#acl Narf:read,write,delete,revert,admin FacultyGroup:read,write All:read == Geometrical Optics == ''PIRA classification 6A'' ||<#dddddd>Grayed Demos are either not available or haven't been built yet. || = 6A.01 Speed of Light = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A01.10 ||speed of light ||pira200 ||A circuit generates a rapped light pulse that is sent through a fiber optic wire of (20m & 0.1m). The speed of light is shown on oscilloscope by comparing two difference lengths of fiber to a reference signal. || ||6A01.39 ||Speed of Light w/Microwave || ||Microwave with Marshmallows or large chocolate bar || = 6A02. Straight Line Propagation = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A02.10 ||light in a vacuum || ||Place a flashing light in the bell jar to emphasize the point. || ||6A02.15 ||straight line propagation of light (Shadows) || ||A good point source shows straight line propagation of light by shadow projection. || ||<#cccccc>6A02.16 ||<#cccccc>propagation star ||<#cccccc> ||<#cccccc>An intense radiation point source limited by a star shaped aperture melts a star shaped pattern on a paraffin backed black foil. || ||6A02.20 ||propagation of light (studio shapes) || ||Using a studio projector LED lamp and masks one can project all sorts of shapes. One can use a 'smoke in a can' to show the straight line propagation of the projected shapes. || ||6A02.35 ||chalk dust || ||chalk dust with a laser beam. || || || || || || = 6A10. Reflection From Flat Surfaces = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A10.10 ||blackboard optics - plane mirror || ||Blackboard optics - plane mirror. || ||6A10.15 ||laser and flat mirror || ||Shine a laser at a flat mirror on the lecture bench and use chalk dust to make the beam visible. || ||6A10.20 ||diffuse/specular reflection || ||Show a beam on light reflecting off a mirror on an optics board. Replace the mirror with a sheet of paper. || ||6A10.22 ||scattering with aluminum foil || ||Reflect light off a sheet of aluminum foil, then crumple and flatten it to create many facets. || ||6A10.25 ||ripple tank reflection || || || ||6A10.30 ||corner reflector || ||Three reflectors are placed on the inside corner of a box. Look at your image in a corner cube. || ||6A10.31 ||large corner cube || ||Use large mirror wall tiles (12 in sq) to make a large corner reflector. Look at your image in a corner cube. || ||6A10.32 ||corner cube || ||Precisionly ground quartz corner cube. Use a laser to show that the ligth is refracted back out the say direction as it goes in. || ||6A10.35 ||perversion || ||Perversion can be demonstrated in public with a license plate and a plane mirror. Sorry, no inversion. || ||6A10.37 ||parity reversal in a mirror || ||View a Cartesian coordinate system in a mirror. || ||6A10.40 ||mirrors at an angle || ||A candle placed between angled mirrors forms multiple images. Mirrors angled at 60 degrees give one object and five images arranged in a hexagon. || ||6A10.41 ||hinged mirrors || ||Place a light between two mirrors hinged together and standing vertically. Place a sheet of clear glass between the mirrors forming an isosceles triangle. A few more variations are given. || ||6A10.42 ||mirrors, kaleidoscopes || ||mirrors are shown at 60 or 30 degrees withing a kaleidoscope.Hand out and show some kaleidoscopes || ||6A10.45 ||parallel mirrors || ||An infinite number of images are formed with a candle between parallel images. || ||<#cccccc>6A10.50 ||<#cccccc>height of a mirror for full view ||<#cccccc> ||<#cccccc>Shades are pulled up from the bottom and down from the top covering a mirror until a person can just see their entire height. || ||6A10.60 ||candle in a glass of water || ||A candle is placed in front of a sheet of glass and a beaker of water an equal distance behind. Place the entire apparatus on a rotating table. The sheet of glass is between a hidden candle and a glass of water so the image of the candle appears in the glass. (creating a pepper's ghost image) || ||6A10.65 ||half silvered mirror box || || || ||<#cccccc>6A10.65 ||<#cccccc>Mirror Box ||<#cccccc> ||<#cccccc>Two people look into opposite ends of a box containing a half silvered mirror in the center. As the light on one end is dimmed, the light on the other brightens, causing metamorphosis. || ||<#cccccc>6A10.80 ||<#cccccc>chinese magic mirror ||<#cccccc> ||<#cccccc>The decorative pattern on the back of a bronze mirror is revealed when light is reflected from the polished front side onto a screen. || || || || || || = 6A20. Reflection from Curved Surfaces = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A20.10 ||blackboard optics - concave mirror || ||Blackboard optics - concave mirror. || ||6A20.10 ||blackboard optics - convex mirror || ||Blackboard optics - convex mirror. || ||6A20.10 ||concave and convex mirrors ||pira200 ||Shine parallel beams at convex and concave mirrors. Use a thread screen for display. || ||6A20.11 ||optical disc with curved mirrors || ||Use the optical disc with multiple beams and curved lens elements. || ||6A20.11 ||optical disc - curved mirror || ||Mount either concave or convex mirrors in the optical disc. || ||6A20.11 ||large optical disc || ||A large translucent screen and large lens elements scale up the Hartl optical disc. Diagrams. || ||6A20.15 ||parallel lasers and curved mirrors || ||Shine parallel lasers at converging and diverging mirrors and use chalk dust to make the beams visible. || ||6A20.20 ||spherical abberation in a mirror || ||Shine parallel rays at spherical and parabolic mirror elements, noting the difference in aberration. || ||6A20.21 ||off focal point source || ||A picture of the caustic formed by parallel laser rays incident on a parabolic mirror at 30 degrees. || ||6A20.24 ||concave mirrors - caustics || ||Directions for making a large cylindrical or parabolic mirror element. || ||6A20.26 ||variable curved mirrors || ||Aluminized mylar stretched over a coffee can makes a variable positive or negative mirror when the can is pressurized or evacuated. || ||6A20.27 ||elliptical tank || ||A filament lamp is placed at one focus of an elliptically shaped wall of shiny aluminum and chalk dust shows the image at the other focus. || ||6A20.28 ||ellipsoidal mirror || ||Compare the light intensity from the lamps at the near and far focus of an ellipsoidal mirror. Directions for making the mirror element. Diagram. || ||6A20.30 ||flower in a vase || ||A hidden flower at the center of curvature of a parabolic mirror appears in an empty vase. || ||6A20.30 ||lamp in the socket || ||A 40 W lamp is projected onto an empty socket. || ||6A20.30 ||mirror and rose || ||Hints for projecting a real image (rose) on an object (vase). || ||6A20.31 ||cold candle || ||Hold your finger in the inverted image of a candle burning at the center of curvature of a parabolic mirror. || ||6A20.31 ||large concave mirror || ||Hold a candle and other objects at the center of curvature of a large convex mirror. || ||6A20.35 ||optic mirage || ||Same as Oc-7. || ||6A20.35 ||optic mirage || ||Derivation of additional "magic separations" of the Optic Mirage that give images. || ||6A20.35 ||optic mirage || ||Two concave mirrors face each other. Images of objects resting on the bottom mirror appear at the center hole of the top mirror. || ||6A20.36 ||shine an light on the Optic Mirage || ||Shine a light on an shiny object in the Optic Mirage and the reflections will look real. || ||6A20.37 ||red ball in hemisphere || ||Looking at a red ball pendulum suspended from the rim of a hemispherical concave mirror makes one puke. || ||6A20.37 ||swinging lamp and concave mirror || ||A lamp pendulum is swung between the center of curvature and the principle focus on a concave mirror. || ||6A20.40 ||projected arrow with mirror || ||A converging mirror is used to project an image of an illuminated arrow onto a screen. || ||6A20.40 ||image with a concave mirror || ||A concave mirror is used to image a lamp filament on a screen or the wall. || ||6A20.41 ||projected filament with mirror || ||A converging mirror is used to project the image of a light bulb filament onto a screen. Masks can be used to stop down the mirror. || ||6A20.42 ||rotating liquid mirror || ||Rotate a pan of glycerine mixed with dark dye, using a lighted object as a source and ground glass screen or TV camera as a detector. || ||6A20.45 ||no image with convex mirror || ||Try to project the image of a filament from a convex mirror. || ||6A20.45 ||convex and concave mirrors || ||Large 16" convex and concave mirrors are shown. || ||6A20.45 ||concave and convex mirror || ||Project a lamp image with a concave mirror, then try convex. || ||6A20.50 ||amusement park mirrors || ||Cylindrical mirrors are made with ten inch radius of curvature. || ||6A20.51 ||convex mirror || ||View the image of your nose in a 1/2" diameter steel ball through a short focal length lens. || ||6A20.60 ||lighting a cigarette || ||Light a cigarette at the focal point of a parabolic mirror concentrating the beam of an arc light. || ||6A20.60 ||energy at a focal point || ||Remove the projection head of an overhead projector and hold a piece of paper at the focal point until it bursts into flame. || = 6A40. Refractive Index = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A40.10 ||apparent depth with tv camera || ||Focus a camera on a spot and then note how far the camera is moved to refocus when a clear plastic block is placed on the spot. || ||6A40.11 ||apparent depth || ||Look down into a tall graduate and estimate the distance to a coin at the bottom. || ||6A40.12 ||focusing telescope method || ||Move a telescope back and forth on a optical bench to focus on the front and then on the back of a block of plexiglass or container of liquid. || ||6A40.13 ||microwave index of refraction || ||Index of refraction is determined by measuring the distance between minima with a movable plane mirror in a container of liquid. Diagram. || ||6A40.15 ||refractive index of ice || ||Freeze water by pumping in a hollow acrylic prism and measure the minimum deviation. || ||6A40.20 ||Michelson index of refraction || ||Place a gas cell in one leg of the Michelson interferometer and evacuate air or let in a gas while counting fringes. || ||6A40.20 ||Michelson index of refraction || ||Count fringes of laser light as air is let into an evacuated chamber in one leg of a Michelson interferometer. || ||6A40.20 ||Michelson index of refraction || ||A vacuum chamber is put in one leg of a Michelson interferometer and fringes are counted as air or a gas is leaked into the chamber. Reference: TPT 6(4),176. || ||6A40.21 ||Raleigh refractometer || ||Improvements on the Raleigh refractometer to make the fringes more visible for easier counting as the air is let back in to the tube. || ||6A40.25 ||index of refraction of He and SF6 || ||In addition to letting air (21 fringes) into one arm of the Michelson interferometer, let in He (3 fringes) and SF6 (55 fringes). || ||6A40.30 ||Cheshire cat || || || ||6A40.30 ||disappearing beaker ||pira200 ||Place a small beaker in a liquid with an index of refraction matched to the glass (johnsons baby oil or wesson oil). || ||6A40.31 ||more Christiansen filters || ||A table of Christiansen filter pairs. See AJP 25,440 (1957) || ||6A40.31 ||Christiansen filters || ||A mixture of crushed glass and a liquid with the same index of refraction as glass is warmed in a container and exhibits colors. Directions for making a permanent display. Reference. || ||6A40.36 ||grating pattern shift || ||Shine a laser beam through a grating so the beam splits the air/liquid interface and measure the difference in the diffraction pattern for the light passing through the air and liquid. || ||6A40.36 ||grating in aquarium || ||Mount a transmission grating inside an aquarium and measure the diffracted laser beam on the other end with and without water in the tank. || ||6A40.37 ||refraction with shadow and cube || ||A shadow projected through a glass cube has a different length than normal. || ||6A40.38 ||refractive index of beer || ||The ratio of the apparent diameter to the actual diameter of a stick of pepperoni in a glass of beer gives the index of refraction. In the classroom, use a mesh projected on the wall and measure offset of a vertical wire. || ||6A40.39 ||Abbe refractometer || ||A liquid separates the hypotenuses of two right angle prisms. || ||6A40.40 ||variable index of refraction tank || ||Shine a laser beam through an aquarium with an unstirred sugar solution. || ||6A40.40 ||variable index of refraction tank || ||How to make a tank with varying concentrations of benzol and CS2. || ||6A40.42 ||gradient index lens || ||A small gradient index lens is passed around the class. It looks like a glass rod but one sees an inverted image when looking along the axis. || ||6A40.45 ||mirage || ||How to heat a long plate to demonstrate the mirage effect. || ||6A40.46 ||mirage || ||The image from a slide projector is directed just above a brass plate heated with a burner. || ||6A40.47 ||mirage with a laser || ||A laser beam almost grazing a hot plate will show deflection when the hot plate is turned on. || ||6A40.47 ||laser beam deflection - thermal grad || ||An apparatus for cooling a plate to deflect a laser beam downward. || ||6A40.47 ||mirage with laser || ||A laser beam is imaged through a keyhole and the beam then passes through a 1 meter oven. || ||6A40.47 ||superior "superior" image || ||A laser beam passing through a tank of water begins to deflect immediately when heat lamps are turned on. Images are also observed. || ||6A40.48 ||not a mirage with a laser || ||I haven't figured this out and have to go home to eat, so maybe some other time. || ||6A40.49 ||mirage explaination note || ||A note correcting misleading textbook explanations of the mirage. || ||6A40.50 ||oil, water, laser || || || ||6A40.60 ||Schlieren image || || || ||6A40.60 ||cheap Schlieren || ||A small, compact, portable, and inexpensive Schlieren instrument using an ordinary lamp and a light source. || ||6A40.60 ||Schlieren, etc. || ||Show and compare Schlieren, direct shadow, and interferometeric method of detecting small changes in the index of refraction of air. Diagrams, Details in appendix, p. 1352. || ||6A40.61 ||Schlieren image of a candle || ||A simple arrangement with a point source, lens, and candle near the lens, aperture, and screen for lecture demonstration purposes. || ||6A40.61 ||Schlieren image of a candle || ||Laser light is used in Schlieren projection of a candle flame. || ||6A40.62 ||single mirror Schlieren system || ||Two Ronchi rulings are placed at the radius of curvature of a spherical mirror. || ||6A40.63 ||Schmidt-Cassegrain schlieren || ||Two Schmidt-Cassegraion telescopes are used to make a simple inline Schlieren system. || ||6A40.65 ||Toepler Schlieren apparatus || ||A simpler Schlieren setup with colors indicating amount of deviation. || ||6A40.67 ||refraction by gases || ||Shadow project the Bunsen burner (H-137), hold a hot object in one arm on the Michelson interferometer. || ||6A40.70 ||short beer || || || ||6A40.70 ||tall beer || ||Properly designed glassware makes the beer look taller. || ||6A40.70 ||cylindrical lens and short beers || ||Analysis of the apparent inner diameter thick cylinder of a liquid of different index of refraction. || ||6A40.70 ||short beers || ||Paint the inside of the illusion cylinder, (AJP 43(8),741). || ||6A40.70 ||beer mugs || ||Two beer mugs were found that have the same outer dimensions and both appear to hold the same amount of beer when full, but actually differ in volume by a factor of two. || ||6A40.70 ||short beer comment || ||Easy explanation. || ||6A40.90 ||plasma laser-beam focusing || ||An expanded laser beam grazing a flat combustion flame from paint stripper is focused into a line. A second perpendicular flame gives a point. || = 6A42. Refraction at Flat Surfaces = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A42.10 ||blackboard optics - refraction || ||Blackboard optics with a single beam and a large rectangle and prism of plexiglass. || ||6A42.11 ||optical disk with glass block || ||A single beam of light on the optical disc is used to show refraction through a rectangular block of glass. || ||6A42.12 ||refraction/reflection from plastic || ||Rotate a rectangle of plastic in a single beam of light. || ||6A42.15 ||optical disc - semicircle || ||A single beam of light is refracted at the flat but not the curved side if it leaves along a radius. || ||6A42.20 ||Big plastic refraction tank ||pira200 ||The light source can be rotated through 270 degreew to show refraction and total internal reflection for both air/platic and plastic/air interfaces. || ||6A42.20 ||refraction tank || ||A rotatable beam of light in a tank of water containing some fluorescein. || ||6A42.21 ||Nakamara refraction tank || || || ||6A42.22 ||big plastic refraction tank || || || ||6A42.24 ||force table refeaction tank || ||A small refraction tank is mounted on a force table. || ||6A42.27 ||refraction || ||Three refraction demos - optical tank, ripple tank, glass block. || ||6A42.30 ||refraction model - rolling || || || ||6A42.30 ||refraction model || ||An axle with independent 1" wheels rolls down an incline with one wheel on cloth, the other on the plain board. || ||6A42.31 ||string models of refraction || ||String models of refraction representing a water tank, prism, thin lens, comma aberration, and astigmatism are shown. Pictures, Construction details in appendix, p.1345. || ||6A42.32 ||wavefront strips model || || || ||6A42.35 ||ripple tank refraction || || || ||6A42.40 ||penny in a cup || || || ||6A42.40 ||seeing a coin || ||Pour water into a beaker until a coin at the bottom previously hidden by the side is visible. || ||6A42.43 ||light in a tank || || || ||6A42.43 ||small refraction tank || ||Position a lamp in an opaque tank so the filament cannot be seen, then add water until the light from the filament is seen over the edge of the tank. || ||6A42.45 ||stick in the water || || || ||6A42.45 ||stick in water || ||A stick appears bent when inserted into water at an angle. || ||6A42.46 ||rugged refraction demonstration || ||Cast a stick in a tumbler filled with clear casting resin. Pass around the class. || ||6A42.47 ||acrylic/lead glass refraction || ||Hold a stick behind stacked lead glass and acrylic blocks. The image of the stick is shifted when viewed off the normal to the surface of the blocks. || ||6A42.50 ||minimum deviation of a prism || ||At minimum deviation light reflected off the base is parallel to that passing through an equilateral prism. || ||6A42.50 ||minimum angle of deviation || ||Project a line filament through a large prism on a rotating platform with and without monochromatic filters. Reference: TPT 7(9),513. || ||6A42.51 ||three prism stack || || || ||6A42.51 ||three different prisms || ||A stack of three prisms of different glass shows different refraction and dispersion. || ||6A42.55 ||paraffin prism and microwaves || || || ||6A42.55 ||microwave paraffin prism || ||Determine the index of refraction of a large paraffin prism with 3.37 cm microwaves. || ||6A42.60 ||dispersion in different media || ||A multiple element prism is made with layers of different plastic and glass. || ||6A42.65 ||dispersion of liquids || ||A hollow prism is filled with a layer of carbon disulfide and a layer of water. || || || || || || = 6A44. Total Internal Reflection = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A44.10 ||blackboard optics ||pira200 ||Multiple beams of light pass through large scale optical elements. || ||6A44.11 ||optical disk with prism, semicircle || ||A single beam of light on the optical disk shows total internal reflection when passed through a prism. || ||6A44.11 ||semicircular element on disc || ||A beam of light entering a semicircular glass disc normal to the curved surface is reflected off the flat side. || ||6A44.20 ||critical angle in refraction tank || ||A beam in a tank of water is rotated until there is total internal reflection at the surface. || ||6A44.20 ||refraction tank || ||Adjust the path of a beam with mirrors in a tank of water with fluorescein. to show total internal reflection. || ||6A44.20 ||critical angle/ total internal refle || ||Shine a beam through the side of a tank containing fluorescein. Rotate a mirror in the tank so the beam passes through the critical angle. || ||6A44.22 ||big plastic refraction tank || || || ||6A44.25 ||Snell's wheel || || || ||6A44.30 ||ripple tank total reflection || ||Vary the angle of incidence of ripple tank waves to a boundary with water depths of 13 and 3 mm. || ||6A44.35 ||frust. tot. int. ref. || ||see 7A50.12 || ||6A44.40 ||laser and fiber optics || ||Shine a laser into a curved plastic rod. || ||6A44.40 ||laser and fiber optics || ||A laser is used with a bundle of fiber optics, a curled plexiglass rod, and a 1" square lean rod. || ||6A44.40 ||light pipe || ||Light is projected down a clear plexiglass spiral. || ||6A44.40 ||curved glass tube || ||Shine a bright light source through a curved glass tube. || ||6A44.40 ||[[LightPipeUlexite|light pipes--Ulexite]] ||pira200 ||Several light pipes and fiber optics are shown. || ||6A44.40 ||light pipes || ||Shine a laser into a curved plastic rod. || ||6A44.41 ||optical path in fibers || ||Shine a laser down a bent rectangular bar. || ||6A44.42 ||steal the signal || || || ||6A44.43 ||bounce around a tube || ||A laser beam bounces around a thick walled plexiglass tube due to total internal reflection. || ||6A44.45 ||water stream light pipe || ||Shine a laser beam down the water stream issuing from the orifice of a plexiglass tank of water. || ||6A44.45 ||illuminated fountain || ||Shine a light down a stream of water. || ||6A44.45 ||laser waterfall || ||Shine a laser down the center of a nozzle and it follows the water stream. || ||6A44.50 ||light below surface || ||An underwater light illuminates powder on the surface of water to form a central spot of light. || ||6A44.50 ||ring of light || ||Same as Oe-2. || ||6A44.50 ||light below surface || ||An underwater light illuminates powder on the surface of water to form a central spot of light. || ||6A44.51 ||ring of light index of refraction || ||Find the index of refraction of transparent plates by wetting a filter paper on one side, shining the laser in that side, and measuring the diameter of the light circle. || ||6A44.52 ||ring of darkness || ||Shine a laser through a sample to a white diffusely reflecting surface and measure the darkened circle on the top surface. || ||6A44.53 ||water/benzol surface || ||Total internal reflection from a water/benzol surface. || ||6A44.54 ||hidden mercury in a test tube || ||Mercury in a partially filled test tube cannot be seen from above when immersed in water. || ||6A44.54 ||total internal and metallic reflect || ||View a test tube half full of mercury half in water from an angle of 100 degrees to the incident beam. The glass-air interface is brighter. || ||6A44.55 ||black ball turns silver || ||A soot covered ball appears silver under water due to reflected light from air