical reason one general computer can run any simulated world. It also sets the limits on what such a simulation can compute.

Built on: Boolean logic

Led to: The stored-program design

Source: A. M. Turing, ‘On Computable Numbers, with an Application to the Entscheidungsproblem’, Proc. London Math. Soc. s2–42 (1937)

Address: /trees/technology?n=turing

Logic in circuits (1937–38 · Idea)

Claude Shannon’s master’s thesis at MIT (1937, published 1938) showed that networks of relays and switches can be analysed and designed with Boolean algebra. It tied abstract logic to physical circuits. Engineers now had a systematic way to design digital machines.

Built on: Boolean logic

Led to: Electronic computer

Source: C. E. Shannon, ‘A Symbolic Analysis of Relay and Switching Circuits’, MIT thesis (1937)

Address: /trees/technology?n=shannon

Zuse Z3 (1941)

Konrad Zuse completed the Z3 in Berlin in 1941. It had about 2,400 relays, a binary number system and 22-bit floating-point words. The program was read in sequence from punched tape. The IEEE Computer Society’s history site calls it the first fully working program-controlled electromechanical digital computer in the world. It had no conditional branch, and it kept its program outside the machine’s memory.

Built on: Binary arithmetic

Source: IEEE Computer Society, ‘Konrad Zuse’, Computer Pioneers; Rojas, ‘Konrad Zuse’s Legacy: The Architecture of the Z1 and Z3’, IEEE Annals of the History of Computing 19(2), 1997

Address: /trees/technology?n=z3

Colossus (1943–44)

Tommy Flowers’s electronic machines at Bletchley Park read cipher text from paper tape. They used valves (2,500 in the Mark 2) to find the wheel settings of the German Lorenz cipher. They were electronic and configurable, but built for one task. They were kept secret for many years after the war.

Built on: Vacuum tube

Source: The National Museum of Computing, “Colossus”

Address: /trees/technology?n=colossus

Electronic computer (1945–46)

ENIAC was completed at the University of Pennsylvania in 1945 and announced publicly in February 1946. It used about 18,000 vacuum tubes. You could rewire it to solve a wide range of numerical problems. It showed that electronic speed was practical for general computing. But reprogramming took days.

Built on: Vacuum tube; Logic in circuits

Led to: The stored-program design

Source: Encyclopaedia Britannica, ‘ENIAC’

Address: /trees/technology?n=eniac

Stored-program computer (1945 (design); 1948 (first run))

On 21 June 1948 the Manchester Small-Scale Experimental Machine (‘Baby’), built by Williams and Kilburn, ran its first program from its own electronic memory. The program was 17 instructions long and searched for the highest proper factor of a number. Keeping instructions and data in the same memory is what lets software change at electronic speed. It’s also what lets simulations be loaded.

Built on: The stored-program design

Led to: Packet network; Interactive graphics; Simulacron-3; First video games; Aspen Movie Map; Colossal Cave Adventure

Source: University of Manchester, ‘Manchester Baby computer’ (Computer 50 archive)

Address: /trees/technology?n=stored-program

The stored-program design (1945 · Idea)

John von Neumann’s First Draft of a Report on the EDVAC described a computer that keeps its program in the same memory as its data. Almost every computer since has used this layout.

Built on: Electronic computer; Universal machine

Led to: Stored-program computer

Source: von Neumann, First Draft of a Report on the EDVAC (30 June 1945), Internet Archive

Address: /trees/technology?n=edvac

Transistor (1947–48)

John Bardeen and Walter Brattain demonstrated a point-contact transistor at Bell Laboratories in December 1947. William Shockley developed the junction form soon after. The three shared the 1956 Nobel Prize in Physics. It was a solid-state amplifier and switch with no heater and no vacuum. Computers became smaller, faster and far more reliable.

