Alhazen or Alhacen or ibn al-Haytham (965–1039) was a pioneer of modern optics. Some have also described him as a "pioneer of the modern scientific method" and "first scientist", but others think this overstates his contribution. Alhazen's Risala fi’l-makan (Treatise on Place) discussed theories on the motion of a body. He maintained that a body moves perpetually unless an external force stops it or changes its direction of motion. He laid foundations for telescopic astronomy.