In looking at technological revolutions, since the 1700s or so, there've been at least 4 generally acknowledged (textiles, steam, electricity, electronics), though arguably numerous others, among the more notable:<p>1. The textiles revolution, involving automated (repeated-process or repeated-cycle) and powered (waterwheel) processing.<p>2. Steam, itself occurring over at least three stages, Newcomen (1712), Watt (1776), and high-pressure steam (1800). Arguably also the Parsons steam turbine (1884), still a power mainstay.<p>3. Metallurgy, most especially iron and steel, with puddling (Henry Cort, 1784) and Bessemer (1856), though there've been major 20th century improvements. Also aluminium smelting (Hall–Héroult process, 1886), and other strategic metals.<p>4. Coal-tar chemistry, giving rise to the first synthetic dyes and chemicals, 1840s. Closely related, film and photographic techniques.<p>5. Electricity and electrical apparatus: motors, dynamos, lights, phonographs, telegraphy, telephony, radio, speakers, lifts, electrified transport, and more. Generally 1870s - 1890s.<p>6. Petroleum and internal combustion. 1859 - 1880s. Self-contained liquid-fueled powerplants and transport with high power-to-weight ratios and rapid throttle response.<p>7. Petroleum-based chemistry, artificial fibres, explosives, and fertilisers. I'll add in viscose rayon (1889), though most of the synthetic plastics were created ~1920-1940. Nitrogen chemistry gave rise to explosives, with natural gas as a feedstock, but also fertilisers. Artificial rubber and tarmacadam pavements. Other general chemistry might be included, covering organic (carbon-based), carbon allotrope (buckyballs, nanotubes), semiconductor, alloys, battery tech, continuing to present.<p>8. Electronics: radio, television, vacuum tubes, transistors, integrated circuits, and lasers. These all involve channel creation, signal encoding and decoding, amplification, transmission, receivers, and encoding / decoding. 1896 - 1960s.<p>9. Radioactivity and nuclear chemistry and reactions. Applications in both power and informational domains (latter, especially: medical and industrial imaging). 1890s - 1960s.<p>10. Quantum effects: semiconductors, photovoltaics, and other materials/electronics applications for the most part. 1905 - 1960s.<p>11. Genetics. Most especially the structure, nature, and manipulation of DNA, RNA, and proteins. 1953 - present.<p>12. Specific vehicle design and control, most particularly of air- and space-craft.<p>13. Large programme- and system-organisation and control. This includes both engineering projects, and their work-product and processes. Effectively, the management of complexity at scale.<p>14. Awareness, mitigation, and avoidance of second-order effects: unintended consequences and hygiene factors.<p>I've been noodling for a few years on an ontology of techological mechanisms, with nine that seem to stand out: 1) materials, 2) fuels, 3) process knowledge, 4) structural/causal knowledge, 5) power transmission and transformation, 6) networks, 7) systems, 8) information, and 9) hygiene / consequences. There's some overlap between these and the major phases described above.<p>There are also the <i>pre-</i> 1700 technical revolutions, including moveable-type print, advanced architecture, mathematics, writing, the wheel, agriculture, and speech, among others, each with major impacts.<p>Most of the notable developments of the past 50 years have been in the area of information technology specifically. Robert J. Gordon's <i>The Rise and Fall of American Growth</i> looks at numerous areas of technological advance and finds most wanting. I'd argue that the realm of limits is underappreciated -- the environmental movement of the 1950s onward, the oil shocks of the 1970s, the ozone crisis, environmental contamination in the form of lead, tobacco, aasbestos, mercury, and other contaminants, CO2 and climate change, and though pressing awareness has dimmed somewhat, peak oil and its implications. This may become clearer in future, and represents the 9th class of my ontology above.<p>The problem with information technologies alone is that <i>at best</i> they can only focus other efforts and activities (and they often carry their own negative effects and risks).<p>But yeah, delivery has been ... somewhat meh for the past decade.