Another Historical Interlude

1
Another Historical Interlude

• Basically, we now have all of the things we need
  for computing
• variables that store pieces of information
• operators that do some arithmetic
• control structures that let us control the order
  we do things
• A programming language gives us a way to specify
  an effective procedure to solve a problem

2
What is an effective procedure again?

• More often called an algorithmit is a step by
  step procedure for solving problems
• What kind of problems can be solved by
  algorithms?
• digital computers
• Turing machines
• a lot of other things
• The Turing thesis every approach solves the same
  class of problems

3
Alan Turing (1912-1954)

• One of the founders of Computer Science
• What he did
• designed the first stored-program computer in
  Britain
• credited as essentially inventing the computer
• theoretical work on algorithms
• the Turing test in Artificial Intelligence
• cryptanalysis in World War II

4
Alan Turing (1912-1954)

• Turings work in algorithms was too difficult for
  friends and family to understand
• Turings work in WWII was classified until well
  after his death
• He was a homosexual at a time when it was
  illegal, and considered a mental illness
• forced to undergo estrogen treatment, lost his
  security clearance, lost his job
• believed to have committed suicide by eating a
  cyanide-laced apple