Built on: Vacuum tube

Led to: Integrated circuit

Source: Nobel Prize in Physics 1956, summary

Address: /trees/technology?n=transistor

Integrated circuit (1958–59)

Jack Kilby at Texas Instruments built a working integrated circuit in September 1958. Robert Noyce at Fairchild devised a planar silicon version that could be manufactured in 1959. Kilby shared the 2000 Nobel Prize in Physics. Putting many parts on one piece of material made complex electronics cheap. That set up the scaling of computing power.

Built on: Transistor

Led to: Moore’s law; Microprocessor; Arcade video game; Virtual Boy

Source: Nobel Prize in Physics 2000, Jack S. Kilby facts

Address: /trees/technology?n=ic

Moore’s law (1965 (revised 1975) · Idea)

In an April 1965 article in Electronics, Gordon Moore observed that the number of components per integrated circuit had doubled about every year. He projected the trend for a decade. In 1975 he changed the rate to about every two years. The projection held roughly for five decades. It set the pace at which simulated worlds could grow richer.

Built on: Integrated circuit

Led to: Star-scale computer; Molecular nanotechnology; Reversible computing

Source: Computer History Museum, ‘Moore’s Law predicts the future of integrated circuits’

Address: /trees/technology?n=moores-law

Packet network (1969)

ARPANET sent its first host-to-host message from UCLA to SRI on 29 October 1969. Minicomputers called IMPs routed the packets. It grew into a national research network. Shared virtual spaces need machines that swap data in real time. ARPANET was the first large network built on packet switching.

Built on: Stored-program computer

Led to: First-person networked world; Shared text world; The Internet

Source: Computer History Museum, ‘October 29, 1969: Happy 40th birthday to a radical idea’

Address: /trees/technology?n=arpanet

Microprocessor (1971)

Intel’s 4004 came out in November 1971. Hoff, Mazor, Faggin and Shima designed it for a Busicom calculator. It put a programmable central processor on a single chip. General computing became cheap enough for personal machines, consoles and, eventually, phones.

Built on: Integrated circuit

Led to: Graphics processor; Smartphone; Real-time 3D worlds; Brain-computer interface

Source: Encyclopaedia Britannica, ‘Intel 4004’

Address: /trees/technology?n=microprocessor

The Internet (1983)

In January 1983 the ARPANET switched to the TCP/IP protocols. They’re the common language that lets separate networks connect. Shared online worlds run over this network of networks.

Built on: Packet network

Led to: World Wide Web

Source: Computer History Museum, “Internet History of 1980s”

Address: /trees/technology?n=internet

World Wide Web (1989–1991)

Tim Berners-Lee proposed a linked hypertext system at CERN in March 1989. By the end of 1990 he had the first server and browser running there. He announced the software publicly in August 1991. It made the Internet usable for non-specialists. It became the common way to reach shared online spaces.

Built on: The Internet

Led to: Persistent online worlds

Source: CERN, ‘A short history of the Web’

Address: /trees/technology?n=web

Graphics processor (1999)

Nvidia’s GeForce 256 (October 1999) put transformation and lighting on a single chip. It was marketed as the first graphics processing unit. That moved per-pixel and per-vertex work off the CPU. Cheap parallel graphics hardware is what put real-time 3D worlds within reach. Later it did the same for large-scale neural computing.

Built on: Microprocessor

Led to: General-purpose GPU computing; Modern VR headset; Neural rendering

Source: NVIDIA press release, ‘NVIDIA launches the world’s first graphics processing unit: GeForce 256’ (1999)

Address: /trees/technology?n=gpu

General-purpose GPU computing (2006–2007)

Nvidia announced CUDA in 2006 and released it in June 2007. It let programmers write ordinary C-like code for a GPU’s thousands of parallel threads. Graphics hardware became a general parallel computer. That’s what later made training large neural networks practical.

Built on: Graphics processor

Led to: Deep learning on GPUs

Source: Nickolls, Buck, Garland and Skadron, ‘Scalable Parallel Programming with CUDA’, ACM Queue 6(2) (2008)

Address: /trees/technology?n=gpgpu

Smartphone (2007)

Apple announced the iPhone in January 2007 and released it in June. It put a touch display, a capable processor and motion sensors in a pocket device, and mass production of those parts followed. The result was a supply of cheap high-density displays, motion sensors and mobile chips. That made consumer headsets possible.

