{"product_id":"light-reflection-and-refraction-demonstrator-adhesive-backed-optical-reflection-and-refraction-demonstrator-optics-teaching-aid","title":"Optical demonstrator for light reflection and refraction - DIOPTRA","description":"\u003cstyle\u003e\n.aa{font-family:Georgia,'Times New Roman',serif;color:#1A1A1A;line-height:1.7;font-size:15px;max-width:760px;margin:0 auto}\n.aa p{margin:0 0 1rem}\n.aa a{color:#185FA5;text-decoration:underline}\n.aa .aa-title{display:inline-block;border-bottom:2px solid #FAC775;padding-bottom:4px;font-size:16px;font-weight:600;margin:1.75rem 0 .5rem;letter-spacing:.3px;color:#1A1A1A}\n.aa .aa-badge{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.5px;text-transform:uppercase;padding:3px 10px;border-radius:20px;margin:0 4px 4px 0;vertical-align:middle;font-family:Georgia,serif}\n.aa .aa-badge-or{background:#FAC775;color:#1A1A1A}\n.aa .aa-badge-brun{background:#5C3A1E;color:#FFF9E8}\n.aa 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summary::after{content:\"\\2212\"}\n.aa .aa-a{font-size:13px;color:#3a3a3a;margin-top:.5rem}\n.aa .aa-a p{margin:0 0 .5rem}\n@media(max-width:600px){.aa .aa-vars,.aa .aa-ben{grid-template-columns:1fr}}\n\u003c\/style\u003e\n\u003cdiv class=\"aa\"\u003e\n\n\u003cp\u003e\u003cspan class=\"aa-badge aa-badge-noir\"\u003eThe Lab\u003c\/span\u003e \u003cspan class=\"aa-badge aa-badge-bleu\"\u003eOptics\u003c\/span\u003e A ray of light strikes a transparent block: one part bounces back, the other dives in while changing direction. This \u003cstrong\u003ereflection and refraction demonstrator\u003c\/strong\u003e makes this double behavior measurable at a glance. It combines a \u003cstrong\u003ewhite disk graduated in degrees\u003c\/strong\u003e, from 0 to 90 on either side of the axis, mounted on a \u003cstrong\u003eblack base\u003c\/strong\u003e, and a \u003cstrong\u003etransparent semi-cylindrical lens\u003c\/strong\u003e placed at its center. Direct a thin beam toward the center of the disk: the graduation allows you to read the \u003cstrong\u003eangle of incidence\u003c\/strong\u003e, the reflected angle, and the refracted angle directly. By rotating the source, one can verify the equality of reflection angles, rediscover the \u003cstrong\u003eSnell-Descartes law\u003c\/strong\u003e, and then witness the moment the beam no longer emerges: \u003cstrong\u003etotal internal reflection\u003c\/strong\u003e, the principle behind fiber optics. Designed as \u003cstrong\u003eeducational optics equipment\u003c\/strong\u003e, it outfits both classrooms and the desk of any science enthusiast. Important: it is presented as the \u003cstrong\u003edemonstration board\u003c\/strong\u003e; the light source is not stated to be included.\u003c\/p\u003e\n\n\u003ch3 class=\"aa-title\"\u003eWhat the demonstrator shows\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-vars\"\u003e\n\n\u003cdiv class=\"aa-var\"\u003e\n\n\u003cdiv class=\"aa-var-v light\" style=\"background: linear-gradient(135deg,#F5F0E8,#E8F4FA);\"\u003eGRADUATED DISK\u003c\/div\u003e\n\n\u003cdiv class=\"aa-var-i\"\u003e\n\n\u003cspan class=\"aa-var-n\"\u003eDisk graduated in degrees\u003c\/span\u003e\u003cspan class=\"aa-var-d\"\u003eGraduation 0 to 90° on each side of the axis, on a black base\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-var\"\u003e\n\n\u003cdiv class=\"aa-var-v light\" style=\"background: linear-gradient(135deg,#F5F0E8,#E8F4FA);\"\u003eSEMI-CYLINDRICAL LENS\u003c\/div\u003e\n\n\u003cdiv class=\"aa-var-i\"\u003e\n\n\u003cspan class=\"aa-var-n\"\u003eSemi-cylindrical lens\u003c\/span\u003e\u003cspan class=\"aa-var-d\"\u003eTransparent block placed in the center of the disk\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-mat\"\u003e\n\n\u003ch3\u003eReflection, refraction, and total reflection\u003c\/h3\u003e\n\n\u003cp\u003eWhen a light ray encounters the surface separating two transparent media, it divides. One part is \u003cstrong\u003ereflected\u003c\/strong\u003e at an angle equal to the angle of incidence, like a ball bouncing off a wall. The other part is \u003cstrong\u003erefracted\u003c\/strong\u003e: it crosses the surface while changing direction because light does not travel at the same speed in air as in a transparent material. The relationship between the two angles, n₁·sin i₁ = n₂·sin i₂, was described in the early 17th century by Willebrord Snell and then published by René Descartes in 1637: it is called the \u003cstrong\u003eSnell-Descartes law\u003c\/strong\u003e in France.\u003c\/p\u003e\n\n\u003cp\u003eThe semi-cylindrical shape is not a coincidence. A ray directed toward the center crosses the curved face without being deflected, as it arrives perpendicular to it; all deflection occurs on the flat face, at the center of the graduated disk, where the angles are read. When light passes from the material into the air and the angle exceeds a critical value, no ray emerges: this is \u003cstrong\u003etotal internal reflection\u003c\/strong\u003e, which guides light in fiber optics.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eWhy you will love it\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-ben\"\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e✦\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eAngles readable immediately\u003c\/span\u003e\u003cspan class=\"ds\"\u003eThe graduation in degrees around the center avoids protractors and approximate calculations: you read, you note, you compare.