Turing Machine – 1936

Evolution of Computing
Today’s Goal
To learn about the evolution of computing
To recount the important and key events
To identify some of the milestones in computer development
Babbage’s Analytical Engine - 1833
Mechanical, digital, general-purpose
Was crank-driven
Could store instructions
Could perform mathematical calculations
Had the ability to print
Could punched cards as permanent memory
Invented by Joseph-Marie Jacquard
2.1 Turing Machine – 1936
Introduced by Alan Turing in 1936, Turing machines are one of the key abstractions
used in modern computability theory, the study of what computers can and cannot do. A
Turing machine is a particularly simple kind of computer, one whose operations are
limited to reading and writing symbols on a tape, or moving along the tape to the left or
right. The tape is marked off into squares, each of which can be filled with at most one
symbol. At any given point in its operation, the Turing machine can only read or write
on one of these squares, the square located directly below its "read/write" head.
2.2 The “Turing test”
A test proposed to determine if a computer has the ability to think. In 1950, Alan Turing
(Turing, 1950) proposed a method for determining if machines can think. This method is
known as The Turing Test.
The test is conducted with two people and a machine. One person plays the role of an
interrogator and is in a separate room from the machine and the other person. The
interrogator only knows the person and machine as A and B. The interrogator does not
know which the person is and which the machine is.
Using a teletype, the interrogator, can ask A and B any question he/she wishes. The aim
of the interrogator is to determine which the person is and which the machine is.
The aim of the machine is to fool the interrogator into thinking that it is a person. If the
machine succeeds then we can conclude that machines can think