The week is designed to engage people in science and engineering, and is coordinated by the BA with the Engineering and Technology Board, funded by the Department for Innovation, Universities and Skills.
More than half a million people are expected to take part this year.
Use the days to try and answer some of those 'big questions' that have always nagged at you or your family.
There are thousands of events, from building helicopters in the Highlands to learning how to protect the planet in 'Engineering Earth', to firing catapults in the House of Commons at 'The Smallpeice Trust / ETB Trebuchet Challenge'.
Join in, and take someone with you.