aberration self-focusing ring

  • 11photoreception — photoreceptive, adj. /foh toh ri sep sheuhn/, n. the physiological perception of light. [1905 10; PHOTO + RECEPTION] * * * Biological responses to stimulation by light, most often referring to the mechanism of vision. In one celled organisms such …

    Universalium

  • 12physical science — physical scientist. 1. any of the natural sciences dealing with inanimate matter or with energy, as physics, chemistry, and astronomy. 2. these sciences collectively. [1835 45] * * * Introduction       the systematic study of the inorganic world …

    Universalium

  • 13Pentax cameras — This article discusses the cameras – mainly 35 mm SLRs – manufactured by Hoya Corporation s Pentax division (ペンタックス, Pentakkusu?) and its predecessors, Pentax Corporation (ペンタックス株式会社, Pentakkusu Kabushiki gaisha …

    Wikipedia

  • 14Solar sail — Solar sails (also called light sails or photon sails, especially when they use light sources other than the Sun) are a proposed form of spacecraft propulsion using large membrane mirrors. Radiation pressure is about 10 5 Pa at Earth s distance… …

    Wikipedia