602:, one image appears. Two mirrors placed exactly face to face give the appearance of an infinite number of images along a straight line. The multiple images seen between two mirrors that sit at an angle to each other lie over a circle. The center of that circle is located at the imaginary intersection of the mirrors. A square of four mirrors placed face to face give the appearance of an infinite number of images arranged in a plane. The multiple images seen between four mirrors assembling a pyramid, in which each pair of mirrors sits an angle to each other, lie over a sphere. If the base of the pyramid is rectangle shaped, the images spread over a section of a
582:). The image produced is the inverse of one produced by a single mirror. A surface can be made partially retroreflective by depositing a layer of tiny refractive spheres on it or by creating small pyramid like structures. In both cases internal reflection causes the light to be reflected back to where it originated. This is used to make traffic signs and automobile license plates reflect light mostly back in the direction from which it came. In this application perfect retroreflection is not desired, since the light would then be directed back into the headlights of an oncoming car rather than to the driver's eyes.
33:
358:
591:
670:
345:
186:
540:
688:(from about 20 mm to 17 m). As a result, the overall nature of the reflection varies according to the texture and structure of the surface. For example, porous materials will absorb some energy, and rough materials (where rough is relative to the wavelength) tend to reflect in many directions—to scatter the energy, rather than to reflect it coherently. This leads into the field of
469:
560:
When flying over clouds illuminated by sunlight the region seen around the aircraft's shadow will appear brighter, and a similar effect may be seen from dew on grass. This partial retro-reflection is created by the refractive properties of the curved droplet's surface and reflective properties at the
442:
In metals, electrons with no binding energy are called free electrons. When these electrons oscillate with the incident light, the phase difference between their radiation field and the incident field is π (180°), so the forward radiation cancels the incident light, and backward radiation is just the
438:
In the case of dielectrics such as glass, the electric field of the light acts on the electrons in the material, and the moving electrons generate fields and become new radiators. The refracted light in the glass is the combination of the forward radiation of the electrons and the incident light. The
294:
are constructed by creating a converging "tunnel" for the waves. As the waves interact at low angle with the surface of this tunnel they are reflected toward the focus point (or toward another interaction with the tunnel surface, eventually being directed to the detector at the focus). A conventional
609:
Note that these are theoretical ideals, requiring perfect alignment of perfectly smooth, perfectly flat perfect reflectors that absorb none of the light. In practice, these situations can only be approached but not achieved because the effects of any surface imperfections in the reflectors propagate
687:
strikes a flat surface, sound is reflected in a coherent manner provided that the dimension of the reflective surface is large compared to the wavelength of the sound. Note that audible sound has a very wide frequency range (from 20 to about 17000 Hz), and thus a very wide range of wavelengths
574:
for more detail), as this effectively improves the animals' night vision. Since the lenses of their eyes modify reciprocally the paths of the incoming and outgoing light the effect is that the eyes act as a strong retroreflector, sometimes seen at night when walking in wildlands with a flashlight.
402:
618:
In this process (which is also known as phase conjugation), light bounces exactly back in the direction from which it came due to a nonlinear optical process. Not only the direction of the light is reversed, but the actual wavefronts are reversed as well. A
169:
A mirror provides the most common model for specular light reflection, and typically consists of a glass sheet with a metallic coating where the significant reflection occurs. Reflection is enhanced in metals by suppression of wave propagation beyond their
627:
from a beam by reflecting it and then passing the reflection through the aberrating optics a second time. If one were to look into a complex conjugating mirror, it would be black because only the photons which left the pupil would reach the pupil.
321:, which appears to be reversed from left to right because we compare the image we see to what we would see if we were rotated into the position of the image. Specular reflection at a curved surface forms an image which may be
406:
405:
407:
165:
of the reflected waves depends on the choice of the origin of coordinates, but the relative phase between s and p (TE and TM) polarizations is fixed by the properties of the media and of the interface between them.
404:
531:
The light sent to our eyes by most of the objects we see is due to diffuse reflection from their surface, so that this is our primary mechanism of physical observation.
263:
into a medium with a different refractive index. In the most general case, a certain fraction of the light is reflected from the interface, and the remainder is
371:
If the reflecting surface is very smooth, the reflection of light that occurs is called specular or regular reflection. The laws of reflection are as follows:
486:
When light strikes the surface of a (non-metallic) material it bounces off in all directions due to multiple reflections by the microscopic irregularities
411:
2D simulation: reflection of a quantum particle. White blur represents the probability distribution of finding a particle in a given place if measured.
403:
427:
in the individual atoms (or oscillation of electrons, in metals), causing each particle to radiate a small secondary wave in all directions, like a
275:, which can be used to predict how much of the light is reflected, and how much is refracted in a given situation. This is analogous to the way
1015:
938:
867:
610:
and magnify, absorption gradually extinguishes the image, and any observing equipment (biological or technological) will interfere.
41:
837:
787:
382:
The angle which the incident ray makes with the normal is equal to the angle which the reflected ray makes to the same normal.
782:
432:
375:
The incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same
624:
512:. The exact form of the reflection depends on the structure of the material. One common model for diffuse reflection is
1051:
1046:
506:
boundaries of an organic material) and by its surface, if it is rough. Thus, an 'image' is not formed. This is called
217:
290:
Total internal reflection is used as a means of focusing waves that cannot effectively be reflected by common means.
416:
32:
692:, because the nature of these reflections is critical to the auditory feel of a space. In the theory of exterior
62:
so that the wavefront returns into the medium from which it originated. Common examples include the reflection of
280:
1056:
578:
A simple retroreflector can be made by placing three ordinary mirrors mutually perpendicular to one another (a
298:
When light reflects off of a material with higher refractive index than the medium in which is traveling, it
767:
689:
525:
447:
424:
299:
1030:
802:
738:
620:
513:
420:
268:
302:. In contrast, when light reflects off of a material with lower refractive index the reflected light is
742:
713:
658:
175:
557:. The structure of these surfaces is such that light is returned in the direction from which it came.
953:
911:
110:
357:
86:) the angle at which the wave is incident on the surface equals the angle at which it is reflected.
792:
366:
338:
147:
118:
79:
1061:
1012:
977:
797:
508:
481:
473:
376:
276:
153:
55:
661:
off of atoms within a material is commonly used to determine the material's internal structure.
985:
590:
969:
863:
822:
390:
272:
211:
94:
700:
by reflecting some of the sound into the opposite direction. Sound reflection can affect the
161:, but losing the image) depending on the nature of the interface. In specular reflection the
961:
919:
693:
669:
579:
491:
307:
260:
295:
reflector would be useless as the X-rays would simply pass through the intended reflector.
1019:
746:
678:
650:
570:
495:
451:
291:
59:
957:
915:
1066:
827:
777:
701:
654:
548:
499:
428:
284:
259:
In fact, reflection of light may occur whenever light travels from a medium of a given
439:
reflected light is the combination of the backward radiation of all of the electrons.
431:. All these waves add up to give specular reflection and refraction, according to the
1040:
697:
330:
326:
322:
162:
114:
344:
981:
807:
734:
718:
318:
283:
of light from a denser medium occurs if the angle of incidence is greater than the
106:
102:
832:
817:
772:
754:
185:
733:. Study of the deep reflections of waves generated by earthquakes has allowed
539:
385:
The reflected ray and the incident ray are on the opposite sides of the normal.
812:
722:
684:
456:
264:
171:
130:
71:
37:
17:
965:
750:
726:
646:
517:
134:
90:
51:
973:
255:, or in other words, the angle of incidence equals the angle of reflection.
468:
521:
306:
with the incident light. This is an important principle in the field of
303:
419:, light is considered as an electromagnetic wave, which is described by
642:
923:
599:
565:
334:
158:
83:
1024:
883:
Mandelstam, L.I. (1926). "Light
Scattering by Inhomogeneous Media".
137:
can be reflected at shallow angles with special "grazing" mirrors.
730:
668:
603:
589:
538:
503:
467:
423:. Light waves incident on a material induce small oscillations of
400:
356:
343:
314:
184:
179:
126:
122:
98:
67:
63:
31:
271:
for a light ray striking a boundary allows the derivation of the
696:, reflective surface size mildly detracts from the concept of a
109:
in bodies of water. Reflection is observed with many types of
860:
Theory of
Reflection, of Electromagnetic and Particle Waves
446:
Light–matter interaction in terms of photons is a topic of
594:
Multiple reflections in two plane mirrors at a 60° angle
348:
Refraction of light at the interface between two media
279:
in an electric circuit causes reflection of signals.
524:(in radiometry) in all directions, as defined by
205:. By projecting an imaginary line through point
657:. In the physical and biological sciences, the
101:. In geology, it is important in the study of
749:generally, and in particular to prospect for
516:, in which the light is reflected with equal
389:These three laws can all be derived from the
8:
174:. Reflection also occurs at the surface of
1025:Animations demonstrating optical reflection
457:QED: The Strange Theory of Light and Matter
673:Sound diffusion panel for high frequencies
333:. Such mirrors may have surfaces that are
209:perpendicular to the mirror, known as the
1031:Simulation on Laws of Reflection of Sound
939:"Output irradiance of tapered lightpipes"
472:General scattering mechanism which gives
317:. Reflection from a flat surface forms a
729:) may be reflected by layers within the
121:and higher frequencies is important for
27:"Bouncing back" of waves at an interface
850:
543:Working principle of a corner reflector
741:. Shallower reflections are used in
7:
902:M. Iona (1982). "Virtual mirrors".
361:An example of the law of reflection
197:strikes a vertical mirror at point
25:
450:, and is described in detail by
50:is the change in direction of a
838:Two-ray ground-reflection model
788:List of reflected light sources
189:Diagram of specular reflection
145:Reflection of light is either
105:. Reflection is observed with
1:
614:Complex conjugate reflection
568:act as retroreflectors (see
300:undergoes a 180° phase shift
193:In the diagram, a light ray
201:, and the reflected ray is
1083:
725:or other sources (such as
711:
676:
598:When light reflects off a
546:
479:
364:
313:Specular reflection forms
783:Huygens–Fresnel principle
737:to determine the layered
632:Other types of reflection
561:backside of the droplet.
433:Huygens–Fresnel principle
417:classical electrodynamics
281:Total internal reflection
178:media, such as water or
966:10.1364/JOSAA.27.001985
885:Zh. Russ. Fiz-Khim. Ova
768:Anti-reflective coating
690:architectural acoustics
641:Materials that reflect
490:the material (e.g. the
448:quantum electrodynamics
803:Reflection coefficient
739:structure of the Earth
674:
659:reflection of neutrons
623:can be used to remove
595:
553:Some surfaces exhibit
544:
514:Lambertian reflectance
477:
412:
362:
349:
190:
58:between two different
44:
858:Lekner, John (1987).
745:to study the Earth's
743:reflection seismology
714:reflection seismology
712:Further information:
672:
593:
542:
471:
410:
360:
347:
215:, we can measure the
188:
125:transmission and for
35:
1033:By Amrita University
683:When a longitudinal
586:Multiple reflections
526:Lambert's cosine law
454:in his popular book
111:electromagnetic wave
93:, reflection causes
1013:Acoustic reflection
958:2010JOSAA..27.1985M
916:1982PhTea..20..278G
793:Negative refraction
621:conjugate reflector
520:(in photometry) or
421:Maxwell's equations
367:Specular reflection
269:Maxwell's equations
230:angle of reflection
141:Reflection of light
80:specular reflection
1052:Geometrical optics
1047:Physical phenomena
1018:2019-01-04 at the
937:I. Moreno (2010).
