A text-book of physics, largely experimentalOn the Harvard college "Descriptive list of elementary physical experiments." . FIG. 100. If the rays of light proceeding from a point are by anymeans made falsely to appear to diverge from a differentpoint, as in Fig. 100, then the second point is called anunreal, or virtual, image of the first. A virtual image has 156 PHYSiCS. no real existence in space, and would not show upon ascreen placed where it appears to be. Evidently the image formed by a plane mirror is an un-real image. 133. Images of Images.—If any of the rays from 0(Fig. 101) after ref
A text-book of physics, largely experimentalOn the Harvard college "Descriptive list of elementary physical experiments." . FIG. 100. If the rays of light proceeding from a point are by anymeans made falsely to appear to diverge from a differentpoint, as in Fig. 100, then the second point is called anunreal, or virtual, image of the first. A virtual image has 156 PHYSiCS. no real existence in space, and would not show upon ascreen placed where it appears to be. Evidently the image formed by a plane mirror is an un-real image. 133. Images of Images.—If any of the rays from 0(Fig. 101) after reflection from the mirror A fall upon asecond plane mirror B, they will be treated by this secondmirror just as if they really came from 7t; that is, we shall,looking into the mirror B in the right direction, see animage of the image 71; and this second image, 72, will appear. FIG. 101. just as if it were the image of an actual object sendingrays from 7X. The rays reflected first from A and next from B mightthen fall upon a third mirror, and give an image of theimage 72, and so on; but at each reflection there is someloss of light, and an image formed after many reflectionsmight be dim. c\ REGULAR REFLECTION OF LIGHT. 157 134. Positions of the Various Images.—Let A and B inFig. 102 represent the positions oftwo plane mirrors meeting at rightangles with each other at the J3point C. Let 0 be a small objectplaced between the mirror faces. We shall have one image, 71; formed by mirror A without any z~ -o help from mirror B, and another,/,. formed by B without help from FIG 102 A. There is also I3, the image of 7,, seen in B, and there is I4, the image of 72, seen in A. 73 and 74 fall at the same spot. We cannot with this arrangement of the mirrors getimages of 73 and 74; because rays leaving mirror A as ifdiverging from 74 would not strike the face of B} and
Size: 1349px × 1852px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectphysics