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e◆\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eThree phenomena in one\u003c\/span\u003e\u003cspan class=\"ds\"\u003eReflection, refraction, and total reflection are demonstrated with the same setup, simply by rotating the source.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e➤\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eWell-thought-out geometry\u003c\/span\u003e\u003cspan class=\"ds\"\u003eThe semi-cylindrical lens concentrates all deflection on its flat face, at the exact point where angles are measured.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e✦\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eVisible to an entire class\u003c\/span\u003e\u003cspan class=\"ds\"\u003eThe white disk contrasts with the colored beam: the light path can be seen from a distance.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e◆\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eFrom middle school to university\u003c\/span\u003e\u003cspan class=\"ds\"\u003eFrom simple observation to measuring the refractive index, the object follows the progression of curricula.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e➤\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eAn intriguing object\u003c\/span\u003e\u003cspan class=\"ds\"\u003eOn a desk, this graduated dial and its transparent block have the look of an antique laboratory instrument.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-des\"\u003e\n\n\u003cp class=\"t\"\u003eLight caught in the act\u003c\/p\u003e\n\n\u003cdiv class=\"x\"\u003e\n\n\u003cp\u003eSince antiquity, it has been noted that a stick dipped in water appears broken. Ptolemy attempted to measure this break, Ibn Sahl described it in the 10th century, and Snell and Descartes provided the law. This demonstrator condenses centuries of research into a simple object: a \u003cstrong\u003egraduated dial\u003c\/strong\u003e, a \u003cstrong\u003etransparent block\u003c\/strong\u003e, a beam.\u003c\/p\u003e\n\n\u003cp\u003eIn the dim light, when the red ray splits at the center of the disk, the magic happens. You see the reflected line depart symmetrically, the refracted line bend, and then, with a slight movement of the source, the transmitted beam vanish and all the light bounce back inside the block. This is the same phenomenon that makes cut stones sparkle and transports our data across the oceans. A demonstration that remains etched in memories much more than a formula copied off a chalkboard.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-steps\"\u003e\n\n\u003ch4\u003ePerforming the experiment in four steps\u003c\/h4\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e1\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003ePrepare the source.\u003c\/strong\u003e Obtain a light source that produces a thin beam, such as a low-power laser pointer or a slit lantern. It is not stated to be included with the demonstrator.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e2\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003ePosition the lens.\u003c\/strong\u003e Verify that the flat face of the semi-cylindrical lens is correctly aligned with the diameter of the disk and that its center coincides with that of the graduation.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e3\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003eAim at the center.\u003c\/strong\u003e In a slightly darkened room, direct the beam grazing the surface of the disk toward its center. Read the angle of incidence, then the reflected and refracted angles.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e4\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003eVary the angle.\u003c\/strong\u003e Gradually turn the source and take the measurements. By entering through the curved face, increase the angle until the transmitted ray disappears: you have reached the critical angle.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eComparison: three phenomena, one demonstrator\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-cmp\"\u003e\n\n\u003ctable\u003e\n\n\u003cthead\u003e\n\n\u003ctr\u003e\n\n\u003cth\u003ePhenomenon\u003c\/th\u003e\n\n\u003cth\u003eWhat is observed\u003c\/th\u003e\n\n\u003cth\u003eWhat is measured\u003c\/th\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/thead\u003e\n\n\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eReflection\u003c\/td\u003e\n\n\u003ctd\u003eThe ray bounces off the flat face\u003c\/td\u003e\n\n\u003ctd\u003eReflected angle equal to angle of incidence\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr class=\"hl\"\u003e\n\n\u003ctd\u003eRefraction (air to block)\u003c\/td\u003e\n\n\u003ctd\u003eThe ray approaches the normal upon entering\u003c\/td\u003e\n\n\u003ctd\u003eRatio of sines, therefore the block index\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eRefraction (block to air)\u003c\/td\u003e\n\n\u003ctd\u003eThe ray moves away from the normal upon exiting\u003c\/td\u003e\n\n\u003ctd\u003eVerification of the law in the other direction\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr class=\"hl\"\u003e\n\n\u003ctd\u003eTotal reflection\u003c\/td\u003e\n\n\u003ctd\u003eNo more ray emerges, everything is reflected\u003c\/td\u003e\n\n\u003ctd\u003eCritical angle specific to the material\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eConcrete application\u003c\/td\u003e\n\n\u003ctd\u003eFiber optics, sparkle of cut stones\u003c\/td\u003e\n\n\u003ctd\u003eRelationship between index and critical angle\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\n\n\n\u003c\/table\u003e\n\n\n\u003c\/div\u003e\n\n\u003cp\u003eFascinated by light? Our \u003ca href=\"\/collections\/lumiere-et-levitation\"\u003elight and levitation\u003c\/a\u003e universe gathers plasma lamps, mirror cubes, and luminous objects that extend the experience.\u003c\/p\u003e\n\n\u003cdiv class=\"aa-info\"\u003e\n\n\u003cp\u003e\u003cstrong\u003eGood to know:\u003c\/strong\u003e the demonstrator is presented as the \u003cstrong\u003eoptical board\u003c\/strong\u003e (graduated disk, base, and lens). The \u003cstrong\u003elight source is not stated to be included\u003c\/strong\u003e; plan to use a thin beam. The manufacturer mentions a back designed for wall mounting, without specifying its exact mode.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-tip\"\u003e\n\n\u003cp\u003e\u003cstrong\u003eTip:\u003c\/strong\u003e for a beam that is clearly visible throughout its length, have it graze the white surface of the disk rather than aiming above it. A dimmed room, without total darkness, offers the best compromise between beam visibility and reading the graduations.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eTechnical specifications\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-sp\"\u003e\n\n\u003ctable\u003e\n\n\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eType\u003c\/td\u003e\n\n\u003ctd\u003eReflection and refraction demonstrator\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eDial\u003c\/td\u003e\n\n\u003ctd\u003eSemicircular white disk graduated in degrees\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eGraduation\u003c\/td\u003e\n\n\u003ctd\u003e0 to 90° on either side of the axis\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eOptical element\u003c\/td\u003e\n\n\u003ctd\u003eTransparent semi-cylindrical lens\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eSupport\u003c\/td\u003e\n\n\u003ctd\u003eBlack base\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eMounting\u003c\/td\u003e\n\n\u003ctd\u003eBack designed for boards according to the manufacturer (exact mode not specified)\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eLight source\u003c\/td\u003e\n\n\u003ctd\u003eNot stated to be included\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eDemonstrated phenomena\u003c\/td\u003e\n\n\u003ctd\u003eReflection, refraction, total reflection\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eIllustrated law\u003c\/td\u003e\n\n\u003ctd\u003eSnell-Descartes\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eUsage\u003c\/td\u003e\n\n\u003ctd\u003eOptics teaching, scientific desk object\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\n\u003ctd\u003eNot communicated\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eWeight\u003c\/td\u003e\n\n\u003ctd\u003eNot communicated\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\n\n\n\u003c\/table\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-warn\"\u003e\n\n\u003cp\u003e\u003cstrong\u003ePrecautions:\u003c\/strong\u003e if you use a laser pointer, \u003cstrong\u003enever\u003c\/strong\u003e direct the beam toward eyes, neither directly nor via a reflective surface: the flat face of the lens reflects part of the light. Consider reflected rays when placing spectators. The lens is a small part: keep out of reach of children under 3; with students, the experiment should be conducted under adult supervision.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-gift\"\u003e\n\n\u003ch3\u003eA luminous gift for the curious\u003c\/h3\u003e\n\n\u003cp\u003eFor a \u003cstrong\u003ephysics-chemistry teacher\u003c\/strong\u003e wishing to enrich their lab, an optics student, a photographer passionate about light, or a teenager constantly asking questions about the world, this demonstrator is an intelligent and durable gift.\u003c\/p\u003e\n\n\u003cp\u003ePair it with other finds from our \u003ca href=\"\/collections\/objets-scientifiques\"\u003eLab scientific objects\u003c\/a\u003e or an object from \u003ca href=\"\/collections\/bureau-et-hi-tech\"\u003eoffice and high-tech\u003c\/a\u003e to compose a complete gift.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eFrequently asked questions\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-faq\"\u003e\n\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eIs the laser source provided?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eIt \u003cstrong\u003eis not stated to be included\u003c\/strong\u003e. The presentation photos show the demonstrator in action with a red beam, but the manufacturer does not confirm the presence of a light source in the package, and the product is presented as the \u003cstrong\u003edemonstration board\u003c\/strong\u003e: graduated disk, base, and semi-cylindrical lens. Therefore, plan for a source producing a thin beam, such as a \u003cstrong\u003elow-power laser pointer\u003c\/strong\u003e or a slit lantern. If you need confirmation before your purchase, write to us: we will reply with the information we have regarding the exact contents.