ALAN TURNINGThe father of computing

BRITISH MATHEMATICIAN

Born 1912, died 1954 Invented the basic theory of computers Helped build some of the early

computers

LIFE BEFORE COMPUTERS

Lots of tedious information processing had to be done by humans Banks needed to manually total up

account balances Index cards used to store information

for search

ADDITION AND SUBTRACTION

Done manually Mechanical machines, as in http://

www.youtube.com/watch?v=PhiRiWzj5K0

Either way, labor intensive and error prone

PROCESSING LOTS OF INFORMATION

The census: Count all the people in the country,

divided per state Get additional economic information Need to get totals http://

www.youtube.com/watch?v=9HXjLW7v-II

WHAT TURING DID

Came up with a theoretical model of what a computer does: http://www.youtube.com/watch?v=gJQTFhkhwPA

Helped figure how to implement it.

WWII

Huge war, 1939-1945 (in Europe) Allies: Britain, US, and USSR (after

the Germans attacked them in 1941) Axis: Germany, Japan, Italy

GERMAN COMMUNICATIONS

Radio allows quick communication But everybody can listen to the radio,

including the enemy Solution: encryption: http://

www.youtube.com/watch?v=dq27B1-6F5k

THE TURING SOLUTION

Build a bunch of Enigmas to run in parallel

Check if the settings make sense.http://www.youtube.com/watch?v=Dr1U7Bva6Sw

Worked well enough the English command knew what the Germans were planning.