Built on: Microprocessor

Led to: Modern VR headset; Standalone headsets

Source: Apple Newsroom, ‘Apple reinvents the phone with iPhone’ (9 January 2007)

Address: /trees/technology?n=smartphone

Deep learning on GPUs (2012)

In September 2012 AlexNet won the ImageNet image-classification contest by a wide margin. It was a convolutional network that Krizhevsky, Sutskever and Hinton trained on two GPUs. The result showed that large neural networks trained on parallel hardware beat hand-built methods at perception tasks.

Built on: General-purpose GPU computing

Led to: Transformer architecture; Neural rendering; Learned world models; Diffusion models

Source: Krizhevsky, Sutskever and Hinton, ‘ImageNet classification with deep convolutional neural networks’, NeurIPS 25 (2012)

Address: /trees/technology?n=deep-learning

Transformer architecture (2017)

Vaswani and colleagues at Google introduced the Transformer in 2017. It’s a network built on attention. It handles sequences in parallel and scales well with data and computing power. It’s the architecture behind large language models, which can produce open-ended, conversational behaviour.

Built on: Deep learning on GPUs

Led to: Generated interactive worlds; Human-level AI

Source: Vaswani et al., ‘Attention Is All You Need’, NeurIPS (2017), arXiv:1706.03762

Address: /trees/technology?n=transformer

Learned world models (2018)

Ha and Schmidhuber trained a neural network to model a game environment. Then they trained an agent inside the model’s own imagined version of it. A world could now be learned from watching, not written by hand.

Built on: Deep learning on GPUs

Led to: Generated interactive worlds

Source: Ha and Schmidhuber, “World Models”, arXiv:1803.10122 (2018)

Address: /trees/technology?n=learned-worlds

Diffusion models (2020)

Ho, Jain and Abbeel showed that a network trained to remove noise step by step can generate high-quality images from random input. The method sits under most later image, video and interactive-world generators.

Built on: Deep learning on GPUs

Led to: Generated interactive worlds

Source: Ho, Jain and Abbeel, “Denoising Diffusion Probabilistic Models”, arXiv:2006.11239 (2020)

Address: /trees/technology?n=diffusion

Molecular nanotechnology (2010–2030s · Forecast)

Forecasters in the 1990s–2000s dated programmable molecular assembly and brain-entering nanobots to 2010–2029. Diamondoid assembly was forecast for 2010–2015 and hasn’t been demonstrated. So this is a record of dates that passed.

Built on: Moore’s law

Led to: Full-immersion VR; Star-scale computer

Address: /trees/technology?n=nanotech

Human-level AI (2027–2047 · Forecast)

Forecasts for machines that beat humans at every task run from 2026–2030, in statements by AI-lab leaders, to a 2047 median in the 2023 survey of 2,778 researchers. Surveys have moved earlier over time. They gave 2040–2050 in 2012–13, 2060 in 2022 and 2047 in 2023.

Built on: Transformer architecture

Led to: Whole-brain emulation; Superintelligence

Address: /trees/technology?n=agi

Reversible computing (2027–2040 · Forecast)

Reversible logic avoids the Landauer minimum energy cost of erasing bits. It’s proposed as the route to far more computing per watt. A startup projects a first inference chip in 2027 and a 4,000-fold efficiency gain 10 to 15 years later. A 2014 expert interview didn’t expect wide use by 2030.

Built on: Moore’s law

Address: /trees/technology?n=reversible

Superintelligence (2027–2045+ · Forecast)

Surveyed experts expect superintelligence within 30 years of human-level machine intelligence. Scenario authors and Kurzweil give dates between 2027 and 2045. Researchers surveyed in 2023 put substantial but not majority odds on a fast ‘intelligence explosion’.

Built on: Human-level AI

Address: /trees/technology?n=asi