Can Computers Think?

	Dijkstra: Whether a computer can think is about as interesting as whether a submarine can swim.

Thinking with Electricity

	The inventors of ENIAC, 1st computer, said it “thinks with electricity”
			Do calculators “think”?
			Does performing arithmetic, which is entirely algorithmic, require thinking?
			Once, performing arithmetic, was thought to be divinely or magically conferred

Thinking with Electricity

	The inventors of ENIAC, 1st computer, said it “thinks with electricity”
			Do calculators “think”?
			Does performing arithmetic, which is entirely algorithmic, require thinking?
			Once, performing arithmetic, was thought to be divinely or magically conferred

Turing’s Test

	A.M. Turing, computer pioneer, worried about intelligence in humans & machines and proposed a test (1950)
			Aware that it’s intelligence til it’s understood Turing devised this experimental setup:

What To Ask

	Formulate questions a person can answer but a computer can’t

Seeming To Be Intelligent

	Joel Weizenbaum’s “Doctor” was an program that appeared intelligent
			User: I’m depressed.
			Doctor: Why are you depressed?
			User: My mother is not speaking to me.
			Doctor: Tell me about your mother.
			User: She doesn’t want me to major in CS.
			Doctor: No?
			User: No, she wants me to go into medicine.

Artificial Intelligence

	The study of making computers act intelligently
			They already act intelligent … e.g. they can correct your spelling mistakes
			Is this intelligent behavior?  Most AI researchers would say “no” … algorithmic
			Playing grandmaster level chess in a tournament became an AI goal (1952)
			- Minimizes real world knowledge
			- Clear goal, formal system

Playing Chess

	Chess is a game, so it uses a game tree
			At each node is a ‘board’-- easily digitized
			Below it are all boards created in 1 move

Deep Blue vs Kasparov

	An IBM system, Deep Blue, played world champion Gary Kasparov
			In 1996 Kasparov won, but Deep Blue played 1 game well!!!
			In May 11, 1997 Deep Blue won 3.5-2.5

Intelligent?

	Does Deep Blue’s performance show that a computer can be intelligent?
			No -- it repeat’s its designers intelligence
			Yes -- it’s better than anyone in the world at something people find interesting and fun
			Maybe -- it shows intelligence in chess, but can it apply its intelligence elsewhere?

Being Creative

	Computers can do things deemed creative in the past
			Create designs in the style of Piet Mondrian
			Composing Bach: EPI, Bach, Professor

Being Creative

	Computers can do things deemed creative in the past
			Create designs in the style of Piet Mondrian
			Composing Bach: EPI, Bach, Professor
			Audience Thought: Bach Prof   EPI

Definition of Creativity

	Creativity has two forms: “flash out of the blue” and “incremental revision”
			“Flash,” i.e. inspiration, is rare; is it just luck?
			“Revision”, i.e. hard work, is common and to a large degree algorithmic

Computers Can’t Debug

	There are some things computers cannot do … and we can prove it!
			No computer program can tell, give another program P, if P loops forever … halting prob
			If possible, it would be handy for debugging
			In fact, it seems possible … look closely at the program, check the for-statements (and other looping structures we didn’t learn)
			Suppose Loop_Check (P, Q) tests pgm P on input Q, answering “yes/no” to loops forever

Loop_Check Cannot Be

	Loop_Check could not work, because if it did we’d make a new program

Intelligence & Creativity

	The bottom line on the “intellectual skills” of computers …
			It has long been an interesting question
			Computers are amazing, but probably not intelligent
			When a task becomes algorithmic computers (and humans) can do it well