1. The father of computing
ALAN TURNING

2. BRITISH MATHEMATICIAN
Born 1912, died 1954
 Invented the basic theory of computers
 Helped build some of the early computers


3. 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

4. ADDITION AND SUBTRACTION
Done manually
 Mechanical machines, as in
http://www.youtube.com/watch?v=PhiRiWzj5
K0
 Either way, labor intensive and error prone


5. 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

6. WHAT TURING DID
Came up with a theoretical model of what a
computer does:
http://www.youtube.com/watch?v=gJQTFhkh
wPA
 Helped figure how to implement it.


7. WWII
Huge war, 1939-1945 (in Europe)
 Allies: Britain, US, and USSR (after the
Germans attacked them in 1941)
 Axis: Germany, Japan, Italy


8. GERMAN COMMUNICATIONS
Radio allows quick communication
 But everybody can listen to the radio,
including the enemy
 Solution: encryption:
http://www.youtube.com/watch?v=dq27B16F5k


9. THE TURING SOLUTION
Build a bunch of Enigmas to run in parallel
 Check if the settings make sense.
http://www.youtube.com/watch?v=Dr1U7Bva6
Sw


Worked well enough the English command
knew what the Germans were planning.