City streets Human factors Traffic signal lights need to warn as many people as possible. Many people, particularly men are … More

Submarine – a vessel that goes under water. Most large submarines are war vessels. Some small ones are used for … More

Stonehenge – a prehistoric monument located in the English county of Wiltshire, near Salisbury. One of the most famous prehistoric … More

Stethoscope – a medical device for listening to the internal sounds of an animal or human body. It is often … More

steam engine – a heat engine that performs mechanical work using steam as its working fluid. Steam engines are external … More

Stop motion animation is a film making technique that makes inanimate objects appear to move on their own. Think Gumby … More

Statics is concerned with the analysis of loads (force and torque, or “moment”) on physical systems in static equilibrium – … More

Star fort – fortification layout specifically designed to resist attack by cannon. The structure is composed of many triangular bastions, … More

Steel is an alloy of iron and other elements, including carbon. The following elements are always present in steel: carbon, … More

stained glass is glass that has been colored by adding metallic salts during its manufacture. The colored glass is crafted … More

Sputnik 1 In the 1950s the United States and Russia were working to open the next frontier – space. Once … More

Robert Hooke (1625 – 1703) was employed as an assistant to Robert Boyle, for whom he built the vacuum pumps … More