Introduction to AI - Week 1

Dreams in Science and Technology

• Flying, Travel to other planets/solar systems,
• Immortality, health, superhuman power,
• Understanding the physical structure of the universe,
• Utopia, a just, peaceful, wealthy society
• Build machines that do the work for us
• Understanding ourselves, our origins, our thinking, our wishes

Calculators - Schickard, Pascal, Leibniz

Wilhelm Schickard (1592-1635)		Blaise Pascal (1623-1662)

The dream of the automation of computation - partly realised

The Dream of a Universal Computer
Charles Babbage and Ada Lovelace

Charles Babbage (1792-1871)	Ada Lovelace (1815-1852)

Difference Engine/Analytical Engine

The dream of a universal computing machine, almost realised

Science or Mystery?

Understanding the Mind

Understanding the Mind (Cont'd)

Understanding the Mind (Cont'd)

Intelligent Machines - Fakes
Speech

Intelligent Machines - Fakes
Chess

Predicting the Future

Pierre Simon Laplace
(1749-1827)

Science Fiction - Building Companions

1. A robot must not harm a human being or allow by inactiveness that a human being is harmed.
2. A robot must obey to orders given by a human being unless the execution of the order is in conflict with law 1.
3. A robot must protect its own existence, unless this is in conflict with laws 1 or 2.

AI = Build Machines that Behave as in the Movies

Metropolis	2001 (HAL)	Star Wars (R2-D2)

Literature    

• Artificial Intelligence: A New Synthesis, Nils J. Nilsson, Morgan Kaufmann 1998.
• Artificial Intelligence - A Modern Approach, Stuart Russell & Peter Norvig, Prentice Hall, 2nd edition.
• Artificial Intelligence, 3rd Edition, Patrick Henry Winston, Addison-Wesley, 1992.
• Artificial Intelligence, 2nd Edition, Elaine Rich & Kevin Knight, McGraw Hill 1991.

Logic

Aristotle
(384-322 B.C.)

It's raining     If it's raining then the street gets wet
--------	-------------	-------------
The street gets wet

The Idea of the Mechanisation of Logic

Raimundus Lullus
(1235-1316)

Regulae ad directionem ingenii

René Descartes
(1596-1650)

• translate any problem into a mathematical problem
• transform any mathematical problem into a system of equations
• translate any system of equations into one equation
• solve this one equation

Calculemus = Let's calculate

Gottfried Wilhelm Leibniz
(1646-1716)

• Lingua characteristica universalis:
  Find a universal language which can be used to represent any problem
• Calculus ratiocinator:
  Can solve any problem automatically (without dispute): Calculemus

The Laws of Thought

George Boole
(1815-1864)

• Foundations of propositional logic
• Investigate the algebraic laws of logic, e.g.: A &  A  <->  A (i.e., A and A is the same as A)
• purpose: "to collect ... some probable intimations concerning the nature and constitution of the human mind."

Special Reasoning Machines

Earl Stanhope's Logic Demonstrator, 1777

• machine for solving syllogisms, numerical problems in in logical form, elementary questions of probability.

William Jevons' Logic Machine, 1869

• Machine for Boolean algebra and Venn diagrams, able to solve logical problems faster than human beings

Classical Logic

Gottlob Frege
(1848-1925)

• Begriffsschrift, foundations of classical logic

Bertrand Russell
(1872-1970)

• Paradoxes, types, principia mathematica

Strength and Limitations of Classical Logic

Kurt Gödel
(1906-1978)

• Completeness of first-order logic, that is, any reasoning whether something is a logical consequence of something else can be mechanised in this powerful reasoning system
• Incompleteness of sufficiently rich logic, there are truths which do not have a finite proof

Modern Computers

Alan Turing
(1912-1954)

• What can be computed by a computer? - Halting problem
  Turing test for intelligence

John von Neumann
(1903-1957)

• von Neumann architecture: give a description that is independent from the particular realisation of a computer

The Role of Logic

• McCarthy: The relationship between computation and math. logic will be as fruitful as that between physics and analysis

• Logic as powerful knowledge representation formalism

• Logical reasoning as a model for human reasoning

• Mechanisation of reasoning by logical rules

• Extensions to logic necessary for adequate reasoning:
  • probabilistic reasoning
  • fuzziness
  • non-monotonicity (revision of judgements)
  • non-deductive reasoning (analogy, induction, abduction)

Brain science - Neuroscience

• Brain (vs heart) as seat of the soul and the mind
• Understand the function of the brain
  • ventricle theory (ventricles = empty parts of the brain do the job)
  • brain as a big gland
  • phrenology (which part does what)
  • understand brain as a highly connected set of neurons, 10¹⁰ neurons with each 100 connections on average
  • neuron as a digital entity which either does or does not fire depending whether an activation threshold is exceeded or not

Brain science - Neuroscience (Cont'd)

Gives raise to neural nets,
subsymbolic representation of knowledge

Psychology

Sigmund Freud
(1856-1939)

• Founder of psychoanalysis

• Try to understand the psyche
• Try to understand motivations as well as anomalies of human behaviour/human mind/human soul (clues to mental activity/conflicts)
• The conscious vs the unconscious
• Psychoanalysis

Relationship between psychology - cognitive science - artificial intelligence

Darwinism

Charles Darwin
(1809-1882)

• "On the origin of species by means of natural selection"

• different species develop by natural selection
• cross-over and random mutation
• survival of the fittest (only the fit ones mate and reproduce)

Gives raise to evolutionary computation (rather than programming, breed programs)

Summary

• Different origins of AI: philosophy, logic, computation, psychology, biology
• In this module we follow mainly the logical/computational origins: symbolic representation of knowledge

Reading    

• Introduction chapters in the AI books
• The story of Cybernetics, Maurice Trask, Studio Vista, 1971.
• Minds, Brains & Computers, edited by R. Morelli et al., Ablex Publ., 1992.
• Gehirn, Bewusstsein und Erkenntnis, E. Oeser, Franz Seitelberger, Wissenschaftliche Buchgesellschaft, 1988.