Alhazen's problem

Ibn al-Haytham's work on catoptrics in Book V of the Book of Optics contains the important Islamic mathematical problem known as Alhazen's problem.

The problem comprises drawing lines from two points in the plane of a circle meeting at a point on the circumference and making equal angles with the normal at that point. This is equivalent to finding the point on the edge of a circular billiard table at which a cue ball at a given point must be aimed in order to canon off the edge of the table and hit another ball at a second given point. Thus, its main application in optics is to solve the problem, "Given a light source and a spherical mirror, find the point on the mirror where the light will be reflected to the eye of an observer." This leads to an equation of the fourth degree.[1][2][3]

This eventually led Ibn al-Haytham to derive the earliest formula for the sum of the fourth powers, and using an early proof by mathematical induction, he developed a method for determining the general formula for the sum of any integral powers. He used his result on sums of integral powers to perform an integration, in order to find the volume of a paraboloid. He was thus able to find the integrals for polynomials up to the fourth degree, and came close to finding a general formula for the integrals of any polynomials. This was fundamental to the development of infinitesimal and integral calculus.[4]

Ibn al-Haytham solved the problem using conic sections and a geometric proof, but Alhazen's problem remained influential in Europe, when later mathematicians such as Christiaan Huygens, James Gregory, Guillaume de l'Hôpital, Isaac Barrow, and many others, attempted to find an algebraic solution to the problem, using various methods, including analytic methods of geometry and derivation by complex numbers.[5] An algebraic solution to the problem was finally found in 1997 by the Oxford mathematician Peter M. Neumann.[6]

References

  1. ^ O'Connor, John J.; Robertson, Edmund F., "Abu Ali al-Hasan ibn al-Haytham", MacTutor History of Mathematics archive, University of St Andrews, http://www-history.mcs.st-andrews.ac.uk/Biographies/Al-Haytham.html .
  2. ^ MacKay, R. J.; Oldford, R. W. (August 2000), "Scientific Method, Statistical Method and the Speed of Light", Statistical Science 15 (3): 254–78 
  3. ^ Weisstein, Eric. "Alhazen's Billiard Problem". Mathworld. http://mathworld.wolfram.com/AlhazensBilliardProblem.html. Retrieved 2008-09-24. 
  4. ^ Victor J. Katz (1995), "Ideas of Calculus in Islam and India", Mathematics Magazine68 (3): 163–174 [165-9 & 173-4]
  5. ^ John D. Smith (1992), "The Remarkable Ibn al-Haytham", The Mathematical Gazette 76 (475): 189–198
  6. ^ Highfield, Roger (1 April 1997), "Don solves the last puzzle left by ancient Greeks", Electronic Telegraph 676, http://www.telegraph.co.uk/htmlContent.jhtml?html=/archive/1997/04/01/ngre01.html, retrieved 2008-09-24