I. Langdon Winner: "artefacts have politics" -- Robert Moses Bridges on Long Island.
Thomas P. Hughes: "The Evolution of Large Technological Systems"
(most examples from electrical power history)
1. Both socially constructed and society-shaping. ex: electrical companies stimulated interest in home appliances that would use power in low-demand hours. Rather than just adapting to environment (e.g. consumer need), they can mold it, transform it to encourage system growth.
2. Natural, artificial, and social components all interact in a "seamless web."
3. In addition to obvious interactions (financial backing is needed to produce an invention), causal chains can occur indirectly. ex: As electrical systems changed from dc to ac, engineering schools began more courses on ac. These connections are diverse: professors were acting as consultants of firms, alumni had become employed by firms, firm owners may sit on governing boards of engineering schools.
4. Technological style: 1920 electrical power in Berlin: 6 large power plants. In London: 50 small power plants. Due to difference in centralized political power.
5. Momentum: Above difference also due to copper shortage during WWI Germany; even after shortage ended, the design style remained. Actor Networks add to momentum because of vested interests.
6. Reverse Salients: analogy to fluid flow; the progress in development is slowed by certain components, so engineering often focused on these. ex: Edison had to compete financially with gas lighting, so high cost of copper conductors was reverse salient -- he focused on high-resistance filament to create low-current demand, thus lowering amount of copper in wires. Edison failed to solve the dc reverse salient; ac was introduced.