'Virtual image' definitions:

Definition of 'virtual image'

From: WordNet
noun
A reflected optical image (as seen in a plane mirror)

Definition of 'Virtual image'

From: GCIDE
  • Image \Im"age\ ([i^]m"[asl]j; 48), n. [F., fr. L. imago, imaginis, from the root of imitari to imitate. See Imitate, and cf. Imagine.]
  • 1. An imitation, representation, or similitude of any person, thing, or act, sculptured, drawn, painted, or otherwise made perceptible to the sight; a visible presentation; a copy; a likeness; an effigy; a picture; a semblance. [1913 Webster]
  • Even like a stony image, cold and numb. --Shak. [1913 Webster]
  • Whose is this image and superscription? --Matt. xxii. 20. [1913 Webster]
  • This play is the image of a murder done in Vienna. --Shak. [1913 Webster]
  • And God created man in his own image. --Gen. i. 27. [1913 Webster]
  • 2. Hence: The likeness of anything to which worship is paid; an idol. --Chaucer. [1913 Webster]
  • Thou shalt not make unto thee any graven image, . . . thou shalt not bow down thyself to them. --Ex. xx.
  • 4, 5. [1913 Webster]
  • 3. Show; appearance; cast. [1913 Webster]
  • The face of things a frightful image bears. --Dryden. [1913 Webster]
  • 4. A representation of anything to the mind; a picture drawn by the fancy; a conception; an idea. [1913 Webster]
  • Can we conceive Image of aught delightful, soft, or great? --Prior. [1913 Webster]
  • 5. (Rhet.) A picture, example, or illustration, often taken from sensible objects, and used to illustrate a subject; usually, an extended metaphor. --Brande & C. [1913 Webster]
  • 6. (Opt.) The figure or picture of any object formed at the focus of a lens or mirror, by rays of light from the several points of the object symmetrically refracted or reflected to corresponding points in such focus; this may be received on a screen, a photographic plate, or the retina of the eye, and viewed directly by the eye, or with an eyeglass, as in the telescope and microscope; the likeness of an object formed by reflection; as, to see one's image in a mirror. [1913 Webster]
  • Electrical image. See under Electrical.
  • Image breaker, one who destroys images; an iconoclast.
  • Image graver, Image maker, a sculptor.
  • Image worship, the worship of images as symbols; iconolatry distinguished from idolatry; the worship of images themselves.
  • Image Purkinje (Physics), the image of the retinal blood vessels projected in, not merely on, that membrane.
  • Virtual image (Optics), a point or system of points, on one side of a mirror or lens, which, if it existed, would emit the system of rays which actually exists on the other side of the mirror or lens. --Clerk Maxwell. [1913 Webster]

Definition of 'Virtual image'

From: GCIDE
  • Virtual \Vir"tu*al\ (?; 135), a. [Cf. F. virtuel. See Virtue.]
  • 1. Having the power of acting or of invisible efficacy without the agency of the material or sensible part; potential; energizing. [1913 Webster]
  • Heat and cold have a virtual transition, without communication of substance. --Bacon. [1913 Webster]
  • Every kind that lives, Fomented by his virtual power, and warmed. --Milton. [1913 Webster]
  • 2. Being in essence or effect, not in fact; as, the virtual presence of a man in his agent or substitute. [1913 Webster]
  • A thing has a virtual existence when it has all the conditions necessary to its actual existence. --Fleming. [1913 Webster]
  • To mask by slight differences in the manners a virtual identity in the substance. --De Quincey. [1913 Webster]
  • Principle of virtual velocities (Mech.), the law that when several forces are in equilibrium, the algebraic sum of their virtual moments is equal to zero.
  • Virtual focus (Opt.), the point from which rays, having been rendered divergent by reflection of refraction, appear to issue; the point at which converging rays would meet if not reflected or refracted before they reach it.
  • Virtual image. (Optics) See under Image.
  • Virtual moment (of a force) (Mech.), the product of the intensity of the force multiplied by the virtual velocity of its point of application; -- sometimes called {virtual work}.
  • Virtual velocity (Mech.), a minute hypothetical displacement, assumed in analysis to facilitate the investigation of statical problems. With respect to any given force of a number of forces holding a material system in equilibrium, it is the projection, upon the direction of the force, of a line joining its point of application with a new position of that point indefinitely near to the first, to which the point is conceived to have been moved, without disturbing the equilibrium of the system, or the connections of its parts with each other. Strictly speaking, it is not a velocity but a length.
  • Virtual work. (Mech.) See Virtual moment, above. [1913 Webster]