798:Ocean surface wave
708:Seismic reflection
675:
637:Neutron reflection
596:
545:
509:diffuse reflection
482:Diffuse reflection
478:
476:by a solid surface
474:diffuse reflection
464:Diffuse reflection
413:
363:
353:Laws of reflection
350:
277:impedance mismatch
218:angle of incidence
191:
82:(for example at a
45:
36:The reflection of
924:10.1119/1.2341067
823:Signal reflection
498:material, or the
443:reflected light.
408:
391:Fresnel equations
273:Fresnel equations
241:law of reflection
151:(mirror-like) or
76:law of reflection
16:(Redirected from
1074:
1000:
999:
997:
996:
990:
984:. Archived from
952:(9): 1985–1993.
943:
934:
928:
927:
899:
893:
892:
880:
874:
873:
855:
694:noise mitigation
665:Sound reflection
651:nuclear reactors
580:corner reflector
492:grain boundaries
409:
325:or demagnified;
308:thin-film optics
292:X-ray telescopes
261:refractive index
117:. Reflection of
21:
1082:
1081:
1077:
1076:
1075:
1073:
1072:
1071:
1057:Physical optics
1037:
1036:
1020:Wayback Machine
1009:
1004:
1003:
994:
992:
988:
941:
936:
935:
931:
904:Physics Teacher
901:
900:
896:
882:
881:
877:
870:
857:
856:
852:
847:
842:
763:
716:
710:
681:
679:Acoustic mirror
667:
655:nuclear weapons
639:
634:
616:
588:
571:tapetum lucidum
555:retroreflection
551:
537:
535:Retroreflection
496:polycrystalline
484:
466:
452:Richard Feynman
401:
399:
369:
355:
254:
249:
238:
227:
157:(retaining the
143:
97:and is used in
28:
23:
22:
15:
12:
11:
5:
1080:
1078:
1070:
1069:
1064:
1059:
1054:
1049:
1039:
1038:
1035:
1034:
1028:
1022:
1008:
1007:External links
1005:
1002:
1001:
929:
894:
875:
868:
849:
848:
846:
843:
841:
840:
835:
830:
825:
820:
815:
810:
805:
800:
795:
790:
785:
780:
778:Echo satellite
775:
770:
764:
762:
759:
709:
706:
702:acoustic space
666:
663:
649:, are used in
645:, for example
638:
635:
633:
630:
615:
612:
587:
584:
564:Some animals'
549:Retroreflector
547:Main article:
536:
533:
480:Main article:
465:
462:
429:dipole antenna
398:
395:
387:
386:
383:
380:
365:Main article:
354:
351:
327:curved mirrors
285:critical angle
252:
247:
236:
225:
142:
139:
78:says that for
26:
24:
18:Non-reflective
14:
13:
10:
9:
6:
4:
3:
2:
1079:
1068:
1065:
1063:
1060:
1058:
1055:
1053:
1050:
1048:
1045:
1044:
1042:
1032:
1029:
1026:
1023:
1021:
1017:
1014:
1011:
1010:
1006:
991:on 2012-03-31
987:
983:
979:
975:
971:
967:
963:
959:
955:
951:
947:
940:
933:
930:
925:
921:
917:
913:
909:
905:
898:
895:
890:
886:
879:
876:
871:
869:9789024734184
865:
861:
854:
851:
844:
839:
836:
834:
831:
829:
826:
824:
821:
819:
816:
814:
811:
809:
806:
804:
801:
799:
796:
794:
791:
789:
786:
784:
781:
779:
776:
774:
771:
769:
766:
765:
760:
758:
756:
752:
748:
744:
740:
736:
735:seismologists
732:
728:
724:
720:
719:Seismic waves
715:
707:
705:
703:
699:
698:noise barrier