trapped on the surface of the ball. || ||6A44.55 ||soot ball || ||A ball covered with soot appears silvery in water due to the air trapped on the soot forming an air water interface. || ||6A44.55 ||silver soot ball || ||A ball coated with soot appears silver in water. || ||6A44.56 ||glass-air interface || ||Two thin strips of glass are sealed with an air barrier and immersed in water. Turned to the proper angle to the incident beam it will exhibit total internal reflection. || ||6A44.56 ||near critical angle || ||Use the entrapped air slide in a water bath or air between right angle prisms to show the colors of the transmitted and reflected light near the critical angle. Dispersing the two beams will show complementary spectra. || ||6A44.59 ||add water to snow || ||Project light through snow or chopped ice and add water. || ||6A44.60 ||diamond || ||A thin beam of light is directed on a diamond and the reflections are projected onto a cardboard. || ||6A44.65 ||inversion with a right angle prism || ||Project an image upside down and place a right angle prism in the beam to invert the image. || ||6A44.65 ||right angle prism inverter || ||A right angle prism placed in a projected beam inverts the image. || ||6A44.66 ||right angle prism - double reflectio || ||A beam entering the hypotenuse of a right angle prism is inverted and reversed. || ||6A44.67 ||two right angle prisms - inversion || ||Two right angle prisms are arranged to invert and pervert the image. || ||6A44.68 ||prisms || ||Several prisms demonstrate total internal reflection. || ||6A44.70 ||Goos-Haenchen shift || ||The sideways displacement of a beam at total internal reflection is shown with 3 cm microwaves. || = 6A46. Rainbow = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A46.10 ||rainbow || ||An arc lamp directed at a sphere of water forms a rainbow on a screen. || ||6A46.10 ||rainbow || ||Project a beam through a spherical flask of water and view the rainbow on a screen placed between the light and the flask. || ||6A46.11 ||artifical rainbow || ||Form a vertical circle "rainbow" by placing a tube of water between a prism and screen. || ||6A46.12 ||secondary rainbow || ||Use a single sphere with the back surface coated with a reflecting material to show both primary and secondary bows with increased intensity. || ||6A46.15 ||rainbow droplets || ||Small droplets formed by spraying an atomizer on a soot covered glass plate glisten like colored jewels when viewed at 41 degrees. || ||6A46.16 ||[[RainbowDust|rainbow dust]] || ||On using small glass spheres to generate bows and halos. || ||6A46.20 ||rainbow model || ||Depict a three dimensional model of the rainbow with strings representing light rays. || ||6A46.25 ||rainbow || ||A mechanical model for demonstrating rainbow formation shows why the rainbow is produced and why size depends on the time of day. || ||6A46.26 ||rod and dowel raindrop model || ||A rod and dowel raindrop model is used to show why a rainbow is bow-shaped. || ||6A46.30 ||optical disc with spherical lens || ||A single beam into a circular glass element is refracted, totally internally reflected, and refracted out again. || ||6A46.30 ||rainbow disc || ||A single beam is used with a spherical glass element on an optical board to show the path of refracted light that produces a rainbow. || = 6A60. Thin Lens = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A60.10 ||blackboard optics - thin lens || ||Blackboard optics are used with convex and concave thin lens elements. || ||6A60.11 ||optical disk with thin lens || ||The optical disk is used with multiple beams and a thin lens element. || ||6A60.11 ||optical disc - lenses || ||Various lens elements are used with the optical disc. || ||6A60.12 ||optical disc - refraction at curved || ||A long plastic slab with a concave surface at one end and a convex surface at the other is used in the optical disc. || ||6A60.15 ||ripple tank convex lens || || || ||6A60.15 ||ripple tank - lens model || ||Refraction due to depth differences over a lens shaped area in the ripple tank. || ||6A60.16 ||ripple tank concave lens || || || ||6A60.20 ||parallel lasers and lenses || ||Parallel lasers are passed through converging and diverging lenses. Chalk dust illuminates the beams. || ||6A60.20 ||parallel lasers and lenses || ||Parallel lasers are used with chalk dust to show the path of rays through a lens and combinations of lenses. || ||6A60.20 ||ray tracing with lenses || ||Show parallel rays passing through a lens element and converging. || ||6A60.30 ||thin lens projection || ||Project the filament of a lamp with a thin lens. || ||6A60.30 ||projected filament with lens ||pira200 ||Project the filament of a light bulb on the wall. The lens can be stopped down. || ||6A60.30 ||thin lens projection || ||Project the filament of a lamp with a thin lens. || ||6A60.30 ||real image formation || ||With a source and screen at the ends of a long optical bench, show the two positions a lens will produce an image. || ||6A60.31 ||projected arrow with lens || ||Use an illuminated arrow with a converging lens to project an image on a screen. || ||6A60.32 ||thin concave lens || ||Try to project an image with a thin concave lens. || ||6A60.33 ||image location || ||A set of lenses for demonstration the six general cases for object and image distances. || ||6A60.35 ||lens magnification || ||Place various lenses between a backlit grid and the class. || ||6A60.40 ||position of virtual image with TV || ||Find the virtual image location by focusing on an object through a lens removing the lens, and moving the object to a focused position. Also the apparent depth with TV method. || ||6A60.45 ||focal length of a lens - mirror || ||When a lamp is at the focal length, the image is at the same place if a mirror is placed directly behind the lens. || ||6A60.48 ||effect of medium on focal length || ||Find the focal length of a lens, then find the focal length of the same lens in water. || ||6A60.49 ||lenses || ||All sorts of focal length stuff. || ||6A60.50 ||pinholes projected with lens || ||Pinholes are pricked in a black paper covering a long filament bulb. Bring the multiple images into one image with a converging lens. || ||6A60.50 ||action of a lens || ||Project the images of a filament through several pinholes and then add a lens to collect the many into a single image. || ||6A60.60 ||paraffin lens and microwaves || || || ||6A60.60 ||microwave lens || ||Construct a microwave lens and prisms of stacks of properly contoured aluminum sheets separated by just over one half the wavelength. || = 6A61. Pinhole = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A61.10 ||pinhole projection || ||Place a lamp in a box covered with heavy paper and poke a hole in the paper with a wire 1-2 mm in diameter. Poke more holes for more images. Try different size holes. || ||6A61.10 ||pinhole projection || ||Interpose a metal plate with two holes between a lamp and a screen on an optical bench. || ||6A61.15 ||pinholes projected/lens || ||see 6A60.50 || ||6A61.20 ||pinhole camera || ||Place film at the back of a box with a hole. || ||6A61.20 ||pinhole camera || ||Project a lamp filament onto a screen. Vary the distance of the screen and the size of the pinhole. Includes animation. || ||6A61.21 ||pinhole camera || ||A sliding box with has pinhole at one end and a frosted glass at the other. Try a 1" diameter hole in the shutter of a window in a darkened room. Directions on making a pinhole camera. || ||6A61.22 ||pinhole imagery || ||A complete discussion of pinhole imagery. || ||6A61.23 ||pinhole camera || ||A small tube covered with tin foil with a small hole replaces the lens of a TV camera. || ||6A61.30 ||fish-eye camera || ||A pinhole camera filled with water or solid Lucite gives a fish-eye view. Diagram, Pictures. || = 6A65. Thick Lens = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A65.09 ||computer assisted optics || ||The authors describe a program that covers spherical and chromatic aberration in addition to other topics. BASIC, PC, available from authors. || ||6A65.10 ||improving an image with a stop || ||Use a stop to improve the image through a short focal length lens. || ||6A65.11 ||depth of focus || ||Use a six inch long glowing wire as an extended object for showing the effect of stopping down a lens. || ||6A65.15 ||optical disc - circular glass plate || ||Use a circular plate of glass with the optical disc as an example of a thick lens. || ||6A65.20 ||chromatic aberration || ||A diaphragm moved near the focus selects red or blue light from beams passing through the edge of a lens. || ||6A65.21 ||aplanic properties of a sphere || ||Aplanic systems show no spherical aberration or coma for some special position of object and image demonstrated here with a spherical lens. || ||6A65.21 ||chromatic aberration || ||Project spots of light on a screen from several points on a lens. Note chromatic aberration and then add a second correction lens. || ||6A65.22 ||chromatic aberration || ||Show the image formation distance for red and uv light using a fluorescent screen to display the uv. || ||6A65.23 ||lens aberrations with a laser || ||Good quality telescope and microscope objectives are used to show aberrations in optical systems. || ||6A65.24 ||chromatic and spherical aberration || ||Use diaphragms with central, annular, and other openings to show spherical and chromatic aberration. || ||6A65.30 ||barrel and pincushion distortion || ||Project an illuminated wire mesh with a large lens. Place a diaphragm between the lens and the mesh for barrel distortion and between the lens and the screen for pincushion distortion. || ||6A65.31 ||off axis distortion || ||Parallel rays of light pass through a lens element held off axis. || ||6A65.34 ||astigmatism || ||Focus light from a circular hole on a screen, then add a cylindrical lens. || ||6A65.35 ||astigmatism and distortion || ||An illuminated wire mesh is projected onto a screen with a short focal length condenser lens. Turn the lens about an axis parallel to either set of wires and the horizontal and vertical wires will focus at different points. || ||6A65.40 ||spherical aberration || ||Project an image with a spherical planoconvex lens. Stop the outer portion of the lens, then the center. || ||6A65.45 ||abberation with a plano convex lens || ||A series of parallel beams around the outside edge of a plano convex lens made visible with chalk dust are better focused when the light enters the curved side. || ||6A65.46 ||spherical abberation and coma /laser || ||Diagram and pictures of a setup to project lens aberrations with a laser. || ||6A65.52 ||water lens || ||A beam of light is directed through a round flask filled with water. || ||6A65.52 ||fillable air lenses || ||Convex and concave lenses are filled with water and air in water and air. || ||6A65.53 ||spherical lens || ||Compare a thermometer at the center of a water filled flask to one at the far side. Picture. || ||6A65.54 ||wine bottle lens || ||Fill a round flask with a wine bottle bottom with water and fluorescein to show diverging light. || ||6A65.55 ||watch glass lens || ||A vertical lens can be formed by pouring various liquids into a watch glass. || ||6A65.56 ||CHOICE OXIDE || ||CHOICE OXIDE GLASS LAMP is viewed through a tube filled with water. || ||6A65.58 ||light beam strikes rod || ||A light beam incident on the side of a glass rod at some angle will produce a cone with the half angle equal to the angle of incidence. || ||6A65.60 ||plastic lenses || ||The advantages of plastic lenses. || ||6A65.70 ||Fresnel lens history || ||An article on the discovery of stepped lenses. || ||6A65.70 ||Fresnel lens || ||Fresnel lens magnification. Animation showing construction of a Fresnel lens. || = 6A70. Optical Instruments = ||<10% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''PIRA #''' ||'''Demonstration Name''' ||'''Subsets''' ||<60% style="& amp; quot; & amp; amp; quot; & amp; amp; amp; quot;text-align:center& amp; amp; amp; quot; & amp; amp; quot; & amp; quot; ">'''Abstract''' || ||6A70.10 ||model microscope || ||Make a demonstration microscope with a short focal length lens and reading glass. || ||6A70.12 ||microscope chart || ||A diagram on a wall chart shows the action of a microscope. || ||6A70.13 ||fake microscope || ||A mirror arrangement and fake microscope make normal objects seem miniaturized. || ||6A70.14 ||primative microscope || ||A Leeuwenhoek 100 X magnifier is made with a glass bead on the end of a tapered tube. || ||6A70.20 ||telescope || ||Set up astronomical, terrestrial, and Galilean telescopes for students to look through individually. || ||6A70.21 ||real telescope || ||Observe with a Questar telescope. || ||6A70.22 ||sun telescope || ||Make a heliostat for a room with a south facing window. Reference: AJP 38(3),391-2. || ||6A70.23 ||large telescopes || ||Large telescopes are available on the roof for observations. || ||6A70.25 ||telephoto lens || ||An illuminated wire mesh is projected on a screen using a telephoto lens setup. || ||6A70.30 ||camera model || || || ||6A70.31 ||cameras || ||Several cameras are exhibited. || ||6A70.35 ||projector model || || || ||6A70.40 ||superposition of images || ||A wire screen placed at the point where a real image is formed is projected through a second lens to form a combined image. || ||6A70.45 ||lens combinations || ||A projection lantern double lens system. || ||6A70.50 ||measuring with moire fringes || ||A long discussion on measuring with moire fringes. Diagrams, Construction details in appendix, p.1346. || ||6A70.60 ||changing beam size || ||The beam size may be changed with or without inversion by placing the second lens at the sum or difference of the focal lengths. || ||6A70.65 ||entrance and exit pupil || ||An optical bench setup shows the concept of entrance and exit pupil. || [[Demonstrations]] [[Instructional|Home]]