The difference in air pressure made the rocket behave abnormally, and probably contributed to the crash.

ECONOMIST: Hypersonic aviation

This tracks the difference in air pressure between Iceland and the Azores and, during the winter months, determines the strength of the winds, temperatures and rainfall in the St Kilda archipelago.

ECONOMIST: Evolution and climate change

The difference between turbocharging and supercharging is simple: a turbocharger boosts engine air pressure by using exhaust gas to power a turbine that pushes more air into the combustion chamber.

FORBES: 2012 Audi A7 Test Drive and Review - High-Tech Meets High Style