695:
691:
686:
680:
671:
664:
662:
660:
656:
652:
648:
644:
636:
631:
629:
626:
622:
613:
611:
607:
605:
601:
592:
585:
583:
581:
576:
573:
572:
567:
562:
558:
556:
550:
541:
534:
532:
529:
527:
523:
519:
515:
511:
510:
505:
501:
497:
493:
489:
483:
475:
470:
463:
461:
459:
458:
453:
449:
444:
440:
436:
434:
430:
426:
422:
418:
396:
394:
392:
384:
381:
378:
374:
373:
372:
368:
359:
352:
346:
342:
340:
336:
332:
331:optical power
328:
324:
320:
316:
311:
309:
305:
301:
296:
293:
288:
286:
282:
278:
274:
270:
266:
262:
257:
256:
246:
242:
235:
231:
224:
220:
219:
214:
213:
208:
204:
200:
196:
187:
183:
181:
177:
173:
167:
164:
160:
156:
155:
150:
149:
140:
138:
136:
132:
128:
124:
120:
116:
115:visible light
112:
108:
107:surface waves
104:
103:seismic waves
100:
96:
92:
87:
85:
81:
77:
73:
69:
65:
61:
57:
53:
49:
43:
39:
34:
30:
19:
993:. Retrieved
986:the original
949:
945:
932:
907:
903:
897:
888:
884:
878:
862:. Springer.
859:
853:
808:Reflectivity
721:produced by
717:
682:
640:
617:
608:
597:
577:
569:
563:
559:
554:
552:
530:
507:
487:
485:
455:
445:
441:
437:
425:polarisation
414:
388:
370:
319:mirror image
312:
297:
289:
258:
251:
244:
243:states that
240:
233:
229:
222:
216:
210:
206:
202:
198:
194:
192:
168:
152:
146:
144:
88:
75:
47:
46:
29:
833:Sun glitter
828:Snell's law
818:Ripple tank
773:Diffraction
755:natural gas
723:earthquakes
625:aberrations
267:. Solving
176:transparent
172:skin depths
131:hard X-rays
72:water waves
42:Mirror Lake
1041:Categories
995:2011-09-03
910:(5): 278.
845:References
813:Refraction
757:deposits.
727:explosions
685:sound wave
677:See also:
135:gamma rays
113:, besides
48:Reflection
38:Mount Hood
1062:Acoustics
751:petroleum
647:beryllium
518:luminance
397:Mechanism
339:parabolic
335:spherical
323:magnified
265:refracted
91:acoustics
56:interface
52:wavefront
1016:Archived
974:20808406
761:See also
643:neutrons
522:radiance
304:in phase
228:and the
148:specular
982:5844431
954:Bibcode
912:Bibcode
566:retinas
154:diffuse
129:. Even
1027:by QED
980:
972:
946:JOSA A
891:: 381.
866:
600:mirror
488:inside
315:images
239:. The
212:normal
159:energy
95:echoes
84:mirror
74:. The
54:at an
1067:Sound
989:(PDF)
978:S2CID
942:(PDF)
747:crust
731:Earth
604:torus
504:fiber
494:of a
377:plane
329:have
180:glass
163:phase
127:radar
123:radio
99:sonar
68:sound
64:light
60:media
970:PMID
864:ISBN
753:and
653:and
500:cell
133:and
70:and
962:doi
920:doi
502:or
415:In
337:or
250:= θ
119:VHF
89:In
40:in
1043::
976:.
968:.
960:.
950:27
948:.
944:.
918:.
908:20
906:.
889:58
887:.
704:.
606:.
528:.
460:.
435:.
393:.
341:.
310:.
287:.
232:,
221:,
203:OQ
195:PO
182:.
66:,
998:.
964::
956::
926:.
922::
914::
872:.
379:.
253:r
248:i
245:θ
237:r
234:θ
226:i
223:θ
207:O
199:O
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