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eWhy is the lens semi-cylindrical?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThis shape greatly simplifies measurement. A ray directed toward the \u003cstrong\u003ecenter of the disk\u003c\/strong\u003e meets the curved face of the lens perpendicularly: it crosses it without changing direction. All deflection therefore occurs on the \u003cstrong\u003eflat face\u003c\/strong\u003e, exactly at the center of the graduation, where the angles are read. This allows for studying refraction in both directions: from air to the block by entering through the flat face, or from the block to air by entering through the curved face. It is this second configuration that allows for observing \u003cstrong\u003etotal reflection\u003c\/strong\u003e beyond the critical angle.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eWhat is total reflection and how can it be observed?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eWhen light passes from a more refractive medium, such as the transparent block, to a less refractive medium, such as air, the refracted ray moves away from the normal. As the angle of incidence increases, it moves further away until it grazes the surface. Beyond this \u003cstrong\u003ecritical angle\u003c\/strong\u003e, no more light emerges: the entire beam is reflected inside the block. To observe it, have the ray enter through the \u003cstrong\u003ecurved face\u003c\/strong\u003e while aiming for the center, then gradually rotate the source. This is the principle that guides light in \u003cstrong\u003efiber optics\u003c\/strong\u003e and gives cut stones their sparkle.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eCan the refractive index of the lens be measured?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eYes, it is even one of the most classic experiments. Have the beam enter through the flat face at several angles of incidence, for example 20, 40, and 60 degrees, and record the refracted angle on the graduation each time. The \u003cstrong\u003eSnell-Descartes law\u003c\/strong\u003e indicates that the ratio between the sine of the angle in air and the sine of the angle in the block is constant: this is the \u003cstrong\u003erefractive index\u003c\/strong\u003e of the material. By plotting a graph of the sines, students obtain a straight line whose slope gives this index. The manufacturer does not disclose the expected value, which makes the investigation all the more interesting.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eHow is the demonstrator mounted?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThe manufacturer describes a demonstrator whose \u003cstrong\u003eback is designed for wall mounting\u003c\/strong\u003e, allowing it to be used vertically in front of a class. However, they do not specify if it is an adhesive surface or a magnetic mount, and we cannot confirm this from the photos. The demonstrator can also be used laying flat on a table, on its \u003cstrong\u003eblack base\u003c\/strong\u003e, which is often the most practical configuration for hands-on activities in small groups or for a demonstration on a desk. Contact us if this point is a deciding factor.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eFrom what grade level can it be used?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThe demonstrator accompanies the entire progression in optics. In \u003cstrong\u003emiddle school\u003c\/strong\u003e, it is used to qualitatively observe that light travels in a straight line, reflects, and \"breaks\" when changing media. In \u003cstrong\u003ehigh school\u003c\/strong\u003e, it allows for verifying the Snell-Descartes law and measuring a refractive index. In \u003cstrong\u003ehigher education\u003c\/strong\u003e or scientific outreach, it illustrates total reflection and its applications. For younger users, the experiment should always be conducted under adult supervision, especially if the source used is a laser pointer, which should never be directed toward eyes.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eHow do I maintain the lens and the disk?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThe transparent lens is the most sensitive element: a scratch or a fingerprint diffuses light and blurs the beam. Handle it by the edges and clean it with a clean, dry \u003cstrong\u003emicrofiber cloth\u003c\/strong\u003e, like eyeglass lenses. Avoid abrasive or solvent-based products, which could dull it. The \u003cstrong\u003egraduated white disk\u003c\/strong\u003e can be dusted with a dry or slightly damp cloth, without scrubbing the graduations. Between uses, store the lens away from dust, for example in a fabric pouch, to preserve the clarity of your demonstrations.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Atelier Atypique","offers":[{"title":"Default Title","offer_id":54860801245507,"sku":"1005012693912743-Default Title","price":58.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0231\/3365\/0991\/files\/Sd461af0eddae41c38e3fdb5b7ee13fa9O.webp?v=1791060929","url":"https:\/\/atelier-atypique.com\/products\/light-reflection-and-refraction-demonstrator-adhesive-backed-optical-reflection-and-refraction-demonstrator-optics-teaching-aid","provider":"Atelier Atypique","version":"1.0","type":"link"}